Article

Green tea and grape seed extracts—Potential applications in food safety and quality

Authors:
To read the full-text of this research, you can request a copy directly from the authors.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... Flavonoids are part of plant secondary metabolites and they are widely found in fruits, vegetables, nuts, seeds, stems, flowers, tea, propolis, cocoa and honey and they possess anti-microbial activities among others [132,133]. Most of the plant extracts that are rich in flavonoids are generally recognized as safe (GRAS) by the FDA [134][135][136]. In this part of the review, an overview of research studies focusing on the plant extracts and propolis that naturally contain flavonoids, their anti-microbial activity and their application on meat products will be presented. ...
... Grape seed extract (GSE) is a by-product of vinification and grape juice processing and it is rich in flavonoids, such as procyanidins [135]. It is beneficial for human health; however, its use is limited because of its poor solubility in water, degradation at high temperatures and low bioavailability [152]. ...
... GSE has significant anti-microbial activity against pathogenic and spoilage bacteria [153]. The anti-microbial mechanism of GSE against bacteria is based on the presence of flavonoids and it includes disruption of the cell membrane, inhibition of enzymes in the membrane and dissipation of the proton motive force [135]. ...
Article
Full-text available
Microbial food contamination is a major concern for consumers and food industries. Consumers desire nutritious, safe and “clean label” products, free of synthetic preservatives and food industries and food scientists try to meet their demands by finding natural effective alternatives for food preservation. One of the alternatives to synthetic preservatives is the use of natural anti-microbial agents in the food products and/or in the packaging materials. Meat and processed meat products are characteristic examples of products that are highly perishable; hence natural anti-microbials can be used for extending their shelf-life and enhancing their safety. Despite several examples of the successful application of natural anti-microbial agents in meat products reported in research studies, their commercial use remains limited. This review objective is to present an extensive overview of recent research in the field of natural anti-microbials, covering essential oils, plant extracts, flavonoids, animal-derived compounds, organic acids, bacteriocins and nanoparticles. The anti-microbial mode of action of the agents, in situ studies involving meat products, regulations and, limitations for usage and future perspectives are described. The review concludes that naturally derived anti-microbials can potentially support the meat industry to provide “clean label”, nutritious and safe meat products for consumers.
... Oxidized proteins are more vulnerable to proteolysis. Elevation in the oxidized proteins in the cells can result in cellular dysfunction and hence loss of selected physiological function [54,55]. ...
... In the plasma membranes of all the cells, lipids have a structural and functional role [7,9,55]. Polyunsaturated fatty acids are more vulnerable to ROS attack. ...
... DNA damage renders DNA susceptible to oxidation that leads to base degeneration, cross-linkage to proteins, and single-strand breakage. Damage caused to DNA by free radicals is highly associated with cancer and aging [55,59]. ...
Chapter
Full-text available
Compounds that act as inhibitors of the process of oxidation are termed antioxidants. These compounds exert such potential even at relatively small concentrations. Cellular activity retarding free radicals are among the end products of an oxidation chemical reaction, which react in chain reactions to cause damage to the cells of an organism which in turn lead to serious disorders. Under oxidative stress, the cells of the body show an elevation in the production of free radicals that mostly include hydroxyl radicals, superoxide anion radicals, and hydrogen peroxide among others. Such compounds are given the name reactive oxygen species (ROS). When produced beyond the control of their natural stabilizers and neutralizers, i.e., enzymatic antioxidants [e.g., catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), etc.], there is a need to increase the concentration of nonenzymatic antioxidants in the body that act as radical scavenging agents. Such antioxidants can be taken in the form of dietary supplements and mostly include ascorbic acid (vitamin C), α-tocopherol (vitamin E), glutathione (master antioxidant), carotenoids, flavonoids, etc. These beneficial antioxidants have the potential to minimize oxidative stress and thus prove promising in the treatment of several human diseases like cancer, aging, cardiovascular diseases, autoimmune disorders, inflammatory diseases, etc. It has been revealed by some researchers that two-thirds of the world’s plant species possess great antioxidant potential as these beneficial compounds occur naturally in their stems, roots, leaves, fruits, and flowers. Naturally occurring antiradicals are much more effective in stabilizing free radicals than synthetic ones. As natural compounds, phytochemicals like phenolics, flavonoids, and carotenoids are potent agents that convert harmful radicals to less reactive species. Among fruits and vegetables, apples also pack a big antioxidant punch as they are loaded with compounds like quercetin, catechin, chlorogenic acid, phloridzin, and vitamin C, all of which have been found too potent to inhibit the proliferation of cancer cells, minimize oxidation of lipids, decrease cholesterol level, improve heart function, and enhance skin tone. Such benefits are attributed to their antioxidant potential. Phytoalexins, apart from acting as antioxidants in all biological systems, within the plant physiology framework, serve to cope up with stresses, e.g., resisting a pathogen attack. It is an admitted fact that phenols are incorporated in immune responses in plants. In this chapter, efforts have been made to present some information about the role of antioxidants in health and disease along with their properties to defend pathogens that invade different apple species of Kashmir. Our ongoing research on that very theme is underway.
... Particularly, nisin, a bacteriocin produced by Lactococcus lactis, is a generally recognized as safe (GRAS) compound (FDA, 1988), highly effective in the inactivation of a wide range of Gram-positive bacteria and spores resistant to high temperatures. Natamycin (pyramycin) is an antifungal produced by Streptomyces natalensis (Delves-Broughton & Weber, 2011) designed as a natural preservative by the European Union (EEC N° 235), and green tea extracts (GTE) have demonstrated antibacterial, antiviral, antifungal, and antioxidant activity and promote numerous health benefits, particularly the prevention of various types of cancer and cardiovascular diseases (Perumalla & Hettiarachchy, 2011). The effectiveness of these treatments has been proven in several fruit juices (Bevilacqua et al., 2012;Bi et al., 2020;Cassani et al., 2017;Lafarga et al., 2019;Noguera et al., 2021;Park et al., 2021). ...
... The exception was observed in the sample containing GTE that presented values 11, 14, and 12 times higher than the control for TPC, DPPH, and FRAP, respectively. This was associated with the high content of polyphenols of green tea and its recognized antioxidant activity (Ananingsih et al., 2013;Perumalla & Hettiarachchy, 2011). Reductions of 30, 67, and 50% of TPC, DPPH, and FRAP at day 28 were observed in control samples due to deterioration during storage. ...
... On the other hand, the combination of UST with GTE showed a 1.7 log reduction differing statistically from the other treatments. The effect of GTE on E. coli reduction was observed by other authors, using considerably higher concentrations than the one applied in the present work (Fernandez et al., 2017;Perumalla & Hettiarachchy, 2011). The proposed mechanism of action of GTE on Gram-negative bacteria involves damage to the cell wall, such as pore-like lesions, and further membrane degradation (Perumalla & Hettiarachchy, 2011), processes that can be accelerated or enhanced by US action. ...
Article
Full-text available
Fruit and vegetable natural beverage market is growing around the world, but their intrinsic characteristics lead to a high microbial and enzymatic activity, showing a short shelf life when not treated. The present work aims to evaluate the effect of ultrasound (US) treatments on the main spoilage factors and some quality indicators of a mixed fruit and vegetable smoothie (F&VS). Likewise, the advantages of combining US with green tea extract (GTE), nisin (Ni), or natamycin (Na) on the shelf life and stability of the F&VS were assessed. Temperature control was needed to avoid high temperatures during treatment and consequent nutrients and organoleptic degradation. Length of treatment lower than 15 min was required to avoid poliphenoloxidase activation. Ultrasound-selected treatment (UST) was of 70% of amplitude during 4 min, since presented the greatest reduction of peroxidase activity (71.6%) and well performance on microbial control. Both UST and UST + GTE treatments extended F&VS microbial shelf life by 1 week, while UST + Na and UST + Ni by at least 2 weeks. UST greatly increased betalain extractability (55–80%). Its combination with GTE significantly increased the TPC and the antioxidant capacity of the product, as well as enhanced betalain stability during storage. Finally, remarkable results on Listeria initial reductions were obtained with UST + Ni (> 4 log) and on Escherichia coli with UST + GTE (1.7 log) when contamination was simulated. Indeed, the potential of US and their combination with natural antimicrobials on quality preservation as well as on shelf life extension and safety assurance of the F&VS was probed with very promising results.
... Oxidized proteins are more vulnerable to proteolysis. Elevation in the oxidized proteins in the cells can result in cellular dysfunction and hence loss of selected physiological function [54,55]. ...
... In the plasma membranes of all the cells, lipids have a structural and functional role [7,9,55]. Polyunsaturated fatty acids are more vulnerable to ROS attack. ...
... DNA damage renders DNA susceptible to oxidation that leads to base degeneration, cross-linkage to proteins, and single-strand breakage. Damage caused to DNA by free radicals is highly associated with cancer and aging [55,59]. ...
... One of the most important sources of proanthocyanidins is grape seeds, which account for approximately 50 mg/kg of whole seeds (Zhong et al., 2005). Numerous studies have demonstrated that proanthocyanidins have a variety of effects, such as anti-inflammatory, antioxidant, antibacterial, antiviral, anti-allergic, among others (Perumalla & Hettiarachchy, 2011;Zhai et al., 2014). Based on these functions, proanthocyanidins are widely used in food, nutritional, cosmetic and medical industries (Bladé et al., 2016;Chai et al., 2018;Cos et al., 2004;Mielnik et al., 2006;Perumalla & Hettiarachchy, 2011). ...
... Numerous studies have demonstrated that proanthocyanidins have a variety of effects, such as anti-inflammatory, antioxidant, antibacterial, antiviral, anti-allergic, among others (Perumalla & Hettiarachchy, 2011;Zhai et al., 2014). Based on these functions, proanthocyanidins are widely used in food, nutritional, cosmetic and medical industries (Bladé et al., 2016;Chai et al., 2018;Cos et al., 2004;Mielnik et al., 2006;Perumalla & Hettiarachchy, 2011). Besides, dietary proanthocyanidins from grape seeds have attracted considerable attention as a dietary additive to improve the health status and growth of livestock (Brenes et al., 2010;Fang et al., 2020;Gessner et al., 2015;Jerónimo et al., 2010;Quifer-Rada et al., 2016;. ...
Article
An 8-week growth trial was performed to evaluate the effects of grape seed proanthocyanidins (GSPs) on growth, digestive enzymes, body composition, intestinal microbiota, serum immunological, anti-oxidative and biochemical parameters of juvenile hybrid sturgeon (Acipenser baeri Brandt ♀ × A. schrenckii Brandt ♂). Fish were randomly divided to control, GSPs-50 and GSPs-100 groups, which were fed with a basal diet and basal diet supplemented with 50 and 100 mg/kg GSPs, respectively. Growth performance and digestive enzymes were improved by GSPs in sturgeon (p < .05). Lysozyme was clearly increased in serum when sturgeon fed with GSPs diets, while the thiobarbituric acid reactive substances (TBARS) displayed opposite trend (p < .05). Myeloperoxidase and glutathione peroxidase in serum of GSPs-50 were higher than control and GSPs-100 (p < .05). Serum parameters showed alanine aminotransferase, alkaline phosphatase and γ-glutamyl transpeptidase of GSPs-50 were lower than control (p < .05). Compared with the control treatment, GSPs-100 reduced alanine aminotransferase and γ-glutamyl transpeptidase and increased aspartate aminotransferase and lactate dehydrogenase (p < .05). High-throughput sequencing revealed that adding 50 mg/kg GSPs not only modified the microbiota diversity, but also reduced the relative abundance of Aeromonas in sturgeon intestine. In conclusion, GSPs are a promising feed additive to promote growth, immunity, antioxidant and digestive enzyme activities and improve serum biochemical parameters and intestinal microbiota of hybrid sturgeon.
... Research showed that grape seed contains the highest amount of polyphenols, making it the primary extraction [22], [23]. Many methods have been developed to increase the yield of polyphenolic compounds in GSE. ...
... Recent studies have shown that GSE effectively increases the shelf-life of cold storage meat and fruit while used in food film packaging [20]- [22]. This likely happens due to GSE's capability to decrease aerobic mesophilic bacteria's growth rate, Pseudomonas spp., mold, and yeast in food, thus reducing the rate of oxidation and maintaining the color stability of the product [42], [45]. ...
Article
Full-text available
The food industry is a life-long and highly demanded industry as it is an essential human need. Food safety has become an urgent discussion related to this industry since the foodborne disease has gradually increased. One of the causes of the disease is L. monocytogenes, usually discovered in fresh meat, ready-to-eat meat, vegetables, and milk. L. monocytogenes causes an infection known as listeriosis. Food packaging plays an essential role as it protects the food from external contaminants to increase the shelf life. The high usage of conventional food packaging derived from fossil fuel contributes to the environmental issue as it creates long-term wastes. Therefore, biobased food packaging has been in favor as it is biodegradable. However, it lacks antimicrobial properties, so the development of biobased material as the antimicrobial food packaging is a potent solution in the food safety scope. This review paper intends to summarize current advancements in incorporating antimicrobial agents with nanocellulose biobased food packaging to increase the packaging’s functional value. Pediocin is the antimicrobial agent produced by Pediococcus sp . integrated with Grape Seed Extract (GSE), which gives an antioxidant property that boosts the food packaging’s antimicrobial effect. Observations show that incorporating these antimicrobials agents obstructs the growth of L. monocytogenes in biobased food packaging. Incorporating antimicrobial agents into nanocellulose matrix shifts the tendency to make biobased packaging that gives better mechanical strength and longer shelf life. Overall, this greener antimicrobial food packaging could be a solution to environmental waste as well as foodborne pathogens.
... However, increase in environmental awareness has increased the demand for natural and non-toxic biological preservatives for usage in food processing, storage, and transportation. Tea polyphenols extracted from green tea are biological preservatives that contain polyphenolic compounds, such as catechins, flavanols, and phenolic acids with antibacterial and antioxidative activities [4,5]. Tea polyphenols have previously been used to maintain the quality and extend the shelf life of fish, such as silver carp [6,7], crucian carp [8], large yellow croaker [9], and weever [10]. ...
Article
Full-text available
We investigated the effects of tea polyphenol treatments on the quality and microbiota of crisp grass carp fillets during cold storage at 4 °C. Changes in the total viable count (TVC) and total volatile base nitrogen (TVB-N) of fillets were measured. The microbiota of the crisp grass carp was analyzed using high-throughput sequencing technique. The results indicated that tea polyphenol treatments inhibited bacterial growth and reduced TVB-N values of fish fillets, and subsequently extended their shelf life by 6 days. The high-throughput sequencing result showed that Pseudomonas was the most abundant bacteria in tea polyphenol-treated fish fillets at the end of shelf life, while Pseudomonas and Aeromonas were the most abundant bacteria in control samples. These findings suggested that tea polyphenol treatments could be used in future to extend the shelf life of crisp grass carp fillets and alter the bacterial communities responsible for spoiling fish.
... Likewise, the incorporation of high concentration of PEs in ECs may result in off-flavours. Perumalla and Hettiarachchy [48] identified several factors affecting the selection of PEs for use in ECs, including cost effectiveness, final sensory quality of food product, availability, and bioactive properties. Cerqueira et al. [49] outlined that, while higher concentration of PEs is associated with greater antioxidant capacity, the active components of PEs may negatively alter permeability, thermal, and mechanical properties of the ECs. ...
Article
Full-text available
This study determined the antimicrobial and antioxidant activity of lemongrass (LO), thyme (TO), and oregano (OO) essential oils and ethanolic extracts of pomegranate peel (PPE) and grape pomace (GPE) as candidate ingredients for edible coatings. Antifungal effects against Botrytis cinerea and Penicillium spp. were tested using paper disc and well diffusion methods. Radical scavenging activity (RSA) was evaluated using 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonic acid assays. Gas chromatography-mass spectrometry analysis identified limonene (16.59%), α-citral (27.45%), β-citral (27.43%), thymol (33.31%), paracymene (43.26%), 1,8-cineole (17.53%), and trans-caryphellene (60.84%) as major compounds of the essential oils. From both paper disc and well diffusion methods, LO recorded the widest zone of inhibition against tested microbes (B. cinerea and Penicillium spp.). The minimum inhibitory concentrations of LO against B. cinerea and Penicillium spp., were 15 µL/mL and 30 µL/mL, respectively. The highest (69.95%) and lowest (1.64%) RSA at 1 mg/mL were recorded for PPE and OO. Application of sodium alginate and chitosan-based coatings formulated with LO (15 or 30 µL/mL) completely inhibited spore germination and reduced the decay severity of ‘Wonderful’ pomegranate. Lemongrass oil proved to be a potential antifungal agent for edible coatings developed to extend shelf life of ‘Wonderful’ pomegranate.
... 11 It is made by removing, drying and grinding seeds of different grapes (Vitis vinifera). 12 Remarkably, the highest percentage of total polyphenols in grapes is present in their seeds. Therefore, GSE contains fibre (35%), fat (13%), protein (11%), water (7%), different vitamins and minerals (3%) and a heterogeneous mixture of polyphenolic compounds including monomers (5%-30%), oligomers (17%-63%) and polymers (11%-39%). ...
Article
Background: Grape seed extract (GSE) seems to have antioxidant and anti-inflammatory properties due to its high polyphenolic content. Nevertheless, the scientific literature in this field is controversial and inconclusive. Therefore, we aimed to conduct a systematic review and meta-analysis of controlled trials to evaluate the effect of supplementation with GSE on biomarkers of oxidative stress and inflammation. Methods: Medline, Scopus, Cochrane Library, Google Scholar and Web of Science databases were searched up to 10 September 2020 using appropriate keywords without restrictions. In the systematic review phase, all biomarkers of oxidative stress and inflammation were considered as outcomes. In the meta-analysis phase, six biomarkers were selected as outcomes, and weighted mean difference (WMD) or standardised mean difference (SMD) with 95% confidence interval (CI) was calculated for them using a random-effects model. Results: Twenty-three studies were included in the systematic review, and 19 studies were included in the meta-analysis. GSE supplementation caused a significant decrease in malondialdehyde (SMD: −1.04, 95% CI: −1.65, −0.42), oxidised low-density lipoprotein (SMD: −0.44, 95% CI: −0.75, −0.13) and high-sensitivity C-reactive protein (WMD: −0.48 mg/L, 95% CI: −0.94, −0.03) and a marginally significant increase in total antioxidant capacity (SMD: 0.49, 95% CI: −0.05, 1.04) but did not significantly influence C-reactive protein (WMD: −0.36 mg/L, 95% CI: −1.02, 0.30) and white blood cell count (WMD: 0.12 × 109/L, 95% CI: −0.25, 0.48). Conclusion: It appears that GSE supplementation can remarkably modulate the body's redox system, particularly through the inhibition of lipid peroxidation, but has neutral or mildly beneficial effects on inflammatory responses.
... The seed coats having high antioxidant activity could be added to food packaging films as a protective barrier against oxidation reactions and microbial growth. Additionally, these seed coats could be potential food-derived ingredients in cosmetic and skin care products, as prodelphinidin-rich extracts, such as grape seed extract, were reported to reduce skin hyperpigmentation and promote wound healing [63]. Recent research has shown a growing interest in the biological activities of proanthocyanidin-rich food byproducts as a renewable and environmentally friendly resource to be used in pharmaceutical, cosmetic and food applications [64]. ...
Article
Full-text available
Pulse crop seed coats are a sustainable source of antioxidant polyphenols, but are typically treated as low-value products, partly because some polyphenols reduce iron bioavailability in humans. This study correlates antioxidant/iron chelation capabilities of diverse seed coat types from five major pulse crops (common bean, lentil, pea, chickpea and faba bean) with polyphenol composition using mass spectrometry. Untargeted metabolomics was used to identify key differences and a hierarchical analysis revealed that common beans had the most diverse polyphenol profiles among these pulse crops. The highest antioxidant capacities were found in seed coats of black bean and all tannin lentils, followed by maple pea, however, tannin lentils showed much lower iron chelation among these seed coats. Thus, tannin lentils are more desirable sources as natural antioxidants in food applications, whereas black bean and maple pea are more suitable sources for industrial applications. Regardless of pulse crop, proanthocyanidins were primary contributors to antioxidant capacity, and to a lesser extent, anthocyanins and flavan-3-ols, whereas glycosylated flavonols contributed minimally. Higher iron chelation was primarily attributed to proanthocyanidin composition, and also myricetin 3-O-glucoside in black bean. Seed coats having proanthocyanidins that are primarily prodelphinidins show higher iron chelation compared with those containing procyanidins and/or propelargonidins.
... Grape seed extract (GSE) is rich in polyphenolic compounds and secondary metabolites, which have significant antimicrobial activities against different pathogens, such as Gram-negative and Gram-positive bacteria [4]. The effectiveness of GSE inhibition depends on the concentration of the extract, percentage of phenols, and the type of bacterium [5]. Furthermore, GSE was tested for its possible anti-inflammatory, cardioprotective, chemopreventive, anticarcinogenic, and antioxidant activities, which might be of pharmacological and medical importance [6]. ...
Article
Full-text available
Grape seed extract (GSE) is a natural source of polyphenolic compounds and secondary metabolites, which have been tested for their possible antimicrobial activities. In the current study, we tested the antibacterial and antifungal activities of aqueous GSE and the biosynthesized silver nanoparticles loaded with GSE (GSE-AgNPs) against different pathogens. The biosynthesized GSE-AgNPs were assessed by UV spectroscopy, dynamic light scattering (DLS), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), and gas chromatography/mass spectrometry (GC/MS). The antimicrobial activities were assessed against different bacterial and fungal species. DLS analysis showed that GSE-AgNPs had a Z-Average of 91.89 nm while UV spectroscopy showed that GSE-AgNPs had the highest absorbance at a wavelength of ~415 nm. FTIR analysis revealed that both of GSE and GSE-AgNPs consisted of different functional groups, such as hydroxyl, alkenes, alkyne, and aromatic rings. Both FE-SEM and TEM showed that GSE-AgNPs had larger sizes and rough surfaces than GSE and AgNO3. The results showed significant antimicrobial activities of GSE-AgNPs against all tested species, unlike GSE, which had weaker and limited effects. More studies are needed to investigate the other antimicrobial activities of GSE.
... It was shown that LVEO treatments had antioxidant activity, due to a high content of neral (75), as evidenced by lower TBA values in the large yellow croaker samples packaged with LVEO coatings. Perumalla and Hettiarachchy (76) reported that the antioxidant activities of the EOs are mainly manifested in the binding of transition metal ion catalysts, the prevention of radical chain initiation, interaction with the free radicals and decomposition of peroxides. ...
Article
Full-text available
Active coating could improve the fish quality and extend the shelf life. This study investigates the effect of locust bean gum (LBG) and sodium alginate (SA) active coatings containing lemon verbena (Lippa citriodora Kunth.) essential oil (LVEO) emulsions on microbiological, physicochemical and organoleptic evaluation of large yellow croaker (Larimichthys crocea) samples during refrigerated storage at 4°C. Results showed that LBG-SA coatings incorporated with 0.30 or 0.60% LVEO emulsions significantly inhibited the growth of mesophile bacteria, Pseudomonas spp., H2S-producing bacteria, lactic acid bacteria (LAB) and psychrophilic bacteria, and reduce the productions of trimethylamine (TMA), total volatile basic nitrogen (TVB-N) and ATP-related compounds. Further, the LVEO treatments also retarded the water migration and maintained the organoleptic evaluation results of large yellow croaker during storage at 4°C. In conclusion, the LBG-SA active coatings incorporated with LVEO emulsions maintained the quality and extended the shelf life of large yellow croaker during refrigerated storage.
... Schnitzler et al. (2010) investigated propolis compounds and reported that chrysanthemum and galangal reduced free HSV-1 plaque formation by 56.4 % and 68.0 %, respectively, compared to the untreated control group. Su and D'Souza (2011) also reported a similar case of GSE, which also contained epicatechin 3-O-gallate, catechins, and epicatechins (Perumalla & Hettiarachchy, 2011). In our study, the antiviral effects of propolis on human norovirus and its surrogates could be due to the phenolic components in PEE. ...
Article
Human noroviruses (HuNoVs) outbreaks have been linked to contaminated fresh-cut produce. Propolis has been used as a folk medicine because of its extensive bioactivity and antimicrobial properties. The aim of this study was to investigate the antiviral properties of propolis water extracts (PWE) and propolis ethanol extracts (PEE) against noroviruses, and its application in fresh-cut produce. Extraction yields, total phenolic content, total flavonoid, and soluble carbohydrate content of the propolis extracts were measured to estimate their antiviral compounds. The HuNoV GII.4 and its surrogates (murine norovirus MNV-1 and bacteriophage MS2) were used to evaluate the anti-noroviral activities of propolis extracts. The polyphenol-rich extract (PEE) showed better antiviral activities than PWE. Time-of-addition experiments and TEM images suggested that PEE denatured the viral capsid protein and likely prevented adsorption and internalization of viruses into cells. The application of PEE for natural preservative in fresh juices was also analyzed. After 30 min of treatment of the four different juices, 500 μg/mL PEE reduced MNV-1 and MS2 titers by > 3.0 log10. Therefore, the PEE containing high amounts of polyphenol improved the safety of fresh juices and could be potential candidates for the development of novel natural antiviral preservative for fresh juices.
... AgNPs mainly exert their antimicrobial effects through the disruption of the cell wall and cell membrane that finally leading to bacterial cell death. Additionally, there are some other mechanisms including attack on bacterial surface and membrane through interaction with sulfur-containing proteins [40], disruption of cell permeability and respiration, form the pits on the cell surface and induce the proton leakage that causes cell death [41], inhibition of respiratory enzymes of bacterial cells by combining with the thiol group [42] as well as cell retention of DNA replication and preventing cellular division [43] might widely contributed to the antibacterial effects of AgNPs. The entrance of AgNPs also produce higher amount of ROS molecules that is linked to deactivation of the respiratory enzymes and disrupt the cellular membrane and damage DNA molecule [44]. ...
Article
Full-text available
Background: The present study was aimed to examine the influence of extraction method on the morphology, physico-chemical characteristics and antimicrobial properties of AgNPs synthesized from Melissa officinalis. Methods: AgNPs were prepared by two extraction methods. The properties of obtained nanoparticles were characterized by SEM, UV-Vis, XRD and FTIR techniques. Accordingly, SEM images showed different shape, size and morphology of AgNPs using two different extracts types. Results: The UV-Vis spectroscopy confirmed the formation of AgNPs by observing a distinct surface Plasmon resonance band around 450 nm. SEM images showed different shape, size and morphology of AgNPs using two different extracts types. AgNPs derived from the aqueous extract were rod-shaped with a diameter of 19 to 40 nm whereas spherical particles were synthesized by the methanolic extract found smaller with size distribution ranging from 13 to 35 nm. The XRD pattern indicated that AgNPs formed by the reduction of Ag+ ions using the methanolic extract were crystal-like in nature. The functional groups of the methanolic extract involved in synthesis and stabilization of AgNPs were investigated by FTIR. In addition, AgNPs containing methanolic extract showed higher antioxidant activity. Conclusion: In this respect, the biosynthesized particles showed potential bio-functionality through which higher antioxidant property and antimicrobial profile against infectious strains were observed. By and large, these results have shown that Dehghan Nayeri et al. Int. J. Adv. Biol. Biomed. Res. 2021, 9(3):270-285 271 | P a g e using medicinal plants for biosynthesis of AgNPs can boost the quality of prepared particles for exhibiting trustworthy functionalities.
... The result can be attributed to the total phenols and antioxidant effects of tomato extract. The mechanism of action is related to the decomposition of primary peroxides, connection of transition metal ion catalysts, prevention of radical chain initiation, and interaction with free radicals [49,50]. The greatest reduction of peroxide value and malondialdehyde with 51.54 and 36.51% was observed in sausage samples formulated with 1% pectin and 2% tomato paste. ...
Article
Full-text available
Effect of active pretreatment of tomato pectin and paste on physicochemical, textural, microstructure and organoleptic attributes of chicken sausage during deep-fat frying was investigated in this study. Compared with the control sample, pectin and tomato paste (TP) treatments decreased the oil uptake and moisture loss of deep-fried chicken sausage by 13.28% and 10.16, respectively. Adding pectin along with tomato paste to chicken sausage formulation decreased chewiness and springiness forces to 21.36 N and 0.70, respectively. Using tomato paste and pectin increased the cohesiveness (9.1%) and softness (19.11%) of the tissue. The deep-fried sausage samples were analyzed for PV (peroxide value), TBARS (thiobarbituric acid reactive substances) and sensory attributes. The most reduction in lipid oxidation (51.45% for PV and 36.51% for TBA) was observed when sausage samples were enriched with 1% pectin and 2% tomato paste, while the control samples had the highest values of TBARS and PV after the deep-fat frying process. Based on the results of the sensory attribute, significant differences in texture, color, smell, and taste were observed among the treatments (p < 0.05). However, based on overall acceptability, enriched chicken sausage with 1% pectin and 2% TP had the highest scores. By considering the results of nutritional, structural and sensory evaluations, using of active pretreatment of pectin and tomato paste reduced oil uptake and lipid oxidation, resulting in a healthier fast-food product after the deep-fat frying process.
... The researchers have also reported that the black cumin seeds possess antibacterial activities against multi-drug resistant bacteria [11,12] .The past research has revealed that the essential oils of spices have antimicrobial activity against food borne pathogens [13]. They also show antimicrobial and antioxidant activities [14,15,16]. The constituents of medicinal plants, herb and spices have been shown to possess antimicrobial activity and act as a source of antimicrobial agents against food pathogens [17]. ...
Research
Full-text available
In the present study, the extracts of Nigella sativa seeds were prepared by Soxhalate, Hot and Cold extraction methods using water and methanol as solvent. The free radical scavenging activity of all extracts were investigated by DPPH (2,2-diphenyl-1-picrylhydrazyl). The super coiled pBR322 plasmid was used to study the protection of DNA against H 2 O 2-induced oxidative damage. Antimicrobial activity of each extract was determined by Well Diffusion method. The results of DPPH and DNA damage assay revealed that methanol is better solvent than water and the Soxhalate method and Hot extraction methods are effective techniques to get antioxidant rich extract. Methanolic extract prepared by Soxhalate method showed activity against E. coli. The extract obtained by cold extraction technique showed positive antibacterial activity and least antioxidant activity.
... The antioxidants' action of procyanidins dimers depends on the level of polymerization. The higher the level of polymerization, the greater the antioxidant activity(Perumalla and Hettiarachchy, 2011). ...
Article
Full-text available
Given the substantial benefits of grape seed extract (GSE) in reducing oxidative stress, the study aimed development, characterization and comparative analysis of GSE-based formulations. The development entailed extraction of GSE from Vitisvinifera L. HPLC confirmed catechin, epicatechin, gallic acid, epicatechingallate and procyanidin dimers. Storage of Formulations observed, Stability & rheological parameters determined. Olive oil used as a permeability enhancer. Presence of the highest oleic acid content (65-86%) in Olive oil, skin permeability within the stratum corneum was enhanced hence better transdermal skin absorption. Using two-way ANOVA, and T-test, efficacy of formulations and impact on slowing down skin aging by countering exogenous factors of oxidative stress determined. Non-invasive biophysical technique showed emulgel substantially reduced roughness, scaliness, winkles, and sebum content by 55%, 26 %, 23.9% and 30.3% respectively enhancing elasticity and hydration by 50% and 32.2% respectively. Emulsion reduced roughness, scaliness, winkles and sebum content 14%, 13%, 21% and 26.13% respectively enhancing elasticity and hydration 45.3% and 29.85% respectively. The formulations significantly offset exogenous factors of aging and impact on free radicals and oxidative stress and may be safe to incorporate bio-active botanical antioxidants for evaluation of derma cosmetic benefits in management of dehydrated and aged facial skin.
... The antimicrobial activity of AgNPs relies upon the size and state of the nanoparticles. Finer particles having the bigger surface area accessible for connection, which will give more bactericidal impact than the bigger particles and since they effectively, enter the cell membrane [22,[52][53][54][55]. It was noticed that Streptomyces rochei produced relatively monodispersed AgNPs due to the presence of single low molecular weight protein in its extracellular environment. ...
Article
Full-text available
Background Bio-nanotechnology is considered as one of the low-cost approaches that have been utilized in production of nanomaterials. The current research aimed at investigating the influence of different types of Actinomycete strains on the final properties of silver nanoparticles (AgNPs) such as size, shape, polydispersity, and antibacterial properties. For this purpose, the following techniques were employed UV spectrophotometer, SDS-PAGE electrophoresis, TEM, FTIR, antibacterial agar diffusion test, and Zetasizer. Results It was found that among 34 Streptomyces isolates collected from the soil, Streptomyces spiralis and Streptomyces rochei were able to reduce silver nitrate into sliver nanoparticles. The diversity and molecular weights of extracellular proteins secreted by these stains were different as proved by SDS-PAGE technique. This consequently resulted in differences in polydispersity of AgNPs which indicate that the sizes of AgNPs were highly dependent on the amount, molecular sizes, and diversity of extracellular matrix proteins of the microorganism. Conclusion This article might give an insight about the importance of molecular sizes of biomacromolecules such as proteins on the physical properties of biogenic synthesized nanoparticles.
... Nevertheless, a 100 % eradication of bacterial colonies was observed against neither of the two bacteria. Several other studies also report a stronger anti-Listerial action of GSE (Perumalla and Hettiarachchy, 2011). ...
Article
Bioactive pectin/pullulan (PEC/PUL) binary blend film combined with Vitis vinifera grape seed extract (GSE) was fabricated. GSE was compatible with PEC/PUL polymer matrix to form a dense film structure with increased mechanical strength. The GSE-containing film offered some antimicrobial activity against E. coli and L. monocytogenes by delaying bacterial growth. Also, the GSE-added film exhibited antioxidant potential because of the free radical scavenging ability of polyphenolic compounds in the extract. The PEC/PUL/GSE films had significant UV blocking properties imparted by pectin and GSE along with the high gas barrier provided by pullulan. Raw and roasted peanuts (Arachis hypogaea) coated with PEC/PUL/GSE film had a 75 % reduction in the peroxide values than uncoated peanuts after 30 days under ambient conditions. The edible coating of PEC/ PUL/GSE film had an excellent ability to prolong the shelf life of stored peanuts by delaying rancidity.
... The results of the study show that increasing the addition of the extract caused a decrease in the value of parameter L and an increase in the value of coordinate a*, indicating a decrease in brightness and an increase in the redness of the analysed sample compared to the control sample. This relationship may result from the increasing content of polyphenols in the samples (Perumalla & Hettiarachchy, 2011). Rubilar et al. (2013) noted that grape seed extract added to chitosan films also reduced their brightness and increased their redness. ...
Article
Full-text available
Biodegradable materials and byproducts from fruit processing have great potential to improve food quality. Chitosan films as natural biopolymers can serve as carriers of active compounds such as polyphenols to provide their sustained release to food during storage and may protect them from oxidation or spoilage. This study assesses the usefulness of the application of chokeberry pomace extracts in the development of innovative biopolymer chitosan films with increased antioxidant properties. Active food packaging films based on chitosan with the addition of fraction 2 isolated on a LiChroprep RP-18 column from chokeberry pomace extract were developed. The effects of fraction 2 incorporation at different levels on the physical and chemical properties of chitosan films were investigated. The chitosan films with extracts showed better antioxidant properties than the control sample. The chokeberry extracts enhanced both the UV–vis light barrier and water vapour barrier properties of chitosan films and reduced their oxygen permeability.
... (3) S. enteritidis; (4) S. Typhimurium; (5) E.coli; and (6) Campylobacter jejun [116,117]. In this respect, cinnamaldehyde (CAL) or (2E)-3-phenyl prop-2-enal (55-76%) isolated from cinnamon trees, camphor, and cassia showed excellent antibacterial and antifungal activity [118][119][120]. ...
Article
Full-text available
Edible polymers such as polysaccharides, proteins, and lipids are biodegradable and biocompatible materials applied as a thin layer to the surface of food or inside the package. They enhance food quality by prolonging its shelf-life and avoiding the deterioration phenomena caused by oxidation, humidity, and microbial activity. In order to improve the biopolymer performance, antimicrobial agents and plasticizers are also included in the formulation of the main compounds utilized for edible coating packages. Secondary natural compounds (SC) are molecules not essential for growth produced by some plants, fungi, and microorganisms. SC derived from plants and fungi have attracted much attention in the food packaging industry because of their natural antimicrobial and antioxidant activities and their effect on the biofilm’s mechanical properties. The antimicrobial and antioxidant activities inhibit pathogenic microorganism growth and protect food from oxidation. Furthermore, based on the biopolymer and SC used in the formulation, their specific mass ratio, the peculiar physical interaction occurring between their functional groups, and the experimental procedure adopted for edible coating preparation, the final properties as mechanical resistance and gas barrier properties can be opportunely modulated. This review summarizes the investigations on the antimicrobial, mechanical, and barrier properties of the secondary natural compounds employed in edible biopolymer-based systems used for food packaging materials.
... Standardized grape seed extracts consist of 74-78% proanthocyanidins and less than 6% of free flavonol monomers related to the dry weight basis, which can subsequently bind to Gallic acid and form esters, then glycosides [110,111]. Other phenolic compounds which are presented in grape seeds, are the precursors of phenolic acid (gallic acid) and stilbenes [112]. Rodríguez Montealegre et al. [113] reported that Gallic acid in grape seed extracts (Vitis vinifera L.) was found in a proportion of 6.8-9.8 mg/kg and protocatechuic acid had values between 3.3 and 8.7 mg/kg. ...
Article
Full-text available
Grape pomace is one of the most abundant solid by-products generated during winemaking. A lot of products, such as ethanol, tartrates, citric acid, grape seed oil, hydrocolloids, bioactive compounds and dietary fiber are recovered from grape pomace. Grape pomace represents a major interest in the field of fiber extraction, especially pectin, as an alternative source to conventional ones, such as apple pomace and citrus peels, from which pectin is obtained by acid extraction and precipitation using alcohols. Understanding the structural and functional components of grape pomace will significantly aid in developing efficient extraction of pectin from unconventional sources. In recent years, natural biodegradable polymers, like pectin has invoked a big interest due to versatile properties and diverse applications in food industry and other fields. Thus, pectin extraction from grape pomace could afford a new reason for the decrease of environmental pollution and waste generation. This paper briefly describes the structure and composition of grape pomace of different varieties for the utilization of grape pomace as a source of pectin in food industry.
... Vitis vinifera (grape) extract as an active ingredient has been explored and validated as an effective antimicrobial and antiplaque agent. A few studies have also expressed that there is decreased collagen degradation by inhibitory interstitial and extracellular collagenase and they could have the potentiality to reduce the origin of several periodontal diseases and their progression [10]. Therefore we designed a study to evaluate the antimicrobial efficacy of 2% grape seed extract mouthwash (GSE) and 0.2% chlorhexidine mouth wash (CHX) with distilled water as control, followed by a short-term clinical trial to investigate the effectiveness of the mouthwash onto gingival index (GI), simplified -oral hygiene index (OHI-S), plaque index (PI) and bleeding on probing (BOP). ...
Article
Full-text available
Background: Grape seed extract contains Proanthocyanin, which reduces collagen degradation by inhibiting interstitial and extracellular collagenase, thus having the potential to reduce the progression of periodontitis. Here we compare and evaluate the aerobic and anaerobic microorganism's CFUs (colony forming units) in plaque samples of Group A, Group B, Group C and severity of periodontal disease on day 0 and 7. Methods: Forty-five subjects in age range 18-30 years were selected among undergraduate students and randomly divided into Group A: 15, 2% grape seed extract mouthwash (GSE), Group B: 15, 0.2% chlorhexidine mouthwash (CHX) and Group C: 15, distilled water (control). The supragingival plaque was collected into transport media. Kruskal Wallis test followed by Mann Whitney test was used to compare the mean CFUs (×103) of microorganisms and severity of periodontal disease was compared, by clinical parameters among all groups on day 0 and 7. Results: There was a significant difference concerning mean scores of all clinical parameters (P<0.001) and mean CFUs of microorganisms between 3 study groups (P=0.005) at 7 days post-intervention period. Intragroup comparison, mean scores were significantly reduced on day 7 as compared to day 0 at (P<0.001) in Group A and B, but no significant difference was noted with Group C. Conclusion: Intervention with GSE mouthwash showed a positive effect on reducing CFUs in the plaque when compared with the control group. GSE group also showed similar results in reducing CFUs in plaque when compared to CHX group, thereby demonstrating the agent's antimicrobial efficacy, therapeutic effect and its potential usefulness in controlling plaque and periodontal diseases.
... Different from the analytical methods of total tea polyphenols, the simultaneous determination of individual tea polyphenols puts forward higher requirements for sample pretreatment and instrumental separation and analysis. Due to the complexity of the tea matrix, the extraction, purification, and separation of individual tea polyphenols are difficult [58,59]. High-throughput and high-sensitivity qualitative and quantitative analyses of individual tea polyphenols usually requires relatively sophisticated and expensive analytical instruments. ...
Article
Full-text available
Polyphenols, the most abundant components in tea, determine the quality and health function of tea. The analysis of polyphenols in tea is a topic of increasing interest. However, the complexity of the tea matrix, the wide variety of teas, and the difference in determination purposes puts forward higher requirements for the detection of tea polyphenols. Many efforts have been made to provide a highly sensitive and selective analytical method for the determination and characterization of tea polyphenols. In order to provide new insight for the further development of polyphenols in tea, in the present review we summarize the recent literature for the detection of tea polyphenols from the perspectives of determining total polyphenols and individual polyphenols in tea. There are a variety of methods for the analysis of total tea polyphenols, which range from the traditional titration method, to the widely used spectrophotometry based on the color reaction of Folin–Ciocalteu, and then to the current electrochemical sensor for rapid on-site detection. Additionally, the application of improved liquid chromatography (LC) and high-resolution mass spectrometry (HRMS) were emphasized for the simultaneous determination of multiple polyphenols and the identification of novel polyphenols. Finally, a brief outline of future development trends are discussed.
... In all treatments, the amount of TBA increased over time (P < 0.05). Perumalla and Hettiarachchy [44] showed that essential oil reduces the amount of TBA in samples by various mechanisms such as preventing the onset of radical formation, and reducing the transfer of metal ion catalysts, as well as peroxide decomposition and reaction with free radicals [45]. TBA level is about 1-2 mgMDA/Kg in fish fillets, which is the starting point for an unpleasant odor. ...
Article
Full-text available
The present study was aimed to evaluate the efficacy of carboxymethyl cellulose (CMC; 1.25 g)/Persian gum (PG; 0.65 g) bionanocomposite films containing titanium dioxide nanoparticles (TiO2; 0.5% w/w) and fennel essential oil (FEO; 2% w/v) in preserving the chemical, microbial and sensory properties of rainbow trout fillets during the storage (0, 3, 6, 9 and 12 days) at 4 ± 1 °C. The lowest values for the minimum inhibitory concentration (8 mg/mL) and the minimum bactericidal concentration (10 mg/mL), and the highest diameter of the inhibitory zone in the disc diffusion (19 mm) for CMC/PG/FEO/TiO2 were observed against Listeria monocytogenes. Moreover, as a microbiological analysis, total viable count (3.01–6.74 log CFU/g), Pseudomonas spp. (3.02–4.86 log CFU/g), lactic acid bacteria (2.02–4.23 log CFU/g), Enterobacteriaceae (2.12–3.99 log CFU/g), and psychrotrophic bacteria (3.42–6.74 log CFU/g) were determined on the rainbow trout fillets covered with different treatments during the storage. Treatments containing FEO and TiO2 had a significant effect on the growth control in the studied bacteria (P < 0.05) and prevented the increase of pH. The amount of thiobarbituric acid (0.13 mgMDA/Kg) increased over time in all treatments, but it was lower in the FEO (0.5 mgMDA/Kg) treatment. Sensory scores of the samples were very high until day 6. In general, the results of this study showed that the use of FEO and TiO2 in the biodegradable films improves the antimicrobial, chemical, and sensory properties of the rainbow trout fillets.
... To overcome this problem, various organic solvents are used for dissolving or delivering these active compounds. However, those organic solvents may affect the biological assessment and application [14]. AGO is immiscible with water and it requires a potential system for water-miscible enhancement. ...
Article
Full-text available
The anesthetic effect of Alpinia galanga oil (AGO) has been reported. However, knowledge of its pathway in mammals is limited. In the present study, the binding of AGO and its key compounds, methyl eugenol, 1,8-cineole, and 4-allylphenyl acetate, to gamma-aminobutyric acid type A (GABAA) receptors in rat cortical membranes, was investigated using a [3H]muscimol binding assay and an in silico modeling platform. The results showed that only AGO and methyl eugenol displayed a positive modulation at the highest concentrations, whereas 1,8-cineole and 4-allylphenyl acetate were inactive. The result of AGO correlated well to the amount of methyl eugenol in AGO. Computational docking and dynamics simulations into the GABAA receptor complex model (PDB: 6X3T) showed the stable structure of the GABAA receptor–methyl eugenol complex with the lowest binding energy of −22.16 kcal/mol. This result shows that the anesthetic activity of AGO and methyl eugenol in mammals is associated with GABAA receptor modulation. An oil-in-water nanoemulsion containing 20% w/w AGO (NE-AGO) was formulated. NE-AGO showed a significant increase in specific [3H]muscimol binding, to 179% of the control, with an EC50 of 391 µg/mL. Intracellular studies show that normal human cells are highly tolerant to AGO and the nanoemulsion, indicating that NE-AGO may be useful for human anesthesia.
... Accordingly, due to its strong antioxidant properties, researchers have proposed including green tea as an ingredient in food [6]. Lante and Dario (2013) [7] studied the oxidative stability of the nanoemulsion of the green tea polyphenols comparison in the result; the oxidative stability is made by the colza oil and not by emulsion. ...
... Both phenolic acids and flavonoids were produced for different function such as colours, favours and defense mechanism [28,29]. In this work, monoflavonoids; catechin (0.10 mg/g) and epicatechin (0.19 mg/g) were found in low contents comparing to other plants [30]. Moreover, a flavonol myricetin (1.92 mg/g) and flavonol glycoside; rutin (0.15 mg/g) generally found in low content [31] as like as obtaining result in this work. ...
Article
Full-text available
The objectives of this work are to quantify the phenolic compounds in the extract of wine production residues using high performance liquid chromatography (HPLC) and its antibacterial activity. The results indicated that gallic acid and quercetin are the highest contents for phenolic acid and flavonoid, respectively. The extract showed efficiency against 12 bacterial strains which have more potency on Salmonella typhi (DMST 16122), Staphylococcus aureus (ATCC 25293) and Bacillus cereus (ATCC 11778). The concentration for inhibition (MIC) and bactericidal (MBC) of the extract on selected bacterial was in range of 500-250 μg/mL. This suggested that the wild grape residues from wine production composed of different phenolic substances, which could be used for inhibition of many bacteria.
... The researchers have also reported that the black cumin seeds possess antibacterial activities against multi-drug resistant bacteria [11,12] .The past research has revealed that the essential oils of spices have antimicrobial activity against food borne pathogens [13]. They also show antimicrobial and antioxidant activities [14,15,16]. The constituents of medicinal plants, herb and spices have been shown to possess antimicrobial activity and act as a source of antimicrobial agents against food pathogens [17]. ...
... Flavonoids have been reported as the highest contents [45]. The catechin and epicatechin have been reported as the main flavonoids in plants [46]. These substances were applied for cancer therapy [47]. ...
Article
Full-text available
Crude ethanolic extracts of four cultivars of sugarcane (Saccharum officinarum L.) were firstly prepared and then fractionated using silica gel column chromatography before the determination of their oxidative substances. The fractionated extracts were then tested for antioxidant activity by various assays. Finally, high-performance liquid chromatography (HPLC) was applied for the quantitative determination of the individual phenolic compounds. Sub-fraction 2 has the highest phytochemical contents as well as antioxidant activity. All tested phytochemicals had positively correlated to antioxidant activity. HPLC analysis showed that the phytochemicals in the fractionated extracts varied by the sugarcane cultivars. The main flavonoid substances found in the fractionated extracts were epicatechin, catechin, quercetin, resveratrol, myricetin and rutin while gallic acid was the main phenolic substance. The obtained information is useful for further studies and applications.
Preprint
Full-text available
Anesthetic activity of Alpinia galanga oil (AGO) has been reported however the mechanism of action in mammals has not been clear. In the present study, the binding effects of AGO and its three active components to gamma-aminobutyric acid type A (GABAA) receptor in cortical membranes of Sprague-Dawley rats were firstly investigated using a [3H]muscimol binding assay. Dimethyl sulfoxide (DMSO) was used to deliver these test samples. The results showed that only AGO and methyl eugenol displayed positive modulation at the highest concentration whereas 1,8-cineole and 4-allylphenyl acetate were inactive. An oil-in-water nanoemulsion containing 20%w/w AGO (NE-AGO) was formulated to deliver AGO instead of DMSO. This NE-AGO significantly enhanced a specific [3H]muscimol binding to 179% of the control with EC50 of 391 µg/mL. The result correlates well to the amount of methyl eugenol in AGO. This result confirms that the anesthetic activity of AGO and methyl eugenol is associated with GABAA receptor modulation, while that of 1,8-cineole and 4-allylphenyl acetate is not and may instead be related to other mechanisms. AGO showed well-tolerated by human cells. Therefore, the formulated NE-AGO might be a promising alternative anesthetic product for humans.
Conference Paper
Full-text available
Tea is the most consumed beverage in the world -after water- due to its pleasant sensory characteristics, cultural characteristics and health benefits. Tea plant (Camellia sinensis L) belongs to the genus Camellia in the family Theaceae which is a perennial and an evergreen suburb. It is worth to mention that the different types of tea are obtained according to the processing method of the fresh leaves and buds of tea plant. The chemical composition of green tea- which is manufactured by preventing oxidation of phenolic compounds- is very complex. Green tea and its extracts contain a wide variety of bioactive compounds including polyphenols, flavones, phenolic acids, amino acids, alkaloids, carbohydrates, minerals, vitamins and enzymes. Tea is a rich source of phenolic compounds compared to other foods. Green tea contains various polyphenolic compounds which have antioxidant activities. However, the most abundant polyphenols in green tea are catechins, which make up 25-35% of the dry weight of green tea leaves. Among these, epigalocatechin-3-gallate is the most examined due to its bioactive properties and functional value. Numerous researches focused on the health effects of green tea due to its content of biologically active compounds compared to the other tea types. Many studies in the resent years have reported that green tea and its extracts have antiproliferative, antimutagenic, antioxidant, antibacterial, antiviral, antiaging and cholesterol lowering effects. In addition it may actually help in the prevention of cardiovascular, cancer, diabetes, parkinson, alzheimer and other chronic diseases. In this review, production methods, chemical composition and health benefit of green tea have been summarized.
Article
In this study, poly(ε-caprolactone) (PCL)/gelatin (GEL) electrospun nanofibers loaded with two different concentrations of Pinus radiata bark extracts (PEs) were fabricated via electrospinning for wound healing applications. The effects of incorporating PE into PCL/GEL electrospun nanofibers were investigated regarding their physicochemical properties and in vitro biocompatibility. All electrospun nanofibers showed smooth, uniform, and bead-free surfaces. Their functional groups were detected by ATR-FTIR spectroscopy, and their total phenol content was measured by a Folin–Ciocalteu assay. With PE addition, the electrospun nanofibers exhibited an increase in their wettability and degradation rates over time and a decrease in their tensile stress values from 20 ± 4 to 8 ± 2 MPa for PCL/GEL and PCL/GEL/0.36%PE samples, respectively. PE was also released from the fibrous mats in a rather controlled fashion. The PCL/GEL/0.18%PE and PCL/GEL/0.36%PE electrospun nanofibers inhibited bacterial activity at around 6 ± 0.1% and 23 ± 0.3% against E. coli and 14 ± 0.1% and 18 ± 0.2% against S. aureus after 24 h incubation, respectively. In vitro cell studies showed that PE-loaded electrospun nanofibers enhanced HaCaT cell growth, attachment, and proliferation, favoring cell migration towards the scratch area in the wound healing assay and allowing a complete wound closure after 72 h treatment. These findings suggested that PE-loaded electrospun nanofibers are promising materials for antibiotic-free dressings for wound healing applications.
Article
Plant growth can be influenced by the application of triazole pesticides as these regulate physiological processes such as plant hormonal levels and enzyme activity. Homology modeling and molecular docking studies suggested that inhibition of ADP-glucose pyrophosphorylase activity in two trans-stereoisomers treatments hinders starch accumulation during the grain filling stage. A field experiment investigated the effects of metconazole racemate, cis-1R,5S-stereostereoisomer, and cis-1S,5R-stereoisomer application at the flowering stage on wheat grain ripening and yield. The concentrations of racemate and both cis-stereoisomers were detected in wheat plant and grain samples. Compared with the racemate, both cis-stereoisomers were more persistent in the matrices. Treatment with cis-1R,5S-stereoisomer decreased grain weight and yield of wheat by delaying chlorophyll degradation, increasing the ethylene content, and decreasing the level of abscisic acid. The germination of harvested seeds was adversely affected by racemate treatment as a result of gibberellin and abscisic acid metabolism regulation and the transcription of signaling-related genes. Therefore, cis-1S,5R-stereoisomer was recommended to be used as metconazole pesticide at the flowering stage.
Chapter
Each year a large amount of agro-industrial by-products are generated as a result of the processing of agricultural materials. These products have been generally used as animal feeds. However, they are rich in fiber, protein, minerals, especially bioactive components such as fatty acid, phenolic components, antioxidant and antimicrobial substances. Numerous scientific researches have been reported regarding the production of antimicrobial and antioxidant products from agro-industrial by-products such as rice bran, wheat germ, rice husk, vegetable peels, fruit seeds, and essential oils from the peel and seeds of various plants. Nowadays, novel strategies have been developed to evaluate by-products generated annually by agro-industrial processing. Nanotechnology is one of the most promising methods to evaluate the bioactive components of by-products. Nanotechnology offers many advantages compared to conventional methods. Nanoscale materials enable an expanded surface area providing more contact areas with food. Also, nanotechnology offers solutions to technological challenges by creating systems that are more resistant to external and internal factors such as heat, light, oxygen, enzymes, etc. This chapter focuses on the antimicrobial, antioxidant properties of cereal/grain, fruit, and vegetable by-products, and the productions and application of different bioactive components obtained from agro-industrial by-products with nanotechnological methods. Two different perspectives are evaluated in the chapter. Firstly; the importance, antioxidant, antimicrobial properties, and the utilization of by-products in different food systems are given, secondly; formulation, the potential usage, and the applications of bioactive nanomaterials obtained from agro-industrial by-products are presented.
Article
On global scale, researchers and industries are investing considerable effort to find suitable green alternative by switching to bioplastic that may help in reducing the negative impact on our environment. Among various plant derived polymers, soy protein isolate (SPI) is garnering much attention owing to its inherent biodegradable nature and fair film forming abilities. However, SPI based edible films face certain challenges like poor mechanical strength, relatively less gas barrier, high water uptake, negligible antimicrobial resistance and weak antioxidizing activity. To overcome these challenges, phenolic acids (caffeic acid, gallic acid and ferulic acid), flavonoids (rutin, catechin and epicatechin) and polyphenolic extract (grape seed, licorice, green tea), obtained from renewable sources, are incorporated in SPI. Plant derived phenols and polyphenolic compounds are widely investigated as promisable additive due to their therapeutic values and biocompatible nature. Food and non-food based polyphenolic compound impart light to dark brown film coloration with better mechanical properties. Polyphenols incorporated SPI film shows considerable antibacterial property against food borne pathogens like Listeria monocytogenes and Salmonella species. Furthermore, polyphenolic compounds are exclusively recognized for their anticancer properties via modulation of several pathways involved in cancer progression and apoptosis. This review is primarily focused on material characterization, antimicrobial, antioxidant properties and biodegradation behavior of several natural polyphenols incorporated SPI films.
Article
Nowadays, the food industry is focused on improving the shelf life of products by controlling lipid oxidation using natural antioxidants. The study of natural antioxidants is a field that attracts great interest because of their greater safety compared to synthetic ones. Plant-derived antioxidants being eco-friendly and effective are increasingly playing an important role in food preservation. When incorporated into active packaging, plant-derived antioxidants have no direct contact with foods, and will not change the colour or taste of the foods. They will, however, inhibit the development of rancidity, retard formation of toxic oxidation products, maintain nutritional quality, and prolong the shelf life of products. This review summarises research on the development of plant-derived antioxidants in food packaging. Antioxidants are found in plants such as green tea, olive leaves, ginkgo leaves, rosemary, Indian gooseberry, cinnamon, savoury, bay leaves, mango leaves, sage and clove etc. Antioxidants can scavenge free radicals and inhibit the activity of polyphenol oxidase. Therefore, they can inhibit lipid oxidation and browning of fruit and vegetables. These active substances can be obtained through extracting the plants using solvents with different polarities. The oxidation resistance of active substances can be determined by DPPH radical scavenging capacity, oxygen radical absorbance capacity, PPO enzyme inhibition capacity and other methods. In recent years, research on the preparation of food packaging with plant-derived antioxidants has also made significant progress. One development is to encapsulate plant-derived antioxidants such as tea polyphenols with capsules containing inorganic components. Thus, they can be blended with polyethylene granules and processed into active packaging film by industrial production methods such as melting, extrusion and blowing film. This research promotes the commercial application of active packaging incorporated with plant-derived antioxidants.
Article
Objective Tea polyphenols are natural extracts used widely throughout the world. However, the severe astringency of tea polyphenols has reduced patient compliance. Based on the analysis of the formation mechanism of astringency, this paper hopes to propose a new method to control the astringency of tea polyphenols and improve patient compliance without changing its effect. Methods Artificial saliva was used to prepare the tea polyphenols solution with different pH, using β-casein to imitate salivary protein, and preparing 1.2 mg/mL β-casein solution. A fluorescence quenching test was used to study the interaction between tea polyphenols and β-casein, combined with the stability test results of the compound, we can choose the pH with weak binding but good stability as the best pH for masking astringency. The taste-masking tablets were prepared under the best pH conditions, and the Xinnaojian Original Tablets were prepared according to the conventional preparation method. The disintegration time limit and solubility were tested respectively. The astringency of Xinnaojian original tablets and taste-masking tablets was evaluated by visual analogue scale (VAS). Results The result of the fluorescence quenching test prompted that the combination force was the weakest when the pH was 4.9. Further synchronous fluorescence analysis showed that an increase in pH resulted in a decrease of the binding sites between tea polyphenols and β-casein, and this decrease was closely related to changes in tryptophan residues in β-casein. Both original and taste-masking Xinnaojian Tablets were prepared. Volunteers’ VAS scores illustrated that the astringency improved significantly with the masking tablets (P < 0.05). Conclusion This pH-adjusting masking treatment had little effect on the recovery of polyphenols from the tablets or the dissolution of the tablets. This study provides a novel and feasible astringency masking technology for tea polyphenols and its preparation.
Article
Edible coatings based on grape juice and cross-linked maize starch enriched with grape seed extract (GSE: 0.5–1.5%) were examined for the effects of the quality properties of strawberries during storage at 4 °C for 12 days. Coating applications reduced the water loss, pH changes, and microbiological counts of strawberries significantly (p < 0.05). The increased amount of GSE in the coating formulation caused a significant decrease in microbial counts and limited the firmness loss. On the final day of storage, coated strawberry samples with solutions containing grape juice and 1.5% GSE had the lowest (p ≤ 0.05) TMAB counts (2.75 ± 0.05 log CFU g⁻¹) and yeast/mold counts (2.88 ± 0.03 log CFU g⁻¹), respectively. Over time, there was a decrease in lightness value and an increase in the redness value of strawberries. These changes were significantly lower (p < 0.05) in strawberries covered with GSE enriched coatings. Also, GSE added coatings preserved ascorbic acid, total anthocyanin, total phenolic content, and antioxidant capacity of strawberries during storage. On the other hand, it was observed that the acceptability value of strawberries coated with high amounts of GSE coating was lower than other coated and uncoated samples. Results showed that coating strawberries with grape derivatives and cross-linked starch can be extend the shelf life of fresh fruit.
Article
Vibrio parahaemolyticus (V. parahaemolyticus) is a common marine foodborne pathogen that causes gastroenteritis. With the long‐term use of antibiotics, many bacteria become resistant strains, therefore, developing antibiotic‐free antimicrobial strategies is urgent. Epigallocatechin gallate (EGCG) as the abundant constituent of polyphenols in tea extract has broad‐spectrum antibacterial activity and non‐toxicity. Here, we took advantage of EGCG to evaluate its inhibition effect on the growth of V. parahaemolyticus 17802 and the biofilm formation, and explore its antibacterial mechanism. It was found that EGCG showed antibacterial activity to V. parahaemolyticus 17802, and the minimum inhibitory concentration (MIC) is 128 μg mL‐1, crystal violet staining and confocal laser scanning microscope (CLSM) evidenced EGCG hindered its biofilm formation. Moreover, the swimming motility and extracellular polysaccharides were also notably inhibited. The antibacterial mechanism was further confirmed by several assays, such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), live/dead staining assay, together with membrane permeability assay, which all suggested that EGCG caused damage to cell membrane and made it lose integrity, eventually resulting in the death of V. parahaemolyticus 17802. The bactericidal activity of EGCG verified its potential as a promising candidate to combat foodborne pathogen.
Chapter
There has been a growing interest in functional bakery products with enhanced health benefits, especially the prevention of some chronic diseases such as type 2 diabetes, cardiovascular diseases and neurodegenerative disorders. Fortification of wheat flour with phytochemicals, plant components with various bio-activities, is one of the promising approaches to improving public health with the ubiquitous consumption of baked goods. This chapter reviews the current knowledge of several representative phytochemicals, mainly plant polyphenols, including catechins, anthocyanins, fucoidan and quercetin extracted from various plant resources, and their application in bakery products, regarding their stability, impact on product quality and potential health benefits.
Article
Migration of glycerol and red grape extract (RGE) components from bioactive soybean protein concentrate (SPC) films into aqueous and fatty food simulants was performed as a function of temperature. GC-MS and HPLC methods were applied to quantify the amount of glycerol and RGE individual components migrated into the simulants. Overall migration (OM) in fatty simulant was below the limit imposed by the legislation of 10 mg/dm². RGE components migrated preferentially to the fatty simulant due to the structural complexity and solubility of the migrant. Contrarily, glycerol was released at higher extent and rate into aqueous medium, due to its inherent hydrophilic nature. Migration process was described by Fick’s diffusion second law, and the apparent diffusion coefficient (Dapp) was derived from an analytical solution. Dapp values ranged from 1.5 10–14 to 1.6 10–13 cm² s–1 under different conditions. The efficiency of SPC films was tested on steam cooked mackerel chunks during storage 4±1 ºC for 21 days. Antioxidant activity of films decayed upon storage but both kept more that 50 % of their initial radical scavenging activity after 21 d. SPC-RGE film delayed the maximum oxidation by 3 d compared to the control and samples packed in SPC film, more likely due to the lower oxygen permeability and higher radical scavenging activity of SPC- RGE film. Findings suggested that films based on SPC containing RGE can be considered as potential sustainable active food packaging material.
Article
Pathogenic bacteria in food cause a considerable number of diseases of global concern with a serious impact on the human health and the economy of a country. In order to ensure microbial food safety, several preservatives are used in foods. The undesirable side effects of these chemical preservatives on human well-being have increased the consumers demand for employing compounds from natural sources as biopreservatives. As plant-based antimicrobials are generally considered to be safe several food companies have focused on the utilization of these compounds in foods to meet consumer demands. Several researchers are tirelessly working to isolate and identify plant compounds with antibacterial activity against foodborne bacteria which can be effectively used in food matrices. Moreover, the use of plant antimicrobials in foods is challenging due to their interaction with the food constituents that can decrease their activity. To tackle this problem, various new approaches and technologies have come up wherein plant antimicrobials could be used in foods. This review highlights the potential antibacterials from plants used against foodborne pathogens and the effect of various food processing techniques on the activity of plant antimicrobials. Further, it discusses several methods adopted to incorporate plant biopreservatives into the food system. Although a number of studies have demonstrated the potential of using plant derived antimicrobials as preservatives in foods, more investigations are required to optimize the quantities to be used in food matrices to be effectively used as antimicrobials without influencing the organoleptic properties of foods.
Preprint
Full-text available
Today, the use of biodegradable packaging containing antimicrobial agents has been approved by the people and industry. In this study, the effect of carboxymethyl cellulose (CMC) film optimized with Persian gum (PG) containing titanium dioxide nanoparticles (TiO 2 ) and fennel essential oil (FEO) was inspected and the sensory, chemical, and microbial properties were evaluated on refrigerated rainbow trout fillets during the storage period (0, 3, 6, 9, and 12 days). The lowest values for the minimum inhibitory concentration (MIC) (8 mg/mL) and the minimum bactericidal concentration (MBC) (10 mg/mL), and the highest diameter of the inhibitory zone in the disk diffusion (19 mm) for FEO were observed against Listeria monocytogenes , Escherichia coli .O157:H7, Pseudomonas fluorescens , and Shewanella putrefaciens , respectively. Moreover, as a microbiological analysis, total viable count (TVC), Pseudomonas spp , lactic acid bacteria (LAB), Enterobacteriaceae , and psychrotrophic bacteria were determined on rainbow trout fillets covered with different treatments (CMC/PG, CMC/PG/FEO, CMC/PG/TiO 2 , and CMC/PG/FEO/TiO 2 ) during the storage at 4°C. The results showed that three treatments of CMC/PG/FEO, CMC/PG/TiO 2 , and CMC/PG/FEO/TiO 2 had a significant effect on growth control in the studied bacteria ( P <0.05). In all treatments, the amount of thiobarbituric acid increased over time, but in the treatment containing FEO, this amount was lower. Sensory scores of the samples were very high until day 6. In general, the results of this study showed that the use of FEO and TiO 2 in biodegradable films improves the antimicrobial, chemical, and sensory properties of rainbow trout fillets.
Article
This study was conducted to evaluate the effect of red‐wine grape pomaces on the quality and sensory attributes of beef hamburger patties. Both phenolic content and antioxidant activity were assessed using Syrah, Merlot and Cabernet Sauvignon pomaces. Following the assessment, hamburger patties were prepared with Merlot pomace at 0%, 2% and 4% for the patty quality and sensory attributes. Grape seeds possessed significantly higher phenolics and antioxidant activities over the seedless pomace (P < 0.05), whereas no significant difference was found for phenolics and antioxidant activities within the seeds and seedless pomaces. The patty pH decreased as the pomace was added for 2% and 4%. Colour values (L*, a* and b*) of patties lowered as the pomace was added. Allo‐Kramer shear force and hardness values increased while cooking yield decreased (P < 0.05) with the addition of pomace. No significant difference between control and Merlot patties was found for flavour, juiciness and colour, whereas lower sensory attributes were observed for texture, taste and overall acceptability. It is observed that the addition of fermented red‐wine grape pomace provides hamburger patties with health promoting factors such as antioxidant and other functional components, but it also provided darker, sourer and lower cooking yield. Grape pomace and seed were pulverized using liquid nitrogen. The powder of grape pomace/seed possessed high levels of phenol contents and radical scavenging activities. Allo‐Kramer shear force and hardness values increased with the addition of grape pomace while cooking yield decreased. No significant difference between the control and Merlot patties was found for flavor, juiciness, and color, whereas lower sensory attributes were observed for texture, taste, and overall acceptability.
Article
This study aimed to investigate melanosis, quality attributes, and bacterial growth of freeze-chilled Pacific white shrimp (Litopenaeus vannamei) during 6 days of chilled storage, as well as the preservative effects of tea polyphenol on shrimp. The results showed that freeze-chilled storage retarded the growth of bacteria and the accumulation of putrescine in shrimp. The growth of spoilage bacteria Photobacterium and Shewanella were inhibited. However, freeze-chilled storage aggravated melanosis and lipid oxidation. The total volatile basic nitrogen (TVB-N) slightly accumulated in the thawed shrimp. The incorporation of tea polyphenol preserved freeze-chilled shrimp. Melanosis and lipid oxidation of shrimp were alleviated. The accumulation of biogenic amines, TVB-N, hypoxanthine riboside, and hypoxanthine were retarded. Meanwhile, the growth of spoilage bacteria Pseudoalteromonas, Photobacterium, Psychrobacter, and Carnobacterium were inhibited. Based on sensory analysis, the shelf-life of chilled, freeze-chilled, and freeze-chilled tea polyphenol shrimp were 4 days, 3 days, and 6 days, respectively.
Article
Current consumption trends indicate a clear increased interest in more natural, nutritious and healthier foods. Accordingly, natural fruits and vegetables (F&V) based beverages (juices, smoothies) companies showed great growth, since perceived as a practical way of ingesting the F&V nutrients and bioactives. However, when untreated, these products have a short shelf-life, mainly due to microbial spoilage. The combination of natural antimicrobials for their preservation constitutes an option in line with consumers’ requirements. This study aims to evaluate different combinations of natural antimicrobials, nisin, natamycin, green tea extract (GTE) and citric acid, to preserve the quality of a mixed F&V smoothie, extending their shelf-life and ensuring their safety. The results obtained suggest that a treatment with nisin 12.5 mg/kg natamycin 200 mg/kg and citric acid (until pH 3.5) could achieve a shelf-life extension of 14 d, a product with great nutritional and microbiological quality until 28 d of storage at 5 °C. Moreover, this treatment would allow controlling a 6 log CFU/mL Listeria monocytogenes contamination. Furthermore, if GTE (0.2%) is added to that combination, a product with fortified antioxidant properties (more than 10 times higher than control) is achieved, fulfilling the requirements of the most demanding natural products consumers.
Article
Full-text available
The antibacterial activity of the methanol and aqueous extract of Camellia sinensis on Listeria monocytogenes were investigated using agar-gel diffusion, paper disk diffusion and microbroth dilution techniques. The results obtained showed that methanol and water extract exhibited antibacterial activities against L. monocytogenes. The leaf extract produced inhibition zone ranging from 10.0 - 20.1 mm against the test bacteria. The methanol extracts of the test plant produces larger zones of inhibition against the bacteria than the water extract. The minimum inhibitory concentration (MIC) for the methanol and water leaf extract was 0.26 and 0.68 mg/ml, respectively.
Article
Full-text available
In the present study, twelve different types of commercial tea samples were assayed to determine their phenolic composition and antioxidant activity. Reverse phase high performance liquid chromatography using a binary gradient system was used for the identification and quantification of individual catechins. Subsequently, total phenolic content was determined spectrophotometrically according to the Folin-ciocalteus method. Total theaflavins and thearubigins were also determined. The radical scavenging behavior of the polyphenols on 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) was also studied spectrophotometrically. The results showed that total polyphenols, total catechins and antioxidant activity were significantly (P<0.05) different in the commercial tea samples. Green tea had the highest levels of catechins, total polyphenols and total antioxidant activity. White tea (silvery tip) a rare specialty type of tea was not significantly different from green tea. Statistical analysis showed an essential catechin content influence of the tea extracts on antioxidant activity. Epigallocatechin gallate (EGCG) was the most potent catechin and the most potent in antioxidant activity (r = 0.989***). Epigallocatechin (EGC) (r = 0.787, P<0.001), epicatechin (EC) + catechin (+C) and epicatechigallate (ECG) also showed significant (P<0.05) antioxidant activity. Black tea contained high levels of theaflavins and thearubigins, which accounted for most of the antioxidant potential in this type of tea product (r = 0.930*** and r = 0.930*** respectively). These results suggest that conversion of catechins during black tea processing did not affect the free-radical potency of black tea. Gallic acid (GA) also showed significant(r = 0.530*) contribution to the antioxidant activity in black tea. Green, black and white tea products processed from Kenyan tea cultivars originally selected for black tea had significantly (P<0.05) higher antioxidant activity than green tea processed from tea cultivars from Japan and China. These results seem to suggest that the cultivar type is critical in determining the antioxidant potency of tea product and that black teas processed from suitable cultivars could be potent in antioxidant activity when compared to green teas.
Article
Full-text available
The aim of this research was to determine in vitro the antibacterial, antioxidant and tanning activity from grape by-products (Vitis vinifera), for its use as alternative ingredients in the poultry industry and food conservation. Polar compound had been extracted of the defatted grape seed (SUD) in a solution with acetone, water and acetic acid, in the 90: 9.5: 0.5 ratio respectively, resulting in a yield of 10.3% of defatted grape seed extract (ESUD). ESUD has high antibacterial activity against strains of S. aureus and E. coli, but not against Salmonella sp. The antioxidant activities of the ESUD had comparable to the ascorbic acid. The capacity to bind proteins was considered low for the seed and high for the ESUD.
Article
Full-text available
Grape seeds are considered rich sources of polyphenolic compounds that show antioxidant or antimicrobial effects. The aim of the present work was to investigate the effect of a grape seed extract (GSE) on two oral anaerobes closely associated with periodontal diseases and its antioxidant action. The antimicrobial activity was determined using the macro dilution broth technique and also tested on a multi-species biofilm grown on saliva-coated hydroxyapatite discs. The evaluation of antioxidant activity was based on the capacity of a sample to scavenge the ABTS radical cation as compared to a standard antioxidant (Trolox). GSE had a bacteriostatic effect on the anaerobes. At a concentration of 2000 μg/ml, it significantly decreased the formation of biofilm. High TEAC values were registered and this extract exhibited greater antioxidant capacity than vitamins C and E. These findings indicated that GSE could be used in oral hygiene for the prevention of periodontitis.
Article
Full-text available
Phenolic compounds commonly occurring in fruits, vegetables and tea were studied for their effects on Listeria monocytogenes (L.m.), Escherichia coli O157:H7 (E.c.) and Salmonella Typhimurium (S.T.) in brain–heart infusion broth (BHI) and meat system. Incubated at 37C for 72 h in BHI, gentistic, benzoic and vanillic acids inhibited L.m., E.c and S.T. at 5,000 µg/mL by 2.8 to 3.0 log CFU/mL, 2.8 to 3.0 log CFU/mL and 2.7 to 2.9 log CFU/mL, respectively. Encapsulation of benzoic acid (1,100 µg/mL) in polylactic-co-glycolic acid nanoparticles inhibited 6.5 log CFU/mL of L.m. and S.T., and 6.0 log CFU/mL of E.c. at 48 h. In raw and cooked chicken meat systems, nanoparticle delivery of benzoic acid was effective against S.T. and L.m. (1.0 and 1.6 log CFU/g reduction of S.T. and 1.1 and 3.2 log CFU/g reduction of L.m. compared with 1.2 log CFU/g without nanoparticles on the days 9 and 14 of storage, respectively). These findings demonstrate the efficacy of phenolics on pathogen reduction delivered by nanoparticles and their potential for commercial food safety applications. Nanotechnology is an emerging and promising technology that has been advocated for the delivery of antimicrobial phenolic compound extracts to effectively inhibit foodborne pathogens. The method improves the rate of inhibition compared with conventional delivery and retains the antimicrobial efficacy for a longer time. This hurdle technology using natural antimicrobials (phenolic compounds) and nanoparticle-mediated delivery system can effectively decontaminate foodborne pathogens and improve food safety. Phenolic compounds can be used as natural and safer alternatives to chemical disinfectants in food systems and delivered using nanoparticles to better control pathogens for commercial food safety applications.
Article
Full-text available
O objetivo neste trabalho foi determinar-se in vitro a atividade antibacteriana, antioxidante e tanante de subprodutos da uva (Vitis vinifera) para seu aproveitamento como ingredientes alternativos na indústria avícola e na conservação de alimentos. Compostos polares foram extraídos da semente de uva desengordurada, em solução contendo acetona, água e ácido acético, resultando em 10,3% de rendimento de extrato de semente de uva desengordurada (ESUD). O ESUD apresentou alta atividade antibacteriana in vitro contra cepas de S. aureus e E. coli, mas não contra cepas de Salmonella sp. A atividade antioxidante do ESUD foi comparável ao ácido ascórbico. A atividade tanante foi considerada baixa para a semente de uva e alta para o ESUD.The aim of this research was to determine in vitro the antibacterial, antioxidant and tanning activity from grape by-products (Vitis vinifera), for its use as alternative ingredients in the poultry industry and food conservation. Polar compound had been extracted of the defatted grape seed (SUD) in a solution with acetone, water and acetic acid, in the 90: 9.5: 0.5 ratio respectively, resulting in a yield of 10.3% of defatted grape seed extract (ESUD). ESUD has high antibacterial activity against strains of S. aureus and E. coli, but not against Salmonella sp. The antioxidant activities of the ESUD had comparable to the ascorbic acid. The capacity to bind proteins was considered low for the seed and high for the ESUD.
Article
Full-text available
The “antioxidant power” of a food is an expression of its capability both to defend the human organism from the action of the free radicals and to prevent degenerative disorders deriving from persistent oxidative stress. Purpose of this study is to analyse the antioxidant capacity (measured by means of the crocin bleaching method) of several samples of Sicilian red wines and to evaluate their dependency on the vintage and on the grape variety. Finally, the correlation between the single flavonoids compounds and the antioxidant capacity has been investigated. The analyses show that the antioxidant properties of red wine appear to be unequally influenced by the vintages for the different cultivars and that the correlation between antioxidant capacity and the total phenolic contents is weak. The latter can be explained by the fact that the wine’s antioxidant properties are influenced differently by each polyphenolic molecule.
Article
Full-text available
Antioxidant capacity and antimicrobial activities of Laetiporus sulphureus (Bull.) Murrill. extracts obtained with ethanol were investigated in this study. The study was aimed at determining the antioxidant activity (DPPH free radical-scavenging, β-carotene/linoleic acid systems), total phenolic content and total flavonoid concentration of L. sulphureus. Inhibition values both of L. sulphureus ethanol and the standards increased parallel with the elevation of concentration in the linoleic acid system. Inhibition values of L. sulphureus (LS) extract, BHA and α-tocopherol standards were found to be 82.2%, 96.4% and 98.6%, respectively, at a concentration of 160μg/ml. DPPH free radical-scavenging activity was found to exhibit 14%, 26%, 55% and 86% inhibition, respectively, at concentrations of 100, 200, 400 and 800μg/ml. Total flavanoids were 14.2±0.12μgmg−1 (quercetin equivalent) while the phenolics were 63.8±0.25μg mg−1 (pyrocatechol equivalent) in the extract. Positive correlations were found between total phenolic content in the mushroom extracts and their antioxidant activities. Edible mushrooms may have potential as natural antioxidants. L. sulphureus showed narrow antibacterial activity against Gram-negative bacteria and strongly inhibited the growth of the Gram-positive bacteria tested. The crude extract exhibited high anticandidal activity on Candida albicans. Therefore, the extracts could be suitable as antimicrobial and antioxidative agents in the food industry.
Article
Full-text available
“Drinking several cups of green tea a day keeps the doctor away” is clearly an overstatement. However, extensive research has revealed that the predominant catechin from tea (Camellia sinensis), epigallocatechin gallate (EGCg), has significant medicinal and health-promoting properties. This review summarizes what is presently known about the antimicrobial properties of EGCg, with a particular focus on the synergistic relationship between EGCg and β-lactams in the inhibition of methicillin-resistant Staphylococcus aureus (MRSA). The mechanisms of action and prospects for use of tea catechins such as EGCg as an anti-infective agent are discussed.
Article
Full-text available
Flavonoids, commonly occurring antioxidants in foods, have been compared in a dose-response manner with vitamins C and E and beta-carotene and found to be powerful antioxidants using an in vitro lipoprotein oxidation model. This model simulates the oxidation of low-density lipoproteins, which results in atherosclerosis. Of the flavonoids and flavonoid-related compounds, flavonols found in tea are the most powerful natural antioxidants. These results provide a mechanism for the beneficial epidemiological effect of dietary flavonoids on heart disease.
Book
Since publication of the first edition in 1971, Fenaroli's Handbook of Flavor Ingredients has remained the standard reference for flavor ingredients throughout the world. Each subsequent edition has listed more flavor ingredients and allied substances, including those conferred food additive status, substances generally recognized as safe (GRAS) by qualified scientists (including the Flavor and Extract Manufacturers' Association Expert Panel) and those substances having undergone GRAS Notification with the Food and Drug Administration (FDA). New in the Sixth Edition 200+ newly approved flavor ingredients Ingredient's safety standing with the Flavor and Extract Manufacturers' Association and/or the FDA Extensive and expanded information on aroma and taste thresholds Updated regulatory information on each flavor ingredient New discussion on botanical substances that serve as flavoring ingredients The fourth and fifth editions added more than 300 new entries and represented a total reorganization and updating of the text, consistent with new data and regulations. This, the sixth edition, is likewise expanded with over 200 new entries, including many botanicals and other natural substances. The addition of botanicals is a response to an expanded readership with an interest in dietary supplements, in which a number of flavoring botanicals serve a dual role.
Article
Inhibition of Clostridium botulinum (strains A, B, and E) growth and toxin production by various concentrations of origanum oil and sodium nitrite was studied for both TYG broth and a model meat system. At concentrations of 100 and 200 ppm, origanum oil was effective in inhibiting C. botulinum growth in TYG broth. In addition, origanum oil acted synergistically with sodium nitrite in inhibiting C. botulinum growth in TYG broth. The inhibitory effect of origanum oil in the meat system was dramatically reduced and had a significant (p≤ 0.05) effect only when used at 400 ppm in combination with 50–100 ppm sodium nitrite.
Article
Overview, A.S. Naidu Lacto-Antimicrobials Lactoferrin. A.S. Naidu Lactoperoxidase, A.S. Naidu Lactoglobulins, E.F. Bostwick, J. Steijins, and S. Braun Lactolipids, M. Lampe and C. Isaacs Ovo-Antimicrobials Lysozymes, J.N. Losso, S. Nakai, and E.A. Charter Ovotransferrin, H.R. Ibrahim Ovoglobulin IgY, J.S. Sim, H.H. Sunwoo, and E.N. Lee Avidin, Y. Mine Phyto-Antimicrobials Phyto-phenols, P.M., Davidson and A.S. Naidu Saponins, W.A. Oleszek Flavonoids, A.S. Naidu, W.R. Bidlack, and A.T. Crecelius Thiosulfinates, B.B. Whitmore and A.S. Naidu Catechins, L.R. Juneja, T. Okubo, and P. Hung Glucosinolates, B.B. Whitmore and A.S. Naidu Agar, A.S. Naidu Bacto-Antimicrobials Probiotics, A.S. Naidu and R.A. Clemens Nisin, L.V. Thomas, M.R. Clarkson, and J. Delves-Broughton Pediocin, B. Ray and K. Miller Reuterin, M.G. El-Ziney, J. Debevere, and M.Jakobsen Sakacin, F. Leroy and L. De Vuyst Acid-Antimicrobials Lactic Acid, J-C. Bogeart and A.S. Naidu Sorbic Acid, J.N. Sofos Acetic Acid, D.L. Marshall, L.N. Cotton, and F.A. Bal'a Citric Acid, R.K. Sharma Milieu-Antimicrobials Sodium Chloride, R. Ravishankar and V.K. Juneja Polyphosphates, A. Prakash Chloro-cides, N. Khanna and A.S. Naidu Ozone, M. Muthukumarappin, F. Halaweish, and A.S. Naidu Appendix (Abbreviations and Symbols) Index
Article
The use of natural antioxidant systems as a viable approach to the reduction of oxidative deterioration and warmed-over flavor (WOF) development in meat products, is discussed. Lipid oxidation in meats prior to cooking essentially follows the well-established lipid autoxidation scheme and affects the flavor and color of meat products. Well-known endogenous antioxidant systems include tocopherols, carnosine, lipoic acid, and various enzymatic systems. Flavor and color considerations are also important and may limit the use of some natural antioxidants.
Article
Correct spelling of co-author's Kalab first name is Milos or Miloslav. The Chinese green tea extract was found to strongly inhibit the growth of major food-borne pathogens, Escherichia coli O157:H7, Salmonella Typhimurium DT104, Listeria monocytogenes, Staphylococcus aureus, and a diarrhoea food-poisoning pathogen Bacillus cereus, by 44–100% with the highest activity found against S. aureus and lowest against E. coli O157:H7. A bioassay-guided fractionation technique was used for identifying the principal active component. A simple and efficient reversed-phase high-speed counter-current chromatography (HSCCC) method was developed for the separation and purification of four bioactive polyphenol compounds, epicatechin gallate (ECG), epigallocatechin gallate (EGCG), epicatechin (EC), and caffeine (CN). The structures of these polyphenols were confirmed with mass spectrometry. Among the four compounds, ECG and EGCG were the most active, particularly EGCG against S. aureus. EGCG had the lowest MIC90 values against S. aureus (MSSA) (58 mg/L) and its methicilin-resistant S. aureus (MRSA) (37 mg/L). Scanning electron microscopy (SEM) studies showed that these two compounds altered bacterial cell morphology, which might have resulted from disturbed cell division. This study demonstrated a direct link between the antimicrobial activity of tea and its specific polyphenolic compositions. The activity of tea polyphenols, particularly EGCG on antibiotics-resistant strains of S. aureus, suggests that these compounds are potential natural alternatives for the control of bovine mastitis and food poisoning caused by S. aureus.
Article
Electrostatic forces have been applied during the spraying of a target to enhance energy efficiency, reduce resource input and environmental pollutant output, and improve overall product quality and economic competitiveness. This study was therefore undertaken to develop a prediction response surface methodology (RSM) model of an electrostatic spray system to maximize solution attachment on the target. A ball with a surface area of 77.3 cm 2 was used as a model to simulate a spherical food sample. Results indicated that the cross-products of height decrement and distance from the target to the sprayer nozzle were the most significant contributing factors for solution attachment to the front and back sides of the target, respectively. Multiple regression yielded models to predict solution attachment as functions of the contributing factors studied (air pressure from 138 to 276 kPa, distance from 80 to 120 cm, and height decrement from 10 to 20 cm) with coefficients of determination (R 2) of 0.69 and 0.75 for the front and back sides of the target, respectively. Within the range of parameters tested, the response predictive model suggested that 7 s of electrostatic spraying with parameter values of 276 kPa air pressure, 100 cm distance, and 10 cm height decrement using a 1.50 mm disk orifice would achieve the most efficient solution attachment to the target. Verification studies on tomatoes and apples supported the findings that electrostatic charge enhanced spray efficiency and uniformity. This study may hence provide guidelines for the development of effective spray applications, such as sanitizing or watering target food materials. © 2007 American Society of Agricultural and Biological Engineers.
Article
Theoretical analysis of droplet charging by electrostatic induction in a cylindrical-electrode field is developed into a mathematical model for spray-charging nozzle design. Experimental analysis of a miniature embedded-electrode charger incorporated into a pneumatic-atomizing nozzle is presented as a function of operational variables.
Article
We found that (-)-epigallocatechin gallate (EGCG), the main constituent of green tea and green tea extract, the lyophilized form of green tea infusion, inhibited both activation of protein kinase C and tumor promotion on mouse skin: The results led us to suggest green tea as a cancer preventive for humans. Inhibition of chemical carcinogenesis in rodents, inhibition of cell growth and induction of apoptosis on human cancer cell lines, organ distribution of 3H-EGCG in mice, multifunctional actions, and the synergistic cancer preventive activity of green tea with sulindac were studied. All our results show that green tea is a promising beverage for the purpose of cancer prevention in humans.
Article
A methanol extract from grape seeds showed a potent antibacterial activity against Echerichia coli. Salmonella enteritidis, and Staphylococcus aureus. A responsible compound was isolated from the extract to be identified as gallic acid by instrumental analysis. Structure-activity correlation assays revealed that three hydroxyl groups of the compound were effective for antibacterial activity against E. coli and S. enteritidis and all of the substituents of the benzene ring were effective against S. aureus. Minimal inhibitory concentration of gallic acid against E. coli and S. enteritidis was 0.5 mM and that against S. aureus was 0.3 mM. Ethanol- and salt-containing foods cooperatively acted on the antibacterial activity of gallic acid.
Article
緑茶より抽出精製したカテキン類の口臭抑制効果を判定するため,CH3SHに対する消臭力,及び唾液にカテキン類を添加し,L-Metと共にインキュベート後発生したCH3SHを定量し,そのCH3SH産生抑制効果を測定した.また,カテキン類を添加したチューインガムを試作し,そのCH3SH産生抑制効果を判定した結果,以下の結論を得た.(1) カテキン類は強いCH3SH消臭力を有し,この効果は,従来より口腔内消臭剤として汎用されているSCCの効果をかなり上回るものであった.(2) 緑茶に含まれる4種のカテキンについて消臭力の測定を行った結果,その効果は,EC<ECg<ECG<EGCgの順に優れており,構造と消臭効果との相関関係が示唆された.(3) 唾液にカテキン類を添加し,これを24時間インキュベートした結果,L-Metを基質としたCH3SHの発生はコントロールと比較して,著しく抑制された.また,この効果はSCCの効果よりも強かった.(4) カテキン類を添加したチューインガムを試作し,唾液のCH3SH発生量を指標として,その口臭抑制効果について評価を行った結果,カテキン0.01%添加ガム咀嚼後においても,CH3SH発生は顕著に抑制された.以上のことからカテキン類は,口臭原因物質として注目されているCH3SHに対し,優れた消臭作用とその産生を抑制する作用を持つものと推定された.また,カテキン類を添加したチューインガムは,口臭抑制の目的で効果的であると考えられた.
Article
Cited By (since 1996):2, Export Date: 18 October 2014
Chapter
Grape seed extract components exhibit a wide range of biological effects as modifiers of inflammation and modulators of various enzyme systems. Potential benefits demonstrated in experimental studies include endothelium-dependent relaxation, impact on inflammatory mediator (cytokine) release by cells and on the oxidation of LDL-cholesterol, effects on platelet aggregation and on nitric oxide metabolism. A very large amount of in vitro data exists, but well-controlled animal studies employing physiological and subphysiological concentrations of GSE are fewer. Moreover, the effects noted do not necessarily predict human results because of differences in bacterial and hepatic metabolism among species. Data from human intervention trials are relatively scant. Furthermore, little is known about the absorption, bioavailability, and bioactivity of GSE associated flavanol oligomers and polymers because of difficulties associated with their reliable quantification in physiological fluids. The small number of adequately controlled human studies generally indicates that sufficient absorption takes place to accomplish transitory changes in the antioxidative capacity of plasma in humans and to afford cellular protection, even though the identification of the metabolites is elusive. However, none of these studies has adequately considered long-term effects. No clear picture has emerged regarding the appearance of catechin monomers or procyanidin dimers in the plasma of human subjects following GSE ingestion. Metabolites arising through bacterial biotransformation by ring fission may have their own unique pharmacologic effects deemed to be beneficial for health. More well-controlled in vivo and clinical studies are needed to extend the application of these compounds outside the realm of scientific research per se.
Chapter
Grape seed extract (GSE) refers to mixtures of catechin monomers, procyanidin oligomers, and procyanidin polymers extracted from Vitis vinifera seeds. These bioactive components are reducing agents and hydrogen- donating antioxidants. Their intrinsic properties are due to the polyphenolic nature. They exert diverse biologic effects in vitro at pharmacologic concentrations and seem to critically influence and modulate cell function, cell activation, cell signal transduction, endothelium-dependent vasodilation, vascular reactivity, inflammatory cascades, immune function, cellular and humoral immunity, cell survival, carcinogenesis, etc., in experimental situations—actions that may be relevant to their potential roles in the prevention of chronic disorders, amelioration of diseases, and maintenance of homeostasis. Grape seed extract also seems to exert a number of specific health-supportive actions clinically. Grape seed extract components exhibit a wide range of biological effects as modifiers of inflammation and modulators of various enzyme systems. Potential benefits demonstrated in experimental studies include endothelium-dependent relaxation, impact on inflammatory mediator (cytokine) release by cells and on the oxidation of LDL-cholesterol, effects on platelet aggregation and on nitric oxide metabolism. A very large amount of in vitro data exists, but well-controlled animal studies employing physiological and subphysiological concentrations of GSE are fewer. Moreover, the effects noted do not necessarily predict human results because of differences in bacterial and hepatic metabolism among species. Data from human intervention trials are relatively scant. Furthermore, little is known about the absorption, bioavailability, and bioactivity of GSE associated flavanol oligomers and polymers because of difficulties associated with their reliable quantification in physiological fluids. The small number of adequately controlled human studies generally indicates that sufficient absorption takes place to accomplish transitory changes in the antioxidative capacity of plasma in humans and to afford cellular protection, even though the identification of the metabolites is elusive. However, none of these studies has adequately considered long-term effects. No clear picture has emerged regarding the appearance of catechin monomers or procyanidin dimers in the plasma of human subjects following GSE ingestion. Metabolites arising through bacterial biotransformation by ring fission may have their own unique pharmacologic effects deemed to be beneficial for health. More well-controlled in vivo and clinical studies are needed to extend the application of these compounds outside the realm of scientific research per se.
Article
The fungus Monilinia vaccinii-corymbosi infects blueberry flowers via the stigma-style ovary pathway to cause mummy berry disease. Previous laboratory experiments documented considerable activity of stigma-applied biofungicides containing the bacteria Bacillus subtilis and, to a lesser extent, Pseudomonas fluorescens against flower infection by the pathogen. However, adequate and targeted delivery of the biocontrol agents to the stigmatic surfaces of open flowers in the field has remained problematic. Here we consider the application of the biofungicides Serenade AS (containing B. subtilis QST713) and BlightBan A506 (containing P. fluorescens A506) to blueberry flowers by air-assisted electrostatic spraying. In laboratory experiments with typical field-use rates, viability of B. subtilis and P. fluorescens was unaffected by different levels of induction-charging voltage (0–1.2 kV) and atomizing pressure (138–276 kPa) applied to an electrostatic spray-charging nozzle, showing that the bacteria in both formulations readily survived exposure to the intense electrical fields and near-sonic atomizing air shear encountered during electrostatic spraying. Electrostatically charged application significantly (P
Article
The antioxidative effect of red grape seed (RGS) and red grape peel (RGP) ethanolic extracts on primary and secondary lipid oxidation in sunflower and conjugated sunflower (SF/CSF) oils was evaluated. Lipid oxidation was analysed at 60°C using three methods; conjugated diene (CD) measurements for primary oxidation product development, static headspace gas chromatography (SHGC), and proton transfer reaction-mass spectrometry (PTR-MS) to follow the formation of secondary lipid oxidation products (propanal, 1-penten-3-one, hexanal and octanal).The phenolic content (200mg/kg) in extracts did not have any effect on the conjugated diene hydroperoxides. After 6 days, high antioxidative effect was found for the secondary oxidation products in CSF for peel extract followed by seed extract. The antioxidative activity for the peel extract was up to 41.2% for propanal measured by PTR as compared with 17.1% for seed extract. On the other hand, at 6 days the peel and seed extracts were shown to expect prooxidative effect on SF for the secondary oxidation products. It has been noticed that SF has high stability for lipid oxidation among all the mixtures tested using the three determination methods. Obviously, PTR-MS succeeded, as an accurate method, to measure the concentration as low as 10μg/kg, and also to solve the solvent interference.
Article
Two procyanidin fractions, namely oligomers and polymers isolated from grape seed methanolic extract were characterized. Phenolic composition and procyanidin purity of these fractions were determined by normal-phase and reverse-phase HPLC, thioacidolysis-HPLC, ESI-MS analyses, formaldehyde-HCl precipitation and elemental analysis. Antioxidant activities of these fractions and other well-known antioxidants were measured using xanthine-xanthine oxidase system for generating superoxide radical ({O2(-)}), the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical method and the Fenton system for generating hydroxyl radical (HO). The results showed that both oligomeric and polymeric procyanidin fractions were highly pure, with the degree of polymerization ranging from 2 to 17-18 and 12 to 32-37, respectively. On the basis of molar concentration, polymeric procyanidins appeared the highest antioxidant activities, followed by oligomeric procyanidins, whereas catechins presented a lower antioxidant activity than its oligomers and polymers. These results indicate that the antioxidant activities of grape seed procyanidins are positively related to their degree of polymerization. Moreover, grape seed procyanidins presented higher antioxidant activities than other well-known antioxidants such as vitamin C, suggesting that grape seed procyanidins might be of interest to be used as alternative antioxidants. Copyright © 2007 Elsevier Ltd. All rights reserved.
Article
Incorporation of bioactive compounds–such as vitamins, probiotics, bioactive peptides, and antioxidants etc.–into food systems provide a simple way to develop novel functional foods that may have physiological benefits or reduce the risks of diseases. As a vital macronutrient in food, proteins possess unique functional properties including their ability to form gels and emulsions, which allow them to be an ideal material for the encapsulation of bioactive compounds. Based on the knowledge of protein physical–chemistry properties, this review describes the potential role of food proteins as substrate for the development of nutraceutical delivery systems in the form of hydrogel, micro-, or nano- particles. Applications of these food protein matrices to protect and delivery-sensitive nutraceutical compounds are illustrated, and the impacts of particle size on release properties are emphasized.
Article
The effects of phenolic compounds on glucan synthase, a membrane-bound enzyme from red beet root, were examined. Different classes of phenolic compounds were screened in the absence and presence of polyphenoloxidase (PPO). At levels less than 1 mM, inactivation occurred with many of the compounds tested. However, in most cases oxidation by PPO was required. Coumarin, previously demonstrated to interfere with cell wall polysaccharide biosynthesis, was not inhibitory. Mechanistic studies utilizing catechol showed that phenolic inactivation could be protected against by PPO inhibitors and thiol protective reagents. However, once inactivation occurred, it could not be reversed. Ommission of thiols and polyvinylpyrolidone from homogenization buffers did not reduce glucan synthase levels of microsomal preparations. It appears that glucan synthase, a membrane-bound enzyme, is as susceptible to phenolic effects as cytosolic enzymes and in situ inactivation is a function of the availability of both endogenous phenolics and PPO.
Article
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.
Article
Efficiency of four concentrations of grape seed extract (0.0, 0.4, 0.8, and 1.6g/kg) in retarding oxidative rancidity was tested with cooked turkey breast meat. Development in lipid oxidation during 13 days of refrigerated storage was evaluated by means of thiobarbituric acid-reactive substances (TBARS) and volatile compound formation. Hexanal, pentanal, octanal, 2-octenal, 1-octen-3-ol, 2-octen-1-ol, and 1-penten-3-ol showed high correlations (r>0.95) with TBARS values and could, therefore, serve as markers for the oxidation process in the cooked turkey breast meat. Supplementation of grape seed extract prior to cooking significantly improved oxidative stability of minced turkey meat during heat treatment and storage. The ability of grape seed extract to prevent lipid oxidation was concentration-dependent. Vacuum-packaging considerably improved oxidative stability of meat regardless of the low concentration of grape seed extract used. It appears that grape seed extract could be very effective in inhibiting lipid oxidation of cooked turkey meat during chill-storage.
Article
The influence of pH and sodium chloride (NaCl) on survival and growth of Listeria monocytogenes in carrot juice was determined. Lethal and inhibitory effect over a 48-h period were greatest in a pH range of 5.0 to 6.4. The order of lethality and inhibition was 10% > 1% > 100% > 0.1 % juice concentrations and increased as the incubation temperature was reduced from 20 to 12°C, and again from 12 to 5°C. At concentrations up to 5%, NaCl protected against inactivation of L. monocytogenes in carrot juice. This effect was most pronounced in 10% juice incubated at 5 or 12°C. Populations of naturally occurring aerobic mesophiles in carrot juice were generally unaffected by pH or NaCl content. The effectiveness of carrot juice as an antilisterial ingredient in food has yet to be determined.