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Effect of different conditioning treatments on total phenolic content and antioxidant activities in two Sargassacean species: Comparison of the frondose Sargassum muticum (Yendo) Fensholt and the cylindrical Bifurcaria bifurcata R. Ross
Abstract
The effects of different conditioning treatments (fresh, freezing, freeze-drying, oven-drying and greenhouse-drying) on the total phenolic content (TPC) and antioxi-dant activities of two brown algae, Sargassum muticum and Bifurcaria bifurcata, were investigated and compared. Phenolic compounds were extracted in a methanol/water (50:50) solution, and TPC was mea-sured by the colorimetric Folin-Ciocalteu assay. Antioxi-dant activity was assessed by the DPPH (2, 2-diphenyl-1-picrylhydrazyl) radical scavenging assay and the b-carotene bleaching method. The dried seaweeds showed lower phenolic contents and lower antioxidant capacities than the fresh and frozen ones, which sug-gests that the phenolic content and antioxidant activi-ties are decreased by the drying treatments, especially, oven-and greenhouse-drying. Relationships between TPC, antioxidant properties and conditioning treat-ments are discussed.
... Some of them are studied for their antifouling and antimicrobial properties Muñoz et al. 2013;Pais et al. 2019). Moreover, some crude aqueous, ethanolic or methanolic extracts have demonstrated high antioxidant (Agregán et al. 2017;Le Lann et al. 2008), antimicrobial (Maréchal et al. 2004Horta et al. 2014) or antitumoral activities (Di Guardia et al. 1999;Moreau et al. 2006;). In particular, it has a phenolic content that can represent 4-5 % DW (Connan et al. 2007;Le Lann et al. 2008). ...
... Moreover, some crude aqueous, ethanolic or methanolic extracts have demonstrated high antioxidant (Agregán et al. 2017;Le Lann et al. 2008), antimicrobial (Maréchal et al. 2004Horta et al. 2014) or antitumoral activities (Di Guardia et al. 1999;Moreau et al. 2006;). In particular, it has a phenolic content that can represent 4-5 % DW (Connan et al. 2007;Le Lann et al. 2008). More generally, B. bifurcata contains more than 70 % of moisture, a high fat content representing 6 % DW, and a protein content of 8 % DW (Alves et al. 2016;Lorenzo et al. 2017). ...
... Results highlighted an increase in phenolic contents in summer for both species, reaching an average of 38 and 44 mg.g -1 DW for B. bifurcata and S. muticum, respectively. This can in part be explained by the protective role of these particular aromatic compounds against high light (Schoenwaelder 2002;Swanson and Druehl 2002;Le Lann et al. 2008) and temperature (Tanniou et al. 2014). However, the seasonal increase was greater for S. muticum and coincided with its reproductive period; by producing more phenolic compounds than B. bifurcata, the invasive S. muticum may thus have additionally increased its tolerance to high light and temperature, as previously suggested by . ...
Marine intertidal macroalgae live in a highly variable environment, currently threatened by human activities which lead to ongoing changes on marine ecosytems worldwide. In this regard, algal populations have to adapt to an evolving environment to avoid disappearance, by migrating or producing particular metabolites for example.Besides, each species has a different adaptive capacity, the species presenting a high phenotypic plasticity being more likely to adapt to future environmental conditions than others. In this context, the aim of this work was to study the acclimation abilities of five macroalgal species (either native or introduced) from Brittany (France), through a one-year monitoring combining both ecological and metabolomic data. The first part focused on red macroalgae and mycosporine-like amino acids. Results suggested that these highly diverse compounds, whose synthesis pathway is not completely elucided, could be multifunctional secondary metabolites. Thus, they could play a key role in the future adaptation of some red algal species such as the native Palmaria palmata, compared to the introduced Grateloupia turuturu.The second part then focused on three species of brown macroalgae (Sargassaceae) and showed that the native Halidrys siliquosa is more threatened than the other native species (i.e. Bifurcaria bifurcata) in the context of global change. Indeed, it is a cold-water affinity species that is all the more threatened as it have to cope both with global change and co-habitation with introduced species such as Sargassum muticum.
... Among these, fucoxanthin is the predominant pigment, it is generally yellowish-brown in color and masks the green color of chlorophyll, giving an overall appearance in the range of olive green to dark brown (Jefferey et al. 1997). Brown seaweeds have enormous amounts of phenolic compounds which are also known for exhibiting antioxidant activities (Dang et al. 2017;Gupta et al. 2011;Lann et al. 2008;Rajauria et al. 2010). These phenolic compounds include mainly chlorogenic acid, phloroglucinol, caffeic acid, kaempferol, 2, 5-dihydroxy benzoic acid, coumaric acid, cirsimaritin, ferulic acid, gallic acid, and syringic acid (Chakraborty et al. 2017;Rajauria et al. 2016 ...
... Fresh seaweeds contain very high moisture content (∼75% -90% w.b) and are highly perishable due to enzymatic deterioration, lipid oxidation, and microbial attack. The functional properties, bioactive compounds, volatile compounds (aroma, flavor) and antioxidant activity in the finished seaweed product are highly affected by the drying method applied, depending on the disintegration of the food matrix during the process (Costa et al. 2015;Dang et al. 2016;Gupta et al. 2011;Lann et al. 2008;Neoh et al. 2016;Tello-Ireland et al. 2011;Vairappan et al. 2014;Wong and Cheung 2001). The most widely used method of drying seaweeds is open sun drying. ...
... The positive correlation between the FRAP and TPC values can also be quantified with the Pearson correlation coefficient (r), the values for S1 and S2 were r = 0.857 and r = 0.936, respectively. The strong correlation between FRAP and TPC was also reported in several seaweeds such as Hormosira banskii (Dang et al. 2017), Sargassum muticum and Bifurcaria bifurcata (Lann et al. 2008). Furthermore, the Pearson correlation between the change in color, ΔE and TPC was -0.729 and -0.273, for S1 and S2, respectively. ...
Recent interest among consumers to avoid added chemical additives/preservatives has led to the recognition of seaweed as a healthy source of fibers, minerals, and antioxidants. Currently, global seaweed aquaculture is valued over US$ 6 billion and is increasing at a steady rate of 8% annually. Moreover, as per NOAA Fisheries the US imports more than 80% of the seafood consumed. This provides huge economic and workforce development opportunities in the seaweed aquaculture industry of Maine. Consequently, farming sugar kelp (Saccharina latissima), a brown seaweed, is gaining momentum along the northeast US coast. Due to its seasonal availability and limited shelf life, seaweeds are sun-dried or using hot-air to remove moisture, preventing oxidation and microbial growth. The goal of this research is to solve the bottlenecks of drying seaweed in Maine by developing an innovative technology focused on a clean, energy-efficient and closed drying system for producing top-notch and local finished products for American consumers. For this project, the effect of drying and storage conditions (temperature, humidity) on the physical, chemical and thermal properties of the final product are studied. Also, a mathematical drying model is developed to understand the drying kinetics and rate of moisture removal in hot-air driers. Investigations carried out throughout this experiment shows controlled environment drying can improve the predictability of drying dynamics significantly for the preservation of health-beneficial components in sugar kelp. The developed model showed drying can be optimized to create a carbon negative and sustainable seaweed processing industry in Maine.
... Phenolic compounds present in algae are especially sensitive to heat and light, particularly UV radiation (López, Caleja, Prieto, Sokovic, Calhelha, Barros, & Ferreira, 2019). These factors may lead to reductions in the biological properties of the compounds, due to their decomposition, as was shown in a study in which two algae extracts from Sargassum muticum (Yendo) Fensholt and Bifurcaria bifurcata R.Ross were submitted to different processes to compare their effects: drying in oven at~55°C for 4 h, and greenhouse drying exposed to light, at 23°C for 72 h, resulting in both methods producing significant reductions (Agregán et al., 2017;Le Lann, Jégou, & Stiger-Pouvreau, 2008;Lim & Murtijaya, 2007). In general, all drying processes that involve temperatures above 40°C are associated with losses of phenolic compounds (Lim & Murtijaya, 2007;Wong & Chikeung Cheung, 2001), although there are always exceptions, such as some polyphenols, which did not suffer apparent degradation during a drying process carried out at 60°C (Larrauri, Rupérez, & Saura-Calixto, 1997). ...
... Another possible cause of degradation of some phenolic compounds is a direct exposure to sunlight, hence greenhouse drying is also not a good idea. In fact, in the extractions carried out in the dark, greater amounts of total phenolic compounds with potent antioxidant activity values were obtained (Le Lann et al., 2008). The use of the drying technique was able to avoid the loss of heat-sensitive products, however, there were changes in the native conformation of certain molecules that could lead to a reduction in bioactive capacities (Franks, 1998). ...
... The use of the drying technique was able to avoid the loss of heat-sensitive products, however, there were changes in the native conformation of certain molecules that could lead to a reduction in bioactive capacities (Franks, 1998). Therefore, the best option is the extraction of phenolic compounds directly from fresh algae, at low temperatures, and in the absence of light, although, if this is not possible, extraction from frozen and/or freeze-dried matrices is recommended (Le Lann et al., 2008). ...
Given the growing tendency of consumers to choose products with
natural ingredients, food industries have directed scientific research in
this direction. In this regard, algae are an attractive option for the
research, since they can synthesize a group of secondary metabolites,
called phenolic compounds, associated with really interesting properties
and bioactivities. The objective of this work was to classify the major
phenolic compounds, compare the effectiveness of the different extractive
techniques used for their extraction, from traditional systems (like heat
assisted extraction) to the most advance ones (such as ultrasound,
microwave or supercritical fluid extraction); the available methods for
identification and quantification; the stability of the enriched extract
in phenolic compounds and the main bioactivities described for these
secondary metabolites, to offer an overview of the situation to consider
if it is possible and/or convenient an orientation of phenolic compounds
from algae towards an industrial application.
... Sun drying and freezing at − 20°C caused extensive protein degradation. According to Le Lann et al. (2008), dried seaweeds showed lower phenolic contents and lower antioxidant capacities than fresh and frozen seaweeds, which suggests that the phenolic content and antioxidant activities are decreased by drying treatments, especially oven-and greenhouse-drying. Badmus et al. (2019) revealed that low-temperature drying, such as freeze drying and oven drying at 40°C, produced products with higher concentrations of nutritionally important chemicals, as well as stronger antioxidant activities. ...
... The FAO (2018) also mentions that algae can be frozen for storage, but without specifying the timing and parameters of this process. French researchers using the example of two species of algae Sargassum muticum and Bifurcaria bifurcata showed that both species did not differ in the TPC level of fresh and frozen samples (Le Lann et al. 2008), considering that frozen samples were stored for 3 weeks at − 20°C. The authors note that despite the fact that the studied species differ in morphology and in the initial TPC level, no significant differences were found between frozen and fresh samples of each species. ...
... Sun drying (Carrillo et al. 1992), oven drying (Hamdy and Dawes 1988), and freeze drying (Mabeau et al. 1992) are three common drying methods used in algae research. When comparing different drying methods, a number of authors noted that when drying in an oven, the TPC level in brown algae decreases by 30-50% (Gupta et al. 2011;Le Lann et al. 2008;Stévant et al. 2018;Amorim et al. 2020). Drying Kappaphycus alvarezii in the sun significantly reduces the total phenols, flavonoids, anthocyanins, and carotenoids compared with samples dried in oven or in the shade . ...
The effect of air drying and freezing at − 25 °C on the total phenolic content, fucoidan, alginate, and amino acids of brown algae Fucus vesiculosus, Fucus distichus, and Ascophyllum nodosum was studied over 365 days of storage every 90 days. The levels of total phenols and polysaccharides in frozen algae samples at 365 days of storage were 75–95% of fresh algae and were higher than in air-dried samples by more than 5–15%. The greatest differences between the fresh and dried samples were in the total phenolic contents. A strong correlation was found between the content of total phenolics and polysaccharides and the water content in frozen samples of F. vesiculosus and A. nodosum. The influence of air drying and freezing processing and storage on the total amino acid content is discussed using F. vesiculosus as an example. The total amino acid content in the air-dried samples increased during storage, but on the 365th day, 99% of the initial content in fresh algae remained. In contrast, the content in the frozen samples had decreased to 82% after the same storage duration. The ratio of the sums of the essential to the total amino acids during storage in the dry and frozen samples increased compared with that in fresh algae from 0.43 to 0.51 after 365 days of storage. Air drying and freezing are suitable procedures in terms of the levels of total phenols, polysaccharides, and amino acids, allowing a shelf life of at least 365 days.
... The most common drying processes used for seaweeds are sun-drying, oven-drying and freeze-drying (Ling et al. 2015). The processing characteristics of each method can change the chemical composition and antioxidant properties of seaweed intended for use as functional bioproducts for food and feed, cosmetic, pharmaceutical and industrial applications (Jiménez-Escrig et al. 2001;Le Lann et al. 2008;Gupta et al. 2011). Although there are few studies describing the effects of the drying processes on seaweed extracts (Rioux et al. 2017), interest in this subject has increased in recent years (Chenlo et al. 2018;Stévant et al. 2018;Badmus et al. 2019;Sappati et al. 2019;Silva et al. 2019;Uribe et al. 2019). ...
... The Folin-Ciocalteu assay showed a significant decrease in the amount of reducing compounds in silica-dried and ovendried samples compared to the frozen ones. Studies with seaweeds (Jiménez-Escrig et al. 2001;Le Lann et al. 2008;Gupta et al. 2011) and terrestrial plants (Lim and Murtijaya 2007;Mudau and Ngezimana 2014) also showed a decrease in the reducing compounds in oven-dried samples. This reduction could be due to degradation of phenolic compounds at high temperatures, starting at 40°C (Le Lann et al. 2008;Moreira et al. 2016). ...
... Studies with seaweeds (Jiménez-Escrig et al. 2001;Le Lann et al. 2008;Gupta et al. 2011) and terrestrial plants (Lim and Murtijaya 2007;Mudau and Ngezimana 2014) also showed a decrease in the reducing compounds in oven-dried samples. This reduction could be due to degradation of phenolic compounds at high temperatures, starting at 40°C (Le Lann et al. 2008;Moreira et al. 2016). Other studies also showed antioxidant potential decrease in macroalgae due to high temperatures. ...
Seaweeds are a source of antioxidants and pigments, which can be used as functional ingredients for food, cosmetic, pharmaceutical, and industrial applications. As fresh seaweed has a large amount of water, it usually goes through a drying process in order to be commercialized, which facilitates transportation and storage and also increases shelf time. However, the drying procedures can change the chemical composition and antioxidant properties of seaweeds. Thus, the aim of this study was to evaluate the antioxidant properties and pigment and protein content of four Brazilian macroalgae (Gracilariopsis tenuifrons, Pterocladiella capillacea, Sargassum stenophyllum, and Ulva fasciata) suitable for use as functional bioproducts after processing with three different drying procedures (freeze-drying, oven-drying and silica-drying), using a fresh frozen treatment as control. Among the studied species, S. stenophyllum presented the highest antioxidant activity. For this species, freeze-drying was the procedure with the highest activity in the Folin-Ciocalteu and metal chelating assays, while for the ABTS, DPPH, and FRAP assays, no significant differences were observed between freeze-drying and silica-drying. Freeze-drying also showed low reduction of photosynthetic pigments in G. tenuifrons, P. capillacea, and U. fasciata and was the method that best-preserved protein content in the four species. In general, the antioxidant potential and pigment and protein content for the studied algae decreased in the following order: fresh frozen (control) > freeze-dried > silica-dried > oven-dried. Freeze-drying was the procedure that presented the lowest alteration in functional properties, as the low temperature prevents the degradation of heat-sensitive compounds. In addition, freeze-drying is a vacuum process and the absence of oxygen prevents oxidation reactions of functional ingredients.
... It is well known that seaweeds have a high percentage of moisture, often exceeding 90% of the wet weight, thus making their biomass highly perishable [13,14]. Hence, it is critically important that appropriate drying and storage conditions are applied to preserve biomass quality and ensure product safety. ...
... For all temperatures, a reduction in TPC and TFC as well as a decrease in antioxidant activity in comparison to fresh biomass was observed [13]. Other studies [14,17] have been done on various seaweed species and have indicated significant alterations of composition and bioactivity as a result of different drying and storage conditions. Similar data is not found for A. taxiformis, which makes this a relevant knowledge gap, especially taking into account the possible future relevance of this species. ...
... This seems to corroborate results at t = 0 month. Moreover, Le Lann et al. (2008) [14] analysed the effects of sun-drying (72 h), oven-drying (50-60 °C, 40 h), and freeze-drying (72 h) on the biomass quality of Sargassum muticum and Bifurcaria bifurcata. These authors reported that phenolic content was higher in freeze-dried samples than in oven-dried samples. ...
The Azorean red seaweed Asparagopsis taxiformis may be used in human and animal diets. This seaweed is deemed to reduce the large production of methane—a major greenhouse gas—by ruminant digestion. Seaweed producers, however, have difficulties in ensuring a reliable and similar product throughout all year and in different years. Changes in biochemical composition and bioactivity are caused not only by natural variability, but also by the particular drying process, storage conditions, and storage time. Regarding the drying process, oven-dried samples had a lower EPA content, 1.9 ± 0.2% of the total FAs, than freeze-dried samples, 8.6 ± 1.7%. The same occurred with the phenolic contents and particularly with the ethanolic extracts. ABTS antioxidant activity results showed freeze-drying as advantageous. With respect to storage temperature, anti-inflammatory activity was higher in A. taxiformis at room temperature after three month storage. Moreover, EPA content in freeze-dried samples decreased to 0.3–1.0% after three month storage. Phenolic content in the ethanolic extracts also declined over storage time. In the case of aqueous extracts, however, variation was in the opposite direction. Antioxidant activity as measured by ABTS showed for almost all samples and types of extracts an increasing trend over time: from 0.26–1.75 to 0.75–4.40 mmol Trolox Eq/100 g dw. Anti-inflammatory activity increased over time from < 30% COX-2 inhibition at the beginning of the trial to > 30% COX-2 inhibition after three month storage. Therefore, there is a relevant bioactive potential in A. taxiformis and the drying process and storage conditions and time affect this potential.
... B. bifurcata is a brown macroalga, and due to its morphology it is classified as a cylindrical species [15] and can be scientifically classified as follows [16]: This brown macroalga lives in rock pools on the lower and middle tidal, needing shores for its settlement, and is distributed along the coast of the Northern Atlantic, between Morocco and Northwestern Ireland [17]. About 56% of the published (and here reviewed) studies concerning the linear diterpenes fraction of B. bifurcata use samples from the coast of France (Figure 1), which may be associated with the high abundance of this macroalga on that area [8,. ...
... B. bifurcata is a brown macroalga, and due to its morphology it is classified as a cylindrical species [15] and can be scientifically classified as follows [16] This brown macroalga lives in rock pools on the lower and middle tidal, needing shores for its settlement, and is distributed along the coast of the Northern Atlantic, between Morocco and Northwestern Ireland [17]. About 56% of the published (and here reviewed) studies concerning the linear diterpenes fraction of B. bifurcata use samples from the coast of France (Figure 1), which may be associated with the high abundance of this macroalga on that area [8,. ...
... According to the main chemical characteristics, linear diterpenes are arranged in three families: A (C-12 oxidized compounds) ( Figure 2); B (two subfamilies: on the one hand, B1 corresponds to C-13 oxidized molecules bearing an OH group, while on the other hand B2 are compounds with a ketone functionality at C-13 position) (Figures 3 and 4, respectively); and C (which are the non C-12/C-13 oxidized compounds) ( Figure 5). These four groups of compounds (A, B1, B2, and C) have metabolic precursors, which are 12-(S)-hydroxygeranylgeraniol (bifurcadiol) (1), eleganediol ((S)-13-hydroxygeranylgeraniol) (9), eleganolone (13-oxogeranylgeraniol or (S)-13-ketogeranylgeraniol) (15), and geranylgeraniol (39), respectively [14]. Concerning the different sampling locals as well as the exposure to different environmental factors, it is expected that this variety of B. bifurcata presents diverse compositions. ...
Marine resources are considered as a very promising source of bioactive molecules, and macroalgae in particular have gained special attention, due to their structurally diverse composition. Particular interest has been devoted to the brown macroalga Bifurcaria bifurcata, due to their abundance in bioactive linear diterpenes. In this appraisal, a thorough review concerning the methodologies used in the extraction, fractionation, and identification of diterpenes from B. bifurcata is provided and discussed in detail. An exhaustive compilation of the mass spectra and nuclear magnetic resonance (NMR) data are also provided. The in vitro and in chemico assays already performed to assess different biological activities attributed to B. bifurcata diterpenes are also reviewed, emphasizing the use of isolated components, enriched fractions, or crude extracts. The associated major strengths and challenges for the exploitation of B. bifurcata diterpenes for high-value applications are critically discussed.
... Drying was one of the earliest techniques for food preservation and is governed by simultaneous heat and mass transfer effects on liquid-vapor phase change (Mujumdar and Passos 2000). The functional properties, bioactive compounds, volatile compounds (aroma, flavor), and antioxidant activity in the finished seaweed product are highly affected by the drying method applied, depending on the disintegration of the food matrix during the process (Wong and Cheung 2001;Lann et al. 2008;Gupta et al. 2011;Tello-Ireland et al. 2011;Vairappan et al. 2014;Costa et al. 2015;Ling et al. 2015;Neoh et al. 2016). The most widely used method of drying seaweeds is open sun drying. ...
... Brown seaweeds have large amounts of phenolic compounds which are also known for exhibiting antioxidant activities (Lann et al. 2008;Rajauria et al. 2010;Gupta et al. 2011;Dang et al. 2017). These phenolic compounds include mainly chlorogenic acid, phloroglucinol, caffeic acid, kaempferol, 2, 5-dihydroxy benzoic acid, coumaric acid, cirsimaritin, ferulic acid, gallic acid, and syringic acid (Rajauria et al. 2016;Chakraborty et al. 2017). ...
... The positive correlation between the FRAP and TPC values can also be quantified with the Pearson correlation coefficient (r); the values for S1 and S2 were r = 0.857 and r = 0.936, respectively. The strong correlation between FRAP and TPC was also reported in seaweeds such as H. banksii (Dang et al. 2017), Sargassum muticum, and Bifurcaria bifurcata (Lann et al. 2008). Furthermore, the Pearson correlation between the change in color, ΔE, and TPC were found to be − 0.729 and − 0.273, for S1 and S2, respectively. ...
Sugar kelp (Saccharina latissima), a marine macroalga, is a rich source of fibers, vitamins, minerals, and antioxidants. However, investigations on the effects of seasonal variation and the drying methods employed on the kelp composition and quality attributes are limited. In this study, the effects of seasonal variation and different drying methods (sun drying, freeze drying) and conditions (temperature, humidity) employed in a heat pump-based drying system on the physicochemical properties, phenolic activity, and antioxidant capacity of S. latissima grown in Maine, USA, were studied. Fresh sugar kelp samples were dried using sun drying, freeze drying, and heat pump-based drying systems at air temperatures of 30, 50, and 70 °C and relative air humidity levels of 25 and 50%. Seasonal variations in kelp harvest (i.e., early May and end of June) have significant effect (p < 0.05) on the proximate composition. Significant effects of the drying methods (p < 0.05) were also observed in the water and oil holding capacities (WHC and OHC), with the highest OHC and the lowest WHC exhibited in freeze dried sugar kelp. At lower drying humidity of 25%, the samples exhibited higher WHC and OHC as compared to higher humidity of 50%. Compared to the fresh kelp, irrespective of the drying method, the total phenolic content (TPC), antioxidant activity, and vitamin C content were observed to decrease by 5–10-fold. Overall, drying at lower temperature (< 50 °C) and lower humidity was found to be suitable in terms of the processing cost, functional properties, and preservation of the bioactive compounds in dried sugar kelp.
... Besides those two potential, phlorotannins also perform other biological activity such as anti-proliferative and antitumor (Nwosu et al., 2011;Yang et al., 2010;Imbs et al., 2008); antidiabetic (Nwosu et al., 2011;Jung et al., 2008); α-Glucosidase and α-Amylase inhibition , angiotensin-I-converting enzyme (ACE I) inhibition (Jung et al., 2006;Athukorala and Jeon, 2005), antiinflammatory Kim et al., 2010); matrix metalloproteinases (MMPs) inhibition , hyaluronidase inhibition (Ferreres et al., 2012;Shibata et al., 2002), tyrosinase inhibition (Yoon et al., 2009;Heo et al., 2009;Kang et al., 2004), phoroprotective (Cha et al., 2012;Le Lann et al., 2008;Heo et al., 2009) and antiallergic Sugiura et al., 2007). ...
... Then the optical density was read against the blank prepared at 620 nm. Phloroglucinol was used as a standard for the calibration curve prepared in different concentrations ranged from 0 -100 µg/mL (Le Lann et al., 2008). ...
... Most of the temperature suggested for the extraction of terrestrial and marine vegetal polyphenols compound was below 60 °C (Le Lann et al., 2008;Dai and Mumper, 2010;Yoon et al., 2010;Tanniou et al., 2013a;Andrade et al., 2015;Ismail and Abdullah, 2015). Organic solvents such as methanol, acetone, and many others tend to evaporate at high temperatures (approximately > 50°C), thus their efficiency decreases due to the shifting of solvents-to-water ratio leading to the change of sample-to-solvent ratio (Tan et al., 2013). ...
En France et Indonésie, Sargassum est une espèce abondante mais elle algue n’a pas encore été exploitée de façon optimale. Sargassum contient de nombreux métabolites primaires ainsi que des composés bioactifs, dont les phlorotannins, ayant une large gamme de propriétés pharmacologiques intéressantes à valoriser. L’hétérogénéité et la complexité de la paroi cellulaire des algues réduisent fortement l’efficacité d’extraction conventionnelle. Cette étude a eu trois principaux objectifs (1) la caractérisation de la composition biochimique de Sargassum et ses variations saisonnières, (2) l'extraction solide-liquide et (3) l'extraction assistée par enzymes des phlorotannins et l’étude de leurs activités biologiques. Dans cette étude, les minéraux de Sargassum représentent d’une valeur importance avec une teneur qui atteint 33% suivi par les protéines avec 24% de la matière sèche. Les sucres ne représentent que 13% de la matière sèche. La composition biochimique de Sargassum, comme pour la plupart des algues, est fortement affectée par les saisons et est liée au cycle de vie de l’algue. La saisonnalité affecte également la production de phlorotannins. L’étude des différents procédés d’extraction montre que les rendements sont plus faibles pour une extraction solide-liquide traditionnelle (5 à 24% de la matière sèche de l'algue) par rapport à l'extraction assistée par enzyme (21 à 38% de la matière sèche de l'algue). L’extraction assistée par enzymes augmente le rendement d’extraction des polyphénols par rapport à l'extraction solide-liquide. Les extraits obtenus par extraction assistée par enzymes présentent une forte activité antiradicalaire.
... Besides those two potential, phlorotannins also perform other biological activity such as anti-proliferative and antitumor (Nwosu et al., 2011;Yang et al., 2010;Imbs et al., 2008); antidiabetic (Nwosu et al., 2011;Jung et al., 2008); α-Glucosidase and α-Amylase inhibition , angiotensin-I-converting enzyme (ACE I) inhibition (Jung et al., 2006;Athukorala and Jeon, 2005), antiinflammatory Kim et al., 2010); matrix metalloproteinases (MMPs) inhibition , hyaluronidase inhibition (Ferreres et al., 2012;Shibata et al., 2002), tyrosinase inhibition (Yoon et al., 2009;Heo et al., 2009;Kang et al., 2004), phoroprotective (Cha et al., 2012;Le Lann et al., 2008;Heo et al., 2009) and antiallergic Sugiura et al., 2007). ...
... Most of the temperature suggested for the extraction of terrestrial and marine vegetal polyphenols compound was below 60 °C (Le Lann et al., 2008;Dai and Mumper, 2010;Yoon et al., 2010;Tanniou et al., 2013a;Andrade et al., 2015;Ismail and Abdullah, 2015). Organic solvents such as methanol, acetone, and many others tend to evaporate at high temperatures (approximately > 50°C), thus their efficiency decreases due to the shifting of solvents-to-water ratio leading to the change of sample-to-solvent ratio (Tan et al., 2013). ...
... Then the optical density was read against the blank prepared at 620 nm. Phloroglucinol was used as a standard for the calibration curve prepared in different concentrations ranged from 0-100 µg mL -1(Le Lann et al., 2008). ...
In France and Indonesia, Sargassum is quite abundant yet this alga has not been optimally exploited. Sargassum contains macro and micro molecules and also bioactive compounds, the most known is phlorotannins, showing a wide range of pharmacological properties. Therefore, it is interesting to further valorize this alga for various industrial applications, such as food, pharmacology and cosmetic. Knowledge on biochemical composition of this alga, which also represents its nutritive value, is essential for food industries. Concerning the bioactive compound, solid-liquid extraction is the most commonly used technique in the extraction of phlorotannins from brown algal biomass. However, phlorotannins of brown algae are known to be bound with algal cell wall and the high content of various cell wall polysaccharides in macroalgae limit the active compound accessibility. Thus, these cell walls strongly reduced the extraction efficiency application of conventional extraction. As a consequence, it is important to consider the degradation of algal cell wall as a way to liberate more phlorotannins. Application of enzymes is considered as one process that might facilitate the degradation of algal cell wall leading to the recovery of phlorotannins from brown algae.This study had three main subjects of interest; they were (1) the characterization of Sargassum biochemical composition and its seasonal variation, (2) solid-liquid extraction and (3) enzyme-assisted extraction of Sargassum phlorotannins and their bioactivities. The bioactivities analyzed in this study included antioxidant (DPPH radical scavenging and FRAP reducing power), antibacterial, tyrosinase, elastase, biofilm inhibition, cytotoxicity and antiviral activity.In this study, minerals represented a significant value with a content reaching 33% followed by proteins with 24% of algal dry material. In the contrary, sugars showed only 13% of algal dry material. The study of seasonal variability demonstrated that the biochemical composition of Sargassum, as for most algae, is strongly affected by the season and it appears to be related to the life cycle of the algae. Same cases happened with the polyphenol compound of Sargassum.Nevertheless, suitable extraction method is important to choose in order to increase the yield. Solid-liquid extraction yielded lower (5-24% of algal dry material) compared to enzyme-assisted solid-liquid extraction (21-38% of algal dry material). Regarding the polyphenol content, enzyme-assisted extraction also yielded a better yield, 32%, compared to 26% of algal dry material if the extraction is carried out without enzyme.After the screening of eight enzymes to extract the polyphenols from S. muticum, Viscozyme - a cellulase, released a greater quantity of phenolic compounds according to Folin Ciocalteu method, result was also confirmed by the anti-free radical activity of (IC50 0.6 ± 0.1 mg mL-1). This extract also managed toprevent 43.7 ± 4.2%, higher than the other extracts, of biofilm formation generated by P. aeruginosa.Other than antiradical activity, it seems that each enzyme showed different potential. In reducing power, the most important activity was shown by AMG (an exo-amylase) extract (60.8 ± 1.8 μM of Fe2+). Ultraflo (a xylanase) extract had promising potential in inhibiting the tyrosinase at 24.5 ± 2.6%, while Shearzyme (cellulose and xylanase) extract showed higher inhibition elastase activity than the other extracts, 30.9 ± 5.9%. Viscozyme extract was able to hamper 43.7 ± 4.2% of film formation generated by P. aeruginosa. However, Shearzyme extracts exhibited strong biofilm inhibition activity against the E. coli, 60.3 ± 10.3% of inhibition.The application of enzymes in the extraction of the Sargassum phenolic compound is quite effective. In addition, Sargassum enzyme extracts demonstrate a wide range of bioactivity. It is important to consider that, using enzymes, the phenolic compound is probably not the only compound extracted from the algal matrix by the enzymes. As a result, it will be interesting to continue working on the purified samples pretreated by enzyme-assisted extraction in the future. In addition, the characterization of the Sargassum phenolic compound could help to better understand the mechanisms of their bioactivity.
... Regarding biological activity of these species, most available information concerns antioxidant properties, for B. bifurcata (Le Lann, Jégou, & Stiger-Pouvreau, 2008;Pinteus et al., 2017), E. selaginoides (Pinteus et al., 2017;Vizetto-Duarte et al., 2016), and Codium sp. (Pinteus et al., 2017). ...
... Vizetto-Duarte et al. (2016), also specifically for C. tamariscifolia (now E. selaginoides), obtained higher antioxidant activity as measured by DPPH, but in ethyl acetate extracts. Likewise, for B. bifurcata and methanol-water extracts, higher DPPH values have been measured (Le Lann et al., 2008). Seasonality of the antioxidant activity as measured by DPPH has been studied in the case of C. tamariscifolia (Celis-Plá et al., 2016). ...
The biological activity and nutraceutical potential of two brown seaweed species (Bifurcaria bifurcata, Ericaria selaginoides) and one green seaweed (Codium sp.) were evaluated taking seasonal effects into account. The phenolic content of B. bifurcata was higher than those of the other two species regardless of season, 10.13–11.01 mg Gallic Acid Equivalent (GAE) g–1 dw seaweed. The ethanol extracts of B. bifurcata were more antioxidant as measured by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) technique than the equivalent extracts from E. selaginoides, 0.428–0.442 mg Ascorbic Acid Equivalent (AA Eq) g dw seaweed–1 vs 0.338–0.361 mg AA Eq g dw seaweed–1. Regarding Ferric Ion Reducing Antioxidant Power (FRAP), the highest activity was measured in Codium sp. extracts and no difference was detected between B. bifurcata and E. selaginoides. The 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) results differed from the FRAP values in that the ethanol extracts from Codium sp. were less antioxidant as measured by ABTS than those of the other two species. Summer E. selaginoides extracts were more antioxidant. The most anti-inflammatory extract was obtained from E. selaginoides harvested in Summer, exhibiting 94.2 ± 4.0% inhibition of cyclooxygenase-2 (COX-2). The extracts from Codium sp. had the lowest activity, 13.6–15.5%. For both B. bifurcata and E. selaginoides, Summer extracts were more anti-inflammatory than Winter extracts. © 2022 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
... Antioxidant activity measured using the β-carotene bleaching method (41,42) was determined following the protocols published by (38,43). Briefly, 2 mL of a solution of β-carotene in chloroform (0.1 mg/mL) was added to round-bottom flasks containing 20 mg of linoleic acid and 200 mg of Tween 40. ...
... All samples were assayed in triplicate. Antioxidant activity coefficient (AAC700 in mg per mL) was calculated as described Le Lann et al. (43). A low AAC700 indicates a strong antioxidant activity. ...
Osteoporosis is an aging-related disease and a worldwide health issue. Current therapeutics have failed to reduce the prevalence of osteoporosis in the human population, thus the discovery of compounds with bone anabolic properties that could be the basis of next generation drugs is a priority. Marine plants contain a wide range of bioactive compounds and the presence of osteoactive phytochemicals was investigated in two halophytes collected in Brittany (France): the invasive Spartina alterniflora and the native Salicornia fragilis. Two semi-purified fractions, prepared through liquid-liquid extraction, were assessed for phenolic and flavonoid contents, and for the presence of antioxidant, mineralogenic and osteogenic bioactivities. Ethyl acetate fraction (EAF) was rich in phenolic compounds and exhibited the highest antioxidant activity. While S. fragilis EAF only triggered a weak proliferative effect in vitro, S. alterniflora EAF potently induced extracellular matrix mineralization (7-fold at 250 μg/mL). A strong osteogenic effect was also observed in vivo using zebrafish operculum assay (2.5-fold at 10 μg/mL in 9-dpf larvae). Results indicate that polyphenol rich EAF of S. alterniflora has both antioxidant and bone anabolic activities. As an invasive species, this marine plant may represent a sustainable source of molecules for therapeutic applications in bone disorders.
... Dans la littérature, plusieurs extraits de B. bifurcata ont montré des activités antioxydantes : un extrait hydrométhanolique (Le Lann et al., 2008), un extrait au méthanol et au dichlorométhane fouling contre deux bactéries marines ainsi que des larves de balanes (Maréchal et al., 2004). Par ailleurs, un extrait au méthanol et au dichlorométhane a montré une activité anti-tumorale . ...
... Les teneurs en CP de B. bifurcaria retrouvées dans la littérature peuvent atteindre 4,5% du poids sec de l'algue avec un extrait hydrométhanolique (Le Lann et al., 2008). Glombitza & Rösener (1974) ...
La recherche de molécules naturelles dans de nombreux domaines industriels se développe dans une optique d’éco-responsabilité, notamment en cosmétique. Les macroalgues sont une ressource intéressante, riche en de nombreux métabolites tels que les composés phénoliques qui présentent des activités photoprotectrices, antioxydantes ou encore anti-âge. L’objectif de ce travail de thèse était d’analyser les algues brunes bretonnes en termes de composés phénoliques au stade précoce ou au stade macroscopique, obtenir des fractions enrichies en composés phénoliques actifs, les identifier et les inclure dans des formulations cosmétiques. Les résultats de ces travaux ont montré des teneurs élevées en composés phénoliques notamment chez les Fucales et une variation saisonnière de leur teneur pouvant varier selon les espèces.Cette étude a montré que les méthodes alternatives éco-responsables d’extraction et de purification des composés phénoliques permettent d’obtenir des fractions enrichies en ces composés de manière similaire voire supérieure aux méthodes classiques.D’autre part, une analyse HPLC a permis de séparer nos composés d’intérêt, devant cependant être couplée à une méthode de spectrométrie de masse pour permettre l’identification des composés. Enfin, ce travail a mis en évidence la capacité de valorisation en cosmétique des composés phénoliques par leur activité anti-âge et leur stabilité à l’état sec. Leur stabilité au sein de formulation cosmétique reste à être validée dans différentes galéniques, la stabilité d’une seule ayant été testée dans cette étude.
... The most exploited phenolic compounds are phlorotannins, which are exclusively present in high concentration in brown seaweeds [17,124] and are involved in defense activities [150][151][152], showing strong antioxidant properties and antimicrobial activity, which help to inhibit bacterial growth [17]. Phlorotannins can be exploited in different biotechnological sectors. ...
... Their bioactive compounds have positive effects on human health. For example, Tanniou et al. [149] identified the brown alga Sargassum muticum as a potential source of bioactive phenolic compounds: this species showed a strong antioxidant activity [150] and anti-proliferative activity in breast cancer cells [160] that may suggest the involvement of S. muticum in biotechnological applications. ...
Seaweeds are a potential source of bioactive compounds that are useful for biotechnological applications and can be employed in different industrial areas in order to replace synthetic compounds with components of natural origin. Diverse studies demonstrate that there is a solid ground for the exploitation of seaweed bioactive compounds in order to prevent illness and to ensure a better and healthier lifestyle. Among the bioactive algal molecules, phenolic compounds are produced as secondary metabolites with beneficial effects on plants, and also on human beings and animals, due to their inherent bioactive properties, which exert antioxidant, antiviral, and antimicrobial activities. The use of phenolic compounds in pharmaceutical, nutraceutical, cosmetics, and food industries may provide outcomes that could enhance human health. Through the production of healthy foods and natural drugs, bioactive compounds from seaweeds can help with the treatment of human diseases. This review aims to highlight the importance of phenolic compounds from seaweeds, the scope of their production in nature and the impact that these compounds can have on human and animal health through nutraceutical and pharmaceutical products.
... Recently, NMR metabolic profiling has been successfully applied as a taxonomical tool for the genus Cystoseira (J egou et al. 2010), as well as in the differentiation of S. muticum samples from different geographical origins (Tanniou et al. 2015). In the same way, different methods of sample extraction have been tested using this technique (Le Lann et al. 2008, Gupta et al. 2013, allowing the identification of the main metabolites depending on sample processing. Thus, the objective of the present investigation was to study the metabolic differences between the main Sargassum species found either as beach cast material or forming patches in Puerto Morelos (Quintana Roo) on the east coast of the Mexican Caribbean, as well as evaluate the effect of some drying and extraction methods, to identify suitable conditions to evaluate their main metabolites in Sargassum species studied. ...
... As presented above, the exploration of the metabolic profile from invasive Sargassum species may be of help in setting the conditions to propose NMR profiling as a useful technique in the taxonomical identification of species and morphotypes (Hamid et al. 2019). Further investigation including more pelagic and other benthic species of Sargassum could lead to the detection and isolation of chemomarkers that could be tested and proposed as molecules of interest (Le Lann et al. 2008). ...
The genus Sargassum is well represented by benthic and pelagic species, some of which forms massive aggregates that can travel large distances due to the force of the ocean currents. Although they constitute an essential habitat for fish and invertebrate species, large accumulations of Sargassum in coastal areas generates several economic, environmental and health impacts. It’s important to recognize the species forming these aggregates, and identify the metabolites they produce, these would allow its exploitation, and therefore, better management practices. NMR metabolic profiling is a technique which can discriminate samples while detecting their unique or differential chemical features, and has been successfully used in the study and classification of several algal species. The present investigation studied the metabolic profiling of Sargassum species found on strandings at Puerto Morelos (Quintana Roo) east coast of the Mexican Caribbean. PCA of the ¹H‐NMR profiles corresponding to S. natans, S. natans (morphotype VIII), S. fluitans and a benthic Sargassum buxifolium allowed the discrimination of samples between them. Furthermore, discrimination between the two forms of S. natans was also observed. The PCA loading plot revealed that glutamine and glutamate have the highest influence in the clustering of the benthic Sargassum, while a high abundance of lactate, Myo‐inositol and trimethylamine is a unique feature from S. natans morphotype VIII. Additional PLS‐DA models showed that the heat‐drying process improved the extraction of metabolites. Maceration and microwave‐assisted extraction with water‐ethanol led to similar profiles and thus any of them could be used in future investigations.
... Samples collected in the rocky coast of Cape Estai during 2010-2011 were characterized after oven-drying and grinding (Balboa et al. 2016). Oven drying is a methodology similar to that used in industrial factories preparing seaweed for food use; although this conditioning methodology can affect some bioactive compounds in comparison to those found in fresh, frozen, and freeze-dried material Plouguerné et al. 2006;Le Lann et al. 2008). ...
... The mass ratio for fucose/galactose/glucose/xylose/ mannose was 1:0.44:0.33:0.22:0.09. The phenolic content of the extracts was almost independent on the processing temperature, the concentration being under 14% and the DPPH radical scavenging activity was maximum at 190°C, with IC 50 0.72 g L −1 (González-López et al. 2012a), comparable to those for synthetic antioxidants, 0.24 and 2.79 g L −1 for BHA and BHT, respectively, or in solvent extracts from oven-dried S. muticum (1.5 g L 1 ) (Le Lann et al. 2008). The reducing capacity at 0.59 g L −1 was also maximal at this temperature, equivalent to 1.48 mM FeSO 4 and to 0.57 mM ascorbic acid in the FRAP assay, and the antioxidant activity in the emulsion was comparable to those found for BHA and BHT at 0.5 g L −1 (González-López et al. 2012a). ...
Sargassum muticum is an invasive brown seaweed which could not be eradicated from the Atlantic coasts. Therefore, periodic collection and valorization of its components has been suggested. Efficient multistage and multiproduct processes for the obtaining of valuable fractions from this seaweed, which also could be applicable to other brown seaweeds, were developed. This review discusses the potential of conventional and emerging technologies for the sequential extraction of S. muticum bioactives of interest for food, cosmetic, and pharmaceutical applications.
... The objective of the present study was to improve fish quality during chilled storage by the application of a preliminary dipping treatment containing a seaweed extract. A brown alga (Bifurcaria bifurcata) was chosen on the basis of its great availability in Western Europe and its relevant content of preservative compounds with antioxidant and antimicrobial activities (Le Lann et al. 2008;Zubia et al. 2009;Miranda et al. 2016). In order to investigate such preservative effect on fish quality, megrim (Lepidorhombus whiffiagonis), a fish species of relevant commercial value in Western countries, was chosen. ...
... Thus, different polyhydroxyphenyls and phenylethers were isolated and their structures established by NMR and IR spectroscopy by Glombitza et al. (1976). On the basis of different in vitro assays (DPPH, reducing activity and betacarotene methods), the antioxidant activity of different kinds of B. bifurcata extracts has been reported (Connan et al. 2007;Le Lann et al. 2008;Zubia et al. 2009). Interestingly, the inclusion of an ethanolic extract of B. bifurcata in the icing medium has been shown to produce an inhibitory effect on the development of lipid hydrolysis (FFA formation) and oxidation (TBA value and fluorescent compounds formation) in chilled megrim . ...
The present study addressed the quality enhancement of chilled fish by applying a preliminary dipping treatment containing a bioactive extract of the alga Bifurcaria bifurcata. Megrim (Lepidorhombus whiffiagonis) specimens were dipped in ethanolic–aqueous solutions containing two different concentrations of the alga extract (high: HAC batch and low: LAC batch). Two types of control batch were considered (ethanol–water dipping and no dipping). Microbial, chemical and sensory qualities were monitored in fish throughout a 13-day storage period. An inhibitory effect (p < 0.05) of the dipping treatment (washing and the presence of alga extract) on microbial activity was observed, as determined by microbial (Enterobacteriaceae, lipolytic bacteria and psychrotrophs) and chemical (trimethylamine and free fatty acid formation) analyses. In most cases, this effect was found to be more intense for prolonged storage times and in fish specimens corresponding to the HAC batch. However, the combined effect of washing and the inclusion of alga extract in the dipping medium did not affect (p > 0.05) the rate of lipid oxidation events during storage. Interestingly, average scores revealed increased sensory quality in megrim corresponding to the HAC batch for prolonged storage (9–13 days). Consequently, the use of a bioactive extract of B. bifurcata alga as a preliminary dipping treatment can be considered of interest for further fish storage due to both its simplicity and beneficial effects on fish quality enhancement.
... This proliferation cannot be controlled and it hampers certain human activities in summer period [9] . However, this abundant and under exploited marine living resource contains a lot of bioactive substances whose applications are numerous in food industry, cosmetics or pharmaceutics [11][12][13][14][15][16][17][18][19][20][21][22][23] . As demonstrated in the majority of the previously cited references, Sargassum muticum is particularly rich in phenolic compounds (phlorotannins) presenting biological activities such as antioxidant, radical-scavenging, antibacterial, photoprotection, etc. Industrialists are very interested by natu-ral antioxidants in food industry because of the restricted use of synthetic anti-oxidants suspected to have toxic effects [24,25] . ...
... The AAC700 corresponds to the concentration of the extract (mg/mL) necessary to have an AAC of 700, which is the value obtained with the positive control as described by Le Lann et al [12] . So, a low value of AAC700 corresponds to a high antioxidant activity. ...
... The higher temperature created the higher solvent diffusion rate and mass transfer, while lower in the solvent viscosity and surface tension made more polyphenols dissolve into the extraction medium (Hossain et al. 2012), so the extraction yield increased. However, there was the limitation in using high temperature for extracting active components of plants, especially algae, due to the effect of high temperature on thermosensitive compounds (Shahidi et al. 1992;Le Lann et al. 2008). On the other hand, it could be that a reduction of the cavitation by high temperature resulted in the decrease in extraction yield as well as TPC (Dey and Rathod 2013). ...
... This finding is supported by Matanjun et al. (2008) who indicated that the phenolic compounds mainly contributed to FRAP of the methanolic extracts (r 2 = 0.96). Previous studies also illustrated the role of phenolic compounds in antioxidant activity based on the positive correlation between phenolic hydroxyl groups and DPPH free radical scavenge activity in several brown algae: Fucus vesiculocus, Laminaria ochroleuca, Sargassum muticum, Bifurcaria bifurcata, Laminaria sp. and Undaria pinnatifida (Jiménez-Escrig et al. 2001;Le Lann et al. 2008;Amorim et al. . 2012). ...
This study aimed to optimise ultrasound-assisted extraction (UAE) conditions of the brown alga Hormosira banksii for total phenolic content (TPC) and antioxidant activities including total antioxidant capacity (ABTS), DPPH free radical scavenging capacity (DPPH) and ferric reducing antioxidant power (FRAP) using response surface methodology (RSM). Box–Behnken design was employed to assess the effect of ultrasonic temperature, time and power on the TPC and antioxidant activities of the extracts. The results showed that RSM was an accurate and reliable method in predicting TPC and antioxidant activities (ABTS, DPPH and FRAP) of the extracts with R² values of 0.97, 0.96, 0.92 and 0.94, respectively. The ultrasonic temperature and time had the significant impact on TPC and antioxidant capacities. The optimal UAE conditions for the maximal values of TPC and antioxidant activities were of 30 °C, 60 min and power 60%, or 150 W. The values of TPC and antioxidant activities (ABTS, DPPH, FRAP) achieved under these parameters were 23.12 (mg GAE g⁻¹), 85.64 (mg TE g⁻¹), 47.24 (mg TE g⁻¹) and 12.56 (mg TE g⁻¹), respectively. UAE was found to be more efficient in comparison to conventional extraction, with shorter time for extraction and higher of TPC level and antioxidant activities. Therefore, ultrasonic-assisted extraction using RSM is effective for extraction and further isolation and purification of phenolic compounds from H. banksii. In addition, this alga could be a potential rich source of natural antioxidants applied in food and pharmaceutical fields.
... Los procesos de secado más comunes utilizados para las algas marinas son: el secado al sol, el secado al horno y la liofilización 10 , el procesamiento de cada método puede cambiar la composición química y las propiedades antioxidantes de las algas destinadas a ser utilizadas como bioproductos funcionales para alimentos y piensos (alimento para el ganado), aplicaciones cosméticas, farmacéuticas e industriales 11,12 . Si bien existen diferentes técnicas de secado disponibles, varios factores como el costo, el consumo de energía, la efectividad y el impacto en la calidad de los alimentos deben tenerse en cuenta al seleccionar el método más apropiado 13,14 . ...
La Acanthophora spicifera un alga roja de fácil adaptación a diferentes condiciones ambientales, por su capacidad de regenerarse por fragmentación, convirtiéndola en una especie invasora en áreas tropicales y subtropicales. Además, es conocida por sus componentes bioactivos (antioxidantes, fitohormonas, fitopigmentos). En este estudio se plantea determinar las condiciones óptimas de extracción de compuestos antioxidantes de la macroalga que crece en la zona intermareal de la playa de San Pedro de la provincia de Santa Elena, en dos procesos de secado (horno y liofilización) y extracción etanólica (digestión y ultrasonido) a diferentes concentraciones de etanol (50% y 70%) en rangos de tiempo y temperatura para su posterior determinación de actividad antioxidante por los métodos DPPH, ABTS, fenoles, flavonoides y auxinas totales en microplacas. Los datos se analizaron mediante análisis de varianza (ANOVA) usando el software estadístico R.4.2.0 e InfoStat, observan que los mejores resultados se dieron por digestión con una concentración de etanol al 50% y se obtuvieron valores para: la actividad captadora de radicales DPPH 3.65±0.011 µmol ET/g ps, mayor actividad inhibidora del radical catiónico ABTS 14.06±0.03 µmol ET/g ps, para flavonoides 1278.58±2.94 µg EQ/g ps, para fenoles 900±0.129 µg GEA/g ps. Las condiciones óptimas para la extracción etanolica de la macroalga A. spicifera., fueron 47 °C y 47 minutos para la actividad captadora de radicales DPPH y 47 °C y 39 minutos para la actividad inhibidora del radical catiónico ABTS, 45 °C y 37 minutos para Fenoles totales y 43 °C y 38 minutos para Flavonoides totales. Palabras clave: actividad antioxidante, Acanthophora spicifera, optimización
... These seaweeds, either sun-dried or shade-dried, are currently marketed in Portugal. Drying is a crucial operation due to the high percentage of moisture in seaweed, frequently surpassing 90% of the wet weight, which renders seaweed materials highly perishable (Le Lann et al. 2008;Gupta et al. 2011). Simple air drying and/or sun-drying are typical processes. ...
The influence of drying (sun-drying and shade-drying) on the elemental composition of two brown seaweeds (Treptacantha abies-marina, Cystoseira humilis) and two red seaweed species (Asparagopsis armata and Asparagopsis taxiformis) harvested in the Faial Island (Azores Islands, Portugal) was assessed. The contents of sixteen nutritionally and toxicologically relevant elements were determined: sodium (Na), magnesium (Mg), phosphorus (P), sulphur (S), potassium (K), calcium (Ca), chromium (Cr), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), arsenic (As), bromine (Br), cadmium (Cd), iodine (I), and lead (Pb). While the most abundant macroelement in T. abies-marina and C. humilis was K (64.1–71.0 g kg−1 dw), for both Asparagopsis species, this position was held by Na (85.6–115.3 g kg−1 dw). Iodine content did not surpass 0.1 g kg−1 dw in the brown seaweeds and varied between 4.6 and 5.7 g kg−1 dw in Asparagopsis species. The I Dietary Reference Intake may be ensured by less than 1 g of dried A. armata or A. taxiformis per week. For T. abies-marina and C. humilis, 10.5 g or more of dried seaweed per week may be required. However, excessive I can be a health risk: 1–2 g of dried A. armata or A. taxiformis per week may result in I-related health risks. Moreover, there are As-related health risks for the consumption of C. humilis and, especially, T. abies-marina. The type of drying did not show a clear effect upon the elemental composition.
... Physical characteristics of the three studied beaches (Le Lann et al., 2008). Two replicates of approx. 1 g of fresh tissue ...
... Physical characteristics of the three studied beaches (Le Lann et al., 2008). Two replicates of approx. 1 g of fresh tissue ...
Wrack supply represents the main organic input in sandy beaches ecosystems and is a common feature of beaches around the world. The chemical composition of the wrack is important in determining the extent and rate of the decay; in particular, phenolic compounds may affect consumption rates by wrack-associated macrofauna and, consequently, modify the nutrient processing and recycling in sandy beaches. The aim of this research was to investigate the possible links between phenolic content of wrack supplies and the macrofaunal community inhabiting them. To achieve this, patches of wrack in three beaches of the NW coast of Spain were analysed and the phenolic contents and macrofaunal distribution, both at spatial and temporal scales, were assessed. Wrack and macrofaunal samples were collected along two shore-parallel transects, coinciding with the wrack lines of previous tidal deposition. The results showed a general spatial distribution in the phenolic content of the beach-cast according to their tidal position on the beach. Thus, two distinct zones were identified: the “spring-tide deposited” zone located in the upper beach close to the base of the dunes and composed by wrack material with the lowest phenolic concentrations; and a “freshly deposited” zone with wrack deposits containing the highest concentrations of deterrent compounds. Nevertheless, only supratidal grazers, mostly linked to fresh deposits, have shown a slightly negative association between their abundance and the increasing phenolic contents of the stranded macroalgae. The lack of a consistent pattern in macrofaunal occupation of fresh and decayed drift lines detected suggests the species could be selecting habitats for reasons other than phenolic content.
... Variation in biochemical composition and bioactivity does not only depend on the natural variability of the seaweed but also on preservation processes, as shown in the case of A. taxiformis (Regal et al., 2020). These affect the concentration, composition and bioactivity of algal metabolites (Jiménez-Escrig, Jiménez-Jiménez, Pulido, & Saura-Calixto, 2001;Le Lann, Jegou, 255 & Stiger-Pouvreau, 2008;Stévant, Rebours, & Chapman, 2017), highlighting the critical importance of appropriate drying and storage conditions to preserve biomass quality and ensure product safety (Gupta, Cox, & Abu-Ghannam, 2011;Le Lann et al., 2008;Regal et al., 2020). ...
Ruminant mammals extract nutrients from plant-based food through fermentation in the rumen; fiber and starch are pre-digested by microorganisms and methane is produced as a by-product, which released into the atmosphere acts as a potent greenhouse gas. In an effort to reduce enteric methanogenesis, dietary additives for ruminants have been investigated, and marine macroalgae have proven particularly promising, e.g., the inclusion of 0.2% dry matter of the red alga A. taxiformis into cow feed decreased in vivo methane production by up to 98%. Thus, if globally applied, the addition of algae in ruminant diets could revolutionize the management of greenhouse gas emissions across the livestock sector. However, the ozone-depleting nature of halogen compounds produced in Asparagopsis sp. and the reported adverse health impacts on humans, along with impracticability issues and the difficulty to produce, commercialize and distribute algae widely, has sown some doubt on the feasibility of using macroalgae as methane mitigation instruments. To circumvent such obstacles, and taking into account the paradigm that eukaryotic hosts cannot be understood without considering interactions with their associated microbiome, the exploration of marine algae associated microorganisms is anticipated. Following the notion that in the close and intimate relationships between algae-hosts and their microbiota the origin of chemical response mechanisms is often unclear, and that compounds initially assigned to algae have previously been shown to stem from host-associated microbes, it is not unreasonable to think that these may be involved in the antimethanogenic effects of marine algae in the rumen. Once identified, such microorganisms could lead to antimethanogenic feed additives, and reduce enteric methanogenesis from livestock ruminants substantially. This review is three-fold: it provides a brief, historic overview of macroalgae as feed supplements for ruminants, sums up the difficulties related to using whole-macroalgae as large-scale antimethanogenic feed additives, and describes the macroalga microbiome, including its potential to serve as an antimethanogen for enteric fermentation.
... Drying by heat of the vegetal sample before extraction is a very complex stage. Some studies suggested that oven drying of the sample reduces drastically the yield and the bioactivity of the extracts [46][47][48]. High temperatures and oxygen expositions tend to damage the compounds of interest. However, on the other hand, some studies showed that the drying increased yields and bioactivities [44], or at least does not have any effect [49]. ...
The marine environment is a generous source of biologically active compounds useful for human health. In 50 years, about 25,000 bioactive marine compounds have been identified, with an increase of 5% per year. Peculiar feature of algae and plants is the production of secondary metabolites, such as polyphenols, synthesized as a form of adaptation to environmental stress. Posidonia oceanica is a Mediterranean endemic and dominant seagrass and represents a biologically, ecologically and geologically important marine ecosystem. Within this study, methanolic and ethanolic extracts were generated from fresh and dried Posidonia oceanica leaves, with the aim to employ and valorize the beach cast leaves. The best yield and antioxidant activity (polyphenols content equal to 19.712 ± 0.496 mg GAE/g and DPPH IC50 of 0.090 µg/µL.) were recorded in 70% ethanol extracts (Gd-E4) obtained from leaves dried for two days at 60 °C and ground four times. HPLC analyses revealed the presence of polyphenols compounds (the most abundant of which was chicoric acid) with antioxidant and beneficial properties. Bioactive properties of the Gd-E4 extracts were evaluated in vitro using fibroblast cells line (HS-68), subjected to UV induced oxidative stress. Pre-treatment of cells with Gd-E4 extracts led to significant protection against oxidative stress and mortality associated with UV exposure, thus highlighting the beneficial properties of antioxidants compounds produced by these marine plants against photo damage, free radicals and associated negative cellular effects. Beach cast leaves selection, processing and extraction procedures, and the in vitro assay results suggested the potentiality of a sustainable approach for the biotechnological exploitation of this resource and could serve a model for other marine resources.
... Folin-Ciocalteu Assay. The phenolic content of the semi-purified fraction was evaluated using the Folin-Ciocalteu assay slightly adapted from previous studies [17,82] and modified by Le Lann et al. [83]. Briefly, 100 mL of semi-purified fraction was mixed with 50 mL of Folin-Ciocalteu reagent, 200 mL of Na 2 CO 3 (15%) and 650 mL of distilled water. ...
Five native Sargassaceae species from Brittany (France) living in rockpools were surveyed over time to investigate photoprotective strategies according to their tidal position. We gave evidences for the existence of a species distribution between pools along the shore, with the most dense and smallest individuals in the highest pools. Pigment contents were higher in lower pools, suggesting a photo-adaptive process by which the decreasing light irradiance toward the low shore was compensated by a high production of pigments to ensure efficient photosynthesis. Conversely, no xanthophyll cycle-related photoprotective mechanism was highlighted because high levels of zeaxanthin rarely occurred in the upper shore. Phlorotannins were not involved in photoprotection either; only some lower-shore species exhibited a seasonal trend in phlorotannin levels. The structural complexity of phlorotannins appears more to be a taxonomic than an ecological feature: Ericaria produced simple phloroglucinol while Cystoseira and Gongolaria species exhibited polymers. Consequently, tide pools could be considered as light-protected areas on the intertidal zone, in comparison with the exposed emerged substrata where photoprotective mechanisms are essential.
... Among brown seaweeds, Bifurcaria bifurcata represents an interesting choice on the basis of its great availability in the Atlantic coast of France, Spain, Portugal, Ireland, and the United Kingdom [29,30]. Interestingly, previous studies have shown the presence of hydrophilic (phlorotannins, phenolic acids, flavonoids, alginates, polisaccharides in general) [31][32][33] and lipophilic (polyphenols and sterols) [34][35][36] preservative compounds in B. bifurcata. ...
This work addressed the preservative behaviour of different icing media containing extracts from the alga Bifurcaria bifurcata. A comparative study of the antimicrobial and antioxidant effects of aqueous and ethanolic extracts of this macroalga was carried out. Whole hake (Merluccius merluccius) pieces were stored in ice containing either kind of extract and analysed for quality changes throughout a 13-day storage period. A progressive loss of microbial and biochemical quality was detected in all batches as chilling time increased. A significant inhibitory effect (p < 0.05) on microbial activity could be observed as a result of including the aqueous (lowering of psychrotrophic and lipolytic counts and pH value) and ethanolic (lowering of psychrotrophic and lipolytic counts) extracts. Additionally, both kinds of extract led to a substantial inhibition (p < 0.05) in the lipid hydrolysis rate (formation of free fatty acids), greater in the case of the batch containing ethanolic extract. Concerning lipid oxidation, a similar inhibitory effect (p < 0.05) on the formation of secondary compounds (thiobarbituric acid substances) was noticed in fish specimens corresponding to both alga extracts; however, more (p < 0.05) peroxide formation was detected in fish corresponding to the ethanolic extract batch. A preservative effect can be concluded for both kinds of extract; this effect agrees with previous studies reporting the presence of hydrophilic and lipophilic bioactive compounds in B. bifurcata.
... To prevent the degradation of the compounds, different storage conditions and treatments are available including freezing, freeze drying, sun-, or oven drying. Le Lann et al. (2008) studied several storage condition treatments on two brown Fucales. They reported that oven-and greenhouse drying reduced by around 50% the phenolic contents, respectively, for Sargassum muticum and Bifurcaria bifurcata, to the high temperatures. ...
Marine algae, representing a polyphyletic group, are considered as a rich food source as these organisms produce a great variety of molecules including proteins, polysaccharides, dietary fiber, amino acids, minerals, vitamins, and aromatic compounds. Among them, phenolic compounds are metabolites present in various organisms, including marine algae, and are known to be synthesized in response to different environmental conditions. In particular, they protect these organisms against herbivores or epiphytes, bacterial infection, or UV radiation. Once consumed, they may be beneficial to human health and chronic disease risk prevention since they have a wide range of bioactivities. They can exhibit antioxidant, antimicrobial, anti‐inflammatory, antitumor, antiaging, or pro‐mineralogenic activities, or act as modulators of cardiovascular disease risk. This review presents phenolic compounds encountered in marine algae, i.e. micro‐ and macroalgae, their chemical structures, together with their biological activities and their potential valorization for medical and cosmetic industries.
... An effective processing method used to retain the content of antioxidants, phenols, vitamins, and other bioactives in natural products is freeze-drying [24][25][26][27]. To date, freeze-drying biomass of A. taxiformis (henceforth referred to as Asparagopsis) also yields the highest concentration of bromoform compared with other post-harvest processing methods [23]. ...
Asparagopsis taxiformis (Asparagopsis) inhibits the production of enteric methane in ruminants. A next critical step in the implementation of this technology is the delivery of a naturally-derived product that maximises the concentration and longer-term retention of bromoform. This study (1) quantified the effects of solvent (water or oil), initial processing (intact or homogenised), and temperature (4 or 25 °C) on the stabilisation of bromoform over time, and (2) assessed the effects of increasing the biomass loading (g biomass mL⁻¹ solvent) of Asparagopsis on the concentration of bromoform in a formulation. The most effective method was to homogenise freshly-collected Asparagopsis in oil, which resulted in the highest concentration of bromoform (19.2 ± 2.1 mg g⁻¹ dw algae) in the homogeneous product in the shortest time (one day). In addition, the final product had a shelf life of at least 12 weeks, even when stored at room temperature (25 °C). Notably, there was an increase in the concentration of bromoform per mL of oil between each increment of biomass loading tested, with the highest concentration of bromoform of 4.04 ± 0.51 mg mL⁻¹ in the maximum ratio of biomass to oil of 120 g 100 mL⁻¹. The method described here provides a viable processing alternative to freeze-drying, resulting in the stabilisation of the bromoform from Asparagopsis, which will be critical to the success of using Asparagopsis on a larger scale to mitigate the production of methane in ruminants.
... Marine macroalgae also exhibited strong antiprotozoal and leishmanicidal activities with no cytotoxic effect towards mammalian skeletal myoblast cells (Orhan et al., 2006;Allmendinger et al., 2010; besides their great antioxidant potential (Kanimozhi & Sridhar, 2017). Phenolic compounds extracted from brown algae are considered to be a chemical defender against grazers and microbes (Plouguerne et al., 2006;Le Lann et al., 2008). Ellagic acid (EA) and velutin are two examples of highly active phenolic compounds. ...
Marine macroalgae are considered as a promising source of chemical compounds with a broad array of biological activities. The bioactive compounds of five marine seaweeds (Ulva lactuca, Padina boryana, Cystoseira myrica, Liagora farinosa and Acanthophora spicifera) were extracted by chloroform, dichloromethane and ethanol. We managed to extract two polyphenolic compounds (ellagic acid and velutin) from the dichloromethane extract of P. boryana and ethanol extract of A. spicifera, respectively. The biological activities of the two isolated compounds as well as the crude extracts were screened. All tested algal extracts showed high antimicrobial activity against target bacteria and fungi except for Pseudomonas aeruginosa was resistant to U. lactuca and C. myrica extracts. Chloroform and ethanol extracts of A. spicifera, and dichloromethane extract of C. myrica showed the highest antimicrobial activity against Bacillus subtilis and Staphylococcus aureus. Dichloromethane extract of P. boryana had the highest antiprotozoal activity against Trypanosoma cruzi and Leishmania donovani (IC50 values, 3.5 and 4.8 μg/mL, respectively), and potent antioxidant activity up to 60 %. Overall, marine macroalgae with high polyphenols and flavonoids content exhibited excellent antimicrobial, antiprotozoal and antioxidant properties. Purified velutin recorded high antimicrobial activities as compared to the tested antibiotics and both ellagic acid and velutin also possessed considerable antiprotozoal activities. This study suggests that, ellagic acid and velutin comprise the key players for the antimicrobial and antiprotozoal activities of P. boryana and A. spicifera extracts, respectively. Thus, these two compounds could be used as pharmaceutically bioactive natural compounds.
... Numerous research evidence are calming that the biological activities of macroalgae due to the presence of various macro and small molecules (Nogueira et al., 2014;Mendes et al., 2013;Namvar et al., 2013;Mtolera and Semesi, 1996). The important biologically active compounds including antibacterial (Amiguet et al., 2011;Glombitza et al., 1975;Amico et al., 1988), antifungal (Arumugam and Rajendran, 2019;Peres et al., 2012;Martinez-Lozano et al., 2000;Bennamara et al., 1999), antiviral (Thompson and Dragar, 2004;Lapshina et al., 2006;Reunov et al., 2009), antimalarial (Chen et al., 2009), anticancer (Vaikundamoorthy et al., 2018;Nishibori et al., 2012;Vizetto-Duarte et al., 2012), anti-inflammatory (Khan et al., 2009;Cumashi et al., 2007), antioxidant (Sullivan et al., 2011;Le Lann et al., 2008) and UV protection. ...
Candidiasis in the genital region induces serious infections that can be faced by sexually active women worldwide. Especially, the therapeutic failure of Candida species in the past decades has garnered significant research focus. In this study, we investigated the anti microbial activities of six different seaweeds (red, green and brown) were collected from the Gulf of Mannar region using well diffusion and micro dilution technique. An average zone of inhibition obtained were ranged frim 0 to 17 mm. Among the different seaweeds, the methanol extract of Dictyota bartayresiana was more susceptible (17.4±0.62 mm) and Chaetomorpha sp was least effective (12.29±0.99 mm) against Candida albicans. However, the zones of inhibition of methanolic extract of seaweeds were several folds higher than the fluconazole. Micro dilution and time dependent kinetics studies revealed that all the seaweeds have only moderate activity towards C. albicans and MFC/MIC show less than 4 for all tested extracts. Conversely, DCM extract of Turbinaria ornata showed minimum inhibitory for Candida biofilm. The results clearly confirmed that all the extract represent the fungistatic mechanism of inhibition rather than fungicidal except amphotericin B, suggesting that instead of using seaweed extract for killing C. albicans better to use to prevent their virulence property.
... There is a significant difference between the phenolic levels in all four samples; however, the mixed sample (2.95%) has nearly five times the level of phenolics than the next highest sample (0.66%) (S. natans I). Phlorotannins, the primary phenolics in brown seaweed, are secondary metabolites that are produced in response to stress, particularly from attack by herbivores [101,102]. The high levels found in this study may be due to the presence of herbivores and other epiphytes. ...
The Caribbean has been experiencing beach inundations of pelagic Sargassum, causing environmental, health and financial issues. This study showed variations in the composition and methane potential (MP) between the species of Sargassum. The MPs for S. natans VIII, S. natans I and S. fluitans (145, 66 and 113 mL CH4 g −1 Volatile Solids) were considerably below theoretical potentials, possibly due to the high levels of indigestible fibre and inhibitors. The mixed mats Sargassum composition was substantially different from the individual species, being higher in ash, calcium, iron, arsenic and phenolics. The mixed mats produced no methane, perhaps due to the high levels of phenolics. There was a strong correlation between MP and phenolic content. Heavy metals and metalloids were at levels that should not cause concern, except for arsenic (21-124 mg kg −1 dry weight). Further work on the speciation of arsenic in Sargassum is required to fully determine the risk to health and agriculture. Both protein and lipid levels were low. The 'indispensable amino acid' profile compares favourably with that recommended by the World Health Organisation. Lipids had a high proportion of Polyunsaturated Fatty Acids. The use of Sargassum for biogas production could be challenging, and further work is required.
... Zaragoza et al (2008) demonstrated some interesting activities like preventive and curative activities against atheroms of a hydro alcoholic extract from Fucus. Several antibacterial and antifungal (Nagayama et al 2002;Lopes et al 2012), antilarval and antialgal activities (Ragan & Glombitza 1986;Bhadury & Wright 2004;Hellio et al 2004), as well as UV-protection (Connan 2004;Le Lann et al 2008) were observed for phlorotannins isolated from macroalgae. ...
Indonesia is known for its marine biodiversity, including the richness of its brown seaweed, Sargassum. This genus has attracted many attention as it produces active compounds showing potential for the food, pharmacology and cosmetic industries. In this study, a mixture of S. duplicatum, S. echinocarpum and S. polycystum extracts was applied as an additive in a moisturizer cream serving as an antibacterial agent. Proximate analysis was conducted to evaluate the chemical composition in Sargassum spp. There were 5 moisturizer creams prepared: A (standard), B (without antibacterial agent), C (with antibacterial agent), D (with Sargassum extracts and antibacterial agent) and E (with Sargassum extracts but without antibacterial agent). Antibacterial analyses showed that cream E had the best antibacterial activity in this study. It indicates that the crude extract of Sargassum added in the cream could inhibit the development of bacteria for a longer period of time. Bioactive compounds contained in S. duplicatum, S. echinocarpum, S. polycystum are steroids, quinones, flavonoids and alkaloids. Saponins were only found in S. duplicatum. The five cosmetic creams presented adequate odor and color. These results indicate that Sargassum shows a promising potential as a cosmetic additive that could replace commercial antibacterial agents.
... [13,14] However, the dehydration of marine algae by solar methods requires long drying periods, so that a desired increase in production rates can only be through application of industrial drying methods, [15] which should be selected based on product quality obtained at optimal cost and yield. [16,17] In this respect, several drying methods, such as solar, convective hot-air, microwave, vacuum, or freeze drying [18][19][20] have been applied to seaweeds and their corresponding effects on nutritional and bioactive properties have been reported; hydrothermal drying methods have been applied to Himanthalia elongata, Laminaria saccharina, and Laminaria digitata; [21] freeze-drying, oven drying, and greenhouse drying to brown seaweeds Sargassum muticum and Bifurcaria bifurcata; [22] or sun drying, oven drying, and freeze-drying to Sargassum hemiphyllum (Turn.) C. Ag. [23] among others. ...
The effects of vacuum, solar, convective, infrared, and freeze drying (VD, SD, CD, IRD, FD) on Durvillaea antarctica were evaluated in terms of nutritional composition, color, bioactive components, and antioxidant and antidiabetic activities. Nutritional composition of the dried seaweeds scarcely varied, while a tendency to lose the reddish tone occurred. CD-seaweed had highest phytochemical and vitamin contents, while FD-samples showed best retention of pigments. Both samples also exhibited the strongest antioxidant and antidiabetic activities. The highest essential amino acids and polyunsaturated fatty acids contents were found in IRD- and SD-samples, respectively. In general, FD and CD were proved to be viable drying options for D. antarctica.
... For example, phenolic compounds (capable of acting as antioxidants) are often depleted when using certain drying methods, which may then result in reduced antioxidant activity (Ling et al. 2015;Cruces et al. 2016). Other valuable biomolecules such as amino acids, proteins, lipids, fatty acids and other bioactive compounds in seaweeds can also be affected by drying procedures (Chan et al. 1997;Le Lann et al. 2008;Ling et al. 2015;Cruces et al. 2016;Neoh et al. 2016;Hamid et al. 2018;Sappati and Nayak 2018;Silva et al. 2019). These studies have demonstrated the value of selecting appropriate drying treatments in order to preserve important bioactive compounds within seaweeds that are destined for use as functional foods. ...
Seaweeds are potentially a valuable resource for the food, drink and pharmaceutical sectors. The effective utilization of seaweed usually requires post-harvest dehydration in order to prevent decomposition, increase shelf life and aid the extraction of certain chemical constituents. Drying is an expensive, time-consuming and energy-intensive process. Here, the presence of a range of nutritionally important compounds was studied in five brown seaweeds (Fucus spiralis, Laminaria digitata, Fucus serratus, Halidrys siliquosa, Pelvetia canaliculata) after oven-drying at 40 and 60 °C, freeze-drying and microwave-drying at 385, 540 and 700 W. Antioxidant potential (total flavonoid content, total phenolic content, total antioxidant capacity and radical scavenging activity), soluble protein, lipid, amino acid and fatty acid profiles were determined in each case. Overall, results showed that low-temperature drying, such as freeze-drying and oven-drying at 40 °C, produced products with higher concentrations of nutritionally important chemicals, as well as stronger antioxidant activities. Results suggest that concentrations of nutritionally important chemicals and antioxidant activity are influenced by both the drying treatment and seaweed species used. Where rapid drying techniques are found to be beneficial to levels of specific chemicals, microwave-drying could be a useful alternative to oven-drying, as it helps overcome issues associated with prolonged duration drying (contamination and oxidation). No single drying procedure could be identified as consistently superior for all species or all compounds of interest—indicating that the appropriate drying technique should be selected and optimized for each seaweed species whilst also taking into account potential end-use of the final product.
... Air drying temperatures higher than 60ºC significantly decreased the SA of Bifurcaria bifurcata aqueous extracts. The reduction in TP content and SA at high drying temperatures may be due to several factors: release of phenolic compounds bound to cell wall during drying; thermal degradation by oxidative enzymes; phenolic compounds may rapidly degrade at drying temperatures above 40ºC; binding of polyphenols to other substances (proteins) or alterations in their chemical structure [5,10,11]. ...
The purpose of this study was to determine the effects of convective air-drying at different temperatures (35, 50, 60 and 75°C) on the color of Bifurcaria bifurcata (BB) seaweed powders obtained after milling, the antioxidant activity and polyphenolic and carbohydrate content of the aqueous extracts obtained by ultrasound-assisted extraction. BB seaweed powders exhibited significant color differences between powders obtained from BB dried at 35ºC (yellowish-green) and 50–75 °C (brown). High air drying temperature (above 60ºC) significantly reduced the total polyphenolic, carbohydrate content and scavenging activity of aqueous extracts of BB. Keywords: Phaeophyceae Antioxidant activity Carbohydrates Color Polyphenols
... High levels of phenolics are found in many seaweeds, with brown seaweed containing up to 14% DW [181]. The phenolic compounds in cell wall structures are generally considered to be used as a chemical defence mechanism against grazers, bacteria, fungi, and other epiphytes [72,182]. ...
Macroalgae represent a potential biomass source for the production of bioethanol or biogas. Their use, however, is limited by several factors including, but not restricted to, their continuous supply for processing, and low biofuel yields. This review examines recent pre-treatment processes that have been used to improve the yields of either biogas or bioethanol from macroalgae. Factors that can influence hydrolysis efficiency and, consequently, biofuel yields, are highly affected by macroalgal composition, including content of salts, heavy metals, and polyphenols, structural make-up, as well as polysaccharide composition and relative content of carbohydrates. Other factors that can influence biofuel yield include the method of storage and preservation.
... 12,21 Variations in reported TPC among brown algae are partly attributed to differences in the methods used both in sample preparation and phenol extraction, since different solvents vary in their extraction efficiency. 20,22,23 As we used the same method in this interspecific analysis of TPC, differences can be attributed to other factors such as thallus morphology, life cycle, bathymetric level and grazing pressure. ...
Marine algae synthesize secondary metabolites such as polyphenols that function as defense and protection mechanisms. Among brown algae, Fucales and Dictyotales (Phaeophyceae) contain the highest levels of phenolic compounds, mainly phlorotannins, that play multiple roles. Four temperate brown algae ( Cystoseira amentacea, Cystoseira compressa, Dictyopteris polypodioides and Padina pavonica ) were studied for total phenolic contents. Total phenolic content was determined colorimetrically with the Folin-Ciocalteu reagent. Significant differences in total phenolic content were observed between leathery and sheetlike algae and also within each morphological group. Among the four species, the sheet-like alga D. polypodioides , living in the upper infralittoral zone, showed the highest concentration of phenolic compounds. These results are in agreement with the hypothesis that total phenolic content in temperate brown algae is influenced by a combination of several factors, such as growth form, depth, and exposition to solar radiation.
... Therefore, the antibacterial activities could be attributed to the type and amount of these free fatty acids which have a role in the overall defenses against the studied pathogenic Gram-positive and-negative bacteria (Benkendorff et al., 2005). In addition, the phenolic compounds in brown algae have a primary role in the structure of cell walls and are generally considered to be a chemical defender against bacteria (Rao and Parekh, 1981;Le Lann et al., 2008;Plouguerne et al., 2006;Lee and Jeon, 2013). Marine macroalgae-extracted polysaccharides, in particular ulvans from green algae (Chlorophyta), alginates, fucans and laminarin form brown algae (Phaeophyta), and carrageenans and porphyran from red algae (Rhodophyta) and their derived oligosaccharides, have been found to stimulate plant defense responses and protections against a wide spectrum of plant-infecting pathogens (Vera et al., 2011;Kraan, 2012). ...
Marine macroalgae are plant-like organisms with simple internal structures that generally live in coastal areas. They mainly include different communities of red, brown and green macroalgae. Marine macroalgae commonly occupy intertidal and sublittoral-to-littoral zones on rocks and other hard substrata. They are considered to be an excellent natural biosource in different aspects of agricultural fields. They have great proficiency in improving soil physical and chemical properties. Marine macroalgae are also characterized by producing a large array of biologically active biocidal substances against plant-infecting pathogens. Unfortunately, most available literatures on marine macroalgae and their derivatives mainly focused on their pharmaceutical applications but their potential utilization in sustainable agriculture development is still often regarded as a secondary goal. However, a relatively considerable dataset on marine macroalgae showed that they could play a major role in plant protection and improvement. This review summarizes different aspects of potential macroalgal applications in agriculture. Commercial production and exploitation of specific compounds with interesting biotechnological importance from marine macroalgae including microbicides, nematicides, insecticides, biofertilizers, biostimulators and soil conditioners are highlighted and discussed in detail. Bioactive compounds like fatty acids (in particular polyunsaturated fatty acids (PUFAs), proteins (amino acids), bioflavonoids, sulfated polysaccharides, carotenoids, polyphenols and carbohydrates are considered to have bactericidal, antiviral and fungicidal effects against some plant-infecting pathogens. These biocontrol agents provide multiple benefits and act as useful pointers for improving cultivation practices in diverse habitats. Marine macroalgae can be generally considered as promising multifunctional bioinoculants and ecofriendly environmental tools in recent trends of organic farming.
Sargassum sp. is a worldwide distributed brown seaweed genus traditionally used as food or as medicinal remedy. More recently, it is regarded as a source of valuable compounds with diverse structures, such as sulfated polysaccharides, phlorotannins, fatty acids, amino acids, terpenoids or sterols. The study of the biological properties of the whole seaweed or its components will accelerate the development of novel food, cosmetic and pharmaceutical applications.KeywordsBrown seaweedBioactivesFucoidanPhlorotanninsNovel products
The effect of drying on two brown seaweed (Treptacantha abies-marina and Cystoseira humilis) and two red seaweed species (Asparagopsis armata and Asparagopsis taxiformis) was evaluated based on the levels of biological activity, such as antioxidant and anti-inflammatory properties. Moreover, the contents of some significant compound classes, such as polyphenols and beta-glucans, were determined. Seaweeds C. humilis and T. abies-marina showed high polyphenol levels (1.76–6.78 mg gallic acid equivalents g⁻¹ dw), which clearly exceeded those determined in the Asparagopsis genus regardless of drying process. This was partially reflected in the antioxidant activity as measured by DPPH and FRAP methods, which showed that extracts from C. humilis and T. abies-marina in most cases had stronger antioxidant activity than those from Asparagopsis species. The influence of the drying technique upon the antioxidant activity was relatively limited, since in many instances there was no effect. Concerning anti-inflammatory activity, in the case of shade-dried samples, C. humilis had a higher activity (>30% COX-2 inhibition) than A. armata. However, this activity in C. humilis was not rendered available in the upper gastrointestinal (GI) tract. Indeed, only A. taxiformis displayed anti-inflammatory activity in the fraction available in the upper GI tract, showing an upper GI tract availability in the 90–100% range. Therefore, though bioactivity levels were higher in C. humilis and T. abies-marina, Asparagopsis species also had substantial levels of bioactive compound. Sun-drying produced more negative effects than shade-drying, but these effects were not very extensive.
The effects of simulated gastrointestinal digestion on the content and antioxidant activity of phenolics of seven seaweeds were investigated: Two methods of digestion were used – simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) to mimic the stomach and upper intestinal environment. Results showed that SIF can significantly increase the free phenolic content of all tested seaweeds. The total phenolic content of the seaweeds increased in range from 4.16 to 17.24 mg GAE/g before simulated digestion to 4.08 to 40.37 mg GAE/g after digestion. The antioxidant activity of seaweed‐bound phenolics was superior to that of free phenolics. Among the seven varieties of seaweeds, Sargassum thunbergii and Sargassum kjellmanianum contained the highest content of bound phenolics after SGF digestion. Bound phenolics of Undaria pinnatifida and Sargassum thunbergii showed the highest in vitro ABTS+ free radical scavenging ability, while Sargassum thunbergii and Sargassum fusiforme showed the highest in vitro FRAP antioxidant activity.
This chapter goes through the processes of seaweed invasion, from their introduction stage and their introduction vectors, to their invasive success. It addresses impacts and possible management practices. Particularly, there will be a focus on the Iberian Peninsula, where some examples of the existing introduced species of seaweeds are presented along with their possible potential uses such as biofuels, biofertilizers, food, feed and others. As species move from their native geographical range to a new colonized area, different vectors can be responsible for species introductions. There are different species, including seaweeds, which can be sold in shops or websites to aquarium hobbyists. Species that are more efficient in using resources are more likely to be successful invaders as they grow faster than the native ones. Invasive species are considered to have many major negative impacts on biodiversity and on ecological processes.
Drying is an industrial operation that consumes a large amount of energy. The design of the dryer and the optimization of the drying conditions are critical for the economy and sustainability of the industrial process. This chapter assesses different drying technologies applied to edible seaweeds from the traditional methods (sun drying) up to the more promising techniques still tested only at pilot-plant scale. Hot air drying is the most employed method in the industry, and the fundamentals of modeling applied to seaweeds are shown. The effects of drying on final seaweeds properties and the main uses of dried edible seaweeds are also reported. To carry out these aims, a review of literature was carried out to establish the current state of art.
Thermophysical properties such as thermal conductivity (k), bulk density (ρ), specific heat (C), and thermal diffusivity (D) are crucial for simulating dynamic thermal processes such as drying and temperature-controlled storage. In this study, the effects of product temperatures (T) and moisture contents (MC) on different thermophysical properties of kelp were studied. The thermal conductivity and thermal diffusivity of the samples were measured using a KD2 Pro dual-needle sensor for a temperature range of 30–70° C and moisture content varying from 6 to 90 g (100 g sample)⁻¹. The particle density and the bulk densities of the samples were estimated using a pycnometer with toluene as a working liquid. The k, C, and D values were fitted with a regression equation considering the individual and interaction factors (MC × T). Moisture content and temperature of the sample have significant effects (p < 0.05) on its thermophysical properties. The thermophysical properties calculated using the Choi and Okos' model based on the mass fraction of individual components present in sugar kelp and temperature were significantly (p < 0.05) different as compared to the experimental values. An artificial neural network (ANN) model evaluated eight different configurations of neurons in a single hidden layer for 180 data. The prediction performances of the ANN were evaluated in terms of mean absolute error (MAE), mean relative error (MRE), standard error (SE) and coefficient of determination in MATLAB. Overall, the ANN model’s performance was superior to the Choi and Okos empirical model in predicting the thermophysical properties with a relatively high coefficient of determination and low MAE, MRE, and SE.
Marine seaweeds produce protective and defensive compounds, for example, carbohydrates and phenolic compounds that are a source of bioinspiration for molecules with cosmetic and human health applications. This chapter provides a general description of seaweeds, together with a brief overview of the adaptive and chemical defenses developed by these organisms. Among the great diversity of metabolites produced by seaweeds, we focus on specific carbohydrates (floridoside and mannitol) and phenolic compounds (mycosporine‐like amino acids and phlorotannins) produced by macroalgae. Particular attention is paid to their highly variable chemical structure and methods for their extraction and purification. Their mechanisms of action are discussed, focusing on osmoregulation, desiccation, and photoprotection, which affect seaweed ecophysiology. Finally, we review their utility for cosmetology as moisturizers, sunscreens, and antiaging agents, for human health as wound dressings, and for skin regeneration. We point out the challenges faced when using these natural compounds in the cosmetic and human health sectors and the problems linked to the exploitation of this natural resource.
Phlorotannins are a diverse set of polyphenolic polymers synthesized only by brown algae, which are structurally and to some extent functionally analogous to terrestrial plant tannins. Since the nineteenth century, they were proposed to be important for brown algal physiology in cell wall structure, UV protection, and defense against herbivores, but their physiological functions are not fully understood. Similar to the well‐characterized biosynthesis of terrestrial plant tannins from alcoholic monomers, phlorotannins are produced by polymerization of phloroglucinol (1,3,5‐trihydroxybenzene) monomer units in a variety of combinations. However, the biosynthetic pathway for phlorotannin biosynthesis remained poorly characterized until the recent years. In this chapter, a historical introduction is provided on the discovery of phlorotannins, together with a focus on their isolation and chemical structure. Details about their primary and secondary functions are also illustrated by pertinent examples, and aspects of biosynthesis and the environmental factors that regulate the production and condensation of brown algal phenolics are also provided. Finally, a brief summary of the medical, cosmetic, and biotechnological applications of these primary metabolites with secondary roles is provided.
Background:
The present research focused on the quality of canned fish. Its primary objective was the quality enhancement of canned Atlantic mackerel (Scomber scombrus) by including an aqueous Bifurcaria bifurcata extract in the packing medium. Various alga extract concentrations were tested and compared to a control without alga extract. After a 3-month canned storage, the cans were opened, and quality changes in fish white muscle were analyzed.
Results:
An inhibitory effect on the lipid oxidation development (tertiary compounds formation) and on color parameters (L* and b*) values was observed as a result of the alga presence in the packing medium. On the contrary, the presence of the alga extract did not produce any effect on the formation of volatile compounds (total and trimethylamine) and the lipid hydrolysis (free fatty acids formation) development.
Conclusion:
A preservative effect derived from the use of an aqueous B. bifurcata extract as packing medium is concluded, and this result is primarily linked to the presence of hydrophilic preservative molecules. The packing system proposed in this work constitutes a novel and promising strategy to enhance the quality of commercial canned fish products.
This study aimed to optimise microwave-assisted extraction (MAE) conditions for total phenolic compounds (TPCs) and antioxidant activities of the alga Sargassum vestitum by using response surface methodology with Box–Behnken design. The results showed that solvent concentration had the greatest impact on TPC and antioxidant activities of the extracts, followed by radiation time and power. The optimal MAE conditions were ethanol concentration of 70%, radiation time of 75 s and power of 80%. The optimal MAE method showed much better extraction efficacy of phenolics and antioxidant capacities of the extract than conventional and ultrasonic methods.
This study focuses on the intra-thallus variation in phlorotannin content and antioxidant activity in temperate brown seaweeds. Two species of Fucales (Ascophyllum nodosum and Sargassum muticum) and two species of Laminariales (Laminaria digitata and L. hyperborea) were collected from the shoreline of Brittany (France). Both Fucales contained high phenolic levels along their thallus (ca. 5% DW in A. nodosum and 6% DW in S. muticum). No significant differences were found between vegetative and reproductive parts of A. nodosum. In contrast, intra-thallus and inter-specific variations were observed in phenolic contents of the two species of Laminariales studied. In L. digitata, phenolic content was about 0.2% DW, with a maximum in the holdfast, whereas in L. hyperborea, it averaged about 2.6% DW, with the highest value measured in the basal part of the old blade. In both species, phlorotannin contents were lower in the meristematic region. Intra-thallus variations of the antioxidant activity measured by the DPPH (2,2-diphenyl-1-picrylhydrazyl) method were also detected. Antioxidant activity was correlated to the phenol contents of the different parts of thalli in three species. In L. digitata, no activity was found because of low phenol levels. The observed variations in both the antioxidant activity and the phenol content could result from qualitative features of the phenolic pool.
Tannins, a large and diverse group of phenolic secondary metabolites, are common in terrestrial plants and marine brown algae. It is sometimes desirable to remove the tannins from plant or algal extracts, e.g., when isolating enzymes and nucleic acids, when using certain colorimetric methods to quantify the tannin content, or to create reliable controls when using tannins in experimental studies. Insoluble polyvinylpolypyrrolidone (PVPP) can be used to specifically remove tannins from solution. In the present study, we evaluated the effect of different factors (amount of PVPP, number of PVPP treatments, type of solvent, pH, and incubation time) on the PVPP removal of dissolved brown algal phlorotannins. Our results imply that there is a limited amount of phlorotannins that can bind to a given amount of PVPP, and that it is preferable to use low quantities of PVPP repeatedly, compared to using fewer treatments with a high amount of PVPP. Furthermore, we found no consistent effect on the removal of phlorotannins due to solvent type (acetone, methanol, distilled water or filtered seawater). There was a slight decrease in the amount of phlorotannins removed from extracts with increasing pH when repeatedly treated with PVPP. All phlorotannins were removed from extracts with pH 6.2, and 89% of the initial phlorotannin content was removed at pH 9.7. These results are compared with previous methodological studies on tannin removal with PVPP. Furthermore, the implications of phlorotannin removal in analytical and ecological investigations are discussed.
In vitro antioxidant activities of three selected Indian brown seaweeds – viz., Sargassum marginatum, Padina tetrastomatica and Turbinaria conoides – were investigated. Total phenolic content and reducing power of crude methanolic extract were also investigated. The activity of total methanolic extract and five different fractions (viz., petroleum ether (PE), ethyl acetate (EA), dichloromethane (DCM), butanol (BuOH) and aqueous) were studied using total antioxidant activity, DPPH radical scavenging and deoxyribose assays. EA fraction of S. marginatum exhibited higher total antioxidant activity of 39.62 mg ascorbic acid equivalent/g extract (or 0.31 mg ascorbic acid equivalent/g seaweed on dry weight basis) among the all the fractions. Among the fractions obtained from different seaweeds, EA fraction of S. marginatum showed higher DPPH scavenging activity of 23.16%; while PE fraction of T. conoides exhibited lower deoxyribose activity of 47.81%. Higher phenolic content (49.16 mg gallic acid equivalent/g extract or 0.86 mg GAE/g of seaweed on dry weight basis) was noticed in aqueous fraction of T. conoides. Reducing power of crude methanolic extract increased with increasing concentration. Reducing power of T. conoides and P. tetrastomatica were higher compared to standard antioxidant (α-tocopherol). Among the seaweeds, total methanolic extract of T. conoides had significantly higher phenol content (P < 0.05) compared to the other two species. In vitro antioxidant activity of methanolic extracts from all the three seaweeds showed an increase with increasing concentration indicating the dose dependency of these properties.
The introduced macroalga Sargassum muticum (Yendo) Fensholt is currently observed along the coasts of Brittany. From February 2003 till June 2004, variations in density, reproductive status, length and phenolic content were assessed at three sites. Seasonal variability of the density was pronounced at two exposed sites (Fort Bloqué and Pointe du Diable), but absent at the sheltered site (Callot), where the macroalga was observed year-round. Thalli were generally longer in Summer (up to 73.2 ± 2.7 cm at Fort Bloqué), and had reproductive receptacles from May to September at Pointe du Diable, though only from June to September in the other stations (Callot and Fort Bloqué). Phenolic content was maximal during the reproductive period, which could be interpreted as chemical protection of the receptacles. Finally the collected data were used to explain the persistence of S. muticum and its proliferation in Brittany.
Phlorotannins are ubiquitous secondary metabolites in brown algae that are phenotypically plastic and suggested to have multiple ecological roles. Traditionally, phlorotannins have been quantified as total soluble phlorotannins. Here, we modify a quantification procedure to measure, for the first time, the amount of cell-wall-bound phlorotannins. We also optimize the quantification of soluble phlorotannins. We use these methods to study the responses of soluble and cell-wall-bound phlorotannin to nutrient enrichment in growing and nongrowing parts of the brown alga Fucus vesiculosus. We also examine the effects of nutrient shortage and herbivory on the rate of phlorotannin exudation. Concentrations of cell-wall-bound phlorotannins were much lower than concentrations of soluble phlorotannins; we also found that nutrient treatment over a period of 41 days affected only soluble phlorotannins. Concentrations of each phlorotannin type correlated positively between growing and nongrowing parts of individual seaweeds. However, within nongrowing thalli, soluble and cell-wall-bound phlorotannins were negatively correlated, whereas within growing thalli there was no correlation. Phlorotannins were exuded from the thallus in all treatments. Herbivory increased exudation, while a lack of nutrients had no effect on exudation. Because the amount of cell-wall-bound phlorotannins is much smaller than the amount of soluble phlorotannins, the major function of phlorotannins appears to be a secondary one.
Covering: up to December 2005
Black tea was extracted for 2, 8 and 18 h with absolute acetone, N,N-dimethyl-formamide (DMF), ethanol and methanol and their 50% aqueous solutions. The extracts were screened for total polyphenol contents, antioxidant and antibacterial activities. The polyphenol content of the extracts was found to be in the range of 0.44-114.01 mg gallic acid equivalents (GAE)/g dry weight tea, depending on the solvent used and the length of the extraction process. In general, aqueous acetone or DMF extracts displayed the highest polyphenol contents and antioxidant activity, while absolute acetone was the least efficient solvent. Antioxidant activities of tea extracts tested using the reducing power and 2,2-diphenyl-1-picryhydrazyl (DPPH) radical methods ranged from 0.09 to 1.18 and from 2.60 to 95.42 %, respectively, depending on the extraction conditions and the antioxidant activities correlated well with the polyphenol concentrations. Aqueous solvent black tea extracts also possessed antibacterial activity, depending on the solvent used and bacterial species tested. Staphylococcus aureus was found to be the most sensitive to all tea extracts, except for the methanol extract. Tea extracts were not effective against Y. enterocolitica, L. monocytogenes and E. coli O157:H7.
Methanol extracts from seven species of Indonesian seaweeds were evaluated for their anti-oxidant activities in a fish oil emulsion system. The system was incubated at 50 ∞ C for 3 and 24 h, in the presence of ferrous ion as a catalyst. Peroxide value (POV), ferrous ion chelating effect in the oil emulsion system and ferrous ion binding effect in methanol extracts were determined as oxidation markers. In the presence of ferrous ion catalyst, all of the methanol extracts from seaweeds showed significantly lower POV of the emulsion than the control, and the extract from Caulerpa sertularoides had the strongest anti-oxidant activity. The highest chelation on ferrous ion was also found in the extract from C. sertularoides and it was significantly different compared to the other methanol extracts both in 3 and 24 h incubation. Methanol extracts from seaweeds had excellent ferrous ion binding effect; however, their ability decreased in the fish oil emulsion system.
This review deals with the main issues relating to the analysis of hydrolysable tannins (HTs). It covers briefly their distribution in the plant kingdom and describes their main structural features. HTs have often been ignored because they are apparently more difficult to analyse than condensed tannins. Meaningful analytical data are critically dependent on appropriate sample preparation, storage and extraction techniques. This requires some understanding of the reactivities of hydrolysable tannins. Mixtures of HTs have been measured by general tannin assays, such as precipitation with metals or proteins, and by colorimetric assays for total phenols. Some HTs can also be measured by more specific colorimetric tests. Although colorimetric assays are widely used for tannin analyses, they generally do not provide accurate quantitative data. At best, they provide data for comparative purposes. Thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) are useful tools to screen samples for the different types of tannins, hydrolysable or condensed tannins. In addition, there are physicochemical techniques, such as nuclear magnetic resonance (NMR) and mass spectrometry (MS), which are used to identify pure tannin compounds. More recently, other MS techniques have been developed that are capable of yielding molecular weights of crude tannin mixtures.
There is currently much interest in phytochemicals as bioactive components of food. The roles of fruit, vegetables and red wine in disease prevention have been attributed, in part, to the antioxidant properties of their constituent polyphenols (vitamins E and C, and the carotenoids). Recent studies have shown that many dietary polyphenolic constituents derived from plants are more effective antioxidants in vitro than vitamins E or C, and thus might contribute significantly to the protective effects in vivo. It is now possible to establish the antioxidant activities of plant-derived flavonoids in the aqueous and lipophilic phases, and to assess the extent to which the total antioxidant potentials of wine and tea can be accounted for by the activities of individual polyphenols.
The effect of sun-drying, oven-drying, and freeze-drying methods on the nutritional composition of the seaweed Sargassum hemiphyllum (Turn.) C. Ag. was investigated. Proximate and nutrient compositions (amino acids, fatty acids, minerals, and vitamin C) of the seaweed dried by the above methods were determined. The results indicated that dietary fiber and ash were the most abundant components of seaweed S. hemiphyllum. No significant differences in the content of crude protein and crude lipid were found among all three dried seaweed samples. Freeze-dried seaweed had the highest content of total amino acids, total polyunsaturated fatty acids, and total vitamin C when compared with sun-dried and oven-dried seaweed. However, sun-dried seaweed has the lowest values of ash, mineral, and total vitamin C contents among the three dried seaweed samples. This might be due to the leaching effect and long exposure time to air during sun-drying. Although oven-dried seaweed had the greatest nutrient losses, probably due mainly to the effect of high temperature during drying, it contained the highest mineral content. Thus, it can be concluded that the nutritional composition of seaweed S. hemiphyllum is greatly affected by different drying methods. Keywords: Seaweed; freeze-drying; oven-drying; sun-drying; nutritional composition
The effect of drying temperature (60, 100, and 140 °C) on the polyphenols' content and antioxidant activity of red grape pomace peels was studied. Freeze-dried samples were used as reference. Differences on the CIE-LAB color, total extractable polyphenols, condensed tannins, UV−vis spectra, and antioxidant activity were evaluated. When drying temperature was 100 and 140 °C, a significant reduction in both total extractable polyphenols (18.6 and 32.6%) and condensed tannins (11.1 and 16.6%) was observed, as well as a decrease of 28 and 50% in the antioxidant activity of the samples, respectively. Hue angle and total color difference in the sample dried at 140 °C were significantly higher than in the freeze-dried reference material. A red color loss at 140 °C was also confirmed by lower absorbance values in the spectra at 525 nm. Drying at 60 °C did not significantly affect the sample characteristics evaluated. Keywords: Wine byproducts; grape pomace peels; antioxidant activity; drying temperature
Phenolic acids, bound to the cellular walls of the germinated barley, are very interesting potential antioxidants of beer. Indeed, the antioxidant activity due to these bound compounds is about 2-fold higher than the activity due to the free phenolic compounds. Seven phenolic acids were separated by HPLC after alkaline hydrolysis of the cake resulting from a methanolic extraction of barley or malt. Three main compounds, trans-ferulic acid, trans-p-coumaric acid, and cis-ferulic acid, were quantified using an external standard method. They respectively represent 177.79, 78.50, and 47.15 mu g/g of dry matter of germinated barley. Responsible for 20-40% of the antioxidant activity of the hydrolyzed cake, they probably have a real influence on the evolution of this activity during kilning.
The antioxidant activity of aqueous/organic extracts of processed and raw edible seaweeds was determined using three methods, namely (a) free radical (DPPH·) scavenging, (b) ferric-reducing antioxidant power (FRAP) and (c) inhibition of copper-catalysed in vitro human low-density lipoprotein (LDL) oxidation. Scavenging activity correlated well (r = 0.73) with the corresponding total polyphenolic content measured by the Folin–Ciocalteu procedure and expressed as phloroglucinol equivalents (PGE). Of the seaweeds tested, Fucus showed the highest antioxidant activity in two of the test methods used (1 g (dry matter) had a DPPH· activity and a FRAP value equivalent to those 0.18 and 0.07 mmol of Trolox respectively) and the highest total polyphenolic content (41.4 gPGEkg−1 dry matter). The antioxidant activity and the content of phenolic compounds decreased with processing and storage in the seaweeds tested. In addition, Fucus showed good efficiency in the in vitro inhibition of LDL oxidation.© 2001 Society of Chemical Industry
We have used light and electron microscopy to study the secretion of phenolic substances into the primary walls and cross walls of zygotes and embryos of the brown algae Hormosira banksii (Turner) Decaisne (Hormosiraceae) and Acrocarpia paniculata (Turner) Areschoug (Cystoseiraceae). Phenolic compounds packaged within physodes are a major cytoplasmic component of brown algae. Physodes accumulate at the zygote periphery early in development and are secreted into the primary zygote wall. At germination, physodes accumulate at the rhizoid tip. The first sign of impending cytokinesis is the lining up of these phenolic vesicles in the plane of cell division. This precedes the arrival of other wall constituents. Physodes, together with other wall components, contribute to the development of the cell plate. We conclude that phenolic compounds play an important role in cell-wall construction in these species.
Methanol extracts from seven species of Indonesian seaweeds were evaluated for their anti-oxidant activities in a fish oil emulsion system. The system was incubated at 50°C for 3 and 24 h, in the presence of ferrous ion as a catalyst. Peroxide value (POV), ferrous ion chelating effect in the oil emulsion system and ferrous ion binding effect in methanol extracts were determined as oxidation markers. In the presence of ferrous ion catalyst, all of the methanol extracts from seaweeds showed significantly lower POV of the emulsion than the control, and the extract from Caulerpa sertularoides had the strongest anti-oxidant activity. The highest chelation on ferrous ion was also found in the extract from C. sertularoides and it was significantly different compared to the other methanol extracts both in 3 and 24 h incubation. Methanol extracts from seaweeds had excellent ferrous ion binding effect; however, their ability decreased in the fish oil emulsion system.
The anti-oxidant activity of extracts from 36 vegetables was evaluated by using a model system consisting of β-carotene and linoleic acid. The total phenolics of the extracts was determined spectrophotometrically according to the Folin–Ciocalteau procedure and ranged from 34 to 400 mg (100 g)−1 on a fresh weight basis. Mint, aonla, black carrots, chenopodium, fenugreek, kachnar and ginger had high phenolic contents. The anti-oxidant activity expressed as per percent inhibition of oxidation ranged from a high of 92% in turmeric extracts to a low of 12.8% in long melon. Other vegetables found to have high anti-oxidant activity (>70%) were kachnar, aonla, ginger, fenugreek, mint, beetroot, black carrots, Brussels sprouts, broccoli, lotus stem, yam, coriander and tomato. Anti-oxidant activity correlated significantly and positively with total phenolics (r2=0.6578, P < 0.05). The results indicate that vegetables containing high phenolics may provide a source of dietary anti-oxidants.
The effects of different drying treatments (oven- andfreeze-drying) on protein extractability of three subtropical brownseaweeds, Sargassum hemiphyllum, S. henslowianum and S. patens, as well as in vitro protein digestibility and amino acid profileof their protein concentrates (PCs) were investigated. When comparedwith freeze-drying, oven-drying not only improved significantly (p Sargassum species but also the protein quality (in vitroprotein digestibility) of their PCs. Therefore, oven-drying was found to bemore suitable for protein extraction of brown seaweeds. The relationshipsbetween the protein extractability and total phenolic content in seaweedsand between in vitro protein digestibility and total phenolic contentin PCs were also discussed.
Ecklonia stolonifera and Ecklonia kurome are traditional edible brown algae in the fisheries towns in Far East Asia. In the Noto Peninsula area, Ishikawa, Japan, both the Ecklonia are called ‘kajime’ and people believe that the algae improve the property of blood. To determine the varieties of antioxidant and antibacterial properties E. stolonifera and E. kurome products, assays for total phenolic content and antioxidant activities, including DPPH radical-scavenging activity, superoxide anion radical-generated by non-enzymatic system, ferrous-reducing power and WST-8, a tetrazolium salt, redox activity of four dried and two boiled E. stolonifera, and four dried and two raw E. kurome preparations were tested in this study. Furthermore, antibacterial activity of the products was tested. Though the total phenolic content, the antioxidant activity and the antibacterial activities of E. stolorifera and E. kurome products were high, these properties were varied by manufacturers or each product. Especially, two dried and two boiled products of E. stolonifera showed low activities. The results of this study indicate that the contents of functional compounds and their activities were affected or decreased greatly by the processing method.
The total phenolic content (TPC) and antioxidant activity of fresh and dried Phyllanthus amarus plant materials were evaluated using the Folin-Ciocalteau method, 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity and ferric reducing antioxidant power (FRAP) assays. Different drying treatments led to significant reduction (P<0.05) in antioxidant properties of P. amarus methanolic extracts, with microwave drying causing the highest decrease in TPC and antioxidant activity exhibited by the reduction in both radical scavenging activity and FRAP. On the other hand, boiling water extracts appeared to exhibit significantly stronger antioxidant potentials (P<0.05) even in dried plant materials due to greater solubility of compounds, breakdown of cellular constituents as well as hydrolysis of tannins. Its strong free radical scavenging activity suggests that it has great potential in the food industry as functional food ingredient.
Three tomato cultivars (Excell, Tradiro, and Flavourine) grown under hydroponic conditions in a commercial greenhouse in New Zealand were semi-dried at 42 °C. The semi-dried tomatoes contained low levels of 5-hydroxymethyl-2-furfural and were significantly (p < 0.05) darker (lower CIELAB L* values) and had a higher mean a*/b* value (1.6) than the fresh tomatoes (1.2). The mean total phenolics in the semi-dried samples of tomatoes (300 mg gallic acid equivalents, GAE/100 g dry matter (DM)) was significantly lower than that of fresh tomatoes (404 mg GAE/100 g DM). The mean total flavonoid, and lycopene contents in the fresh samples (206 mg rutin equivalents/100 g DM, 63 mg/100 g DM, respectively) also showed a significant decrease after semi-drying (179 mg rutin equivalents/100 g, 54 mg/100 g DM, respectively). Ascorbic acid content in fresh tomatoes (284 mg/100 g DM) decreased to 223 mg/100 g DM after drying. The total antioxidant activity of the semi-dried tomatoes (1783 μmole trolox equivalents antioxidant capacity (TEAC)/100 g DM) was significantly (p < 0.05) lower than that of the fresh samples (2730 μmole TEAC/100 g DM).
Beverages were successfully prepared from four sea algae. The antioxidant properties of these beverages were investigated using four different methods: autoxidation test, superoxide anion radical, DPPH radical, and hydroxyl radical scavenging tests. Among them, sea trumpet showed strong effects against autoxidation and the scavenging of superoxide anion radical. The antioxidant activities of these beverages correlated with their contents of polyphenols. This shows that these beverages have a potential as health drinks with functional properties and for patients suffering cancer, cardiovascular diseases, and diabetes.
The cortex of 14 French apple varieties (12 cider and 2 juice varieties), one English cider variety, and one dessert apple (i.e., Golden Delicious) were studied for their polyphenol composition. Total polyphenols were assayed by the Folin-Ciocalteu method, and the precise polyphenolic composition (monomeric catechins, proanthocyanidins, hydroxycinnamic acids, and dihydrochalcones) was obtained by HPLC following thiolysis. ESI-MS and ESI-MS/MS analyses showed that chlorogenic acid and p-coumaroylquinic acid were methylated under the conditions of thiolysis. Depending on the variety, the global polyphenol concentration varied from 1 to 7 g per kilogram of fresh cortex. Cider varieties globally showed a higher polyphenol concentration than the dessert apple Golden Delicious, bitter varieties being the more concentrated. The proportion of the polyphenol classes varied greatly from one cultivar to another. For all varieties, procyanidins were always the predominant class. They were mainly constituted of (-)-epicatechin units with a small proportion of (+)-catechin as a terminal unit. The average degree of polymerization ranged between 4.2 and 7.5 depending upon the variety with an exception for the sharp varieties Guillevic and Avrolles which showed significant concentrations of procyanidins with DPn of 40 and 50, respectively.
The product and process parameters that determine successful freeze-drying are described and their interrelationships are explored. It is shown that the thermochemical and thermomechanical properties of water-soluble, amorphous materials form the basis of effective formulation design and that coordinated approaches to formulation and process development achieve optimum results with a minimum of trial-and-error experimentation.
Methods for determining primary antioxidant activity were evaluated. A beta-carotene bleaching method and a free radical method using 2, 2-diphenyl-1-picrylhydrazyl (DPPH(*)) were modified to rapidly test samples for potential antioxidant activity. Malonaldehyde production in a linoleic acid emulsion system assayed by an HPLC method was also used to determine antioxidant and prooxidant activities initiated by a metal catalyst (Cu(2+)). All methods were used to assess activity of selected phenolic compounds including several anthocyanidins/anthocyanins and selected berry extracts. Most phenolic compounds had prooxidant activity at low concentrations, unlike synthetic antioxidants (BHA and BHT). Compounds with similar structures exhibited comparable trends in antioxidant activity. Antioxidant activity usually increased with an increase in the number of hydroxyl groups and a decrease in glycosylation. The antioxidant activity of many phenolic compounds and extracts was comparable to those of synthetic antioxidants using the beta-carotene bleaching and HPLC methods.
Three methods widely employed in the evaluation of antioxidant activity, namely 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method, static headspace gas chromatography (HS-GC) and beta-carotene bleaching test (BCBT), have been compared with regard to their application in the screening of plant extracts. The strengths and limitations of each method have been illustrated by testing a number of extracts, of differing polarity, from plants of the genus Sideritis, and two known antioxidants (butylated hydroxytoluene and rosmarinic acid). The sample polarity was important for the exhibited activity in the BCBT and HS-GC methods but not for the DPPH method. The complex composition of the extracts and partition phenomena affected their activity in each assay. The value of the BCBT method appears to be limited to less polar samples. Although slow, the HS-GC method is preferable for assessing the antioxidant inhibitory properties on the formation of unwanted secondary volatile products. Being rapid, simple and independent of sample polarity, the DPPH method is very convenient for the quick screening of many samples for radical scavenging activity.
To screen algal phlorotannins with antioxidative activities, 50% ethanol extracts of 25 Japanese marine algae were evaluated. Scavenging activity against superoxide anion radicals was frequently found with a high content of total phenolic compounds. Among these, the extract from the brown seaweed, Sargassum ringgoldianum, showed the strongest scavenging activity. The active fraction contained a mixture of high molecular weight polyphenols, phlorotannins that were found to be polymerized bifuhalol, as analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The scavenging activity of the fraction against superoxide anion radicals was estimated to be 1.0 microg/ml (IC(50)), which were approximately five times stronger than that of catechin.
Phlorotannins, brown algal polyphenols
- Ragan
Ragan, M. A. and Glombitza, K.-W. 1986. Phlorotannins, brown algal polyphenols. Prog. Phycol. Res. 4: 129–241.
Phlorotannins as radical scavengers from the extract of Sargassum ringgoldianum
- M Nakai
- N Kagayama
- K Nakahara
- W Miki
Nakai, M., Kagayama, N., Nakahara, K. and Miki, W. 2006.
Phlorotannins as radical scavengers from the extract of
Sargassum ringgoldianum. Mar. Biotechnol. 8: 409–
14.
Analysis of hydrolysable tannins
- Mueller-Harvey