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Cereal and legume grains and their processing by-products are rich sources of bioactives such as phenolics with considerable health potential, but these bioactives suffer from low bioaccessibility and bioavailability, resulting in limited use. Several studies have demonstrated that solid-state fermentation (SSF) with food-grade microorganisms is effective in releasing bound phenolic compounds in cereal and legume products. In this review, we discuss the effect of SSF on cereal and legume grains and their by-products by examining the role of specific microorganisms, their hydrolytic enzymes, fermentability of agri-food substrates, and the potential health benefits of SSF-enhanced bioactive compounds. SSF with fungi ( Aspergillus spp. and Rhizopus spp.), bacteria ( Bacillus subtilis and lactic acid bacteria (LAB) spp.) and yeast ( Saccharomyces cerevisiae ) significantly increased the bioactive phenolics and antioxidant capacities in cereal and legume grains and by-products, mainly through carbohydrate-cleaving enzymes. Increased bioactive phenolic and peptide contents of SSF-bioprocessed cereal and legume grains have been implicated for improved antioxidant, anti-inflammatory, anti-carcinogenic, anti-diabetic, and angiotensin-converting-enzyme (ACE) inhibitory effects in fermented agri-food products, but these remain as preliminary results. Future research should focus on the microbial mechanisms, suitability of substrates, and the physiological health benefits of SSF-treated grains and by-products.

The bioavailability and anti-inflammatory activity of the phenolic compounds derived from gastrointestinal digestates of navy bean and light red kidney bean milks and yogurts were investigated in both Caco-2 mono- and Caco-2/EA.hy926 co-culture cell models. Instead of being transported directly, the ferulic acid ester derivatives in common bean milks and yogurts were found to be metabolized into ferulic acid and then be transported through the Caco-2 cell monolayer with an average basolateral ferulic acid concentration of 56 ± 3 ng/mL after 2 h. Strong anti-inflammatory effects were observed in the basolateral EA.hy926 cells of the co-culture model, and modulations of oxLDL-induced inflammatory mediators by the transported phenolics were verified to be through the p38 MAPK pathway. The present results suggest that the common bean-derived phenolics can be metabolized and absorbed by the intestinal epithelial cells and have antioxidant and anti-inflammatory effects against oxidative stress injury in vascular endothelial cells, hence contributing to the amelioration of vascular diseases.

Increased processing of pulses generates large volumes of hulls, which are known as an excellent source of phenolic antioxidants. However, the bioavailability and in vivo activity of these phenolics are rarely reported. This research was therefore carried out to study the absorption, metabolism, and in vivo antioxidant activities of green pea hull (GPH) phenolics using ultrahigh-pressure liquid chromatography with a linear ion trap-high-resolution Orbitrap mass spectrometry and an oxidative stress rat model. A total of 31 phenolics, including 4 phenolic acids, 24 flavonoids, and 3 other phenolics, were tentatively identified. Ten of these phenolics and 49 metabolites were found in the plasma and urine of rats, which helped to explain the favorable changes by GPH phenolics in key antioxidant enzymes (superoxide dismutase, glutathione peroxidase, and glutathione) and indicators (total antioxidant capacity, malondialdehyde) in the plasma and different tissues of rats. This is the first comprehensive report on dry pea hull phenolics and their bioavailability, metabolic profiles, and mechanisms of in vivo antioxidant activities.

Radix Tetrastigma (RT), a herbal medicine and functional food in China, showed strong antiproliferative activities in vitro. However, the effects and the underlying mechanism of phenolic-rich extract of RT in H22 tumor-bearing mice are still unknown. Thus, the phenolic profiles and antitumor/antioxidant activities of a solid phase extraction (SPE) semi-purified extract of RT were investigated by a combination of chemical assays, LC-QTOF-MS/LC-QqQ-MS techniques and a tumor-bearing mice model. As a result, the total phenolic/flavonoid contents (TPC/TFC) and 24 individual phenolics were identified and quantified, which showed higher contents than that of crude extract. Results also indicated that RT extract could inhibit tumor growth and induce apoptosis by regulating the expression of Bcl-2 family proteins and activating the caspase family proteins as well as suppressing tumor angiogenesis by inhibiting vascular endothelial growth factor (VEGF) expression. Besides, the interleukin-2 (IL-2) levels, tumor necrosis factor-α (TNF-α) production, CD4 + /CD8 + ratio, and NK cell levels were increased by RT administration, while RT significantly increased superoxide dismutase (SOD)/glutathione peroxidase (GSH-Px) activities and decreased malondialdehyde (MDA) content. Summarily, the findings clearly demonstrated that RT extract could inhibit tumor growth by inducing apoptosis and inhibiting angiogenesis as well as preventing cancer by improving the immune functions and antioxidant activities.

Unextractable phenolics from plant foods and their role in health benefits have become increasingly important. Meal residues of three quinoa seeds free of fat and extractable phenolics were subjected to acid, alkaline, and enzymatic hydrolyses. The total and individual phenolic compounds released were analyzed, and 19 phenolics, predominantly phenolic acids and several flavonoids, were identified. The concentration of bound phenolics was highest in black quinoa followed by red and white, regardless of the hydrolysis method. Higher phenolic contents also showed stronger antioxidant activities and inhibition of α-glucosidase and pancreatic lipase activities. Carbohydrases, that is, pectinase, xylanase and feruloyl esterase, which effectively liberated bound phenolics are known to be secreted by colonic bacteria, suggesting potential antioxidant and anti-inflammatory effects by these compounds in the large intestine during colonic fermentation. These results can also be applied to treat foods high in bound phenolics to enhance bioaccessibility.

Cranberry beans from regular (RR) and nondarkening (CND) genotypes were pressure cooked, and free, conjugated, and bound phenolics were analyzed. Simulated in vitro gastrointestinal digestion was used to assess the bioaccessibility of these phenolic fractions. Total phenolic content decreased after cooking and digestion, whereas individual phenolic compounds were affected differently. Cooking significantly increased the release of bound ferulic and sinapic acids and flavanols, whereas digestion released p-coumaric, ferulic, and sinapic acids in both genotypes, and p-hydroxybenzoic acid, epicatechin, and catechin in only RR. Bioaccessibility of phenolics in RR and CND was 8.75 and 14.69%, respectively. Difference in total phenolics was smaller after digestion, and enzymes potentially secreted by colonic bacteria released similar amounts of phenolic acids in both varieties. Resistant and slowly digestible starch contents showed no differences between RR and CND. These results suggest that the lower phenolic content in raw CND may not completely negate its impact on gut health.

Cranberry beans (Phaseolus vulgaris L.) from 7 different cultivars were characterized for phytochemicals and assessed for antioxidant activities. In vitro colorimetric methods were used to measure total phenolic (TPC) and total proanthocyanidin (PAC) contents. Free, conjugated and bound phenolic acids and flavonoids were also identified and quantified using HPLC-DAD/ESI-MS(n). Regular-darkening (RD) seeds contained higher TPC, PAC and flavonoids which were absent in the non-darkening (ND) seeds. Bound and conjugated phenolics in RD and ND mainly included cinnamic and benzoic acids. DPPH, FRAP and ORAC showed strong positive correlation with TPC, PAC, and with specific phenolics such as free catechin and bound p-hydroxybenzoic acid. Lipophilic extracts were rich in polyunsaturated fatty acids (69.20-76.89%). Carotenoid and tocopherol were limited to γ-tocopherol and β-carotene. Results from this study can contribute to the development of cranberry bean cultivars with increased health benefits and addresses specific phenolic contributors to antioxidant activity., (Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.)

Phenolic extracts from 20 Canadian lentil cultivars (Lens culinaris) were evaluated for total phenolic contents and composition, antioxidant activities (DPPH, FRAP, ORAC), and inhibitory properties against α-glucosidase and pancreatic lipase. Twenty one phenolic compounds were identified in the present study, with the majority being flavonoids, including kaempeferol glycosides, catechin/epicatechin glucosides and procyanidins. These phenolic compounds not only contributed significantly to the antioxidant activities, but they were also good inhibitors of α-glucosidase and lipase, two enzymes, respectively, associated with glucose and lipid digestion in the human intestine, thus contributing significantly to the control of blood glucose levels and obesity. More interestingly, it was the flavonols, not the flavanols, which showed the inhibitory activities against α-glucosidase and pancreatic lipase. Our result provides supporting information for developing lentil cultivars and functional foods with improved health benefits and suggests a potential role of lentil consumption in managing weight and control of blood glucose., (Copyright © 2014. Published by Elsevier Ltd.)

Quinoa (Chenopodium quinoa Willd.) is known for its exceptional nutritional value and potential health benefits. The present study identified the composition of different forms of extractable phenolics and betacyanins of quinoa cultivars in white, red and black, and how they contribute to antioxidant activities. Results showed that at least 23 phenolic compounds were found in either free or conjugated forms (liberated by alkaline and/or acid hydrolysis); the majority of which were phenolic acids, mainly vanillic acid, ferulic acid and their derivatives as well as main flavonoids quercetin, kaempferol and their glycosides. Betacyanins, mainly betanin and isobetanin, were confirmed for the first time to be the pigments of the red and black quinoa seeds, instead of anthocyanins. Darker quinoa seeds had higher phenolic concentration and antioxidant activity. Findings of these phenolics, along with betacyanins in this study add new knowledge to the functional components of quinoa seeds of different cultivar background., (Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.)

The phytochemicals and antioxidant activity in lipophilic and hydrophilic (extractable and bound) fractions of lentils before and after domestic cooking were investigated. The hydrophilic fractions in lentils contributed much more to the antioxidant activity than the lipophilic fraction. The phenolic content of lentils was mainly composed of extractable compounds. Significant changes (P < 0.05) in carotenoid, tocopherol, total phenolic, and condensed tannin contents of both extractable and bound phenolics fractions, as well as in antioxidant activities, were found in lentils before and after cooking. More specifically, cooking was found to favor the release of carotenoids and tocopherols and flavonols (kaempferol glycosides), but led to losses of flavanols (monomeric and condensed tannin). Whereas reduced flavanols and other phenolic compounds may have negatively affected the antioxidant activity, other components, especially the lipophilic antioxidants, were increased. The present study suggests that incorporation of cooked lentils into the diet will not cause significant loss to the phytochemical antioxidants and thus will retain the potential health benefits.

A common protocol for the extraction of phenolic aglycons or bound phenolics in plants generally involves hydrothermal hydrolysis in an aqueous methanol or ethanol solution containing 2-4 N HCl. However, as shown in the present study, this process also forms 5-(hydroxymethyl)furan-2-carbaldehyde (HMF) and its derivative products 5-(methoxymethyl)furan-2-carbaldehyde (MMF) and 5-(ethoxymethyl)furan-2-carbaldehyde (EMF), as identified by HPLC-DAD-ESI-MS/MS and NMR. These compounds are commonly misidentified as phenolics due to similar UV absorption at 280 nm. In this study, production of HMF, MMF, and EMF was shown to be dependent on the solvent condition and duration and temperature of hydrolysis. Fruits and vegetables produced HMF more readily than grains. HMF and its derivatives were subjected to various spectrophotometric antioxidant assays [2-diphenyl-1-picryhydrazyl radical scavenging activity (DPPH), ferric-reducing antioxidant power (FRAP), and oxygen radical absorbing capacity (ORAC)] and displayed antioxidant activity mainly in the ORAC assay. Results of this study help avoid overestimation of phenolic content and antioxidant activities of plant foods.

The polyphenolic compositions of three heartnut (Juglans ailanthifolia var. cordiformis) varieties (Imshu, Campbell CW1, and Campbell CW3) were examined and compared with those of two Persian walnut (Juglans regia L.) varieties (Combe and Lake). The nuts were defatted, extracted, and separated into three different fractions, the free phenolic acid (FPA), acid-hydrolyzable phenolic acid (AHPA), and bound phenolic acid (BPA) fractions. The total phenolic contents (TPCs) in both FPA and AHPA of the Persian walnuts were significantly higher (P < 0.001) than those of the heartnuts, but not in the BPA (P = 0.20). LC-ESI-MS(n)() studies revealed that except for the FPA fraction, the major polyphenolics in both heartnut and Persian walnut were ellagic acid and valoneic acid dilactone. Persian walnuts contained an average of 0.29 and 1.31 mg of ellagic acid/g nut in the 80% methanol extractable fractions FPA and AHPA, respectively. Heartnuts contained an average of 0.16 and 0.60 mg of ellagic acid/g nut in the respective fractions. Bound ellagic acid in the residue was 0.93 and 0.70 mg/g of nut in the Persian walnut and in the heartnut, respectively. Valoneic acid dilactone was tentatively identified and quantified as milligrams of ellagic acid equivalent per gram of nut. These components were found to contribute to the strong total antioxidant activities measured using ferric reducing antioxidant power and photochemiluminescence methods.

The antioxidant activities of eight apple cultivars were studied by using the ferric reducing/antioxidant power (FRAP), the beta-carotene-linoleic acid model system (beta-CLAMS), and the photochemiluminescent (PCL) assays. The antioxidant activity of apples is highly correlated to the total phenolic content (TPC) measured by the Folin-Ciocalteu method and the total polyphenolic index (TPI) obtained by HPLC. Extracts of the peel and flesh were analyzed and assayed separately. The FRAP activities of both peel and flesh extracts correlate well with the TPC (r = 0.95 and 0.99, respectively) and the TPI (r = 0.82 and 0.99, respectively). Similar results were found in the beta-CLAMS activities, showing correlation coefficients of r = 0.90 and 0.91 with the TPC for the peel and flesh extracts and of r = 0.90 and 0.84 with the TPI for the peel and flesh extracts, respectively. The antioxidant activity measured by the PCL assay was not correlated with TPC or TPI due to the lack of integratable lag phase in this method with the flavan-3-ols/procyanidins. Among the five major polyphenolic groups, flavan-3-ols/procyanidins had the highest positive correlation with the FRAP and beta-CLAMS activities: r = 0.84 and 0.88 for the peel extracts, respectively; and r = 0.98 and 0.87 for the flesh extracts, respectively. At individual compound level, epicatechin and procyanidin B2 were the major contributors to the antioxidant activity of apple. Hydroxycinnamic acids may have a significant role in the flesh.

Two isomeric phenylethanoid glycosides, acteoside and isoacteoside were isolated and purified from the seeds of Plantago psyllium L. for the first time by high-speed counter-current chromatography (HSCCC) using a solvent system consisting of ethyl acetate-water (1:1, v:v). By injecting 200 mg of the n-butanol extract of P. psyllium for five consecutive times, the two-step HSCCC procedure yielded a total of 165 mg of acteoside and 17.5 mg of isoacteoside from 978 mg extract. The recovery rates for acteoside and isoacteoside were 90 and 84%, respectively, and the purities were 98 and 94%, respectively. The HSCCC fractions were analyzed by HPLC and the structures were identified by UV, LC-APCI-MS in negative ion mode, and confirmed by NMR experiments.

An HPLC method is reported for the separation and quantification of five major polyphenolic groups found in fruits and related products: single ring phenolic acids (hydroxybenzoic acid and hydroxycinnamic acid derivatives), flavan-3-ols, flavonols, anthocyanins, and dihydrochalcones. A binary mobile phase consisting of 6% acetic acid in 2 mM sodium acetate aqueous solution (v/v, final pH 2.55) (solvent A) and acetonitrile (solvent B) was used. The use of sodium acetate was new and key to the near baseline separation of 25 phenolics commonly found in fruits. A photodiode array detector was used and data were collected at four wavelengths (280, 320, 360, and 520 nm). This method was sensitive and gave good separation of polyphenolics in apple, cherry, strawberry, blackberry, grape, apple juice, and a processing by-product. The improved separation has led to better understanding of the polyphenolic profiles of these fruits. Individual as well as total phenolic content was obtained, and the latter was close to and correlated well with that obtained by the Folin-Ciocalteu method (FC). The HPLC data can be used as a total phenolic index (TPI) for quantification of fruit phenolics, which is advantageous over the FC because it has more information on individual compounds.

Polyphenolic compounds of apple may play an important role in physiologic functions related to human health. Different polyphenolics may have varied biological activities including antioxidant activity. The objective of this study was to investigate the profiles of polyphenolic compounds in different apple varieties and different parts of an apple. The total and individual polyphenolics differed significantly among the eight apple cultivars grown in Ontario, and the peels had higher concentrations than the flesh. Among the tested cultivars, Red Delicious and Northern Spy had the highest concentrations and Empire the lowest. Five major polyphenolic groups with a total of 16 identified individual compounds were found, among which the dihydroxycinnamic acid esters, phloretin glycosides, and flavan-3-ols were found in both flesh and peel, whereas quercetin glycosides were almost exclusively found in the peel. Cyanidin 3-galactoside was unique to and found only in red apple peels. In both apple peel and flesh, the predominant group of polyphenolics was the procyanidins, followed by quercetin glycosides in the peel and hydroxycinnamic acid esters in the flesh. 3-Hydroxyphloretin 2'-xyloglucoside was newly identified in apple. The results obtained in this study will further the understanding of the polyphenolic composition of apples and their roles in health-promoting physiological functions.

BACKGROUND: The aim of this study was to investigate the effects of variety (Nantes and Imperator), soil fertility status (high and low) and agronomic treatments on yield and quality traits of carrot composition and sensory factors. The treatments compared synthetic nitrogen at conventionally recommended amounts with compost‐sourced nitrogen (high and low rates) and a range of amendments (compost, compost tea, micronutrients and foliar treatments). Additionally, we intended to identify factors affecting polyacetylene accumulation in carrots, owing to the growing interest in their health effects and paucity of agronomic information on their bioaccumulation in carrots. RESULTS: Imperator accumulated more minerals, produced more phytochemicals and had higher antioxidant capacity than Nantes, which had more carotenoids. However, consumers preferred the flavor of Nantes over Imperator. High‐fertility soil produced carrots of superior nutritional quality than did low‐fertility soil, regardless of year‐of‐application amendments, the effects of which were often variety‐dependent. High soil biological activity was able to overcome low fertility status and stimulate greater yield. Carrot phosphorus was correlated with falcarindiol biosynthesis. Chlorogenic acid and falcarindiol were correlated with antioxidant capacity, but not falcarinol or total phenolic compounds. CONCLUSION: Carrots were not strongly affected by agronomic treatments in terms of yield or phytochemical status; however, soil biological activity overcame a soil nutrient deficit in terms of yield. Phenolic compounds and antioxidant status were generally higher in the high‐fertility site, whereas polyacetylenes were variety‐dependent. Chlorogenic acid and falcarindiol were associated with antioxidant capacity, but not total phenolic compounds and carotenoids. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Flaxseed (FS), a dietary oilseed, contains a variety of anti-inflammatory bioactives, including fermentable fiber, phenolic compounds (lignans), and the n-3 polyunsaturated fatty acid (PUFA) α-linolenic acid. The objective of this study was to determine the effects of FS and its n-3 PUFA-rich kernel or lignan- and soluble fiber-rich hull on colitis severity in a mouse model of acute colonic inflammation. C57BL/6 male mice were fed a basal diet (negative control) or a basal diet supplemented with 10% FS, 6% kernel, or 4% hull for 3 wk prior to and during colitis induction via 5 days of 2% (wt/vol) dextran sodium sulfate (DSS) in their drinking water (n = 12/group). An increase in anti-inflammatory metabolites (hepatic n-3 PUFAs, serum mammalian lignans, and cecal short-chain fatty acids) was associated with consumption of all FS-based diets, but not with anti-inflammatory effects in DSS-exposed mice. Dietary FS exacerbated DSS-induced acute colitis, as indicated by a heightened disease activity index and an increase in colonic injury and inflammatory biomarkers [histological damage, apoptosis, myeloperoxidase, inflammatory cytokines (IL-6 and IL-1β), and NF-κB signaling-related genes (Nfkb1, Ccl5, Bcl2a1a, Egfr, Relb, Birc3, and Atf1)]. Additionally, the adverse effect of the FS diet was extended systemically, as serum cytokines (IL-6, IFNγ, and IL-1β) and hepatic cholesterol levels were increased. The adverse effects of FS were not associated with alterations in fecal microbial load or systemic bacterial translocation (endotoxemia). Collectively, this study demonstrates that although consumption of a 10% FS diet enhanced the levels of n-3 PUFAs, short-chain polyunsaturated fatty acids, and lignans in mice, it exacerbated DSS-induced colonic injury and inflammation. [ABSTRACT FROM AUTHOR]

The total phenolic composition (TPC) and the total antioxidant capacity (TAC) of eleven strawberry genotypes selected from the AAFC breeding program (BC2-72-17, BC2-90-43, BC96-33-4 and BC98-49-34 from British Columbia; and APF937-1, APF939-71, LL981-24, LL9819-14, LL982-14, LL0220-10 and SJ9332-7 from Quebec) were evaluated using high-performance liquid chromatography (HPLC) and ferric reducing/antioxidant power (FRAP) assays. TPC and TAC values of these genotypes were compared to those of four commercially grown cultivars ('Chambly,' 'Kent,' 'Veestar' and 'Yamaska') and the effects on fruit quality and shelf life were studied. Several groups of phenolic compounds, including anthocyanins, flavonols, hydroxycinnamic, ellagic and benzoic acids, were identified and quantified by HPLC. Significant variation of TPC was observed between genotypes, and anthocyanins were found to be the predominant phenolic group, contributing to 79.2% of the TPC. A significant correlation (r = 0.96) was observed between TPC and anthocyanin content. BC2-72-17 had the highest anthocyanin content and differed significantly from the other genotypes. Although the highest TPC (2123.8 μg g-1) was found in BC2-72-17, this genotype did not have the highest antioxidant capacity. The highest TAC (2259.0 μg g-1) was found in BC2-90-43, indicating that other phenolics may have made a greater contribution than anthocyanins to the high TAC. At room temperature, LL0220-10, SJ9332-7 and 'Yamaska' had a three-day shelf life, while it was only two days for all other genotypes. There was a negative correlation between shelf life and ellagic acids, flavonol and anthocyanin levels but this relationship was not significant (p > 0.0.). The fruit soluble solids content (SSC) and titratable acidity (TA) varied between genotypes. 'Veestar' and LL981-24 had the highest SSC (7.5). These results point to the importance of identifying genotypes with high phenolic monomer activities in screening for lines with high TAC, to ensure their use in breeding programs aimed at improving the nutritional value of strawberry. [ABSTRACT FROM AUTHOR]

The agronomic characteristics and chemical composition of seven advanced day-neutral strawberry lines and a commercial cultivar 'Seascape' were evaluated for their horticulture and quality attributes. The results showed that the advanced strawberry lines had the best horticultural characteristics, such as more resistance to diseases, less weight and juice losses and better fruit glossiness during storage, compared to 'Seascape'. Among the advanced lines, FIN005-55 had the better fruit quality with higher soluble solids content (SSC)/titratable acidity (TA) ratio and highest SSC, FIN005-7 had the highest total phenolic content (TPC) and antioxidant capacity (AC), and both had potential for commercial trials. [ABSTRACT FROM AUTHOR]

• Insoluble-bound phenolics were significantly reduced in lentil hulls upon fermentation. • Contents of phenolics, kaempferol tetraglucoside and quercetin were increased upon fermentation. • Bioconversion of insoluble-bound to soluble phenolics was noticed only for a few phenolics upon fermentation. Fermentation is an effective non-thermal food processing operation used for enhancing the nutritional and functional properties of food. HPLC-ESI-MS/MS analysis and inhibitory capacity of the soluble- and insoluble-bound phenolics in lentil hulls in retarding the oxidation of LDL and DNA strand scission were determined following fermentation. In HPLC-ESI-MS/MS analysis, most insoluble-bound phenolics in lentil hulls were significantly decreased, indicating their liberation from the cell wall matrix upon fermentation. However, the released insoluble-bound phenolics did not show an efficient conversion into the bioavailable soluble phenolics as reflected in the inhibitory capacity against oxidation of LDL and DNA strands. The low efficiency in bioconversion from insoluble-bound to soluble phenolics might be due to the loss of the released bound phenolics during the fermentation process. Following the alterations of individual insoluble-bound phenolics in legumes upon fermentation in this work may fill the existing gap in the related areas. [ABSTRACT FROM AUTHOR]

Abstract: The Chinese green tea extract was found to strongly inhibit the growth of major food-borne pathogens, Escherichia coli O157:H7, Salmonella Typhimurium DT104, Listeria monocytogenes, Staphylococcus aureus, and a diarrhoea food-poisoning pathogen Bacillus cereus, by 44–100% with the highest activity found against S. aureus and lowest against E. coli O157:H7. A bioassay-guided fractionation technique was used for identifying the principal active component. A simple and efficient reversed-phase high-speed counter-current chromatography (HSCCC) method was developed for the separation and purification of four bioactive polyphenol compounds, epicatechin gallate (ECG), epigallocatechin gallate (EGCG), epicatechin (EC), and caffeine (CN). The structures of these polyphenols were confirmed with mass spectrometry. Among the four compounds, ECG and EGCG were the most active, particularly EGCG against S. aureus. EGCG had the lowest MIC90 values against S. aureus (MSSA) (58mg/L) and its methicilin-resistant S. aureus (MRSA) (37mg/L). Scanning electron microscopy (SEM) studies showed that these two compounds altered bacterial cell morphology, which might have resulted from disturbed cell division. This study demonstrated a direct link between the antimicrobial activity of tea and its specific polyphenolic compositions. The activity of tea polyphenols, particularly EGCG on antibiotics-resistant strains of S. aureus, suggests that these compounds are potential natural alternatives for the control of bovine mastitis and food poisoning caused by S. aureus. [Copyright &y& Elsevier]

Cereal, pulse and oilseed processing by-products, specifically the brans/hulls, are enriched sources of phenolic compounds with antioxidant properties, yet they are typically disregarded as low-value animal feed or waste. Potential health-promoting effects of by-product phenolics are limited by the poor bioaccessibility and bioavailability of their bound phenolic constituents. Accumulating studies have shown solid-state fermentation (SSF) as an efficient strategy to enhance the release of bound phenolics from agro-industrial residues, leading to possible newfound human health attributes and greater value. In this review, we thoroughly discuss recent research on the effects of SSF on the composition, antioxidant activity, bioaccessibility, bioavailability and potential health benefits of phenolics from selected low-value cereal, pulse and oilseed processing by-products. We supplement this discussion by summarizing current knowledge on the phenolic profiles and existing limitations of these by-products to determine untapped research areas for SSF application. Existing research on the phenolic profiles of various cereal, pulse and oilseed processing by-products indicate the presence of a wide variety of phenolics, making them excellent candidates for value-added use. SSF has been found to effectively enhance the bioaccessible and bioavailable phenolic contents in several of these by-products, allowing for improved in vitro antioxidant activities. Currently, there is a lack of in vivo studies to validate findings in vitro. Investigating the physiological health benefits of SSF treated processing by-products, in relation to various chronic diseases, is essentially a novel area of research that can drive the transformation of low-value by-products into value-added functional food ingredients. [Display omitted] • Grain processing by-products are enriched sources of bioactive phenolic compounds. • Solid-state fermentation (SSF) can enhance contents and in vitro antioxidant activities of by-product phenolics. • Bioaccessibility and bioavailability of by-product phenolics may be improved by SSF. • SSF is a promising technology to valorize grain processing by-products. • Future research: in vivo studies with a focus on low-grade inflammation and gut health for fermented processing by-products. [ABSTRACT FROM AUTHOR]

Diets rich in phenolics are associated with multiple health benefits. The majority of related studies have focused nearly exclusively on soluble free and conjugated phenolics in plant-based foods, whereas a large amount of insoluble phenolics bound to food matrix in the remaining solid residues are neglected. The fate of bound phenolics in human digestive tract and health implications are not well understood. In this review, we provide a thorough literature review regarding the occurrence, chemistry and potential health implications of the insoluble-bound phenolics in food matrix. Research gaps were identified and future perspectives on insoluble-bound phenolics have been proposed. Significant amount of phenolic compounds occurs in insoluble forms through covalently binding to cell wall structural components in plant food matrix. These bound phenolics must be released by various pretreatments such as hydrolysis by enzyme, alkali and acid, or other assisted technologies before they can be identified and characterized, and there is no standard method currently. The health benefits of insoluble-bound phenolics are not only largely governed by their intrinsic content in food matrix, but their bioaccessibility and bioavailability in human body. Insoluble-bound phenolics obtained via hydrolysis possess antioxidant and anti-inflammatory activities in vitro , and have been implicated in different health benefits. Recent studies have suggested their involvement in modulating gut microbiota and intestinal immune response as a dietary component; however, the roles of bound phenolics and phenolic metabolites in intestinal inflammation and gut health and the interplay mechanisms are still poorly understood. This contribution provides an update on the insoluble-bound phenolics in food matrix and new perspectives for future studies. Image 1 • ISBP are covalently linked to cell wall structural components in food matrix. • ISBP are often neglected for their contribution to health. • Enzyme, alkali and acid hydrolyses improve the release of ISBP. • ISBP may play significant roles in modulating microbiota and intestinal inflammation. • Future research: roles of ISBP in the gut-low grade inflammation-metabolic syndrome axis. [ABSTRACT FROM AUTHOR]

Common beans are rich in phenolic compounds and nondigestible fermentable components, which may help alleviate intestinal diseases. We assessed the gut health priming effect of a 20% cranberry bean flour diet from two bean varieties with differing profiles of phenolic compounds [darkening (DC) and nondarkening (NDC) cranberry beans vs. basal diet control (BD)] on critical aspects of gut health in unchallenged mice, and during dextran sodium sulfate (DSS)-induced colitis (2% DSS wt/vol, 7 days). In unchallenged mice, NDC and DC increased (i) cecal short-chain fatty acids, (ii) colon crypt height, (iii) crypt goblet cell number and mucus content and (iv) Muc1, Klf4, Relmβ and Reg3γ gene expression vs. BD, indicative of enhanced microbial activity and gut barrier function. Fecal 16S rRNA sequencing determined that beans reduced abundance of the Lactobacillaceae (Ruminococcus gnavus), Clostridiaceae (Clostridium perfringens), Peptococcaceae, Peptostreptococcaceae, Rikenellaceae and Pophyromonadaceae families, and increased abundance of S24-7 and Prevotellaceae. During colitis, beans reduced (i) disease severity and colonic histological damage, (ii) increased gene expression of barrier function promoting genes (Muc1-3, Relmβ, and Reg3γ) and (iii) reduced colonic and circulating inflammatory cytokines (IL-1β, IL-6, IFNγ and TNFα). Therefore, prior to disease induction, bean supplementation enhanced multiple concurrent gut health promoting parameters that translated into reduced colitis severity. Moreover, both bean diets exerted similar effects, indicating that differing phenolic content did not influence the endpoints assessed. These data demonstrate a proof-of-concept regarding the gut-priming potential of beans in colitis, which could be extended to mitigate the severity of other gut barrier-associated pathologies. [ABSTRACT FROM AUTHOR]

Abstract: While other extraction methods have been tempted, a microwave-assisted extraction (MAE) method coupled with the orthogonal array design was investigated for efficient extraction of the phenolic compounds in potato downstream wastes. Four parameters were examined for the MAE of the total phenolic content (TPC) and optimized at 60% ethanol, 80°C, 2min, solid-to-solvent ratio 1:40 (g/ml). The MAE was proven more efficient than the conventional solvent extraction by refluxing. The optimized model showed that the downstream wastes, both the supernatant and the residue contained high TPC, particularly the former (11.0±0.26mgGAE/gDW). The antioxidant activities (DPPH and FRAP) closely correlated with the TPC of the samples (r =0.92–0.97). Chlorogenic acid and caffeic acid were found to be the predominant phenolic acids. The extracts of the downstream wastes from potato processing can be a promising candidate for functional foods and nutraceutical ingredients. [Copyright &y& Elsevier]

Abstract: Twelve highly pigmented (red or purple) vegetables (carrots, cabbage, cauliflower, potatoes, onions, asparagus and eggplant) were investigated for their total anthocyanin contents (TAC) and compositions of the individual anthocyanins and anthocyanidins by UPLC and LC–DAD–ESI–MS, and their antioxidant activities by DPPH, FRAP (ferric reducing antioxidant power) and ORAC (oxygen radical absorption capacity) assays. While a total of 26 anthocyanins were identified, the main aglycones were only found to be limited to 4 anthocyanidins (cyanidin, petunidin, pelargonidin and delphinidin). The TAC ranged from 0.08 to 2.01mg Cyanidin-3-glucoside (C3G)/g DW and the total phenolic contents (TPC) was from 1.30 to 2.19mg GAE/g DW suggesting that anthocyanins were the main phenolics in certain vegetables but not others. DPPH radical scavenging activities were 54.91–81.94%, FRAP values 10.00–70.07μmol AAE/g DW and ORAC values were 3.74–189.32μmol TE/g DW. The two cruciferous vegetables (purple cauliflower and cabbage) showed the highest TPC, TAC, DPPH and FRAP values, and the onions the lowest. The antioxidant activities in the DPPH and FRAP assays correlated well with the TPC and TAC, but ORAC did not. Results of this study are comparable and provide a rapid and effective method for the identification and quantification of all major anthocyanidins and their glycosides (anthocyanins), and how they might contribute to the antioxidant activity, therefore important information in developing anthocyanin-rich nutraceuticals and functional foods. [Copyright &y& Elsevier]

Abstract: Microwave-assisted extraction (MAE) was investigated for extraction of phenolic compounds from tomato with maximised antioxidant activities using response surface methodology (RSM) coupled with a central composite design, and in vitro antioxidant assays (FRAP and ORAC). MAE was more efficient for greater antioxidant activities and higher total phenolic contents than solvent extraction. The optimal MAE processing parameters were 96.5°C, 2.06min, 66.2% ethanol for FRAP, and 96.5°C, 1.66min, 61.1% ethanol for ORAC. The models were successfully applied to 20 tomato cultivars, whose total phenolic contents (TPC) and indexes (TPI) were 489.30–997.45mg gallic acid equivalent/100g dry weight (DW) and 281.34–468.52mg/100gDW, respectively. Eight phenolic compounds were identified. Individual phenolics were 6.10–42.73mg/100gDW. The FRAP, but not the ORAC value showed good correlation with the TPC or TPI. The methodologies developed and the knowledge acquired in this study will provide useful information to tomato breeders and food processors. [Copyright &y& Elsevier]

• First comprehensive profiling of free, conjugated and bound phenolics in lentil hulls. • Catechin/proanthocyanins, hydroxycinnamates and hydroxybenzoic acids were the main phenolics. • First comprehensive profiling of carotenoids, tocochromanols and essential fatty acids in lentil hulls. • Lutein/zeaxanthin and δ-tocotrienol/γ-tocotrienol were the main carotenoids and tocochromanols. • All phenolics, carotenoids and tocochromanols contributed significantly to antioxidant activities in vitro. A systemic approach was taken in profiling the hydrophilic and lipophilic antioxidants in lentil hulls using a combination of HPLC, LC-ESI-MS2 and GC techniques. A total of 37 phenolics were tentatively identified in the hydrophilic fractions, while four carotenoids and three tocopherols were found in the lipophilic fraction. Results showed that in addition to the high free extractable phenolics, phenolic compounds in conjugated and bound forms also exist in similar amounts. Information on conjugated and bound phenolics are particularly important as these forms of phenolics often go unnoticed by chromatographic profiling of extractables. All phenolic, carotenoid and tocopherol fractions contributed to antioxidant activities. Information about bioactives from lentil hulls, specifically conjugated and bound phenolics are reported here for the first time. The comprehensive profiling of these bioactives lays a good foundation for further assessment of the value-added uses of lentil hulls which are by-products of pulse processing. [ABSTRACT FROM AUTHOR]