The use of an enzymatic extraction procedure for the enhancement of highland barley (Hordeum vulgare L.) phenolic and antioxidant compounds

A multistep enzymatic extraction method was compared with a conventional chemical extraction process to evaluate the phenolic content and antioxidant activity of highland barley (Z2, Zangqing 25; CHQK, Changheiqingke). The main phenolic compound extracted was (+)‐catechin, followed by ferulic acid, p‐coumaric acid, caffeic acid and chlorogenic acid. The multi‐enzymatic digestion yielded a higher retrieval of (+)‐catechin compared to the conventional chemical extraction procedure (P < 0.05). Compounds obtained from the multi‐enzymatic digestion process exhibited significantly higher (P < 0.05) antioxidant activities determined by oxygen radical absorbance capacity (ORAC) and cellular antioxidant activity (CAA) when compared to chemical extracts. These results suggest that highland barley subjected to in vitro multi‐enzymatic digestion exhibits a higher phenolic content and antioxidant activity than the chemical extraction, and this multi‐enzymatic digestion coupled with the CAA assay may be a valuable tool to evaluate the antioxidant potential of wholegrains and fruits, as well as vegetables.     

Antioxidant activity and antimicrobial properties of phenolic extracts from acerola (Malpighia emarginata DC) fruit

The antioxidant activity and antimicrobial property of phenolic extracts from acerola (Malpighia emarginata DC) fruit were assessed. The contribution of ascorbic acid and phenolic compounds in the total antioxidant capacity of the extracts was also evaluated. The extracts showed high total phenolic values and possessed high antioxidant activity as expressed by 2,2′‐diphenylpicrylhydrazyl (DPPH) and oxygen radical absorbance capacity assays (ORAC). The ascorbic acid content ranged from 405 to 1744 mg/100 g of fruit on a fresh weight basis. The antioxidant capacity of the phenolic fractions was in the following order: anthocyanins<phenolic acids<flavonoids. The phenolic fractions contributed 7.1–36.5% of the antioxidant activity expressed by ORAC, whereas the contribution of ascorbic accounted for 18–39% of the total activity. Selected extracts from the flavonoids fraction showed some activity against Staphylococcus aureus.     

Phenolic Compounds and Antioxidant Capacities of 10 Common Edible Flowers from China

The free and bound phenolic compounds in 10 common Chinese edible flowers were investigated using reversed phase high‐performance liquid chromatography. Their antioxidant capacities were evaluated using 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical‐scavenging activity, 2,2'‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulphonic acid) (ABTS) radical‐scavenging activity, oxygen radical absorption capacity (ORAC), ferric reducing antioxidant power (FRAP), and cellular antioxidant activity (CAA). Free factions were more prominent in phenolic content and antioxidant capacity than bound fractions. Paeonia suffruticosa and Flos lonicerae showed the highest total phenolic content (TPC) 235.5 mg chlorogenic acid equivalents/g of dry weight and total flavonoid content 89.38 mg rutin equivalents/g of dry weight. The major phenolic compounds identified were gallic acid, chlorogenic acid, and rutin. P. suffruticosa had the highest antioxidant capacity in the DPPH, ABTS, and ORAC assays, which were 1028, 2065, 990 μmol Trolox equivalents/g of dry weight, respectively, whereas Rosa chinensis had the highest FRAP value (2645 μmol Fe²⁺ equivalents /g of dry weight). The P. suffruticosa soluble phenolics had the highest CAA, with the median effective dose (EC₅₀) 26.7 and 153 μmol quercetin equivalents/100 g of dry weight in the phosphate buffered saline (PBS) and no PBS wash protocol, respectively. TPC was strongly correlated with antioxidant capacity (R = 0.8443 to 0.9978, P < 0.01), which indicated that phenolics were the major contributors to the antioxidant activity of the selected edible flowers.     

Characterisation and comparison of phenols,flavonoids and isoflavones of soymilk and their correlations with antioxidant activity

To investigate the relationship between bioactive compounds and antioxidant property, total phenolic content (TPC), total flavonoid content (TFC), individual and total isoflavone content of soymilk and their correlations with oxygen‐radical‐absorbing capacity (ORAC), ferric reducing antioxidant power (FRAP) and 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical scavenging capacity values were evaluated and compared. Results showed that TPC, TFC, isoflavones (including concentration and profiles) and antioxidation activity significantly varied among ten tested soybean cultivars. Significant correlations were established between DPPH and TFC (r = 0.553, P < 0.01), DPPH and TPC (r = 0.753, P < 0.01), FRAP and TFC (r = 0.599, P < 0.01) and FRAP and TPC (r = 0.616, P < 0.01). Positive linear correlations were found between subtotal, total isoflavones and ORAC. Unlike other isoflavone monomers, aglycone isoflavones correlated positively with DPPH and FRAP significantly. DPPH well correlated with FRAP, whereas neither DPPH nor FRAP correlated with ORAC. TPC, TFC, individual and total isoflavone values are potentially useful for soymilk antioxidant activity assessment.     

Fermented coconut jelly as a probiotic vehicle,physicochemical and microbiology characterisation during an in vitro digestion

There is little information on the survival of probiotics in plant-based foods after simulated gastric and intestinal conditions, likewise the microstructure arrangement in the no-dairy fermented food. This work aimed to study if the agar–agar in a fermented coconut jelly confers protection to probiotics, phenolic and antioxidant compounds during in vitro digestion. Samples containing higher agar–agar amounts tend to retain (P < 0.05) antioxidant and phenolic compounds in their network better, even after the in vitro digestion. Also, a compact and homogeneous microstructure was observed by the Confocal Laser Scanning Microscopy. The texture profile analysis shows that 1% of agar samples presented the maximum hardness (P < 0.05) due to more bonding points and intermolecular interactions. Finally, the survival of probiotics remained above the recommended values (10⁶–10⁷ CFU g⁻¹) after the in vitro digestion of a product with probiotic potential.     

Physiochemical and nutritional characteristics,bioaccessibility and sensory acceptance of baked crackers containing broccoli co-products

The effects of the inclusion of broccoli co-products into crackers on the bioaccessibility as well as their overall physical and nutritional quality were evaluated. Crackers were formulated using a 12.5 or 15.0% flour substitution level. Broccoli-containing crackers presented higher specific volume and spread ratio and lower weight and specific volume than control crackers (P < 0.05). Crackers containing broccoli co-products showed an increased green hue and a higher colour intensity (P < 0.05). Incorporation of broccoli co-products into crackers significantly increased the total phenolic content and antioxidant capacity (P < 0.05). A simulated gastrointestinal digestion suggested that the amount of phenolic and antioxidant compounds released during digestion might be higher than what could be expected from common water-organic extracts. The incorporation of broccoli co-products into baked crackers would not only reduce the amount of food discarded as waste but also promote health and open novel commercial opportunities to food processors.     

Effect of simulated gastrointestinal digestion on phenolic composition and antioxidant capacity of cooked cowpea (Vigna unguiculata) varieties

Consumption of diets rich in phenolic compounds has been associated with reduced risk of chronic diseases. The effect of cooking and simulated gastrointestinal digestion on phenolic compounds and antioxidant properties of two cowpea (Vigna unguiculata) types was determined. Phenolic acids, flavan‐3‐ols and flavonols were the main groups of phenolic compounds identified. Cooking and simulated enzyme digestion of the cooked cowpea samples rendered some phenolics less extractable (possibly by promoting binding with other food components) or more extractable (possibly by release of bound forms). Total phenolic contents and radical scavenging properties of the cowpeas were reduced upon cooking, but increased upon simulated enzyme digestion. Cowpea extracts inhibited human LDL oxidation at a concentration of 2 mg mL^?1 possibly due to their phenolic content. Phenolic compounds in cowpea can potentially protect against cardiovascular diseases for which LDL oxidation is a risk factor.     

Effect of addition of Agaricus blazei mushroom residue to milk enriched with Omega‐3 on the prevention of lipid oxidation and bioavailability of bioactive compounds after in vitro gastrointestinal digestion

The residue from a hydroalcoholic extract of the mushroom Agaricus blazei (MAR) was evaluated for phenolic compounds, flavonoids and antioxidant activity. The ability of MAR to slow the oxidation of Omega‐3 resulting from light exposure in milk matrix, and its bioavailability after in vitro digestion was investigated. MAR presented phenolic compounds and flavonoids and showed antioxidant activity. At each concentration, addition of MAR to Omega‐3‐supplemented milk inhibited the production of conjugated dienes and malonaldehyde compared with samples without MAR. The bioavailability assay showed that polyphenols were still present after in vitro digestion and had antioxidant activity.     

Effect of in vitro‐simulated gastrointestinal digestion on the stability and antioxidant activity of blueberry polyphenols and their cellular antioxidant activity towards HepG2 cells

In this study we investigated the influence of in vitro‐simulated gastrointestinal digestion on the bioaccessibility and antioxidant activity of polyphenols from blueberries (Vaccinium spp.). Total phenolic, anthocyanin, and flavonoid content was determined, and extract and digesta compositions were analysed by HPLC‐ESI‐MS/MS. The phenolic compounds were relatively stable under a gastric environment, whereas polyphenols and anthocyanins were unstable under an intestinal environment. The bioaccessibility of polyphenol, anthocyanin, and flavonoid was greatly decreased after the intestinal digestion, and the recoveries were only 13.93%, 1.95%, and 15.68% (the IN sample), respectively. Polyphenolic profile alteration occurred during in vitro‐simulated gastrointestinal digestion. Changes of phenolic compound antioxidant activity during digestion correlated with polyphenol, flavonoid, and caffeic acid concentrations. Digested extract cellular antioxidant activity was lower than non‐digested extract activity (P < 0.05). Polyphenol dose–response correlations with cellular antioxidant activity were observed. These results indicated that in vitro‐simulated gastrointestinal digestion significantly impact polyphenols and their antioxidant activity.     

Effect of ultraviolet‐B irradiation on antioxidative properties of aqueous extracts from shiitake (Lentinus edodes) mushrooms

Antioxidant properties of aqueous extracts from Lentinus edodes treated with UV‐B irradiation were examined in vitro systems including DPPH, ABTS and oxygen radical absorbance capacity (ORAC) assays and in riboflavin‐photosensitised oil‐in‐water (O/W) emulsions. Changes in total phenolics, total flavonoids and vitamin C were also analysed. Lentinus edodes receiving 25 kJ m^?2 UV‐B treatment showed high radical scavenging ability based on DPPH and ABTS assays compared with samples with 0, 50 and 75 kJ m^?2, while those with 50 kJ m^?2 had higher antioxidant capacities than other samples from ORAC assays. Samples with 25 kJ m^?2 UV treatment had significantly 7.1% higher total phenolic content, 12.0% higher total flavonoid content and 8.0% higher vitamin C content than UV‐B‐untreated sample (P < 0.05), respectively. In O/W emulsions under riboflavin photosensitisation, 25 and 50 kJ m^?2 UV treatment significantly increased the oxidative stability compared with other samples based on headspace oxygen content and lipid hydroperoxide analyses (P < 0.05). Aqueous extracts of UV‐B‐treated mushrooms possessed enhanced antioxidant properties compared with untreated mushrooms.     

Assessing the association between phenolic compounds and the antioxidant activity of Brazilian red wines using chemometrics

The objective of this study was to evaluate the association among chemical parameters, the commercial value, and the antioxidant activity of Brazilian red wines using chemometric techniques. Twenty-nine samples from five different varieties were assessed. Samples were separated into three groups using hierarchical cluster analysis: cluster 1 presented the highest antioxidant activity towards DPPH (68.51% of inhibition) and ORAC (30,918.64 μmol Trolox Equivalents/L), followed by cluster 3 (DPPH = 59.36% of inhibition; ORAC = 25,255.02 μmol Trolox Equivalents/L) and then cluster 2 (DPPH = 46.67% of inhibition; ORAC = 19,395.74 μmol Trolox Equivalents/L). Although the correlation between the commercial value and the antioxidant activity on DPPH and ORAC was not statistically significant (P = 0.13 and P = 0.06, respectively), cluster 1 grouped the samples with higher commercial values. Cluster analysis applied to the variables suggested that non-anthocyanin flavonoids were the main phenolic class exerting antioxidant activity on Brazilian red wines.     

Changes in bioactive compounds and antioxidant activity during convective drying of murta (Ugni molinae T.) berries

Murta (Ugni molinae T.) berries were air‐dried at five temperatures (40, 50, 60, 70 and 80 °C), and the changes in β‐carotene, phenolic acids, total phenolic and flavonoid contents and antioxidant capacities (DPPH and ORAC) were investigated. The berries showed a high content of β‐carotene, which decreased during drying temperature between 40 °C and 80 °C. Free and bound phenolic acids were also determined, showing gallic acid to be the prevalent phenolic acid. Total phenolic and flavonoid contents in the dried berries showed a higher decrease at lower temperature due to longer drying time. The radical‐scavenging activity also showed higher antioxidant activity at higher drying temperatures (70–80 °C) than at lower drying temperatures (40–50 °C). Total phenolic content (TPC) and flavonoids showed good correlation with antioxidant capacity. Murta berries proved to be an excellent source of antioxidants and bioactive compounds and are therefore a potential ingredient for new functional food products.     

Phenolic Content and Antioxidant Activity of Moscatel Dessert Wines from the Setúbal Region in Portugal

Moscatel wines from Setúbal were analyzed for their total phenolic (mean value 1,243 mg gallic acid equivalents/L), and total flavonoid (mean value 248 mg catechin/L) composition by spectrophotometric and chromatographic methods were used to quantify phenolic compounds as benzoic acids, cinnamic acids, stilbens, and some flavonoids. Antioxidant activity of the wines was evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH; mean value 70.7% inhibition), ferric reducing antioxidant power (FRAP; mean value 3,098 mg of Trolox equivalents/L) and oxygen radical absorbance capacity (ORAC; mean value 10,724 μmol/L) assays. Results were analyzed using principal component analysis which allowed samples to be grouped in terms of both winemaking producer and vintage. By plotting correlation loadings, it was possible to understand which variables were responsible for sample distribution. The correlation between results obtained for variables show that, in general, total flavonoid content is a better estimation of antioxidant activity in Moscatel samples (r _{ORAC/flavonoids} = 0.832, r _{FRAP/flavonoids} = 0.677) than total phenolic content (r _{ORAC/phenolics} = 0.680, r _{FRAP/phenolics} = 0.372). No major correlations were detected for DPPH assay results (r _{DPPH/flavonoids} = 0.283, r _{DPPH/phenolics} = 0.271). Chromatographic profiles showed important differences among Moscatel wines. Gallic acid contents and results of antioxidant activity tests were strongly correlated (r values in the range 0.74–0.92). Correlations of the results obtained for antioxidant activity tests with contents of other phenolic compounds such as ethyl caffeate, ethyl gallate, caffeic acid, protocatechuic acid, and t-caftaric acid depend on sample and type of test employed. Presented at the “AOAC Europe section international workshop: Enforcement of European Legislation on Food and Water: Analytical and Toxicological Aspects”, in Lisbon, April 2008, and published in abstract form.     

绿茶、橘皮、大豆中酚类物质体外消化前后稳定性及抗氧化活性的研究

本研究以富含3类代表性酚类化合物（黄烷醇、黄烷酮和异黄酮）的3种食物（绿茶、橘皮、大豆）作为原料,模拟其在人体口胃肠中的体外消化过程。采用高效液相色谱-二极管阵列检测器/电喷雾-四极杆-飞行时间串联质谱检测器（HPLC-DAD/ESI-Q-TOF-MS）检测体外消化前后酚类化合物的种类及含量变化,同时测定不同消化阶段总酚含量（TPC）、总黄酮含量（TFC）以及抗氧化活性（DPPH、ABTS、FRAP、ORAC）的变化。结果表明,绿茶提取物中检测出4种酚类化合物（表没食子儿茶素、(+)-儿茶素、表没食子儿茶素没食子酸酯和表儿茶素没食子酸酯）,大豆提取物中检测出4种酚类化合物（大豆苷、染料木苷、大豆苷元和染料木素）,橘皮提取物中检测出2种酚类化合物（柚皮苷和橙皮苷）;三种食物提取物中,经过体外消化后,绿茶提取物中的酚类化合物最不稳定,除(+)-儿茶素外,其余3种酚类物质几乎降解完全,损失率均达95%以上。绿茶、橘皮、大豆提取物的TPC在胃消化阶段显著升高（P<0.05）,在肠消化阶段显著降低（P<0.05）。绿茶提取物TFC在口腔和胃消化阶段显著升高（P<0.05）,在肠消化阶段显著降低（P<0.05）。橘皮、大豆提取物TFC与TPC变化趋势一致。绿茶提取物的四种抗氧化活性经胃肠消化后呈先升高再降低的趋势。大豆提取液体外消化前后ABTS、FRAP抗氧化活性在口腔阶段显著降低（P<0.05）,DPPH、ORAC抗氧化活性在口腔、胃消化阶段显著升高（P<0.05）,在肠消化阶段显著降低（P<0.05）。橘皮提取液ORAC抗氧化活性在肠消化阶段显著升高（P<0.05）,ABTS、FRAP抗氧化活性在体外消化阶段均表现出和总酚含量变化一致的趋势。     

Production of flavonoid and lignan aglycones from flaxseed and soy extracts by Bifidobacterium strains

Flaxseed and soybean are an important source of phytochemical compounds, mainly lignans and isoflavones, but also of flavones, flavanones and flavonols. These compounds appear mainly glycosylated in plant food and are converted into aglycones by the intestinal microbiota, increasing their bioavailability. In this work, we analyse the ability of Bifidobacterium strains (n = 25) to produce lignan and flavonoids aglycones from flaxseed and soybean extracts. Most of the Bifidobacterium strains increased the concentrations of secoisolariciresinol, daidzein, genistein, naringenin, eriodyctiol, luteolin and apigenin. Moreover, Bifidobacterium pseudocatenulatum and Bifidobacterium breve strains showed high production of herbacetin, increased the kaempferol concentration and produced quercetin and quercetagetin. B. pseudocatenulatum INIA P815 and B. breve INIA P367 produced 32.37 ± 2.81 and 28.64 ± 3.36 mg respectively of herbacetin g⁻¹ of lignan extract. Bifidobacterium strains transformed the glycosides of a wide range of flavonoids into their aglycones, increasing the antioxidant activity and improving their bioavailability.     

Cytoprotective effects of polyphenolics on H<Subscript>2</Subscript>O<Subscript>2</Subscript>-induced cell death in SH-SY5Y cells in relation to their antioxidant activities

The cytoprotective effects of five flavonoids (quercetin, rutin, catechin, kaempferol and morin) and four hydroxycinnamic acids (caffeic, ferulic, sinapic and chlorogenic acids) were evaluated by the degree of protection they provided against H₂O₂-induced damage to human neuroblastoma SH-SY5Y cells. All compounds exhibited protection against H₂O₂-mediated cytotoxicity in a dose dependent manner. The concentration required to give a 50% reduction in cell death (EC₅₀ value) were derived from their dose–response relationships. The cytoprotective activities of these phenolic compounds in the order of quercetin > caffeic acid > rutin > chlorogenic acid > catechin > ferulic acid > sinapic acid > morin > kaempferol. The EC₅₀ values of the phenolic compounds were strongly related to their chemical structures. The EC₅₀ values were compared with the antioxidant activities as determined by five different chemically based antioxidant assays [2,2-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid (ABTS), 1,1-diphenyl-2-picrylhydrazyl (DPPH), oxygen radical absorbance capacity (ORAC), ferric reducing antioxidant power (FRAP) and lipid peroxidation inhibition capacity (LPIC)]. The ability of these phenolic compounds to protect from H₂O₂-induced SH-SY5Y cell death correlated (r ² = 0.85) with their determined LPIC values and weakly (r ² = 0.44) with their ABTS activities. There was no correlation between EC₅₀ values and ORAC, FRAP or DPPH activities. The cytoprotection assay is a more biologically relevant measurement than the chemically defined antioxidant activity assays because it uses human cells as a substrate and therefore accounts for some aspects of uptake, metabolism and location of antioxidant compounds within cells.     

Effects of Tissue Culture and Mycorrhiza Applications in Organic Farming on Concentrations of Phytochemicals and Antioxidant Capacities in Ginger (Zingiber officinale Roscoe) Rhizomes and Leaves

Tissue culture and mycorrhiza applications can provide disease‐free seedlings and enhanced nutrient absorption, respectively, for organic farming. Ginger (Zingiber officinale Roscoe) is rich in phytochemicals and has various health‐protective potentials. This study was aimed at determining effects of tissue culture and mycorrhiza applications alone or in combinations in organic farming on phytochemical contents (total phenolics and flavonoids [TP and TF, respectively], gingerol and shogaol homologues, phenolic acids, and carotenoids) and antioxidant capacities (DPPH [2,2‐diphenyl‐1‐picrylhydrazyl] radical scavenging, oxygen radical absorbance (ORAC), and iron‐chelating capacities [ICC]) in solvent‐extractable (Free) and cell‐wall‐matrix‐bound (Bound) fractions of ginger rhizome and Free fraction of the leaves in comparison with non‐organics. Concentrations of the phytochemicals and antioxidant capacities, except for carotenoids and ICC, were significantly higher in organic ginger rhizomes and leaves than in non‐organics regardless of the fractions and treatments (P < 0.05). Mycorrhiza application in organic farming significantly increased levels of TP, TF, gingerols, and ORAC in the Free fraction of the rhizome (P < 0.05). Furthermore, the combined application of tissue culture and mycorrhiza significantly increased concentrations of TF and gingerols and ORAC in the Free fraction of the rhizome (P < 0.05), suggesting their synergistic effects. Considerable amounts of phenolics were found in the Bound fractions of the rhizomes. Six‐gingerol, ferulic acid, and lutein were predominant ones among gingerols, phenolic acids, and carotenoids, respectively, in ginger rhizomes. The results suggest that organic farming with mycorrhiza and tissue culture applications can increase concentrations of phytochemicals and antioxidant capacities in ginger rhizomes and leaves and therefore improve their health‐protective potentials.     

Improvement of Antioxidant Activities in Red Cabbage Sprouts by Lactic Acid Bacterial Fermentation

In the present study, the influence of three types of lactic acid bacteria (Lactobacillus plantarum ATCC 8014, Lactobacillus acidophilus NCFM, Danisco, and Lactobacillus rhamnosus GG E522 (ATCC 53103)) on antioxidant activities of fermented red cabbage sprouts was determined and compared with those of their unfermented/control counterparts. The fermentation resulted in a significant increase (p < 0.05) of antioxidant functionalities as measured by four assays: 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging, Trolox equivalent antioxidant capacity (TEAC), superoxide dismutase (SOD)-like, and β-carotene/linoleic bleaching. The most considerable shift in the antioxidant activities was observed after 24 h of fermentation. These increases were followed by a decrease in total phenolic compounds, anthocyanins, and L-ascorbic acid and by an increase in flavonoids, flavonols, and several phenolic acids (gallic, chlorogenic, caffeic, syringic, p-coumaric, trans-3-hydroxy-4-methoxycinnamic, and trans-o-hydroxycinnamic acid) content. The relationship between the antioxidant activities and the compositional changes in antioxidant compounds due to LAB fermentation was observed. Fermented red cabbage sprouts inoculated with L. plantarum had the highest antioxidant activities (DPPH scavenging: 70.92%; TEAC: 1.94 mM Trolox equivalent; SOD-like activity: 63.40%, and β-carotene/linoleic bleaching: 44.33%), which was almost two-fold higher than those of unfermented treatments. These results indicated that LAB fermentation could be applied as a method to improve the potent antioxidant activities of red cabbage sprouts.     

Purification and identification of rice bran (Oryza sativa L.) phenolic compounds with in-vitro antioxidant and antidiabetic activity using macroporous resins

This study was designed to establish an efficient purification method for phenolic compounds from rice bran and to acquire insightful knowledge of purification impact on its chemical constituents, antioxidant and antidiabetic activity. Among the eight macroporous resins investigated, HPD-300 resin was verified to bosses superior adsorption and desorption qualities for the extract. Purification parameters were optimised. Eighteen phenolic compounds were identified using HPLC-PDA, the contents of ferulic acid and syringaldehyde were significantly (P < 0.05) higher than the other constituents. However, phenolic compounds concentrations varied significantly (P < 0.05) after HPD-300 resin purification. In addition, the extract exhibited a significant (P < 0.05) increase in total flavonoid contents, in vitro antioxidant (DPPH and FRAP) and antidiabetic (α-glucosidase and BSA-glycation inhibition) activity after HPD-300 resin treatment. These findings indicate that selection of resin and applying optimal purification condition is an appropriate economical approach for obtaining bioactive phenolic compounds from rice bran.     

Phenolic acids and flavonoids profiles of extracts from edible wild fruits and their antioxidant properties

In this study, the total phenolic, total flavonoids, phenolic compounds, the mineral content, and antioxidant activity of fruit extracts of seven wild species (Crataegus monogyna Jacq., Prunus spinosa L., Rosa canina L., Hippophaë rhamnoides L., Rubus fruticosus L., Prunus padus, Cornus mas L.) were investigated. The results indicated significant differences (p < 0.05) in the total phenolics and total flavonoids content, between the seven analyzed species. These ranged from 184.69 to 727.29 mg GAE/100 g FW and 17.27 to –165.55 mg QE/100 g FW, respectively. The antioxidant activity found in fruits was not directly affected by the total phenolic content (TPC). This activity was linked to a larger extent to the type of individual phenolic compounds and to a lesser extent to the TPC, because fruits with higher TPC have not always presented the highest values of antioxidant activity. HPLC analysis of methanolic extract showed the presence of phenolic acids (i.e. gallic, vanillic, chlorogenic, caffeic, syringic, p-coumaric, ferulic, sinapic, salycilic, elagic, and trans-cinnamic) and flavonoids (i.e. catechin, epicatechin, rutin, myricetin, and quercetin). Significant differences (p < 0.05) were observed in each individual mineral between fruits from wild flora. The fruits tissues of wild species turned out to be a good source of calcium (Ca), magnesium (Mg), sodium (Na), iron (Fe), manganese (Mn), copper (Cu), chromium (Cr), zinc (Zn), and boron (B). The results demonstrated that wild species possessed great potential for food production as sources of bioactive compounds such as phenolic compounds and minerals, for food supplements or functional foods.