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Direct evaluation of the total antioxidant capacity of raw and roasted pulses, nuts and seeds
Abstract
Pulses, nuts and seeds represent an important part of human diet in many countries and epidemiological studies associated
their consumption with many health benefits. These foods are often consumed after roasting that may destroy some bioactive
compounds, but it can also form antioxidant compounds through the Maillard reaction. In this paper, a direct procedure for
the extraction-independent measurement of the total antioxidant capacity named QUENCHER was applied to raw and roasted pulses,
nuts and seeds. The results highlighted a high value of total antioxidant capacity (TAC) for some raw seed and pulses showing
marked inter-varietal differences among beans examined. TAC value measured by QUENCHER was generally higher than that found
using multiple extraction procedure. The effect of roasting on the TAC is the result of the thermal degradation of naturally
occurring antioxidant compounds and the formation of new Maillard reaction products having antioxidant activity. In most of
the foods studied, the final balance was negative with a substantial loss of antioxidant activity upon roasting. The main
driver of the final TAC is the presence of reactants: in rich-starch materials, such as chickpea, cashew and borlotti beans,
roasting is accompanied by a progressive increase in TAC, which is likely related with the formation of antioxidant Maillard
reaction products.
... Spada, Zerbeto et al. (2017) reported that roasting time and temperature were important factors that influenced the total phenolic content (TPC) and antioxidant activities of jackfruit seeds. Açar, Gökmen et al. (2009) found that the antioxidant activities of hazelnut, peanut and sunflower seeds decreased when roasting time was less than 30 min, and significantly increased thereafter reaching a maximum value at 60 min. The initial decrease was attributed to the reduction of antioxidant compounds, while the increase with longer roasting time was due to the generation of antioxidant products during the Maillard reaction, especially in starch-rich materials. ...
... This increase may be associated with the release of bound antioxidant components or the formation of higher antioxidant activity compounds (Lin et al., 2016). The increase in antioxidant capacity with longer roasting time was likely related to the formation of antioxidant Maillard reaction products, especially in starch-rich materials (Açar et al., 2009). Santos et al. (2016) reported that avocado seeds are rich in starch (42.2%). ...
... ). The initial decrease may be due to the reduction of antioxidant polyphenols, and the later increase may be related to the liberation of bound antioxidant polyphenols with higher roasting temperatures.Açar, Gökmen et al. (2009) further demonstrated that increased roasting time at 150°C increased total antioxidant capacity (TEAC) values significantly for most pulses (borlotti bean, black bean, giant lentils, chickpea, yellow soybean), cashew nut and pine nut that reached a maximum level at the end of 60 min of roasting. The authors suggested that the increase i ...
Avocado by-products present a waste issue for cold-pressed avocado oil processors in New Zealand. The avocado seed contains many extractable compounds that are beneficial to health. This work aims to evaluate the effects of roasting fermented avocado seed to produce a food ingredient with beneficial antioxidant and anticancer properties. Avocado seeds were subjected to natural fermentation and inoculated fermentation with either Lactobacillus plantarum or kefir. The fermented samples were evaluated in terms of total plate count values of lactic acid bacteria acetic acid bacteria and yeasts. The number of microorganisms increased significantly ( p < 0.001) over the 7 days of fermentation for all samples. Fermentation with L. plantarum resulted in significantly ( p < 0.05) higher total phenolic content (TPC) and antioxidant activities compared to kefir and naturally fermented samples. The fermented avocado seeds were further subjected to roasting to yield a shelf-stable dried powder. Roasted samples fermented by L. plantarum had significantly ( p < 0.001) higher total polyphenolic content and antioxidant capacity (CUPRAC and Ferric Reducing Antioxidant Power assays) compared to kefir and naturally fermented samples. The avocado seed powder showed the best inhibition effect on Hep G2 followed by the MDA-MB-231 and MCF-7 cancer cell lines. The roasting conditions for optimal antioxidant and anticancer activities were determined to be at 127°C for 24.7 min. This study demonstrated that fermentation of avocado seeds in combination with roasting yielded a powder with good antioxidant and anticancer activities, which can potentially be incorporated into food for added health benefits.
... However, the PR increased potentially this antiradical property by 11.03% (Table 4). A study on walnut, pistachio, almond, and peanut showed a reduction in total antioxidant activity upon roasting (150 ℃) ranging from 224.0 to 188.7, 48.7 to 28.2, 27.8 to 21.5 and 14.3 to 11.1 mmol Trolox/kg, respectively [61]. The variation among the observed values by other studies for DPPH-and ABTS activity in comparison to the present study might be due to differences in sample types and roasting methods. ...
... The variation among the observed values by other studies for DPPH-and ABTS activity in comparison to the present study might be due to differences in sample types and roasting methods. Ozge Acar et al. [61] roasted the samples in a hot air oven at different times-temperature combinations (at 150 °C for 10, 30, and 60 min), this could be also a reason for the variability. FRAP antioxidant assay analyzed for the chironji kernels showed a significant increase in MR processed samples with 44.66%, whereas PR treatment exhibited a decrease in FRAP activity by 14.50% (p < 0.05). ...
Chironji (Buchanania lanzan Spreng.) is a nut consumed in raw and roasted form in India and other parts of the world. It also contains high levels of oil and other nutrients similar to those found in commonly consumed nuts. However, no published data is available on the comprehensive nutritional profile, phytochemicals, and anti-nutrient factors of chironji. The present study is the first report to evaluate the effect of roasting (pan, microwave, hot air oven) of chironji kernels on the comprehensive nutritional profile, bioactive compounds, and anti-nutrients. The protein, fat, and total dietary fiber content of unprocessed (raw) and roasted chironji kernels ranged between 30.05 to 33.74, 55.94 to 60.60, and 3.38 to 3.54 g/100 g, respectively. Free sugars were significantly decreased by microwave roasting (MR) followed by Pan roasting (PR) and hot air oven roasting (HOR). Among the vitamins, B2, B3, B5 and B6 were decreased by 6.9–24.1%; 6.1–19.2%; 23.4–56.3%; and 15.3–23.7% upon MR, HOR and POR, respectively. The α, β and γ-tocopherols (TP) were also variably decreased depending on the roasting method. Roasting lowered the total carotenoids and β-carotene by 52.2% and 22.7%, respectively. Raw chironji kernels exhibited Fe, Ca, Cu and Zn of 7.17, 34.08, and 1.7 6.16 mg/100 g, respectively, that remained unaffected upon roasting. Total saturated, monounsaturated and polyunsaturated fatty acids were found to be 39, 55.2 and 5.8%, respectively, in raw chironji kernels; however, roasting did not change the fatty acid profile significantly. Catechin (6.74 mg/100 g) and rutin (3.61 mg/100 g) were observed to be the highest in raw chironji kernel and roasting significantly increased most of the individual polyphenols. Total phenolics and total flavonoids content were observed of 1150 mg GAE/100 g and 113.12 mg CE/100 g, respectively, in raw chironji kernels. The PR increased the DPPH- and ABTS- activities significantly. Overall, microwave roasting retained high levels of nutrients, but pan roasting improved the antioxidant potential of chironji kernels.
... The antioxidant capacity of almonds roasted for 20 min at 180 or 200°C is significantly higher than that of raw almonds (Lin et al., 2016). On the other hand, antioxidant compounds may be formed in foods through the Maillard reaction (Açar et al., 2009). The pistachio nuts contained 49.9%-58.5% oils and 35.2-47.9 ...
... Total phenol quantities of kernels of five pistachio cultivar changed between 135.710 (Owhadi) and 137.369 mgGAE g À1 (Akbari) (Taghizadeh et al., 2018). Some bioactive compounds may be destroyed by roasting hazelnuts (Açar et al., 2009). While the total phenol content of our raw Pistacia nut sample was found to be lower than the results of Kashaninejad et al. ...
In the present study, the effect of microwave roasting on the total phenolic quantities, antioxidant activities, phenolic constituents, fatty acids and tocopherol amounts of the pistachio kernel and oil was revealed. The moisture, oil, total phenolic amounts and antioxidant capacity value of raw and roasted pistachio nuts were assessed as 31.13%, 28.58%, 34.79 mgGAE/100 g and 0.75%–3.18%, 56.91%, 18.80 mgGAE/100 g and 2.26%, respectively. The raw pistachio nut contains 1.90 gallic acid, 0.22 3,4‐dihydroxybenzoic acid, 0.87 (+)‐catechin, 0.15 1,2‐dihydroxybenzene, 0.15 rutin trihydrate, 0.16 resveratrol, 0.1 quercetin, 0.19 kaempferol and 0.24 mg/100 g isorhamnetin. In addition, microwave‐roasted nuts contained 0.75 gallic acid, 0.62 3,4‐dihydroxybenzoic acid, 0.83 (+)‐catechin, 0.47 1,2‐dihydroxybenzene, 0.21 syringic acid, 0.17 caffeic acid and 0.17 mg/100 g quercetin. The raw and roasted pistachio nut oils contained 74.12% and 71.16% oleic, 13.76% and 15.23% linoleic, 8.16% and 8.92% palmitic and 2.09% and 2.10% stearic acids, respectively. The oil samples of the raw and roasted kernels contained 8.15 and 0.00 α‐tocopherol, 63.78 and 7.60 β‐tocopherol, 8.72 and 7.40 ɣ‐tocopherol and 5.61 and 6.77 mg g⁻¹ δ‐tocopherols, respectively. The total phenolic quantity of the pistachio kernel roasted by microwave decreased significantly. Phenolic compounds of the pistachio kernel showed partial differences depending on microwave heating. Differences were monitored in the fatty acid profiles of Pistachio kernel oils. β‐tocopherol quantity of the oil of the pistachio kernel heated by microwave significantly decreased.
... Similar trend was also observed in ABTS method (Fig. 2c). This trend agrees with the results reported by Açar et al. (2009) who compared the antioxidant capacities of commercially important treenuts. However, the values obtained in this study is generally higher than those reported by Açar et al. (2009). ...
... This trend agrees with the results reported by Açar et al. (2009) who compared the antioxidant capacities of commercially important treenuts. However, the values obtained in this study is generally higher than those reported by Açar et al. (2009). Again, the differences in phenolic contents and antioxidant capacities observed between the studies could be attributed to different harvesting locations, maturity levels, and seasons of the samples, and also possibly to different varieties of samples employed. ...
The aim of this study was to evaluate and compare the in vitro protein digestibility, phenolic contents, and antioxidant capacities of commercially important tree-nut species (almond, cashew, hazelnut, pistachio, and walnut). To evaluate the protein digestibility, upper gastrointestinal digestion was simulated in vitro in which tree-nuts were treated with pepsin and pancreatin. After the simulation, protein digestibility was calculated by measuring the remaining (undigestible) protein using Kjeltec nitrogen analyzer and by quantifying the primary amino acids formed through TNBS (2,4,6 trinitrobenzene sulfonic acid) method. Total phenolic contents and antioxidant capacities of tree-nuts were assessed spectrophotometrically. Our results revealed that that tree-nuts differ in their protein digestiblities in vitro. Based on the remaining protein calculations, cashew nut had the highest in vitro %protein digestibility (%91.79), followed by almond nut (%87.71), hazelnut (%86.10), pistachio nut (%81.15), and walnut (%44.75). TNBS results also partially agree with this that the lowest primary amino acid content after the digestion was found in walnut samples. The highest phenolic content was obtained in walnut (6.8 mg GAE/g), while cashew nut exhibited the lowest phenolic content (1.3 mg GAE/g). Both antioxidant capacity assays correlated with the total phenolic content; the samples possessing higher phenolic content revealed the higher antioxidant capacity. This study shows that in vitro protein digestibility, total phenolic contents, and antioxidant capacities of commercially important tree-nuts show variations from species to species, with walnut possessing the lowest protein digestibility, the highest phenolic content and antioxidant capacity, but the opposite was true for cashew nut.
... This increase may be associated with the release of bound antioxidant components or formation of higher antioxidant activity compounds (Lin et al., 2016). The increase in antioxidant capacity with longer roasting time was likely related to the formation of antioxidant Maillard reaction products, especially in the starch-rich materials (Açar et al., 2009). Santos et al. (2016) have reported that avocado seeds are rich in starch (42.2%). ...
... The authors attributed the initial decrease due to the reduction of antioxidant polyphenols, and the later increase was related to the liberation of bound antioxidant polyphenols with higher roasting temperature. Açar et al. (2009) further demonstrated that increased roasting time at 150 • C, increased total antioxidant capacity (TEAC) values significantly for most pulses (borlotti bean, black bean, giant lentils, chickpea, yellow soybean), cashew nut and pine nut that reached a maximum level at 60 min of roasting. The authors suggested that the increase in TEAC with longer roasting time was likely due to the release of bound antioxidant components and generation of new antioxidants through Maillard reactions, especially in the starch-rich materials. ...
Studies have demonstrated avocado seeds are a good source of bioactive compounds. This study investigated the effects of roasting on the metabolites and anticancer activities of fermented avocado seeds. All three anti-cancer activities of fermented avocado seeds were higher at lower roasting temperature and time. The best inhibition effect was found against Hep G2 followed by the MDA-MB-231 and MCF-7 cancer cell lines. Untargeted metabolite profiling using gas chromatography-mass spectrometry resulted in identification of 208 metabolites. In total, 41 metabolites identified had VIP values more than 1 using PLS-R that were related to anticancer activities. All amino acids and most sugars were higher at lower roasting temperature and positively correlated to anticancer activity. The roasting conditions for optimal antioxidant and anticancer activities were determined to be 121 °C for 9 min. Findings showed that fermented avocado seed powder has the potential to become a functional food ingredient with beneficial bioctive properties.
... Further, significant differences were observed among all different types of lentils (p < 0.05). This result parallels the findings from [62], in which beans with red or black pigmentation exhibited greater PMA concentrations. The amount of flavonol glycosides, anthocyanins, and condensed tannins (proanthocyanidins) determines the color of lentil seed coats [62]. ...
... This result parallels the findings from [62], in which beans with red or black pigmentation exhibited greater PMA concentrations. The amount of flavonol glycosides, anthocyanins, and condensed tannins (proanthocyanidins) determines the color of lentil seed coats [62]. ...
Background
Lentil (Lens culinaris M.) is a legume widely consumed worldwide. It is rich in bioactive compounds, including polyphenolic compounds that contribute to positive health benefits.
Methods
This study aimed to determine the phenolic content and antioxidant activity of black, red, green, and brown whole lentils. Towards this end, the lentils’ phenolic compounds were evaluated regarding their total phenolic content (TPC), total flavonoid content (TFC), total tannin content (TTC), total condensed tannin (TCT), total proanthocyanin content (TPAC), total anthocyanin content (TAC). For the antioxidant activity 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), 2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), hydroxyl radical scavenging activity (•OH-RSA), ferrous ion chelating activity (FICA), reducing power assay (RPA) and phosphomolybdate (PMA) assay were accessed. To identify individual phenolic compounds, liquid chromatography-electrospray ionization quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS²) was used.
Results
The results showed that green lentils exhibited the highest TPC (0.96 mg gallic acid equivalents (GAE)/g) whereas red lentils presented the highest TFC (0.06 mg quercetin equivalents (QE)/g). Black lentils were noted with the highest TCT (0.03 mg catechin equivalents (CE)/g), TPAC (0.009 mg cyanidin chloride equivalents (CCE)/g), and TAC (3.32 mg/100 g) contents. While the greatest TTC (2.05 mg tannic acid equivalents (TAE)/g) was observed in the brown lentil. Regarding the total antioxidant capacity, red lentils (4.01 mg ascorbic acid equivalents (AAE)/g) presented the greatest activity, whereas the lowest was found in the brown samples (2.31 mg AAE/g). The LC-ESI-QTOF-MS² tentatively identified a total of 22 phenolic compounds, containing 6 phenolic acids, 13 flavonoids, 2 lignans, and 1 other polyphenol. The relationships among phenolic compounds by Venn Diagram showed a high number of overlapping compounds in brown and red lentils (6.7%), and a low number of overlapping compounds between the green, brown, and black lentils (2.6%). Flavonoids were the most abundant phenolic compound within the studied whole lentils, with the brown lentils being the richest in phenolic compounds, especially flavonoids.
Conclusions
This study emphasized a comprehensive understanding of the antioxidant potential of lentils and disclosed the phenolic distribution across various lentil samples. This may increase interest in the development of functional food products, nutraceutical ingredients, and pharmaceutical applications with lentils.
... This flavor originates from the Maillard reaction products generated during food heating with high antioxidant activity. In various foods, such as sesame seeds, cashew nuts, and corn, the browning substances generated from the Maillard reaction are reportedly produced by roasting, with the antioxidant property increasing [11][12][13]. Thus, roasting is expected to improve the flavor and functionality of foods; the powderd form is easier to add to all kinds of dishes. ...
... Many studies concerning roasted beans have reported a high positive correlation between TPC and antioxidant capacity [19][20][21]. Moreover, a positive correlation between color changes due to non-enzymatic browning and TPC can be found in many foods, including beans [11,12]. Our data showed a robust relationship among the measured values. ...
The DPPH radical scavenging activity and ORAC value of soybeans (yellow soybean, blue soybean, and black soybean) were increased by roasting at above 190 °C. Concerning raw beans, black soybeans with the darkest seed coat color had the strongest antioxidant activity, indicating the effect of the coat pigment. However, the degree of increased antioxidant activity by roasting was almost similar regardless of seed coat color, suggesting that coat color is independent of the increased antioxidant activity. Concerning aged beans stored at 37 °C/75% RH for 60 days, the antioxidant activity increased in yellow soybean and decreased in blue and black soybean compared to before storage. Conversely, when roasted at 190 °C for 20 min, the DPPH values of all the aged beans were significantly increased. Other analyses of roasted beans with and without seed coat showed that changes in the components of cotyledons during storage may have contributed to the increased antioxidant activity of aged beans, regardless of seed coat color. These results revealed that roasting effectively improves the antioxidant activity of aged soybeans, regardless of seed coat color. We concluded that roasting is recommended for antioxidant properties, particularly regarding the effective use of aged beans.
... For example, roasted soybean flour (kinako) is known for its strong antioxidant activity, attributed to Maillard reaction products formed during roasting [3,6]. Roasting enhances the antioxidant capacity of various foods, including sesame seeds, nuts, and corn [7][8][9]. Based on this evidence, we hypothesized that roasting could improve the quality of hardened beans that have undergone prolonged storage under adverse conditions. In our previous study, we investigated the effects of storage and roasting on proteinrich soybeans with yellow, blue, and black seed coats stored under high-temperature and high-humidity conditions (30 • C, 75% RH) for 60 days. ...
This study examined the responses of four legumes—chickpeas (Cicer arietinum L.), red kidney beans (Phaseolus vulgaris L., Taishokintoki), adzuki beans (Vigna angularis), and peanuts (Arachis hypogaea)—to storage and roasting under high-temperature and high-humidity conditions (HTC beans). Roasting enhanced antioxidant activity in HTC chickpeas and peanuts, with chickpeas also showing increased resistant starch. In contrast, kidney beans showed reduced resistant starch after storage, with minimal recovery upon roasting, while refrigeration better preserved resistant starch. For adzuki beans, roasting reduced resistant starch in control samples but not in HTC samples. Reducing sugars decreased in all beans after roasting. These findings highlight roasting as a promising method for repurposing HTC chickpeas and peanuts for functional food applications. Limitations include variability among legumes and the need for further mechanistic and sensory studies.
... However, the contribution of higher protein content of CF combined with its health-promoting antioxidants would provide significant benefits to consumers of breads made from wheat flour and CF blends, as shown recently by Pivovarova-Ramich et al. (2020). A significant increase in TEAC during roasting of chickpea seeds has been reported by Acar, Gokmen, Pellegrini, and Fogliano (2009), mainly due to the generation of Maillard reaction products during the roasting process. Microwave cooking of chickpea seeds is reported not only to improve the nutritional quality (by reducing the antinutritional factors and improving digestibility) but also needs lower cooking time (Alajaji & El-Adawy, 2006;Bai et al., 2018). ...
Purpose
The major objective of this research work was to evaluate various physico-chemical characteristics, such as, chemical composition, antioxidant capacity, objective color and texture profile analysis (TPA) of the wheat flour/chickpea flour (CF) blends, so that nutritious baked products could be consumed by the type-2 diabetic persons.
Design/methodology/approach
Wholegrain wheat flour (WGF) and white wheat flour (WWF) were substituted with CF at 0 to 40% levels. These wheat flour/CF blends were analyzed for proximate composition, the prepared dough and baked breads were tested for objective color, antioxidant capacity as trolox equivalent antioxidant capacity (TEAC), malondialdehyde (MDA) and total phenolic content (TPC) and TPA.
Findings
WGF had the highest TEAC (117.42 mM/100g) value, followed by WWF (73.98 mM/100g) and CF (60.67 mM/100g). TEAC, MDA and TPC values varied significantly among all the three flour samples.
Research limitations/implications
Inclusion of whole chickpea (without dehulling) flour in such type of blends would be another interesting investigation during the future research studies.
Practical implications
These research findings have a great potential for the production of these baked products for human consumption on an industrial scale.
Social implications
Production of breads using wheat flour and CF blends would benefits the consumers.
Originality/value
Production of Arabic and pan breads using wheat flour and CF blends would, therefore, combine the benefits of both the needed proteins of plant origin and the health-promoting bioactive compounds, in a most sustainable way for the consumers.
... The total phenolic quantity of the material and the scavenging activity of DPPH decreased significantly as a result of the deterioration of the structure of phenolic constituents in boiled samples 42 . Although the roasting process may reduce some bioactive compounds in nuts, new antioxidant compounds can also be formed through the Maillard reaction as a result of the release of bound phenolic compounds as a result of heat treatment 43 . ...
In this study, the role of boiling and roasting on chemical properties, fatty acid compositions, polyphenols and mineral contents of peanut kernels provided from Mersin (Silifke) province in Turkey was investigated. The oil yields of peanut kernels treated were specified between 48.92% (boiled) and 52.93% (oven roasting). While total phenolic quantities of raw, boiled and roasted-peanut kernels were assessed between 71.98% (boiled) and 178.81 mgGAE/100 g (raw(control)), total flavonoid quantities of treatedpeanut kernels were found to be between 120.36 (boiled) and 530.36 mgQE/100 g (control). The antioxidant activities of peanut kernels ranged from 2.66 (microwave roasting) to 3.90 mmolTE/kg (control). The phenolic constituents of peanut kernels are sensitivities to heat treatment. The maximum reduction in the phenolic compounds of peanut kernels was determined in the peanut kernels roasted in the microwave and oven roasting systems, and followed by the boiled process in decreasing order. Also, while oleic acid quantities of raw, boiled and roasted-peanut kernel oils are determined between 54.06% (boiled) and 57.22% (microwave roasting), the linoleic acid quantities of the oils of peanut kernels treated were specified between 25.18% (microwave roasting) and 27.33% (boiled). The composition of the oil of the peanut kernels roasted in microwave has highly increased (except palmitic and linoleic acids) according to the control. The macro elements found at the highest amounts in raw, boiled and roasted-peanut kernels were P, K, Ca, Mg, S and Na. The most available as micro element has been Fe and Zn. Heat treatments such as roasting and boiling not only change the visible rawness of peanuts, but they can also subsequently cause chemical changes in peanut kernels.
graphical abstract Fullsize Image
... Additionally, (Samaras et al., 2005) found that antioxidant activity increased with higher heating intensity, enhancing the antioxidant capacity of steamed and pressure-cooked soybeans. This phenomenon can be explicated by the formation of new products from the Maillard reaction (Açar et al., 2009;Jannat et al., 2010). Higher temperatures may alter phenolic components, modifying their activity during the roasting process, as observed earlier. ...
This study aimed to assess the impact of the roasting process, conducted in an electric oven, on the oil quality and residue derived from two pumpkin seed species, namely Cucurbita maxima (C. maxima) and Cucurbita pepo (C. pepo), cultivated in Morocco. The seeds underwent roasting at temperatures of 60, 90, 120, and 150 ◦C for 45 min. The cold press extracted oils were characterize in terms of fatty acids, phytosterols, tocopherols and pigment content meanwhile phenolic content and antioxidant activity were evaluated in the residues. The heat treatment did not significantly affect fatty acid content; however, it affected sterols, particularly β-sitosterol, which experienced an 8 % decrease in C. maxima. Instead, total sterols significantly increased in C. pepo from 153.84 to 181.71 mg/100g. Moreover, the heat treatment influenced the tocopherol contents, revealing a substantial in- crease in both species. Phenolic content was significantly affected in C. pepo whereas the variation in C. maxima was statistically nonsignificant. Antioxidant activity exhibited fluctuations during the heat treatment, resulting in an overall increase in the oils. The roasting process influences the composition of bioactive compounds and antioxidant activity in pumpkin seed oil. These findings contribute to a deeper exploration of the functional properties of pumpkin seed products.
... The ORAC, FRAP, and DPPH radical scavenging values indicated that processing at high temperatures helped to enhance the antioxidant activities of sacha inchi seeds, possibly due to the development of non-phenolic antioxidants and/or Maillard reaction products [26,27]. Roasting usually results in the thermal degradation of some naturally occurring phytochemicals in plant materials, but it is also capable of generating antioxidant compounds through the Maillard reaction [28]. Such a phenomenon concerning the positive impacts of thermal processes on antioxidant activities was observed during the roasting of almond and pine nuts [29], concurring with our results. ...
Roasted sacha inchi seeds are now commercialized as a health food product, but the influence of roasting methods on their proclaimed health effects has yet to be explored. This study investigated the total phenolic contents (TPCs), antioxidant potential, and inhibitory activities of raw and roasted sacha inchi seeds in vitro. Individual phenolics in raw seeds were also identified in an attempt to explain the bioactivities of the seeds. The results suggested that roasting in a cooking pan, vacuum oven, and tray dryer had distinct impact on TPC in sacha inchi seeds, and thus differentially altered their antioxidant and inhibitory properties. Seeds that underwent roasting exhibited 1.5–2.7-fold higher antioxidant potentials than raw seeds. Certain roasting methods provided the products with anti-α-amylase and anti-cholinesterase activities, while inhibitions of these enzymes were not detected in raw seeds. Roasted seeds also possessed superior anti-lipase and anti-glycation activities when compared with raw seeds (up to 1.7- and 4.8-fold, respectively). The inhibitory properties observed in the seed samples might be attributed to their p-coumaric acid, ferulic acid, and quercetin, as these potential enzyme inhibitors were predominant in raw seeds. The overall results showed that pan-roasting could be used to obtain relatively high health benefits from the antioxidant and inhibitory activities of sacha inchi seeds. The information obtained from this study may serve as the basis for the proper processing of sacha inchi seeds to optimize their functional food and nutraceutical applications.
... Examples include berries, citrus fruits, tomatoes, broccoli, spinach, and kale [24]. Nuts and seeds: Nuts and seeds, such as almonds, walnuts, and sunflower seeds, are rich in antioxidants such as vitamin E [25]. Herbs and spices: Many herbs and spices, such as turmeric, ginger, and cinnamon, are rich in antioxidants and have been used for their medicinal properties for centuries [26]. ...
Oxidative stress is a physiological condition that occurs when there is an imbalance between the production of reactive oxygen species (ROS) and the cell's antioxidant defense system. ROS are highly reactive molecules that can cause damage to cellular structures such as DNA, proteins, and lipids. the regulation of ROS levels and the antioxidant defense system is crucial for cancer prevention and treatment. Strategies to enhance antioxidant defenses or induce oxidative stress selectively in cancer cells are being developed as potential therapeutic approaches. targeting oxidative stress in cancer treatment is an active area of research with several potential therapeutic approaches being investigated. Developing selective and effective therapies that target oxidative stress in cancer cells while sparing normal cells will be crucial for improving cancer treatment outcomes.
... Compared to kernels roasted at a higher temperature of 150 • C (0.003 and 0.005 ABTS mg GAE kg −1 and 0.001 and 0.006 DPPH mg GAE kg −1 , respectively), 'A4 and 'Beaumont' kernels roasted at 50 • C had a high concentration of antioxidants (0.017 and 0.017 ABTS mg GAE kg −1 and 0.005 and 0.007 DPPH mg GAE kg −1 ). Ref. [63] reported a similar decrease in antioxidants in hazelnuts roasted at 180 • C, which may be due to the oxidation of phenols [64]. It is clear from Figure 4 that roasting 'A4 and 'Beaumont' kernels at 150 • C further reduced the antioxidant activity. ...
Depending on the temperature regime used during roasting, the biochemical and sensory characteristics of macadamia nuts can change. ‘A4′ and ‘Beaumont’ were used as model cultivars to examine how roasting temperatures affected the chemical and sensory quality of macadamia nuts. Using a hot air oven dryer, macadamia kernels were roasted at 50, 75, 100, 125, and 150 °C for 15 min. The quantity of phenols, flavonoids, and antioxidants in kernels roasted at 50, 75, and 100 °C was significant (p < 0.001); however, these kernels also had high levels of moisture content, oxidation-sensitive unsaturated fatty acids (UFAs), and peroxide value (PV), and poor sensory quality. Low moisture content, flavonoids, phenols, antioxidants, fatty acid (FA) compositions, high PV, and poor sensory quality—i.e., excessive browning, an exceptionally crunchy texture, and a bitter flavor—were all characteristics of kernels roasted at 150 °C. With a perfect crispy texture, a rich brown color, and a strong nutty flavor, kernels roasted at 125 °C had lower PV; higher oxidation-resistant UFA compositions; considerable concentrations of flavonoids, phenols, and antioxidants; and good sensory quality. Therefore, ‘A4′ and ‘Beaumont’ kernels could be roasted at 125 °C for use in the industry to improve kernel quality and palatability.
... In addition, high-temperature conditions during IR heating may also result in Maillard browning reactions, yielding compounds with antioxidant properties. This was also shown by Acar et al. [122], who related the increase in antioxidant activity in pulses to high-temperature processing techniques such as roasting. In addition, Mb is thought to be protected from oxidation by the antioxidant phenolics in lentil seed components and the increased ferrous ion chelating ability of soluble protein released by heat treatment [18]. ...
In the last decade, various foods have been reformulated with plant protein ingredients to enhance plant-based food intake in our diet. Pulses are in the forefront as protein-rich sources to aid in providing sufficient daily protein intake and may be used as binders to reduce meat protein in product formulations. Pulses are seen as clean-label ingredients that bring benefits to meat products beyond protein content. Pulse flours may need pre-treatments because their endogenous bioactive components may not always be beneficial to meat products. Infrared (IR) treatment is a highly energy-efficient and environmentally friendly method of heating foods, creating diversity in plant-based ingredient functionality. This review discusses using IR-heating technology to modify the properties of pulses and their usefulness in comminuted meat products, with a major emphasis on lentils. IR heating enhances liquid-binding and emulsifying properties, inactivates oxidative enzymes, reduces antinutritional factors, and protects antioxidative properties of pulses. Meat products benefit from IR-treated pulse ingredients, showing improvements in product yields, oxidative stability, and nutrient availability while maintaining desired texture. IR-treated lentil-based ingredients, in particular, also enhance the raw color stability of beef burgers. Therefore, developing pulse-enriched meat products will be a viable approach toward the sustainable production of meat products.
... In the binary combination of breakfast cereal with yoghurt, no statistical difference (p > 0.05) between TAC measured (11.29 ± 0.15 mmol TE.kg − 1 ) and TAC estimated (9.56 ± 0.95 mmol TE.kg − 1 ) was observed while lower TAC (13.15 ± 3.60 mmol TE.kg − 1 ) was measured compared to the expected from the binary combination of breakfast cereal with milk (37.25 ± 0.70 mmol TE.kg − 1 ), pointing toward a clear antagonistic interaction. It was seen that whole wheat bread, as another main grain product mostly consumed in daily diet, interacted synergistically with green tea and black tea, the sources of the soluble phenolic compounds, while it interacted antagonistically with the seeds (flax seed, chia seed, and sesame) including bound antioxidant compounds, lignans and dietary fiber in their structure (Açar et al., 2009;Aludatt et al., 2013). ...
This study aims to investigate the antioxidant interactions between mostly co-consumed foods in daily diet. Total antioxidant capacities of individual and the binary combinations of certain food samples from different groups including fruits, vegetables, grain sources, dairy and meat products were measured. The types of interactions (synergism, antagonism, and additive) between food samples were determined by a statistical comparison between estimated and measured total antioxidant capacity. The results revealed an antagonism in the combinations of milk with the fruits or green tea extract while a clear synergism was reported in the combination of fruits with breakfast cereal, whole wheat bread, or yoghurt. The selected foods were also subjected to in vitro digestion protocol. Slightly alkaline conditions were found to significantly (p < 0.05) increase the total antioxidant capacity of foods. Synergism was observed during the digestion of the combinations of milk with fruits or tea extracts. Hydroxyl radical scavenging capacity was also determined in the bioaccessible fractions of foods. Green tea extract was found to be the most efficient scavenger (936.48 ± 16.64 mmol TE.kg⁻¹).
... To measure the antioxidant capacity of coffee silverskin, an ABTS radical scavenging assay was used (Acar et al., 2009). Briefly, 0.7 mM ABTS and 2.45 mM potassium persulfate solutions were mixed and left at room tempera-ture overnight (16 h) in the dark to generate a stable ABTS solution. ...
Coffee silverskin is a byproduct of the coffee roasting process contributing to organic waste burdens in urban areas. Silverskin is a potential source of dietary fiber, protein, carbohydrates, caffeine as well as vitamins and minerals. However, phytosterols present in the plant are susceptible to thermal oxidation resulting in the formation of phytosterol oxidation products (POPs) in the silverskin during roasting. In collaboration with a small roastery, the formation of POPs in three coffee varieties with roasting time was monitored by GC‐MS. The objective was to evaluate the safety and potential benefits of incorporating coffee silverskin into value‐added products. The qualitative profile of POPs in the silverskin from the three varieties was similar. Average total POPs were 0.32 g POPs/kg silverskin. POPs from the dominant plant sterol, sitosterol, were present at the highest concentrations. Caffeine, total antioxidant capacity, and total flavonoids were measured in the silverskin of the three coffees. Average values were 1.3 g caffeine/100 g silverskin, TEAC of 11 mmol Trolox/kg silverskin, and 1.94 to 8.60 mg catechin equivalent (CE)/g silverskin, respectively. An analysis of the impact of consuming teas and baked goods containing silverskin was also performed. Using published formulations, a tea or cookie containing silverskin would contribute approximately 1 and 0.3 mg POP per day, respectively. Consumption of these products would not substantially increase dietary exposure to POPs, while increasing fiber and antioxidants while reducing organic waste.
Practical Application
Coffee silverskin has been studied as a possible source of fiber, antioxidants, and caffeine when incorporated in snack foods and used to make teas. To assess possible concerns about increasing dietary oxidized phytosterols, the formation of phytosterol oxidation products (POPs) was investigated in the silverskin fraction during the roasting process in three coffee varieties. In addition, caffeine, antioxidant capacity, and total flavonoids were determined. We found that silverskin can be safely used for value‐added products including caffeinated teas, cookies, and bars with minimal impact on dietary POP exposures.
... The difference in TPC between the two Bambara groundnut landrace could be attributed to genetic factors and variation between cultivars (Amarowicz and Pegg, 2008 ),genetic and growing factor (environment condition) have been reported to affect the concentration of TPC hence the antioxidant activity of the legume extract (Rocha et al., 2007 andAcar et al., 2009). The increase in TPC during thermal processing has been reported by other researchers (Boateng et al., 2008, Duenas et al., 2009Fernandez et al., 2006). ...
Bambara groundnut is a crop that is considered to be indigenous to the African continent. Bambara groundnut is grown mainly for its edible and nutritionally rich seeds. The aim of this study was to explore the effect of domestic processing on the antioxidant potential of Bambara groundnut. Two landraces from Yobe and Kano states, Nigeria were screened in raw and processed forms. The effect of cooking and roasting on antioxidant potentials and phenolic phytochemicals of the two landraces were assessed. The study employed in vitro antioxidant assays 1-1-diphenyl-2-picrylhydrazyl (DPPH) and Ferric reducing antioxidant power (FRAP) to screen for change in antioxidant property and Folin Ciocalteu assay to screen for change in phenolic content respectively. Result were presented in mean ± SD. The Yobe landrace exhibited the highest DPPH free radical scavenging activity with 56.58% ± 0.05 for the roasted Bambara compared to 40.57 % ± 0.08 of the Kano landrace. Again the ferric reducing antioxidant power (FRAP) was higher in the roasted Yobe landrace of Bambara groundnut with 9.40 mmol Fe 2+ /100g ± 0.40 compared to 8.34 mmol Fe 2+ /100g ± 0.36 in the roasted Kano Bambara groundnut. The total phenolic content were 34.22 as GAE ± 0.111 and 28.19 ± 0.25 as GAE in the roasted Yobe and roasted Kano Bambara groundnut respectively. The effect of domestic processing on the antioxidant activity and total phenolic content follows the same trend and the increase was revealed in the following order: RBY>RBK>CBY>CBK>CSY>CSK.
... In this regard, Chuah et al. [27] correlated the high total antioxidant capacity in walnut skin to its high levels of phenolic acids and tannins. On the same manner, due to the heat treatment, Açar et al. [28] indicated that the inactivation of prooxidant enzyme resulted in decreasing the antioxidant activity of cashew nut extracts. DPPH (%) of fresh treatment had the lowest IC 50 indicating a significant effect of processing, namely, blanching and drying on the DPPH inhibition with the exception of avocado and orange peel. ...
Total phenolic content (TPC), total flavonoid content (TFC), ferric reducing antioxidant potential (FRAP), and diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity of avocado peel, avocado seeds, kiwi fruit, orange peel, pineapple peel, and pomegranate skin by-products during processing (i.e., dried, blanched, freezed, and fresh) were determined. It was hypothesized that fruit by-products would add a significant value to the food products. Heat treatments resulted in increasing TPC and TFC and reducing power of fruit by-products with avocado peels TFC of 136.9 and 63.1 mg/100 g of dried and blanched treatments, respectively, compared to 14.4 mg/100 g of fresh and 20.6 mg/100 g of freezed treatments. Orange peels TFC increased from 54.4 mg/100 g of fresh to 194.4 and 380.0 mg/100 g for blanched and dried treatments, respectively. Fresh treatments had the lowest DPPH (%) (IC50), indicating a significant effect of blanching and drying on fruit by-product antioxidant activity with some exceptions. IC50 increased from 20.0 of fresh to 39.8% of dried pineapple peel and from 6.5 to 15.0% for pomegranate skin of fresh and dried treatments, respectively. The use of fruit by-products regardless to its processing as supplements to flours would significantly increase flour’s bioactive availability.
... Another reason could be the occurrence of new compounds with antioxidant properties through the Maillard reaction during roasting. Açar et al. (2009) have reported that the high antioxidant capacity of Maillard products is related to the formation of reductone-type structures and/or metal chelating properties of melanoidins. They also revealed that the increase in total antioxidant capacity (due to the formation of Maillard reaction products with antioxidant properties) could be attributed to roasting process in foods containing starch rich foods, such as cashews. ...
Herein, the effects of roasting levels (rare, medium, and well) on the fatty acid composition, oil and polycyclic aromatic hydrocarbon (PAH) contents of various dried nuts (almonds, hazelnuts, peanuts, and cashews) were investigated. The roasting level affected the moisture and total oil contents, as well as the fatty acid composition. The roasting level had no significant effect (P > 0.05) on saturated fatty acid (SFA), monounsaturated fatty acid (MUFA) contents of the dried nuts, while it had a significant effect (P < 0.05) on polyunsaturated fatty acid (PUFA). In raw and dry roasted nut, the most common SFA, MUFA, and PUFA were palmitic, oleic, and linoleic acid, respectively. The amounts of linoleic acid and ∑PUFA, as well as ∑PUFA/∑SFA ratio were the lowest in the well roasted samples. Additionally, the types of dried nut had a significant effect (P < 0.01) on the amounts of total oil and fatty acid compositions. The highest total oil amount (62.15%) was found in hazelnuts, while the lowest PUFA content (7.54%) was also determined in hazelnuts. From the nutritional perspective of view, the highest ∑PUFA / ∑SFA ratio (2.40) belonged to almonds. Although the recovery rates of PAH standards varied between 70.14%–85.10%, none of the heavy PAH compounds could be detected in raw and roasted samples.
... Hot air roasting is one of the simplest and low-cost methods. However, it usually requires a long period of roasting time which results in undesirable changes in the final product, mainly due to the Maillard reaction [16], [18]. In conventional roasting methods, the outer surface of the nut is scorched while the centre of the nut is not perfectly baked. ...
The following publication presents results of the research on a new, innovative, mild technology of food processing with microwaves technology in order to develop novel food in the form of “on the go” healthy snacks. Different aspects of microwave treatment technologies within the context of physical model of electromagnetic field interaction with a food product, marketing and energy aspects were considered. Furthermore, comparison of sensory quality of conventionally and microwave treated nuts was shown, which is a key feature of nuts, seeds and dried fruits for most consumers. A comparative LCA analysis of convectional and microwave roasting was performed as well.
... The antioxidant capacity as per the method described by Acar et al. (2009) for UGCS and the RGCS The samples (10 mg) were mixed with 90 ml cellulose and then stirred well. Ten mg of the above mixture was mixed further with 1.7 ml of ABTS and solution in cyclomixer. ...
The present work aimed to valorize green coffee spent (GCS) as a food ingredient and its application in food products. About 70% of GCS was obtained after processing green coffee for Chlorogenic acid. The cookies fortified with roasted green coffee spent (RGCS) and unroasted green coffee spent (UGCS) were evaluated for physicochemical properties and food safety. The UGCS and RGCS flour had dietary fiber ranging from 3.3 ± 1.08 and 2.6 ± 0.21%, total polysaccharides with 8.29 ± 0.05 and 16.34 μg/Mg along with fair amount of ash and protein. They also recorded 36.4 and 32.6 mg/100g of polyphenols and 0.32 and 1.25% Trolox equivalent antioxidant activity The UGCS and RGCS contained 4.76 and 8.29 μg/Mg oligosaccharides respectively. The UGCS and RGCS recorded The acrylamide in UGCS and RGCS cookies was 23.4–37.8 ± 0.3 lg ACR/kg d.m. The cookies formulations of RGCS had better sensory attributes such as color and aroma. Thus, RGCS enriched with prebiotic oligosaccharide represent novel functional food supplement.
... Contenidos bajos de humedad (y baja Aw) disminuyen la probabilidad de crecimiento microbiano, fermentaciones imprevistas, germinación prematura en semillas y muchos otros cambios bioquímicos indeseables normalmente asociados con el contenido de humedad. Los resultados obtenidos en contenido de humedad para este estudio son consistentes con otros trabajos reportados en nueces y semillas [31][32][33] [34]. El contenido de fibra cruda de la barra nutritiva (7.13% -7.91%) se encuentra por debajo de la ingesta diaria recomendada por la FDA de 25 g basada en una dieta de 2,000 calorías diarias [35], y donde una sola barra aportaría 1 décimo aproximadamente, de la fibra diaria requerida. ...
The need for nutritious and functional food has increased due to the demand of a demanding public. Consumers, today, not only They want appetizers that satisfy their appetite, but also provide them with essential nutrients to their bodies. This work aimed at a complete study of the physical-chemical characterization of a formulated food bar
based on seeds and nuts free of components of animal origin. The product was analyzed for the proximate composition in percentage by weight (% w / w), dry basis, with result
27% protein, 7.5% raw fiber and 4.4% total sugars. This values position this food bar within the high protein bars with sugar content well below normal bar content in commercial foodstuffs (20 - 40% w / w of added sugar) and a content of 45% w / w in oils that according to their fatty acid profile, it was found to be Composed by 19% saturated fatty acids and 81% w / w unsaturated fatty acids, all these derived from their components by nuts and seeds. The presence of essential minerals was determined such as calcium, magnesium, potassium, sodium, copper, iron, manganese and zinc contents.
The oxidation or rancidity rate of the product was relatively low reaching the value of 10 meq per kg (maximum allowable value) 9 days after the product was kept at 40 ° C. Low values of water activity were observed which is a result of the low moisture content of its components formulation. Texture and Color Tests were carried out with the aim of standardize quality parameters in product characterization. The bars food based on seeds and nuts had a high acceptance among adult population.
... Various processes apply, particularly roasting in order to increase the bioavailability of seeds. Roasting, the most common process, enhances the antioxidant activity of seeds, both degrading some heatsensitive antioxidative components and forming new ingredients with antioxidant activity through the Maillard reaction (Açar et al., 2009;Nicoli et al., 1999). ...
Background:
There has been a resurrection of interest in traditionally cultivated hemp seeds as an alternative food ingredient source over the last few years. Hemp seeds are an excellent food source in terms of protein, dietary fiber, omega fatty acids, vitamins and minerals. In this way, hemp flour allows the development of a product with a high nutritional content for human nutrition.
Methods:
This study aimed to investigate the effects of using raw and roasted hemp flour instead of wheat flour (0-5-10-15-20%) in cookies in terms of physical, chemical and sensorial properties.
Results:
The results showed significant differences (p < 0.05) in some chemical and physical properties among cookies. The addition of raw and roasted hemp flour significantly (p < 0.05) affected the color parameters of the cookie samples; L* and b* values decreased and a* values increased. The cookie formulation with increased hemp flour (raw or roasted) resulted in an increase in ash, protein, fat, total phenolic content and antioxidant activity values in the cookie samples, and the highest values were observed with a 20% level. The raw and roasted hemp flour content significantly decreased the hardness and resulted in softer cookies. For sensory evaluation, the cookies supplemented with raw hemp flour up to 20% and roasted hemp flour up to 15% were found to be more desirable by the panelists in terms of overall acceptability.
Conclusions:
The results showed the effects of the process applied to the seed and the usability of hemp seed in the product formulation. The nutritional values of hemp seed in the cookie samples demonstrated that it can be used as an alternative ingredient in the development of functional foods.
... Various processes apply, particularly roasting in order to increase the bioavailability of seeds. Roasting, the most common process, enhances the antioxidant activity of seeds, both degrading some heatsensitive antioxidative components and forming new ingredients with antioxidant activity through the Maillard reaction (Açar et al., 2009;Nicoli et al., 1999). ...
... Thus, the difference between the ranges reported in the previous studies might depend on this fact (Martinez et al., 2012). The TAA values were determined by QUENCHER method and also found to be 14.3 mmol Trolox/kg in the peanut, 6.5 mmol Trolox/kg in the pine nuts, 8.1 mmol Trolox/kg in the cashew nuts, 6.0 mmol Trolox/kg in the coconut flour, 12.0 mmol Trolox/kg in the sesame seeds/kg and 6.6 mmol Trolox/kg in the pumpkin seeds (Açar et al., 2009). The RCBH given in Table 2 exhibited higher TAA than those of oilseeds and nuts. ...
In this study, wheat flour was substituted with the following ratios of the raw (RCBH) and leached (LCBH) cocoa bean hull (CBH) in pound cakes (PC) (CBH/wheat flour ratios: 20/80 (20%), 30/70 (30%) and 40/60 (40%)), respectively. The proximate composition and the content of bioactive compounds in the cake samples for each weight ratio of RCBH and LCBH and in the hulls were evaluated. Fiber, ash, total antioxidant activity (TAA) and total phenolic compound (TPC) contents increased with the CBH content in the cakes. No significant difference was found in the specific volume among the cake samples. Based on the results of the textural analysis, all cake samples showed higher hardness, lower springiness and cohesiveness than those of the control cake. Regarding to the color of the crumb and crust, the 40% LCBH and RCBH cakes presented the lowest L*, a* and b* values. According to the Principal Component Analysis (PCA), it was observed that the properties with respect to the cell uniformity, adhesiveness, sweetness, oiliness and humidity of the 20LCBH and 20RCBH cakes can be distinguished clearly from the other flour substituted cakes.
... Health benefits of legumes include protection from cardiovascular disease due to the high content of dietary fiber (Alghamdi, 2009), increased iron absorption because they contain vitamin C (Acar et al., 2009) bone health promotion (Hinterthuer, 2016). Moreover, the whole pulses are a plentiful source of some minerals such as iron, zinc, potassium, phosphorus, selenium, folic acid, isoflavones and tocopherol (Jain et al., 2009). ...
... In the present study, the applied roasting temperature was lower, than that used in other studies. In addition to the roasting conditions, the amounts of compounds involved in the Maillard reaction, particularly carbohydrates and proteins will determine the final polyphenol content in roasted nuts [41]. The results previously obtained by Król et al. [42] for the same hazelnut cultivars, showed that cultivars grown in Poland exhibited higher average carbohydrate contents and lower average protein contents compared to hazelnuts originating from Turkey, Spain or Italy. ...
Poland is one of the largest producers of hazelnuts in Europe; however, information about the contents of biologically active compounds in hazelnuts grown in Poland is limited. The aim of this study was to analyze and compare the concentrations of phenolic acids, flavonols, and tocopherols in raw and roasted hazelnut kernels and their skin, in addition to determining the effect of the cultivar and year of cultivation. The experiment was carried out in 2016–2018, and the nuts of six hazelnut cultivars were used for research purposes. Among the detected phenolic acids, p-coumaric acid was the most abundant in roasted and unroasted kernels, whereas the apigenin content represented 43%–45% of the total flavonols. The harvest year had a significant effect on the polyphenol content of hazelnuts, whereas roasting had a minor impact. The hazelnut skin contained 168- to 378- fold higher contents of total phenolic compounds than the raw and roasted nuts. Gallic acid was the most abundant phenolic acid in hazelnut skin, contributing 95.0% of the total polyphenols on average. α-Tocopherol was the most abundant tocopherol in the hazelnut cultivars, followed by β + ƴ-tocopherol and δ-tocopherol in hazelnut cultivars. The statistical analysis showed that roasting and year of cultivation did not affect the tocopherol contents of the investigated samples.
A functional fermented plant-based product was developed by using raw and roasted pistachio kernels. The product was prepared from aqueous pistachio slurries by heating and fermenting with a lactic culture. Antioxidant, ACE-inhibitory and α-amylase inhibitory activities along with soluble protein and phenolic contents of the products were measured during storage. Raw pistachios exhibited significant antioxidant and ACE-inhibitory activity along with a low level of α-amylase inhibitory activity which were further enhanced by fermentation with the lactic culture. On the other hand, roasting pretreatment resulted in lower soluble protein content, antioxidant activity, phenolic content and consequently lower bioactivity in the end product. Plant-based pistachio products can be manufactured from raw pistachios in order to obtain high antioxidant and ACE-inhibitory activities.
This study focused on extracting antioxidants from hazelnut skin, an industrial food waste, using two different methods: conventional extraction (CE) and ultrasound-assisted extraction (UAE). The Response Surface Methodology (RSM) has been utilized using the total phenolic content (TPC) and antioxidant capacity (AC) results as responses in optimizing both method conditions. The independent variables and their levels for the optimal experimental design were adjusted as follows: temperature (50-90°C), time (2-62 min), and loading capacity (5-15%) for CE; and temperature (25-50°C), time (1-30 min), loading capacity (5-15%), and ultrasonic amplitude (20-50%) for UAE. The optimum conditions were determined to be 90°C for 35 min with a 5% loading capacity for CE, and 50°C for 27 min with a 5% loading capacity and 50% amplitude for UAE. The TPC of the extracts were found to be 142.62 mg GAE/g and 129.69 mg GAE/g, while the AC values were 127.02 μmol TE/g and 116.00 μmol TE/g for CE and UAE methods, respectively. In conclusion, it has been demonstrated that hazelnut skin extracts obtained by optimizing CE and UAE methods can serve as natural antioxidant alternatives in food products and may hold significant potential for further applications.
Background: Peanut milk was prepared by different processing methods like fresh, blanching, soaking, roasting and germination methods and analyzed its physico chemical properties like pH, TSS, acidity, viscosity and colour value and also analyzed its antioxidant activity in both the selected local and CO 6 peanut varieties and studied the effect of processing methods on physico chemical properties, organoleptic characteristics and antioxidant activity. Methods: Local and CO 6 peanut variety were selected for preparation of peanut milk by five different processing methods like fresh, blanching (121C 15 psi for 2 mins), soaking for 3 hrs, roasting (roasting for 5 mins followed by soaking 3 hrs) and germination (8 hrs) pretreatments were done. Then grinded (1:3 ratio of kernel to water), filtered by using muslin cloth, slurry was separated. Then the peanut milk was homogenized for 5 mins and double pasteurized (85C for 15 mins). Result: The present study results reported that physico chemical properties of peanut milk (local and CO 6 variety) pH value varied between 6.3-6.9, TSS 11-13Brix, viscosity 4.80-5.00 (Cp/100 ml), acidity 0.04-0.08 (g%), colour value L*a*b was higher (91.02, 0.97, 12.47) in control peanut milk from both the local and CO 6 variety respectively. Antioxidant activity was significantly higher in peanut milk developed from roasting method (roasting for 5 mins followed by soaking 3 hrs) in both the peanut varieties. Antioxidant activity of the peanut milk is also important for maintaining the shelf life of the product and prevent oxidative damage in human being.
As a nutrient rich emulsion extracted from plant materials, plant-based milk (PBM) has been the latest trend and hot topic in the food industry due to the growing awareness of consumers toward plant-based products in managing the environmental (carbon footprint and land utility), ethical (animal well-fare) and societal (health-conscious) issues. There have been extensive studies and reviews done to discuss the distinct perspective of PBM including its production, health effects and market acceptance. However, not much has been emphasized on the valuable antioxidants present in PBM which is one of the attributes making them stand apart from dairy milk. The amounts of antioxidants in PBM are important. They offered tremendous health benefits in maintaining optimum health and reducing the risk of various health disorders. Therefore, enhancing the extraction of antioxidants and preserving their activity during production and storage is important. However, there is a lack of a comprehensive review of how these antioxidants changes in response to different processing steps involved in PBM production. Presumably, antioxidants in PBM could be potentially lost due to thermal degradation, oxidation or leaching into processing water. Hence, this paper aims to fill the gaps by addressing an extensive review of how different production steps (germination, roasting, soaking, blanching, grinding and filtration, and microbial inactivation) affect the antioxidant content in PBM. In addition, the effect of different microbial inactivation treatments (thermal or non-thermal processing) on the alteration of antioxidant in PBM was also highlighted. This paper can provide useful insight for the industry that aims in selecting suitable processing steps to produce PBM products that carry with them a health declaration.
Fox nut (Euryale ferox) is categorized among superior quality foods because of its highly nutritious profile. It also serves as a good protein source for vegetarian diets. However, it is not widely consumed, due to soggy texture and bland flavor as compared to other nuts. In this study, we used roasting and seasoning to enhance its consumer acceptance. Furthermore, we have also compared biochemical, nutritional and physical properties of the roasted and unroasted fox nuts; and their Glycemic Index (GI) in human subjects. Results showed that roasting significantly (P ≤ 0.05) improved the minerals content (from 0.58 to 0.66%), protein content (from 11.40 to 14.57%), total phenolics (from 346.02 to 470.62 mg GAE/100 g), flavonoids (from 4.15 to 4.43 mg CE/g), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity (from 48.54 to 79.13% inhibition) and Ferric Reducing Antioxidant Power (from 662.46 to 957.14 μmol FeSO 4 /g). Consumer acceptance was evaluated with and without seasoning; both salt and spice seasoned roasted nuts had greater overall acceptability as compared to plain roasted and unroasted nuts. Fox nuts also reported low GI (37%) in human subjects (ethical approval #1772/01-06-2020). Thus, roasted fox nuts can be consumed as nutrient rich and low GI snack; not only as a component of healthy diet but can also be served to patients with metabolic disorders like obesity and diabetes.
The present work was aimed at the valorization of roasted spent coffee grounds (SCG), a major valuable and functional by-product of the coffee processing industry by supercritical fluid extraction (SCFE) of the oil therefrom using carbon dioxide, and utilizing the spent residue for the development of functional cookies. The process parameters of SCFE were optimized and compared with conventional Soxhlet extraction using n-hexane, following which the effect of different entrainers was evaluated under optimized conditions of SCFE (300 bar/50°C/90 min) to obtain the maximum yield of spent coffee oil. SCFE with methanol and ethanol as entrainers at 30% (v/w) of SCG showed marginally better yields of 17.65% w/w and 16.02% w/w than 15.89% w/w obtained by hexane extraction for 16h. The residue obtained after extraction (SCGR) was analyzed for total polyphenol content (TPC) and antioxidant activities. The SCGR was used for the preparation of cookies and compared with SCG for their textural, bioactivity, prebiotic activity, and sensory analysis. SCGR at 7% (w/w) showed the highest overall acceptability (7.3) in terms of texture and taste. Thus, the biorefinery approach presented in this work would enable the use of coffee oil as well as the defatted SCGR as a novel ingredient enriched with prebiotic activity in future food formulations.
This review aimed to give comprehensive information about the interactions between free and bound antioxidants naturally found in different food matrices. In this context, firstly, the free and bound antioxidant terms are defined; their place in the daily diet, the path they follow in the body and their characteristics are explained. Factors affecting the interactions have been revealed as a result of the compilation of studies conducted until today, related to bound and free antioxidant interactions. Accordingly, it was observed that many factors such as reaction environment, concentration, pH, chemical structure, source and antioxidant/prooxidant nature of the compounds were effective on interactions. It has been emphasized that the interactions between free and bound antioxidants have a dynamic balance that can easily change under the influence of various factors, which in turn needs the interactions to be handled specifically for each case.
Antioxidants are understood to play a key role in disease prevention; because of this, research and interest in these compounds are ever increasing. Antioxidative phytochemicals from natural sources are preferred, as some negative implications have been associated with synthetic antioxidants. Beans, nuts, seeds, fruits, and vegetables, to name a few, are important sources of phytochemicals, which have purported health benefits. The aforementioned plant sources are reportedly rich in bioactive compounds, most of which undergo some form of processing (boiling, steaming, soaking) prior to consumption. This article briefly reviews selected plants (beans, nuts, seeds, fruits, and vegetables) and the effects of processing on the antioxidant potential, availability, and bioavailability of phytochemicals, with research from our laboratory and other studies determining the health benefits of and processing effects on bioactive compounds.
Expected final online publication date for the Annual Review of Food Science and Technology, Volume 12 is March 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
Babassu oil has high concentrations of phenolic compounds. When seeds are preheated, these compounds tend to migrate to the oil depending on the degree of roasting applied. This study aimed to optimize the roasting conditions of babassu seeds using response surface methodology (RSM) and the Desirability functions. A central composite rotational design (CCRD) was employed to investigate the effects of two independent variables, temperature (X1) and roasting time (X2) which significantly affected response variables viz. yield (%), total phenolics content (TPC), number of phenolic compounds (NPC), ORAC, acid value (AV) and peroxide value (PV). The quadratic model was adjusted for most responses. The roasting temperature of 222°C and the roasting time of 43 min were standardized as ideal conditions. Thus, the oil produced at the optimized conditions showed a yield of 54.47% and TPC of 91.53 mg GAE/100 g. In the control oil sample, the presence of phenolic compounds analyzed by HPLC‐DAD was not observed while under optimized conditions, 7 phenolic compounds were observed. The model of optimized conditions showed a good correlation between the predicted and experimental values. In general, these results demonstrate the effectiveness of optimum roasting conditions in improving the quality of bioactive compounds in babassu oil.
Practical applications: This work aims to optimize the babassu seeds roasting process to obtain oil with a greater number of phenolic compounds and better antioxidant capacity. As the first study on babassu seeds roasting, it contributes to the generation of important data in relation to the identification and quantification of phenolic compounds in the oil. Finally, the optimum roasting conditions established in this work could be explored commercially in babassu oil extraction.
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The influence of simulated in vitro digestion on antioxidant potential of protein fractions of traditional Serbian white-brined cheeses was investigated. Water-soluble (WSF) and water-insoluble fractions (WINF) of three cow's and three ovine white-brined cheeses were fractionated. Total antioxidant capacity , reducing power and iron (II) chelating properties of these fractions before and after in vitro digestion were assayed. The investigated protein fractions had different antioxidant properties. WSFs had a better total antioxidant capacity and reducing power and less pronounced iron (II) chelating properties than WINFs. A strong negative correlation (-0.818, P<0.05) between the total antioxidant capacities of undigested WSF and WINF of traditional cheeses were observed. In vitro digestion greatly improved the total antioxidant capacities of WINFs (by 16.61-34.18 times), their reducing power (up to 95.77 %) and except in the case of Svrljig ovine cheese, the iron (II) chelating ability as well. A less pronounced increase (up to 71.29 %) of the total antioxidant capacity of WSFs was induced by in vitro digestion. In vitro digestion reduced reducing power of WSF of investigated ovine cheeses as well as reducing power of WSF of Homolje cow's cheese. Since there was no significant correlation between the investigated antioxidant properties of digested WSFs and their free amino acids and mineral contents the observed differences should be attributed to different composition and properties of low molecular weight pep-tides. Thus, further investigations related to their isolation and characterization needs to be conducted. However, these results indicate that Serbian white-brined cheeses have great potential as source of antioxidant peptides.
Rice bean ( Vigna umbellata ) is a legume that belongs to Vigna genus. Native to Indo-Chinese region, it is considered to be an ‘under-utilized’ or ‘orphan’ crop. Rice bean is known to possess high nutritional potential and antioxidant activity. But the use of rice bean supplementation in routine diet is limited despite its high nutritional profile due to the presence of non-nutritional factors. Thus, various pre-treatments like soaking, germination, oven roasting, sand roasting, boiling and pressure cooking at different time and temperature were carried out to reduce the anti-nutritional content of rice bean and to study its effect on antioxidant activity and phytochemical content. All the pre-treatments were able to significantly reduce the anti-nutrient content in rice bean, but germination showed the maximum reduction. Also germinated rice bean showed the maximum antioxidant potential and maximum content of total phenols, total flavonoids, vitamin C and carotenoids. Rice bean has been underutilized so far, owing to its antinutrient content and low popularity. This experiment attempted to use low cost processing to reduce the content of antinutrients and track the antioxidant content in rice bean. The concluded processing could be adopted for commercial applications for dietary supplementation.
The effect of roasting conditions on antioxidant activity Opuntia Ficus Indica seeds from Morocco and their phenolic compounds were optimized by the Central Composite Design (CDD) method. The CCD was used to optimize the roasting conditions: temperature (X 1 : 60–200 °C) and roasting time (X 2 : 10–50 min). The best roasting conditions were used in order to optimize the optimal value of the response : TPC (Total Phenolic Content): X1: 200°C, X2: 50min with 104.86±1.94GAE/g extract predicted response, TFC (Total Flavonoids Content) : X1: 200 °C, X2: 50 min with 81.23±0.90 mg QE/g extract predicted responses, TTC (Total Condensed Tannins Content): X1: 128.9°C, X2: 34.92min with 6.12±0.95 mg QAE/g extract) predicted response. Moreover, the optimal potential antioxidant activity by ABTS assay and DPPH assay was found in extracts of Opuntia Ficus Indica seeds roasted: at a high temperature of the roasting. Furthermore, the positive significant correlations were determined by the principal component analysis (PCA) on the one hand, between the antioxidant capacity of the extracts and their antioxidants compounds (TPC and TFC), and on the other hand, between the two assays ABTS and DPPH. Consequently, the results of this work indicated that roasted Opuntia Ficus Indica seeds from Morocco can be considered as an essential ingredient for human foods.
Tree nuts and peanuts are healthful foods with a track record of helping to reduce the incidence of chronic diseases, most notably cardiovascular disease. At the point of consumption, all nuts contain low moisture and ≥ 50% lipid contents, but this is where similarities end. The levels of key nutrients and bioactives including vitamin C, vitamin E, L-arginine, minerals (such as selenium and zinc), and phenolics differ. Distinctions in the types and quantities of phenolic constituents for tree nut species as well as the impact of digestion will affect the nuts’ antioxidant potential in vivo. This chapter provides some insight into the different types of phenolics found in tree nuts and peanuts, the antioxidant potential of phenolic extracts using in vitro chemical assays, the effect of thermal processing on the stability of the nuts’ endogenous phenolics, and the impact on biomarkers of human health arising from randomized clinical trials. Key biomarkers include measures in the reduction of LDL oxidation as well as increases in the levels of vitamin E and selected phenolic compounds in blood plasma postprandially from those of baseline.
Pulses are a staple food cultivated since ancient times, which play an important role in the human diet. From a nutritional point of view, pulses are very interesting foods as they are rich in proteins, carbohydrates and dietary fibre. Dietary antioxidants are a complex mixture of hydrophilic and lipophilic compounds usually present in foods of plant origin, including pulses. In the present study, the phytochemical composition of selected pulses (common beans, fava beans, lentils, chickpeas, peas and lupins) has been reviewed in terms of their content of antioxidant compounds. The content of hydrosoluble antioxidants (organic acids, phenolic compounds), liposoluble antioxidants (tocopherols, carotenoids) and other compounds which exert antioxidant properties, such as dietary fibre and minerals (zinc, selenium), has been studied, reporting that pulses are an interesting source of these compounds, which have important health benefits, including a preventing role in cardiovascular diseases, anticarcinogenic or neuroprotective properties.
It is important to take into account that pulses are not usually consumed raw, but they must be processed before consumption in order to improve their nutritional quality and their palatability, therefore, the effect of different technological and heat treatments (germination, cooking, boiling, extrusion) on the antioxidant compounds present in pulses has been also reviewed. In this regard, it has been observed that as a consequence of processing, the content of phytochemicals with antioxidant properties is usually decreased, but processed pulses maintain relevant amounts of these compounds, preserving their beneficial health effect.
Four bean varieties with different hull colors (white, brown, red, and black) were extracted with 80% acetone and evaluated
for their antioxidant potential. Red, brown, and black bean extracts were able to effectively retain supercoiled DNA against
2,2′-azobis(2-methylpropionamidine) dihydrochloride (AAPH)-induced radical damage at the concentration levels (5, 10, 50,
and 100 ppm) tested. Delphinidin, cyanidin, and procyanidins B2, C1, C2, and X were identified in red, brown, and black bean
hull extracts, whereas white bean hull extract contained only a small amount of flavonoids. Vanillic, caffeic, p-coumaric, ferulic, and sinapic acids were the main phenolic acids identified in bean hull extracts.
Epidemiologic and clinical trial evidence has demonstrated consistent benefits of nut and peanut consumption on coronary heart disease (CHD) risk and associated risk factors. The epidemiologic studies have reported various endpoints, including fatal CHD, total CHD death, total CHD, and nonfatal myocardial infarct. A pooled analysis of 4 U.S. epidemiologic studies showed that subjects in the highest intake group for nut consumption had an approximately 35% reduced risk of CHD incidence. The reduction in total CHD death was due primarily to a decrease in sudden cardiac death. Clinical studies have evaluated the effects of many different nuts and peanuts on lipids, lipoproteins, and various CHD risk factors, including oxidation, inflammation, and vascular reactivity. Evidence from these studies consistently shows a beneficial effect on these CHD risk factors. The LDL cholesterol-lowering response of nut and peanut studies is greater than expected on the basis of blood cholesterol-lowering equations that are derived from changes in the fatty acid profile of the diet. Thus, in addition to a favorable fatty acid profile, nuts and peanuts contain other bioactive compounds that explain their multiple cardiovascular benefits. Other macronutrients include plant protein and fiber; micronutrients including potassium, calcium, magnesium, and tocopherols; and phytochemicals such as phytosterols, phenolic compounds, resveratrol, and arginine. Nuts and peanuts are food sources that are a composite of numerous cardioprotective nutrients and if routinely incorporated in a healthy diet, population risk of CHD would therefore be expected to decrease markedly.
Legume consumption appears to lower serum cholesterol and to increase cholesterol saturation of bile, but the mechanisms of these effects have not been established. We studied nine human subjects on a metabolic ward during two randomly ordered 6-7 week periods: one during consumption of a control diet and the other during consumption of the same diet with 120 gm mixed legumes substituted for foods having equivalent calories, fat, protein, and carbohydrate. Mean serum LDL cholesterol was significantly lower during legume consumption (126 vs. 138 mg/dl, P = 0.039). Legume consumption significantly increased mean cholesterol saturation index of gallbladder bile from 1.07 to 1.26 (P = 0.016), largely because of an increase in hepatic secretion of cholesterol from a mean of 90.2 mumol/h to 100.8 mumol/h (P = 0.042). Fecal neutral sterol output was unaffected by legumes, but fecal acidic sterols increased from a mean of 861 to 1202 mumol/day (P = 0.002) during legume consumption. Mean sterol balance became significantly more negative during legume consumption (-2140 vs. -2700 mumol/day, P = 0.037) indicating an increase in cholesterol synthesis. Mean fractional absorption of bile acid was lower during legume consumption than (0.947 vs. 0.960, P = 0.003). These data suggest that legume consumption lower LDL cholesterol by partially interrupting the enterohepatic circulation of bile acids and increases cholesterol saturation of bile by increasing hepatic secretion of cholesterol.
Increased consumption of dietary fiber is widely recommended to maintain or improve health, but knowledge of the relation between dietary fiber sources and cardiovascular disease risk factors is limited.
We examined the relation between the source or type of dietary fiber intake and cardiovascular disease risk factors in a cohort of adult men and women.
In a cross-sectional study, quintiles of fiber intake were determined from dietary records, separately for 2532 men and 3429 women. Age- and multivariate-controlled logistic models investigated the odds ratios of abnormal markers for quintiles 2-5 of fiber intake compared with the lowest quintile.
The highest total dietary fiber and nonsoluble dietary fiber intakes were associated with a significantly (P < 0.05) lower risk of overweight and elevated waist-to-hip ratio, blood pressure, plasma apolipoprotein (apo) B, apo B:apo A-I, cholesterol, triacylglycerols, and homocysteine. Soluble dietary fiber was less effective. Fiber from cereals was associated with a lower body mass index, blood pressure, and homocysteine concentration; fiber from vegetables with a lower blood pressure and homocysteine concentration; and fiber from fruit with a lower waist-to-hip ratio and blood pressure. Fiber from dried fruit or nuts and seeds was associated with a lower body mass index, waist-to-hip ratio, and fasting apo B and glucose concentrations. Fiber from pulses had no specific effect.
Dietary fiber intake is inversely correlated with several cardiovascular disease risk factors in both sexes, which supports its protective role against cardiovascular disease and recommendations for its increased consumption.
Supplements containing ascorbic acid, alpha-tocopherol, or beta-carotene do not protect against oxidative stress-related diseases in most randomized intervention trials. We suggest that other redox-active phytochemicals may be more effective and that a combination of different redox-active compounds (ie, antioxidants or reductants) may be needed for proper protection against oxidative damage.
We aimed to generate a ranked food table with values for total content of redox-active compounds to test this alternative antioxidant hypothesis.
An assay that measures the total concentration of redox-active compounds above a certain cutoff reduction potential was used to analyze 1113 food samples obtained from the US Department of Agriculture National Food and Nutrient Analysis Program.
Large variations in the content of antioxidants were observed in different foods and food categories. The food groups spices and herbs, nuts and seeds, berries, and fruit and vegetables all contained foods with very high antioxidant contents. Most food categories also contained products almost devoid of antioxidants. Of the 50 food products highest in antioxidant concentrations, 13 were spices, 8 were in the fruit and vegetables category, 5 were berries, 5 were chocolate-based, 5 were breakfast cereals, and 4 were nuts or seeds. On the basis of typical serving sizes, blackberries, walnuts, strawberries, artichokes, cranberries, brewed coffee, raspberries, pecans, blueberries, ground cloves, grape juice, and unsweetened baking chocolate were at the top of the ranked list.
This ranked antioxidant food table provides a useful tool for investigations into the possible health benefit of dietary antioxidants.
Pistacia vera L. is the only species of Pistacia genus producing edible nuts. This paper investigates the antioxidant potential of a Sicilian variety of pistachio nut by chemical as well as biological assays and measured antioxidant vitamins and a number of antioxidant polyphenols in either the hydrophilic and/or the lipophilic nut extract. In accordance with the majority of foods, the total antioxidant activity, measured as a TAA test, was much higher (50-fold) in the hydrophilic than in the lipophilic extract. Substantial amounts of total phenols were measured. The hydrophilic extract inhibited dose-dependently both the metal-dependent and -independent lipid oxidation of bovine liver microsomes, and the Cu+2-induced oxidation of human low-density lipoprotein (LDL). Peroxyl radical-scavenging as well as chelating activity of nut components may be suggested to explain the observed inhibition patterns. Among tocopherols, gamma-tocopherol was the only vitamin E isomer found in the lipophilic extract that did not contain any carotenoid. Vitamin C was found only in a modest amount. The hydrophilic extract was a source of polyphenol compounds among which trans-resveratrol, proanthocyanidins, and a remarkable amount of the isoflavones daidzein and genistein, 3.68 and 3.40 mg per 100 g of edible nut, respectively, were evaluated. With the exception of isoflavones that appeared unmodified, the amounts of other bioactive molecules were remarkably reduced in the pistachio nut after roasting, and the total antioxidant activity decreased by about 60%. Collectively, our findings provide evidence that the Sicilian pistachio nut may be considered for its bioactive components and can effectively contribute to a healthy status.
The total phenolic content (TPC), total antioxidant status (TAS), free radical scavenging capacity, inhibition of low density lipoprotein (LDL) cholesterol and metal chelating capacity of extracts of whole black and whole white sesame seeds and their hull fractions in 80% aqueous ethanol were investigated. The TPC of whole black sesame seeds and hull extracts were 29.9±0.6 and 146.6±0.6mgcatechinequivalents/g crude ethanolic extract, respectively. The corresponding values for white sesame were 10.6±1.6 and 29.7±0.9mgcatechinequivalents/g crude ethanolic extract. The TAS as determined by Trolox equivalent antioxidant capacity assay and expressed as Trolox equivalents was highest for black sesame hulls (65.9±1.7) while white seeds showed the lowest (4.4±0.6). Free radical scavenging capacity of sesame extracts (5–40μg/mL) was measured using 2,2-diphenyl-1-picrylhydrazyl radical. The highest scavenging capacity was obtained at 40μg/mL and was 94.9±0.8, 25.1±0.4, 14.4±0.9 and 2.5±0.4 for black sesame hulls, black sesame seeds, white sesame hulls and white sesame seeds, respectively. Inhibition of LDL oxidation at 100ppm level was highest for black sesame hulls (96.7%) followed by those for white sesame hulls (84.6%), black sesame (78.4%) and white sesame seeds (57.3%). Sesame products displayed good ferrous ion chelating capacities, which ranged from 12% to 46% and 17% to 62% at 50 and 100ppm levels, respectively. Results demonstrated considerable antioxidant activity of sesame products tested especially black sesame hulls.
The study was conducted to assess the content of tocopherols (α-, β-, γ- and δ-) and carotenoids (α- and β-carotene, zeaxanthin, lutein, cryptoxanthin and lycopene) in the unsaponifiable matter as well as the amount of total phenols of 10 different types of nuts. Tocopherols and carotenoids were analysed with HPLC, total phenols photometrically. The mean value of α-tocopherol equivalents ranged from non-detectable (macadamias) to 33.1 mg/100 g extracted oil (hazelnuts). Among all nuts, almonds and hazelnuts had the highest mean α-tocopherol content (24.2 and 31.4 mg/100 g extracted oil, respectively). β- and γ-tocopherols were prevalent in Brazil nuts, cashews, peanuts, pecans, pines, pistachios and walnuts. Mean values oscillated between 5.1 (cashews) and 29.3 (pistachios). Traces of δ-tocopherol (<4 mg/100 g extracted oil) were analysed in cashews, hazelnuts, peanuts, pecans, pines, pistachios and walnuts. There were no carotenoids detected in the tested nuts with the exception of pistachios. The mean content of total phenolics varied between 32 mg gallic acid equivalents/100 g (pines) and 1625 mg (walnuts). The results show the heterogenic amounts of antioxidants in nuts, which emphasises the recommendation of a mixed nuts intake.
Wholegrain and refined (white) wheat breads were prepared with the addition of high-oleic sunflower seed at various levels (8%, 12%, 16% flour basis). The nutritive value of breads was determined by measuring the chemical composition, including the mineral content, the fatty acid composition (saturated, monounsaturated, polyunsaturated, linoleic and linolenic acids) and the contents of tocopherols (α-, β-, γ-, δ-). The obtained data were used to estimate the intakes of nutrients and compare them to the dietary reference intakes (DRIs). The breads made with the addition of sunflower seed were sensorially acceptable, containing significantly more tocopherols, fat, essential fatty acids, crude fibre, copper and zinc. It was estimated that wholegrain supplemented breads would contribute to the corresponding DRIs in the range 33.7–40.8% (adults) for copper and 4.7–18.4% (males), i.e. 6.4–25.3% (females) for zinc, 18.3–26.8% (males), i.e. 25.9–37.9% (females) for linoleic (omega-6) acid, 7.4–7.6% (males), i.e. 10.7–11.0% (females) for alpha-linoleic (omega-3) acid.
Individual components of sesame oil unsaponifiable matter isolated from two different coloured seed varieties (white and brown) were identified and quantified. Unsaponifiables from the brown sesame variety were markedly different in their composition from those of the white variety. The brown variety contained higher amounts of total sterols and tocopherols but lower amounts of sesamin, sesamolin and total hydrocarbons than the white variety. The seeds were roasted at 180 °C for 30 min. Roasting increased some effective antioxidant compounds. These included relatively higher percentages of sesamol, Δ24,28 ethylidene sterols (Δ5 and Δ7-avenasterols), squalene, as well as tocopherols and some active browning substances. These antioxidative components are effective via synergistic action. Additionally, unsaponifiable matter from unroasted (USM) and roasted white sesame seeds (RSM) was added individually to sunflower oil at levels of 0.02, 0.05 and 0.1% and their effectiveness was compared with a control (no additives) at 63 °C. Results indicated that both USM and RSM had antioxidant activity which increased with increasing concentration. Compared to USM, the RSM was a better antioxidant in most cases. Moreover, the addition of 0.1% RSM gave a strong antioxidative efficiency and this could be used as an alternative natural antioxidant for food applications.
A simple and rapid procedure was developed for the direct measurement of the antioxidant capacity of cereals. It entails grinding of cereals, mixing with 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) reagent, centrifugation and measure of the absorbance. The ABTS reagent was dissolved in a mixture of ethanol:water (50:50, v/v), instead of 100% ethanol, in order to overcome low solubility of water-soluble antioxidant compounds of some cereals. A reaction time of 30 min allowed plateau values to be reached during the antioxidant capacity measurement of cereal samples. The accuracy of the direct procedure was confirmed by measuring, in solid state, the antioxidant activity of pure phenolic compounds.The direct procedure gave results of total antioxidant capacities significantly higher than those determined by the traditional procedure (multiple extraction followed by alkaline hydrolysis) for most whole meal cereals, suggesting that such a procedure was not always sufficient to properly assess the antioxidant capacity of bound phenolic compounds in cereals. The proposed extraction-independent procedure for measuring antioxidant capacity of cereals will facilitate the inter-laboratory data comparison, the construction of reliable antioxidant capacity database and the screening of large sampling of cereals for their nutraceutical characteristics.
Pumpkin seed oil is a common salad oil in Austria. It is not only of interest because of its typical taste but also because of its potential in curing prostate disease. Besides the fatty acids, the micronutrients, which comprise vitamin E, phytosterols and lignans, are of special interest. Since the seeds are roasted before pressing of the oil, changes occur in the composition of the fatty acids and micronutrients. The oxidation-sensitive linoleic acid decreases from 54.6 to 54.2% whereas the concentrations of the vitamin E isomers show a decrease during the first 40 min of about 30% followed by an increase during the last 20 min to about the same level as at the beginning of the roasting process. The concentrations of α-tocopherol and γ-tocopherol in the fresh dried seeds are 37.5 and 383 μg/g, respectively. The concentration of the tocotrienols is about one third of the corresponding tocopherols. The initial concentration of the total sterols (1710 μg/g) increases to 1930 μg/g. The increases of the sterols and vitamin E during the roasting process could be attributed to the changes of the seed meal, since at the end of the roasting the oil emerges from the seeds resulting in altered chemical behaviour of the extraction process. Secoisolariciresinol, which is only detectable at the beginning with a concentration of 3.8 μg/g, is destroyed after 20 min.
In this study, antioxidant activities of water-soluble protein extracts from chickpeas and white beans were investigated. The area under the curve (AUC) values of lyophilized crude protein extracts (dialyzed or undialyzed) from thermally processed (121 °C for 20 min) or heat-treated (90 °C for 20 min) chickpeas (73–91 μmol trolox/g) and white beans (39–67 μmol trolox/g) indicated a higher free radical-scavenging capacity and thermostability for chickpea proteins than for white bean proteins. The thermal processing also increased the Fe+2-chelating capacity of lyophilized chickpea crude protein extracts 1.8-fold whereas it caused a 2.3-fold reduction in the Fe+2-chelating capacity of lyophilized white bean crude protein extracts. Dialysis increased the protein content of lyophilized chickpea extracts 1.5–2-fold but it did not affect the protein content of lyophilized white bean extracts significantly. Ammonium sulfate precipitation was not effective for selective precipitation of antioxidant proteins. However, it improved the free radical-scavenging capacity of lyophilized protein extracts from thermally processed chickpeas and white beans by almost 25% and 100%, respectively. DEAE-cellulose chromatography, indicated the presence of five (A1–A5) and three (B1–B3) antioxidant protein fractions in heat-treated and thermally processed chickpea protein extracts, respectively, and can be used for the partial purification of antioxidant proteins. The results of this study showed the good potential of chickpea proteins as thermostable natural food antioxidants.
The radical scavenging activity (RSA) of coffee brews obtained from different types of coffee was studied as a function of the roasting degree and equivalent thermal effect (expressed as ), and the relative contribution of the phenolic fraction (PF) and non-phenolic fraction (NPF) to the overall RSA was evaluated. Brews extracted from medium roasted coffee showed a higher RSA than those from green coffee due to an increase of the RSA of the NPF upon roasting. The RSA of the NPF increased with increasing roasting degree together with the accumulation of brown coloured Maillard reaction products (MRPs). Brews from dark coffee showed lower RSA than those from medium roasted coffee due to polyphenols degradation which, in turn, caused an RSA depletion not counterbalanced by an increase of the RSA of NPF. The relative contribution of NPF to the overall RSA of the brew is in fact much lower than that of the PF. Roasting processes with similar values resulted in the same RSA independent of an average temperature variation from 170 to 190 °C and coffee type.The AOA changes in brews from commercial coffee samples (medium and dark roasted) were more dependent on roasting severity than on the type of coffee.
Nutritional factors are widely considered to be critical for human health. Overwhelming evidence from epidemiological studies indicate that diets rich in fruit and vegetables are associated with a lower risk of several degenerative diseases. These results have created a new perspective concerning the potential of diet in preventing serious diseases in the future. However, the health-promoting capacity of fruit and vegetables strictly depends on their processing history. This aspect has been generally neglected or scarcely considered in present nutritional and epidemiological studies. Processing is expected to affect content, activity and bioavailability of bioactive compounds.The aim of this article, therefore, is to review the effects of processing on the antioxidant properties of foods by means of a multidisciplinary approach. It is believed that the implications of this challenging and rapidly advancing area may contribute to enhanced industrial competitiveness as well as consumer health and well-being.
Browning reactions represent an interesting research area for the implications in food technology, nutrition and health. The development of some non-enzymatic browning reactions, such as Maillard reaction, has been recently associated to the formation of compounds with strong antioxidant capacity. In this paper, the relation between colour changes due to non-enzymatic browning and the formation of compounds with antioxidant activity is discussed. Simple positive or complex correlation between colour and antioxidant properties can be found depending on composition and technological history of the product. Complex relations between these variables are generally obtained in multi-component and in formulated foods, where the simultaneous development of a number of reactions, interacting or prevailing Maillard reaction itself, can affect in opposite ways the overall antioxidant properties and colour of the product.
Extraction-dependent methods were used to evaluate the antioxidant capacity up to now. The extraction conditions applied before the measurement represent a source of variations among laboratories and in some cases are not reliable. The direct procedure described in this paper skips all time-consuming solvent extraction and hydrolysis steps. A review of the solubility and localization of food antioxidant compounds was provided as base to understand the advantage of the direct procedure with respect to the extraction protocols present in the literature. The application of the procedure to some case-studies was also illustrated.
The caffeoylated amino acid clovamide [(−)-N-[3′-4′-dihydroxy-(E)-cinnamoyl]-dihydroxyphenylalanine] was identified in the antioxidant polyphenolic fraction of cocoa (Theobroma cacao L.). As a naturally occurring caffeoyl conjugate, clovamide represents an interesting antiradical/antioxidant compound. We have streamlined the synthesis of clovamide, investigating the effect of roasting on its content in different samples of cocoa beans from different geographic origin. Within the samples analyzed, those from Ghana showed the highest clovamide content (2.637 mg/kg, powder from fermented beans, dry weight; 1.264 mg/kg, powder from roasted nibs, dry weight), while the Arriba samples showed the lowest values. A poor correlation existed between the contents of clovamide and the antioxidant properties of cocoa, while roasting caused a dramatic reduction in the clovamide contents (up to 59.13% in Arriba cocoa), paralleled by an overall decrease of the antioxidant properties, as measured by the DPPH method. Taken together, results show that while roasting is detrimental for the clovamide contents of cocoa, no correlation exists between the concentration of this compound and the overall antioxidant properties of cocoa samples, and suggest that clovamide is important but not critical for the antioxidant activity of cocoa.
Anacardic acids, 6-pentadec(en)ylsalicylic acids isolated from the cashew Anacardium occidentale L. (Anacardiaceae) nut and apple, were found to possess preventive antioxidant activity while salicylic acid did not show this activity. These anacardic acids prevent generation of superoxide radicals by inhibiting xanthine oxidase (EC 1.1.3.22, Grade IV) without radical-scavenging activity. Notably, the inhibition kinetics of anacardic acids do not follow hyperbolic dependence of enzyme inhibition on inhibitor contents (Michaelis–Menten equation) but follow the Hill equation instead. Anacardic acid (C15:1) inhibited the soybean lipoxygenase-1 (EC 1.13.11.12, Type 1) catalyzed oxidation of linoleic acid with an IC50 of 6.8 μM. The inhibition is a slow and reversible reaction without residual enzyme activity. The inhibition kinetics indicate that anacardic acid (C15:1) is a competitive inhibitor and the inhibition constant, KI, was 2.8 μM. Anacardic acids act as antioxidants in a variety ways, including inhibition of various prooxidant enzymes involved in the production of the reactive oxygen species and chelate divalent metal ions such as Fe2+ or Cu2+, but do not quench reactive oxygen species. The C15-alkenyl side chain is largely associated with the activity.
This article has been retracted at the request of the Editor-in-Chief. Please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy).Reason: It has been drawn to the Editors' attention that this paper contains significant parts copied (without citing the reference) from a previously published paper: Biologically Active Components and Nutraceuticals in Peanuts and Related Products: Review. Joel Isanga and Guo-Nong Zhang, Food Reviews International, 23 (2007) 123–140. As it duplicated previously published material, we must retract the paper published in Trends in Food Science & Technology.
Pumpkin (Cucurbita pepo L.) seed oil is a special product of the southern Austrian region. For the production of the oil, prior to the pressing procedure, the seeds are roasted at temperatures up to 130 °C, which leads to the formation of the typical roasty and nutty aroma. In this study, changes of composition of the volatile fraction of the pumpkin seeds in course of the roasting process are investigated. The analyses were performed by gas chromatography–mass spectrometry after headspace solid phase microextraction. The results show very clearly that the roasting process at these high temperatures is necessary to obtain the typical aroma of the pumpkin seed oil. Compounds that are responsible for roasty/nutty aroma notes (alkylated pyrazines, as well as 2-acetylpyrrole) require a roasting temperature of at least 90 °C. Other compounds that show significant changes in concentration are mainly Strecker degradation products, as well as compounds derived from lipid oxidation.
Total phenolic content of seven improved common bean cultivars (Phaseolus vulgaris L.) namely, Negro Altiplano, Negro Durango, Negro Sahuatoba, Flor de mayo sol, Flor de Mayo Bajío, Flor de Mayo 94044MX and Bayo Madero were analyzed. Acetone and methanol extracts from bean cotyledons were obtained by successive extractions. Total phenolic content was evaluated following Folin–Ciocalteu method; antioxidant activity by the DPPH technique; antimutagenic potential by the Ames method; and preliminary identification was realized by 2D-TLC. Results indicated high correlation between total phenol content and antioxidant activity for acetone extracts, and also high correlation between antioxidant and antimutagenic activities. In contrast, low correlation coefficients were obtained for methanol extracts. Three cultivars (two Negro cultivars and a Flor de Mayo type) showed lower antimutagenic activity than catechin.
Peanuts are an important food crop with many health benefits of their consumption realized by consumers worldwide. Limited information is available on non-nutrient phytochemical composition of peanuts and their relative antioxidant values, knowledge that may serve to increase overall marketability of the crop. Shelled peanuts from eight cultivars and four experimental genotypes with either high or normal oleic acid contents were evaluated for phytochemical, antioxidant, and sensory properties (roasted only) before and after dry roasting under constant time and temperature conditions. Peanuts were evaluated for color, total and individual phenolics, and antioxidant capacity while a trained sensory panel evaluated the peanuts for roasted and burnt peanut flavor and aroma, sweetness, and bitterness. Overall, no meaningful differences were observed for phytochemical and antioxidant properties between high and normal oleic acid peanuts, but differences were present among cultivars. However, high oleic acid varieties had higher burnt peanut aroma and burnt peanut flavor compared to normal oleic peanuts but were not necessarily independent from roasted peanut aroma and flavor. Numerous polyphenolics were separated and characterized based on spectral similarities to p-hydroxybenzoic acid, tryptophan, and p-coumaric acid in both free and bound (esterified) forms. Peanuts were found to be a good source of antioxidant polyphenolics, such as p-coumaric acid, that may be contributing factors to potential health benefits of their consumption.
An HPLC method, using detection after postcolumn derivatization with p-dimethylaminocynnamaldehyde (DMACA), was developed for the quantitative analysis of individual flavanols in food. This method was applied to flavanol determination in 56 different kinds of Spanish food products, including fruit, vegetables, legumes, beverages (cider, coffee, beer, tea, and wine), and chocolate. The determined compounds corresponded to the catechins and proanthocyanidin dimers and trimers usually present in food and, therefore, they were representative of the flavanols of low degree of polymerization consumed with the diet. The data generated could be used for calculation of the dietary intake of either individual or total flavanols, which would allow the further establishment of epidemiological correlations with the incidence of chronic diseases. Similar flavanol profiles were found in the different samples of a similar type of product, even though important variations could exist in the concentrations of total and individual flavanols among them. This was attributed to factors such as sample origin, stage of ripeness, post-harvesting conservation, and processing. Total flavanol contents varied from nondetectable in most of the vegetables to 184 mg/100 g found in a sample of broad bean. Substantial amounts were also found in some fruits, such as plum and apple, as well as in tea and red wine. Epicatechin was the most abundant flavanol, followed by catechin and procyanidin B2. In general, catechins were found in all the flavanol-containing products, but the presence of gallocatechins was only relevant in pomegranate, broad bean, lentil, grape, wine, beer, and tea, and most of the berries. Galloyled flavanols were only detected in strawberry, medlar, grape, and tea.
1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity of the 70% aqueous acetone extract from the seed coat of the brown soybean variety, Akita-Zairai, was investigated. The activity of the seed coat of Akita-Zairai was much higher than that of three other reddish-brown varieties, but lower than that of two black varieties, and was closely dependent on the content of phenolic compounds. In the LH20 column chromatography of Akita-Zairai, high DPPH radical-scavenging activities were detected in the fractions eluted with MeOH and 70% aqueous acetone. Proanthocyanidins were also detected in fractions showing high radical-scavenging activities. Matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry analysis showed that the degree of polymerization (DP) of the procyanidins contained in the brown or black soybean seed coat was as high as DP30.
Natural (raw) and roasted hazelnuts were compared for their differences in volatile components and sensory responses. A total of 79 compounds were detected in both hazelnuts, of which 39 (27 positive, 5 tentative, and 7 unknown) were detected in natural hazelnut and 71 (40 positive, 14 tentative, and 17 unknown) were detected in roasted hazelnut. These included ketones, aldehydes, pyrazines, alcohols, aromatic hydrocarbons, furans, pyrroles, terpenes, and acids. Pyrazines, pyrroles, terpenes, and acids were detected in roasted hazelnut only. Concentrations of several compounds increased as a result of roasting and these may play significant roles in the flavor of roasted hazelnut. Pyrazines together with ketones, aldehydes, furans, and pyrroles may contribute to the characteristic roasted aroma of hazelnut. Descriptive sensory analysis (DSA) showed that some flavor attributes such as "aftertaste", "burnt", "coffee/chocolate-like", "roasty", and "sweet" were rated significantly higher in roasted hazelnut compared to its natural counterpart. Natural and roasted hazelnuts can be distinguished using these attributes.
Lentils (Lens culinaris L.) are a popular food in many countries. However, little is known about their phenolic composition. Because polyphenols in lentils are located essentially in their seed coat, the objective of this work was to study the composition of proanthocyanidins, the major group of polyphenols, in this part of the tissue. The use of C(18) Sep-Pak cartridges permitted the fractionation of lentil seed coat extract into monomer, oligomer, and polymer proanthocyanidin fractions. Subsequent thiolysis of oligomer and polymer fractions followed by HPLC analysis allowed the mean degree of polymerization (mDP) and the structural composition of proanthocyanidins to be determined. A fractionation of lentil seed coat extracts on a polyamide column followed by HPLC and HPLC-DAD-MS analyses was used to identify the individual proanthocyanidins. The results showed that the major monomeric flavan-3-ol was (+) catechin-3-glucose, with lesser amounts of (+)-catechin and (-)-epicatechin. In the oligomer fraction, various dimer, trimer, and tetramer proanthocyanidins constituted of catechin, gallocatechin, and catechin gallate units were identified, and several procyanidins and prodelphinidins from pentamers to nonamers constitute the polymer fraction. The most abundant proanthocyanidins in the seed coat of lentils are the polymers (65-75%), with a mDP of 7-9, followed by the oligomers (20-30%), with a mDP of 4-5.
Both lipophilic and hydrophilic antioxidant capacities were determined using the oxygen radical absorbance capacity (ORAC(FL)) assay with fluorescein as the fluorescent probe and 2,2'-azobis(2-amidinopropane) dihydrochloride as a peroxyl radical generator on over 100 different kinds of foods, including fruits, vegetables, nuts, dried fruits, spices, cereals, infant, and other foods. Most of the foods were collected from four different regions and during two different seasons in U.S. markets. Total phenolics of each sample were also measured using the Folin-Ciocalteu reagent. Hydrophilic ORAC(FL) values (H-ORAC(FL)) ranged from 0.87 to 2641 micromol of Trolox equivalents (TE)/g among all of the foods, whereas lipophilic ORAC(FL) values (L-ORAC(FL)) ranged from 0.07 to 1611 micromol of TE/g. Generally, L-ORAC(FL) values were <10% of the H-ORAC(FL) values except for a very few samples. Total antioxidant capacity was calculated by combining L-ORAC(FL) and H-ORAC(FL). Differences of ORAC(FL) values in fruits and vegetables from different seasons and regions were relatively large for some foods but could not be analyzed in detail because of the sampling scheme. Two different processing methods, cooking and peeling, were used on selected foods to evaluate the impact of processing on ORAC(FL). The data demonstrated that processing can have significant effects on ORAC(FL). Considering all of the foods analyzed, the relationship between TP and H-ORAC(FL) showed a very weak correlation. Total hydrophilic and lipophilic antioxidant capacity intakes were calculated to be 5558 and 166 micromol of TE/day, respectively, on the basis of data from the USDA Continuing Survey of Food Intakes by Individuals (1994-1996).
The effect of roasting on some nutritional characteristics of hazelnut lipidic fraction was investigated. Hazelnuts (Corylus avellana L.) were submitted to several different thermal treatments, comprising different temperatures (125-200 degrees C) and times of exposure (5, 15, and 30 min) and analyzed for their moisture and crude fat. Raw and roasted hazelnuts were also analyzed for their compositions in phytosterols and fatty acids (including trans isomers) by GC-FID, triacylglycerols by HPLC-ELSD, and tocopherols and tocotrienols by HPLC-DAD/fluorescence spectroscopy. Minor changes occurred in the fatty acid and triacylglycerol compositions. As temperatures and roasting periods increased, generally, a modest increase of oleic and saturated fatty acids and a decrease of linoleic acid, expressed as relative percentages, occurred. Similarly, an increase of triacylglycerols containing oleic acid moieties and a decrease of those containing linoleic acid moieties were found in the roasted samples. Roasting caused a modest decrease of the beneficial phytosterols (maximum 14.4%) and vitamin E homologues (maximum 10.0%) and a negligible increase of the trans fatty acids.
A method based on a derivatization with dansyl chloride and LC-MS-MS determination was developed for the quantitation of 2-methylbutyl-, 3-methylbutyl-, 2-phenylethyl-, 3-(methylthio)propyl-, and 2-methylpropylamine. Its application on unfermented, fermented, and roasted cocoas from Ghana and Sulawesi revealed an increase of all amines, except the 3-(methylthio)propylamine, during cocoa fermentation, suggesting an enzymic formation from the parent amino acids isoleucine, leucine, phenylalanine, and valine. However, a much more pronounced formation of most of the amines was measured after roasting of the cocoa, leading to concentrations in the milligrams per kilogram range. This result suggested a new "thermogenic" formation pathway of "biogenic amines". A comparison of the amounts of the amines and the aldehydes in roasted cocoa revealed similar concentrations, for example, for 2- and 3-methylbutanal and the respective amines, whereas the amounts of 2-phenylethylamine were much higher as compared to the amounts of phenylacetaldehyde. Strecker-type model systems, in which each parent amino acid was reacted with 2-oxopropanal, revealed the formation of both the amine and the aldehyde; however, in contrast to cocoa, the concentrations of the aldehydes were always much higher as compared to the amines. The results showed for the first time the thermally induced generation of "biogenic amines" from amino acids. Possible reasons for the different ratios of amines versus aldehydes formed during the roasting of cocoa or the model systems, respectively, are discussed.
Phenolic compounds in the aqueous systems were extracted, from hazelnut kernel (HK) and hazelnut green leafy cover (HGLC), with 80% (v/v) ethanol (HKe and HGLCe) or 80% (v/v) acetone (HKa and HGLCa). The extracts were examined for their phenolic and condensed tannin contents and phenolic acid profiles (free and esterified fractions) as well as antioxidant and antiradical activities by total antioxidant activity (TAA), antioxidant activity in a beta-carotene-linoleate model system, scavenging of DPPH (2,2-diphenyl-1-picrylhydrazyl) radical, and reducing power. Significant differences (p < 0.05) in the contents of total phenolics, condensed tannins, and TAA existed among the extracts that were examined. HGLCa extract had the highest content of total phenolics (201 mg of catechin equivalents/g of extract), condensed tannins (542 mg of catechin equivalents/g of extract), and TAA (1.29 mmol of Trolox equivalents/g of extract) followed by HGLCe, HKa, and HKe extracts, respectively. Five phenolic acids (gallic acid, caffeic acid, p-coumaric acid, ferulic acid, and sinapic acid) were tentatively identified and quantified, among which gallic acid was the most abundant in both free and esterified forms. The order of antioxidant activity in a beta-carotene-linoleate model system, the scavenging effect on DPPH radical, and the reducing power in all extracts were in the following order: HGLCa > HGLCe > HKa > HKe. These results suggest that both 80% ethanol and acetone are capable of extracting phenolics, but 80% acetone was a more effective solvent for the extraction process. HGLC exhibited stronger antioxidant and antiradical activities than HK itself in both extracts and could potentially be considered as an inexpensive source of natural antioxidants.
With the aim to expand the Italian total antioxidant capacity (TAC) database, the TAC values of 11 spices, 5 dried fruits, 7 sweets, 18 cereal products, 5 pulses, and 6 nuts were determined using three different assays and considering the contribution of bound antioxidant compounds in fiber-rich foods (i. e. cereals, legumes, and nuts). Among spices, saffron displayed the highest antioxidant capacity, whereas among dried fruits, prune exhibited the highest value. The TAC values of all the chocolates analyzed were far higher than the other sweet extracts measured. Among cereal products, whole meal buckwheat and wheat bran had the greatest TAC. Among pulses and nuts, broad bean, lentil and walnuts had the highest antioxidant capacity, whereas chickpeas, pine nuts and peanuts were less effective. The contribution of bound phytochemicals to the overall TAC was relevant in cereals as well as in nuts and pulses. The complete TAC database could be utilized to properly investigate the role of dietary antioxidants in disease prevention.
Coffee is one of the most popular beverages in the world. It is consumed for its refreshing and stimulating properties. Carbohydrates are the major constituents of coffee beans and serve various functions like binding of aroma, stabilization of foam, formation of sedimentation, and increased viscosity of the extract. The principal low molecular weight carbohydrate is sucrose and no evidence of other simple oligosaccharides has been found. Polysaccharide fraction from green coffee is dominated by arabinogalactan, galactomannan, and cellulose. The polysaccharide content is reduced during roasting due to degradation to low molecular weight carbohydrates (viz., mono and oligosaccharide) and become more extractable. Various methods that can be employed to extract the carbohydrate from roasted coffee are sequential extraction, acid hydroloysis, hot water extraction, enzymatic extraction etc. Carbohydrates from coffee can be quantitatively determined by liquid chromatography, high performance anion exchange chromatography, size exclusion chromatography, and high performance liquid chromatography. Besides improving the organoleptic quality of the coffee beverage, carbohydrates also possess various biological activities such as lowering colon cancer risk. Besides their sheer mass, a variety of evidences testify to the important contribution that the polysaccharide content makes to the character of the final brew. Although a number of chemical and enzymatic methods have been devised to isolate and quantify the carbohydrates of R&G coffee, till date hot water extraction is the only method which can be accepted as a most feasible process and hence, there is wide scope of further research for the efficient and economically viable technology for extraction of carbohydrates from coffee.
The measurement of antioxidant activity was limited to soluble components to date. Functional groups, which are bound to insoluble matters, may exert antioxidant activity by a surface reaction phenomenon. This hypothesis was tested on the insoluble matters of foods, food ingredients, and Maillard reaction products (MRPs). Insoluble matters were prepared by consecutive washes with water and methanol followed by a lyophilization of the insoluble residue. The measurement was performed by a new procedure using 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazil (DPPH) colored radicals. These insoluble matters always showed antioxidant activity. Alkali hydrolysis reduced up to 90% the antioxidant activity of cereal-based insoluble matters, thus confirming that fiber-bound compounds have a major role in their antioxidant activity. The antioxidant activity of the insoluble MRPs was not significantly affected by processing conditions, but severe treatments increased the ratio between insoluble and soluble matters. The contribution of insoluble matter to total antioxidant activity was limited for fruits and vegetables, but it was relevant for cereal-based foods and increased over 50% for dietary-fiber-rich ingredients.
Peanuts are consumed mostly as processed products. Although the effect of processing on isoflavone composition of legumes has been extensively studied, there has been no such study on peanuts. The objective of this study was to evaluate the effect of processing (boiling, oil- and dry-roasting) on the phytochemical composition of peanuts. Boiling had a significant effect on the phytochemical composition of peanuts compared to oil- and dry-roasting. Boiled peanuts had the highest total flavonoid and polyphenol content. The biochanin A and genistein content of boiled peanut extracts were two- and fourfold higher, respectively. trans-Resveratrol was detected only in the boiled peanuts, with the commercial product having a significantly (p < or = 0.05) higher concentration. Ultraviolet and mass spectrometry chromatograms for the boiled peanut extracts show the presence of four additional peaks that were not observed in the raw peanut extracts.
The objective of this study was to characterize the phenolic compounds and antioxidant activities of U.S.-produced cool season legumes. A total of 33 cool season legume samples were selected. Some common beans and soybeans were included for comparisons. Total phenolic content (TPC), total flavonoid content (TFC), and condensed tannin content (CTC) were analyzed. Ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, and oxygen radical absorbance capacity (ORAC) were used for analyzing antioxidant properties. Color of the legume flour and the seed coat was also analyzed. TPC, TFC, CTC, FRAP, DPPH, and ORAC values of legumes were significantly different not only between classes but also among samples within each class. Among cool season legume classes, lentils possessed the highest concentrations of the phenolic compounds and antioxidant activities. Colored common beans and black soybeans exhibited higher TPC, TFC, CTC, FRAP, DPPH, and ORAC values than those of yellow peas, green peas, and chickpeas. Antioxidant activities (FRAP, DPPH, and ORAC) were strongly correlated (r= 0.96, 0.94, and 0.89, respectively, P < 0.01) with TPC. TPC and ORAC were moderately correlated (P < 0.01) with either the seed hull surface color or the flour color.
Antioxidants in food—practical applications EVect of roasting on hazelnut lipids
- J Pokorny
- Schmidt
- J Pokorny
- N Yanishlieva
- Gordon
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Biologically active components and nutraceuticals in sesame and related products: a review and prospect
- P B Kanu
- K Zhu
- J B Kanu
- H Zhou
- PB Kanu
Kanu PB, Zhu K, Kanu JB, Zhou H et al (2007) Biologically active
components and nutraceuticals in sesame and related products: a
review and prospect. Trends Food Sci Technol 18:599–608