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Green tea can influence the gut microbiota by either stimulating the growth of specific species or by hindering the development of detrimental ones. At the same time, gut bacteria can metabolize green tea compounds and produce smaller bioactive molecules. Accordingly, green tea benefits could be due to beneficial bacteria or to microbial bioactive metabolites. Therefore, the gut microbiota is likely to act as middle man for, at least, some of the green tea benefits on health. Many health promoting effects of green tea seems to be related to the inter-relation between green tea and gut microbiota. Green tea has proven to be able to correct the microbial dysbiosis that appears during several conditions such as obesity or cancer. On the other hand, tea compounds influence the growth of bacterial species involved in inflammatory processes such as the release of LPS or the modulation of IL production; thus, influencing the development of different chronic diseases. There are many studies trying to link either green tea or green tea phenolic compounds to health benefits via gut microbiota. In this review, we tried to summarize the most recent research in the area.

The content of polyphenols in chocolate depends on many factors related to the properties of raw material and manufacturing parameters. The trend toward developing chocolates made from unroasted cocoa beans encourages research in this area. In addition, modern customers attach great importance to how the food they consume benefits their bodies. One such benefit that consumers value is the preservation of natural antioxidant compounds in food products (e.g., polyphenols). Therefore, in our study we attempted to determine the relationship between variable parameters at the conching stage (i.e., temperature and time of) and the content of dominant polyphenols (i.e.,catechins, epicatechins, and procyanidin B2) in chocolate milk mass (CMM) obtained from unroasted cocoa beans. Increasing the conching temperature from 50 to 60 °C decreased the content of three basic flavan-3-ols. The highest number of these compounds was determined when the process was carried out at 50 °C. However, the time that caused the least degradation of these compounds differed. For catechin, it was 2 h; for epicatechin it was 1 h; and for procyanidin it was 3 h. The influence of both the temperature and conching time on the rheological properties of chocolate milk mass was demonstrated. At 50 °C, the viscosity and the yield stress of the conched mass showed its highest value.

The Strecker degradation of phenylalanine has been studied in a phenolic compound/phenylalanine wine model system. Six phenolic compounds (3,4-dihydroxybenzoic acid, gallic acid, caffeic acid, ferulic acid, catechin, and epicatechin) were compared in the formation of phenylacetaldehyde when in the presence of glucose or methylglyoxal (MG). The addition of glucose reduced the formation of Strecker aldehyde, independently of the phenolic compound. The addition of MG, on the other hand, increased phenylacetaldehyde formation for hydroxybenzoic acids and decreased phenylacetaldehyde formation for flavan-3-ols, confirming their capacity to trap the dicarbonyl compound. As a target phenolic compound, catechin was chosen to perform kinetic studies to further understand the reaction intermediates involved in the mechanism of phenylacetaldehyde formation, in particular, catechin o -quinone and catechin-MG adduct. The addition of glucose and MG increased the consumption of catechin, while a reduction in the respective o -quinone was observed, suggesting that these substrates have an impact in other reactions involving catechin. In that regard, for the first time, it was demonstrated that the catechin-MG adduct was capable of oxidizing and forming a new o -quinone, contributing to wine instability promoted by oxidation reactions.

Phenolic compounds are known to bind non-covalently with starch, but the impact of this interaction on the stability of the phenolic compounds through processing and digestion has received little attention. In this study, we examined the recovery of intact phenolic compounds (gallic acid-GA, catechin-CAT and epigallocatechin gallate-EGCG) from processed and digested porridges with different formulations (starch or starch/protein). We observed that phenolics were less degraded in presence of starch only than in presence of starch + proteins. This protection seemed to be linked to the ability of the phenolic compounds to form V-type inclusion complexes with starch, with GA, CAT and EGCG in decreasing order of protection. This work could influence formulation of functional cereal-based foods containing phenolic compounds in order to maximize their retention., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The economic value of fig trees has been globally acknowledged due to their utilization in the food industry, being also frequently used in traditional medicine. While ubiquitously distributed in Southeast Asia, Ficus curtipes Corner remains uninvestigated concerning its biological properties and chemical profile. HPLC-DAD-ESI/MS n characterization of methanol extracts obtained from the stem bark and leaves allowed the identification and quantitation of 21 phenolic compounds for the first time; the stem bark was predominantly rich in flavan-3-ols and apigenin derivatives, while solely apigenin-di-glycosides have been identified and quantitated on the leaf extract. Both extracts inhibited 5-lipoxygenase (5-LOX) activity in a concentration-dependent manner, the one obtained from the stem bark being significantly more active (IC 50 = 10.75 μg/mL). The effect of both extracts on lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages was evaluated, and while the stem bark extract did not lead to a noticeable interference on nitric oxide (NO) levels, the extract obtained from the leaves notably decreased NO and L-citrulline levels at concentrations ranging from 250 to 500 μg/mL. Herein, F. curtipes is valorized due to its modulatory effects on inflammatory mediators and also as a source of bioactive phenols, which may fuel further studies on the development of nutraceuticals.

Phenolic extracts from cv Tempranillo grapes subjected to water stress and irrigation treatment, both of them with high and low crop load, were analyzed by front-face fluorescence. Excitation-emission matrices (EEMs) were analyzed by means of unsupervised parallel factor analysis (PARAFAC), PARAFAC supervised by linear discriminant analysis, and discriminant unfolded partial least-squares. All algorithms allowed to differentiate between water stress and irrigation grape samples when the fluorescence maxima region of catechin and epicatechin, and resveratrol was considered. A central composite design was employed for the calibration of catechin, epicatechin and resveratrol. Resveratrol was quantified by U-PLS in both, irrigated and water stressed samples, and levels between 3.46 ± 0.22 and 4.67 ± 0.08 μg mL -1 and 2.43 ± 0.60 and 3.03 ± 0.10 μg mL -1 , respectively, were found. PARAFAC only allowed the determination of the sum of catechin plus epicatechin (R 2  = 0.9397). The determination of total catechin plus epicatechin by means of PARAFAC was successfully validated by liquid chromatography., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

In vitro assays are widely used to analyze the antioxidant potential of compounds, but they cannot accurately predict antioxidant behavior in living systems. Cell-based assays, like the cellular antioxidant activity (CAA) assay, are gaining importance as they provide a biological perspective. When the CAA assay was employed to study phenolic antioxidants using hepatocarcinoma (HepG2) cells, quercetin showed antioxidant activity in HepG2 cells; 25 and 250μM quercetin reduced fluorescence by 17.1±0.9% and 58.6±2.4%, respectively. (+)-Catechin, a phenolic antioxidant present in many foods, bestowed virtually no CAA in HepG2 cells. When Caco-2 cells were employed, more robust antioxidant activity was observed; 50μM (+)-catechin and quercetin reduced fluorescence by 54.1±1.4% and 63.6±0.9%, respectively. Based on these results, likely due to differences in active membrane transport between the cell types, the Caco-2-based CAA assay appears to be a more appropriate method for the study of certain dietary phenolics., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The comprehensive phenolic fingerprint of Calligonum azel Maire plant fractions, collected from the Tunisian Desert, have been assessed for the first time as a source of natural antioxidants. Total phenolic content (TPC), Trolox Equivalent Antioxidant Capacity (TEAC) in scavenging DPPH, ABTS + and Ferric Reducing Antioxidant Power (FRAP) were determined. C. azel Maire showed a relevant content in phenolic compounds, which are related to the antioxidant activity. The flowers presented the highest antioxidant capacity against DPPH free radicals, while the leaves showed the highest scavenging capacity against ABTS. As for the FRAP assay, results showed that the roots had the highest ferric reducing antioxidant power. Methanol extracts of the four organs were screened by ultra high performance liquid chromatography coupled to quadruple time of flight mass spectrometry and the identified phenolics were further quantified. Flavones and flavanols were the most abundant phenolic compounds identified, and were quantitatively measured as luteolin and catechin equivalents. Although the phenolic profile was diverse between the four organs, the obtained results showed that Calligonum azel Maire is an excellent source of various natural antioxidants with high radical scavenging capacities, which could be used in food preservation. Further studies on the isolation of such compounds appear to be of high interest., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Food and agricultural industries generate substantial quantities of phenolic-rich by-products that could be valuable natural sources of antioxidants. The aim of this study was to identify and quantify the phenolic compounds and radical scavenging activities of two by-products (pomace and lees) from Vitis vinifera L. cv Pinot noir. We found a different distribution of phenolic classes (flavanols, flavonols, phenolic acids and stilbenes) and singular scavenging activity against free radicals (hydroxyl, superoxide and peroxyl radicals). The major class of phenolics in pomace was flavanols and in lees was flavonols, with catechin (117.9 ± 2.5 μg g(-1)) and quercetin (42.4 ± 1.2 μg g(-1)) being the most abundant individual compounds. We also found high potential on scavenging activity against superoxide radicals in pomace (80% of scavenging activity) and radical peroxyl (67% scavenging activity). These results show the possibility of using Pinot noir by-products as promising additives or as a source for the development of new products in different segments of the food and cosmetic industries.

This work aimed to evaluate the content of selected phenolic natural products in the wine samples made of three new Serbian Cabernet Franc clones (Nos. 02, 010 and 012, respectively) and mother vine (used as the relevant standard) during the period 2008-2012. Compared with all other wine samples, the Cabernet Franc wine of the clone No. 010 was found to have the highest total content of polyphenolics (1.85 ± 0.02 g/L) and anthocyanins (178.55 ± 3.75 mg/L). In addition, its Folin-Ciocalteu index (36.86 ± 0.12) stood out among the examined samples. Finally, the same wine was enriched with ellagic and gallic acids (3.44 ± 0.29 and 27.46 ± 0.21 mg/L, respectively), catechin (135.16 ± 6.47 mg/L) and epicatechin (51.33 ± 2.33 mg/L), the natural products known to exert significant lipid-lowering effects. Taken all together, the clone No. 010 developed in Serbia may offer new Cabernet Franc wine with geographical indication.

Oligonol is a functional food containing catechin-type monomers and proanthocyanidin oligomer converted from polymer forms via a novel manufacturing process. The catechin component of green tea extract has been associated with nasal toxicity in rats following subchronic exposure. To assess the potential for Oligonol to induce nasal toxicity a 13-week repeated oral dose toxicity study was conducted in rats using doses of 100, 300, and 1000 mg/kg/d. Clinical signs and mortality were not affected by Oligonol treatment. Compound-colored stools and an increase in food consumption were observed in some treated groups; however, there were no treatment-related differences in terminal body weights or with respect to the results of the gross postmortem examinations. Histopathological evaluation of the nasal cavity tissues revealed no treatment-related lesions. The results from this toxicity study indicate that Oligonol does not induce nasal toxicity and further supports the results of previous studies demonstrating the safety of Oligonol for human consumption., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Phenolics in the fruits and leaves of Crataegus grayana were identified by HPLC-UV-ESI-MS. The contents of these compounds and their changes during autumn were also analyzed. Epicatechin [1-7 mg/g dry mass (DM) in fruits and 1-10 mg/g DM in leaves), procyanidins B2 (2-4 and 1-8 mg/g DM) and C1 (2-4 and 1-8 mg/g DM), hyperoside (0.5-1 and 2-11 mg/g DM), and a quercetin-pentoside (0.3-0.5 and 2-6 mg/g DM) were the major phenolics in both fruits and leaves. C-Glycosyl flavones were present in leaves (2-5 mg/g DM), whereas only trace levels were found in fruits. Ideain and 5-O-caffeoylquinic acid were found only in fruits. An additional 11 phenolics were identified/tentatively identified. Total phenolic contents reached highest levels by the end of August in fruits and by the end of September in leaves. The compositional profiles of phenolics in fruits and leaves of C. grayana were different from those of other Crataegus species.

Background: The enrichment of fruit juices with concentrated polyphenolic extracts is an expedient strategy to compensate possible phenolic loss through gastrointestinal processing. Pycnogenol, a standardised procyanidin-rich extract from pine bark, has been proposed as a potential candidate for polyphenol enrichment of foods. In this study the effects of in vitro digestion on the phenolic profile of fruit juices enriched with Pycnogenol were investigated., Results: After in vitro digestion the level of detectable total phenolic compounds (expressed as gallic acid equivalent) was higher in both pineapple and red fruit juices enriched with Pycnogenol than in non-enriched commercial juices. Five phenolic monomeric compounds were identified by high-performance liquid chromatography, namely chlorogenic acid, caffeic acid, ferulic acid, gallic acid and taxifolin, the last two being predominant. In vitro digestion of both Pycnogenol-enriched pineapple and red fruit juices led to a significant (P < 0.05) increase in detectable chlorogenic and ferulic acids, indicating that hydrolysis of more complex molecules occurs. On the other hand, in vitro digestion of non-enriched juices was associated with a decrease in gallic and caffeic acids in pineapple juice and with a decrease in ferulic acid in red fruit juice. In no case did in vitro digestion increase the amount of detectable phenolic compounds in non-enriched juices., Conclusion: The stability of Pycnogenol after in vitro gastrointestinal digestion makes it a good choice for phenolic enrichment of fruit juices., (2010 Society of Chemical Industry.)

Iron is a transition metal that forms chelates and complexes with various organic compounds, also with phenolic plant secondary metabolites. The ligands of iron affect the redox potential of iron. Electrons may be transferred either to hydroxyl radicals, hydrogen peroxide or molecular oxygen. In the first case, oxidative stress is decreased, in the latter two cases, oxidative stress is increased. This milieu-dependent mode of action may explain the non-linear mode of action of juglone and other secondary metabolites. Attention to this phenomenon may help to explain idiosyncratic and often nonlinear effects that result in biological assays. Current chemical assays are discussed that help to explore these aspects of redox chemistry.

The prevention and treatment of non-communicable diseases by using the beneficial biological effects of polyphenolic plants have attracted increasing interest from nutritional scientists. The a-glucosidase inhibitory and antioxidant activities of aqueous and methanolic extracts from 28 common Vietnamese edible plants, comprising 4 groups (plants used for making drinks, edible wild vegetables, herbs, and dark green vegetables), were investigated in vitro. The polyphenol contents of these extracts were determined by the Folin-Ciocalteu method and calculated as catechin equivalents. The extracts from plants used for making drinks showed the highest activities for both a-glucosidase inhibition and as antioxidants, followed by edible wild vegetables, herbs, and dark green vegetables. Positive relationships among alpha-glucosidase inhibitory activities, antioxidant activities and polyphenol contents of these 28 edible plants were found in both aqueous and methanolic extracts. Four new promising materials that are similar to or better than guava leaf extract, including Syzygium zeylanicum, Cleistocalyx operculatus, Horsfieldia amygdalina and Careya arborea demonstrated high alpha-glucosidase inhibitory activity (93, 76, 68 and 67%, respectively) at the final concentration of 0.8 mg lyophilized material/mL solution and antioxidant activity (85, 87, 78 and 80%, respectively) at the final concentration of 30 pg lyophilized material/mL solution. These four edible plants contained significantly high polyphenol contents (equivalent to 251.7, 146.6, 136.6 and 168.6 mg of catechin/g dry weight, respectively). Thus, these four materials might be possible new sources of a-glucosidase inhibition and antioxidants suitable for use as functional foods in the future.

A rapid HPLC-DAD determination of phenols in apple using an RP monolithic column is reported. Because of the hydrodynamic advantages offered by this kind of column and the use of acidified acetonitrile as eluent, assays of apple extracts can be performed in <21 min. Assays of pulp and peel extracts were carried out without the need for time-consuming sample pretreatment except filtration. Several flavanols, hydroxycinnamic acids, dihydrochalcones, and six quercetin glycosides were identified and quantified. A seventh quercetin derivative, two chalcone-related compounds, and three hydroxycinnamic derivatives were also found. Peels proved to be richer in phenols than pulps, the former being composed mainly of (-)-epicatechin, procyanidin B2, chlorogenic acid, phloridzin, hyperin, and avicularin. In pulps, where the chlorogenic acid was the principal phenolic compound, quercetin glycosides were found in very low amounts.

Formation of water-soluble polyphenol-protein complexes was investigated by size-exclusion chromatography (SEC). The combination of (-)-epigallocatechin gallate (EGCG) and bovine serum albumin (BSA), which did not form a precipitate after the solutions were mixed, showed an SEC peak due to complex formation 2-24 h after mixing. Peak size of the complex varied with time, suggesting slow change of the conformation of the protein accompanied by complexation. Formation of the complex was substantiated by ultrafiltration of the mixture; the complex did not pass through a membrane with a 100,000 nominal molecular weight limit (NMWL). The SEC profile varied with the combination of compounds. The peaks due to the complexes showed that the apparent value of the number average molecular weight (M(n)) of the EGCG-BSA complex was 2.8x10(5), while that of a pentagalloylglucose (PGG)-BSA complex was 9.5x10(5) under the conditions used. Dimeric hydrolyzable tannins, oenothein B and cornusiin A, also caused changes in the SEC profile of BSA, although the combinations did not show peaks attributable to formation of such large complexes observed for EGCG and PGG. Procyanidin B3 and (+)-catechin did not cause changes in the SEC profile of BSA. With cytochrome c, EGCG did not show any chromatographic changes.

Crataegus (Hawthorn) has long been used as a folk medicine and is widely utilized in pharmaceutical preparations mainly because of its neuro- and cardiosedative actions and its low toxicity. The pharmacological effects of Crataegus have mainly been attributed to the polyphenolic contents. In this study, the production of polyphenols by ten-year-old Crataegus monogyna calli was studied in relation to growth variation and antioxidant capacity within a subculture period. Assays based on the Trolox equivalent antioxidant capacity (TEAC), ferric reducing antioxidant power (FRAP) and stability in oil-in-water emulsion were used to characterize the antioxidant actions of the callus cultures. High TEAC (3.66 micromol/g dry weight) and FRAP (208.19 micromol Fe2+/g dry weight) values were observed when maximal growth was reached(days 30-35), and this seemed to be influenced by optimum total phenol (47.40 mg/g dry weight), proanthocyanidin (20.81 mg/g dry weight), flavonoid (7.01 mg/g dry weight), anthocyanin (6.18 mg/g dry weight), (-)-epicatechin (1.77 mgl/g dry weight), procyanidin B2 (3.97 mg/g dry weight), and chlorogenic acid (1.11 mg/g dry weight) production during that period. The TEAC values were strongly associated with total flavonoids and to a lesser extent with total phenols, anthocyanins and total proanthocyanidins. The FRAP antioxidant values correlated to total phenols, proanthocyanidins and flavonoids, respectively. The polyphenolic rich calli were as effective as butylated hydroxytoluene (BHT) in preventing hydroperoxide and conjugated diene formation in a 30% oil-in-water emulsion prepared with stripped sunflower oil, during 7days storage at 30 degrees C. Crataegus monogyna cell culture represents an important alternative source for natural antioxidants.

Tea is one of the most popular beverages consumed in the world and has been demonstrated to have anti-cancer activity in animal models. Research findings suggest that the polyphenolic compounds, (-)-epigallocatechin-3-gallate found primarily in green tea, and theaflavin-3,3'-digallate, a major component of black tea, are the two most effective anti-cancer factors found in tea. Several mechanisms to explain the chemopreventive effects of tea have been presented but others and we suggest that tea components target specific cell-signaling pathways responsible for regulating cellular proliferation or apoptosis. These pathways include signal transduction pathways leading to activator protein-1 (AP-1) and/or nuclear factor kappa B (NF-kappaB). AP-1 and NF-kappaB are transcription factors that are known to be extremely important in tumor promoterinduced cell transformation and tumor promotion, and both are influenced differentially by the MAP kinase pathways. The purpose of this brief review is to present recent research data from other and our laboratory focusing on the tea-induced cellular signal transduction events associated with the MAP kinase, AP-1, and NF-kappaB pathways.

A 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-generating system was used to evaluate the antioxidant properties of Korean medicinal plants that have been used widely as folk medicines for several disorders, as well as compounds isolated from them. Among the Rosaceae, Rosa rugosa and Rosa davurica showed strong DPPH radical-scavenging activity. The most effective medicinal plant from families other than Rosaceae was Cedrela sinensis, followed in order by Nelumbo nucifera, Eucommia ulmoides, Zanthoxylum piperitum, Cudrania tricuspidata and Houttuynia cordata. These results serve as a good index of the free radical-scavenging activities of Korean medicinal plants. Furthermore, the polyphenols isolated from these plants, procyanidin B-3, (+)-catechin, gallic acid, methyl gallate, quercetin, quercetin-3-O-beta-D-glucoside, quercetin-3-O-beta-galactoside, quercetin-3-O-rutinose and kaempferol, exerted strong DPPH radical-scavenging activity. These results suggest that the Korean medicinal plants and the polyphenols isolated from them that exhibited effective radical-scavenging activity may be promising agents for scavenging free radicals and treating diseases associated with excess free radicals.

Polyphenols present in red table grape varieties Red Globe, Flame Seedless, Crimson Seedless, and Napoleon, and the white varieties Superior Seedless, Dominga, and Moscatel Italica were analyzed by HPLC-DAD-MS. The anthocyanins peonidin 3-glucoside, cyanidin 3-glucoside (and their corresponding p-coumaroyl derivatives), malvidin 3-glucoside, petunidin 3-glucoside, and delphinidin 3-glucoside were found. In addition, caffeoyltartaric acid, p-coumaroyltartaric acid, and the flavonols quercetin 3-glucuronide, quercetin 3-rutinoside, quercetin 3-glucoside, kaempferol 3-galactoside, kaempferol 3-glucoside, and isorhamnetin 3-glucoside were detected. Flavan-3-ols were also detected, and were identified as gallocatechin, procyanidin B1, procyanidin B2, procyanidin B4, procyanidin C1, catechin, and epigallocatechin. These phenolics were present only in the skin, as the flesh of these grape cultivars was almost devoid of these compounds. Anthocyanins were the main phenolics in red grapes ranging from 69 (Crimson Seedless) to 151 (Flame Seedless) mg/kg fresh weight of grapes, whereas flavan-3-ols were the most abundant phenolics in the white varieties ranging from 52 (Dominga) to 81 (Moscatel Italica) mg/kg fresh weight of grapes. Total phenolics ranged from 115 (Dominga) to 361 (Flame Seedless) mg/kg fresh weight of grapes. This means that a serving of unpeeled table grapes (200 g) could provide up to 72 mg of total phenolics (Flame Seedless). These results indicate that the intake of unpeeled table grapes should be recommended in dietary habits as a potential source of antioxidant and anticarcinogenic phenolic compounds.

Tea polyphenols have been demonstrated as chemopreventive agents in a number of experimental models. However, less is known about the mechanism of chemoprevention by black tea compared with that of green tea. Some beneficial properties of theaflavins, the black tea polyphenols, were investigated in the present study. Theaflavins showed inhibitory effects on H(2)O(2)- and tert-butyl hydroperoxide (tBuOOH)-induced cytotoxicity (evaluated by tetrazolium bromide reduction), cellular oxidative stress (detected by oxidation of 2', 7'-dichlorofluorescin), and DNA damage (measured by amount of 8-OHdG and comet assay) in rat normal liver epithelium cell RL-34 cell lines. In addition, theaflavins also exhibited suppression of cytochrome P450 1A1 induced by omeprazole in the human hepatoma HepG2 cell line. Furthermore, when HepG2 cells were pretreated with omeprazole to induce CYP1A1, then exposed to benzo[a]pyrene (B[a]P), DNA damage was observed using the comet assay. However, theaflavins could inhibit this DNA damage. These results indicated that theaflavins could prevent cellular DNA damage by inhibiting oxidative stress and suppressing cytochrome P450 1A1 in cell cultures.

The effects of addition of hexamethylenetetramine (HMT) or sulfite during mashing on the polyphenol content and oxidative stability of wort and beer have been evaluated in a series of laboratory mashings and pilot brews. HMT reduced the concentration of catechin, prodelphinidin B-3, and procyanidin B-3 in wort and beer, whereas the concentration of ferulic acid was unaffected. Sulfite had only a minor effect on the concentration of phenolics in wort and beer. Addition of HMT or sulfite during mashing increased the oxidative stability of the beer slightly as judged by the tendency of formation of radicals (ESR spin trapping technique), although sensory analysis gave identical flavor acceptance scores to beers produced from untreated and HMT-treated wort and lower scores to beer from sulfite-treated wort. No difference in the oxidative stability of the differently treated sweet worts could be detected as judged by the rate of formation of radicals. HMT addition during mashing has thus been demonstrated to be a valuable experimental tool to control the level of polyphenols in wort and for producing brews with various levels of polyphenols from a single malt.

Plants consumed by humans contain thousands of phenolic compounds. The effects of dietary polyphenols are of great current interest due to their antioxidative and possible anticarcinogenic activities. A popular belief is that dietary polyphenols are anticarcinogens because they are antioxidants, but direct evidence for this supposition is lacking. This chapter reviews the inhibition of tumorigenesis by phenolic acids and derivatives, tea and catechins, isoflavones and soy preparations, quercetin and other flavonoids, resveratrol, and lignans as well as the mechanisms involved based on studies in vivo and in vitro. Polyphenols may inhibit carcinogenesis by affecting the molecular events in the initiation, promotion, and progression stages. Isoflavones and lignans may influence tumor formation by affecting estrogen-related activities. The bioavailability of the dietary polyphenols is discussed extensively, because the tissue levels of the effective compounds determine the biological activity. Understanding the bioavailability and blood and tissue levels of polyphenols is also important in extrapolating results from studies in cell lines to animal models and humans. Epidemiological studies concerning polyphenol consumption and human cancer risk suggest the protective effects of certain food items and polyphenols, but more studies are needed for clear-cut conclusions. Perspectives on the application of dietary polyphenols for the prevention of human cancer and possible concerns on the consumption of excessive amounts of polyphenols are discussed.

We investigated the inhibition of IkappaB kinase (IKK) activity in lipopolysaccharide (LPS)-activated murine macrophages (RAW 264.7 cell line) by various polyphenols including (-)-epigallocatechin-3-gallate, theaflavin, a mixture of theaflavin-3 gallate and theaflavin-3'-gallate, theaflavin-3,3'-digallate (TF-3), pyrocyanidin B-3, casuarinin, geraniin, and penta-O-galloyl-beta-D-glucose (5GG). TF-3 inhibited IKK activity in activated macrophages more strongly than did the other polyphenols. TF-3 strongly inhibited both IKK1 and IKK2 activity and prevented the degradation of IkappaBalpha and IkappaBbeta in activated macrophage cells. The results suggested that the inhibition of IKK activity by TF-3 could occur by a direct effect on IKKs or on upstream events in the signal transduction pathway. Furthermore, geraniin, 5GG, and TF-3 all blocked phosphorylation of IKB from the cytosolic fraction, inhibited nuclear factor-kappaB (NFkappaB) activity, and inhibited increases in inducible nitric oxide synthase levels in activated macrophages. These results suggest that TF-3 may exert its anti-inflammatory and cancer chemopreventive actions by suppressing the activation of NFkappaB through inhibition of IKK activity.

The kinetics of interactions between thiamine and seven polyphenols were followed by two types of thiochrome assays. The assays on the reaction mixture showed the extremely rapid initial phase whereas those on the eluate of the mixture previously treated by the Decalso column did not. The former assay methods also produced higher estimates of thiamine modification than the latter over the period of 3 hours of reaction. Arguments are given to show the probable non-existence of the observed extremely rapid initial phase. Reinterpretation of some past results are also presented.

Measurements were made of the effects of phenolic compounds, some of which are present in the human diet, on the nitrosation of proline by nitrite to give N-nitrosoproline (NPRO). In vitro, resorcinol, catechin, p-nitrosophenol and phenol were catalysts and chlorogenic acid an inhibitor; guaiacol showed a marginal catalytic effect. Both the catalytic and the inhibiting effects were dependent on pH and on the concentration of phenolic compounds; catalysis by resorcinol and catechin was increased at optimal ratios of [nitrite]: [phenolic compound]. Endogenous nitrosation was examined in vivo by co-administration of nitrite, proline and a phenolic compound to rats and by monitoring the amount of NPRO excreted in the urine. Under similar experimental conditions, the catalytic effects observed in vivo decreased in the same order as those observed in vitro: resorcinol greater than p-nitroso-phenol greater than catechin greater than phenol greater than or equal to guaiacol; chlorogenic acid acted as an inhibitor. Catalysis and inhibition of N-nitrosation in rats in vivo appears to occur via mechanisms similar to those in vitro, although the effects in vivo were smaller. The implications of our findings for the endogenous formation of N-nitroso compounds and for variations in exposure due to different dietary constituents in humans are discussed.

An innovative Chardonnay wine flavored with black tea was prepared under optimal ultrasound conditions at 450.0 W for 22.6 min, and its physicochemical features, antioxidant power, total phenolic content, and volatile composition were systematically examined. A total of 165 phenolic and non-phenolic substances were characterized, including 27 newly formed phenolic substances and 10 non-phenolic substances that were not found in both black tea and Chardonnay wine. Catechin was found to be the phenolic compound with the largest amount detected, which was responsible for the potentiated antioxidant activities. The wine exhibited a profile of 44 volatile compounds, with 13 volatiles as odor-active compounds. Black tea infusion resulted in a decline in fruity, fermented and spicy aromas, but an increase in green and citrus odors, while ultrasound processing further intensified these odors. This study anticipated that ultrasound technology could hold promise for crafting flavored wines with heightened functionalities and appealing flavor profiles. Ultrasound-assisted infusion of black tea potentiated the antioxidant activity and enriched the volatile and phenolic profiles of Chardonnay wine. [ABSTRACT FROM AUTHOR]

Leaves of large‐leaved lime, Tilia platyphyllos Scop. (Malvaceae), harbor colonies of Eriophyes tiliae (Pagenstecher) (Acari: Eriophyidae), capable of modifying the leaf structure (inducer of nail‐galls) and physiology. The aerial organs of T. platyphyllos have traditionally been consumed for their high antioxidant capacity, related to the rich polyphenol profile. Here, we investigated the polyphenol profiles and antioxidant activity of T. platyphyllos non‐galled leaves and galls to determine the changes induced by the mite in a Chilean environment with high ultraviolet (UV) radiation. Phenolic compound identification in the methanol extracts of non‐galled leaves and galls was carried out through HPLC. Furthermore, the antioxidant activity of the extracts was quantified through spectrophotometry, and it was compared with the standards of the three major phenolic compounds of both organs. Nine phenolic compounds were detected in non‐galled leaves and galls, with no differences between the two organs, except for the absence of gallic acid in galls. The concentration of phenolic compounds did differ significantly between the two conditions. In leaf galls, epicatechin and cyanidin‐3‐glucoside concentrations and antioxidant capacity increased significantly compared to non‐galled leaves. As chlorogenic acid and cyanidin‐3‐glucoside are active phenols responding to UV radiation stress, their concentration in T. platyphyllos leaves could be a response to the high UV radiation occurring in Chile during spring and summer. The phenolic compounds detected here have been reported to be potent antioxidants, that are probably potentiated by E. tiliae for its own protection against UV‐B radiation, as the two most abundant compounds in the galls exhibited the highest capacity to reduce ABTS and DPPH radicals. However, we do not rule out the participation of phenolics in protection against natural enemies of the gall mite, as chlorogenic acid and epicatechin are powerful antifeedants. [ABSTRACT FROM AUTHOR]

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Summary: Total carotenoid amounts of rocket samples were established between 120.56 μg g−1 (fresh) and 130.06 μg g−1 (microwave). In addition, total phenol and flavonoid results of rockets dried in microwave and oven were found between 655.53 (oven) and 1790.96 mg GAE/100 g (fresh) to 254.03 (oven) and 1668.83 mg/100 g (fresh), respectively. Also, radical scavenging activities (DPPH and FRAP) of rocket samples were measured between 7.55 (oven) and 25.45 mmol kg−1 (fresh) to 35.59 (oven) and 66.74 mg g−1 (fresh), respectively. Gallic acid, 3,4‐dihydroxybenzoic acid, catechin and rutin were the main phenolic compounds found in rocket samples. Catechin contents of rockets dried in microwave and oven systems were recorded between 349.60 (oven) and 442.47 mg/100 g (fresh). Gallic acid and 3,4‐dihydroxybenzoic acid amounts of rocket samples were monitored between 52.84 (oven) and 952.15 mg/100 g (fresh) to 30.92 (oven) and 282.15 mg/100 g (fresh), respectively. The protein amounts of rockets were determined between 11.00% (microwave) and 11.60% (oven). P and K values of fresh and dried rockets were found between 3148.36 (oven) and 3752.33 mg kg−1 (fresh) to 39 363.75 (microwave) and 36 883.41 mg/kg (fw), respectively. Also, Ca and Mg results of fresh and dried‐rockets were found between 26 739.33 (microwave) and 29 534.48 mg kg−1 (fresh) to 3125.32 (microwave) and 3431.70 mg kg−1 (fresh), respectively. The highest S (14 665.30 mg kg−1) was detected in rocket sample dried in microwave. [ABSTRACT FROM AUTHOR]

Summary: Herein, an ultra‐high performance liquid chromatography coupled to a diode array detector (UHPLC‐DAD) based quantification method has been developed for the simultaneous determination of 21 bioactive phenolic compounds present abundantly in food products. The developed method was validated in terms of parameters such as linearity, detection and quantification limits, intra‐day and inter‐day precision and recovery showing ideal results. Further, the developed method was applied for the quantitative analysis of phenolics in commercially procured dietary samples such as spices, green tea, black tea and dark chocolate. The major phenolics quantified in dry weight of different samples were epigallocatechin gallate (425.5 mg/10 g), epicatechin gallate (111.9 mg/10 g) in green tea; gallocatechin (286.8 mg/10 g) in dark chocolate; and naringin (93.9 mg/10 g) in star anise etc. Overall, the UHPLC‐DAD‐based method was found to be reliable, simple and specific for the estimation of phenolics in different targeted food samples. [ABSTRACT FROM AUTHOR]

To obtain more sustainable and active food packaging materials, PHBV films containing 5% wt. of phenolic compounds with different molecular structures (ferulic acid, vanillin, and catechin) and proved antioxidant and antimicrobial properties were obtained by melt blending and compression molding. These were characterized by their structural, mechanical, barrier, and optical properties, as well as the polymer crystallization, thermal stability, and component migration in different food simulants. Phenolic compounds were homogenously integrated within the polymer matrix, affecting the film properties differently. Ferulic acid, and mainly catechin, had an anti-plasticizing effect (increasing the polymer glass transition temperature), decreasing the film extensibility and the resistance to breaking, with slight changes in the elastic modulus. In contrast, vanillin provoked a plasticizing effect, decreasing the elastic modulus without notable changes in the film extensibility while increasing the water vapor permeability. All phenolic compounds, mainly catechin, improved the oxygen barrier capacity of PHBV films and interfered with the polymer crystallization, reducing the melting point and crystallinity degree. The thermal stability of the material was little affected by the incorporation of phenols. The migration of passive components of the different PHBV films was lower than the overall migration limit in every simulant. Phenolic compounds were released to a different extent depending on their thermo-sensitivity, which affected their final content in the film, their bonding forces in the polymer matrix, and the simulant polarity. Their effective release in real foods will determine their active action for food preservation. Catechin was the best preserved, while ferulic acid was the most released. [ABSTRACT FROM AUTHOR]

Using HPLC-DAD the presence of catechin, epicatechin, quercetin, kaempferol and protocatehuic acid was analysed in herb extracts of eight Ephedra species (Ephedra sinica, Ephedra major, Ephedra chilensis, Ephedra ciliata, Ephedra foeminea, Ephedra equisetina, Ephedra gerardiana and Ephedra distachya). For comparison purposes, the same phenolics were determined in Camellia sinensis herb, which is a common source of catechins and a medicinal plant with valuable antioxidant properties. The catechin content in Ephedra spp. ranged between 0.83 mg/g d.w.– 8.77 mg/g d.w., while the epicatechin content was between 0.11 mg/g d.w.– 3.38 mg/g d.w. In comparison to black tea, Ephedra major, Ephedra distachya and Ephedra equisetina had a higher catechin content. The selected Ephedra spp. are rich in catechins and the obtained results serve as the chemical rationale for the anti-inflammatory, antioxidant and anti-proliferative activities of Ephedra that are currently being investigated. [ABSTRACT FROM AUTHOR]

Summary: In this study, the effect of germination in changes on total phenol, flavonoid contents, antioxidant capacity, polyphenols and biogenic elements of raw and germinated barley parts (radicle, foliole and germinated grain) was investigated. Total phenolic and flavonoid contents of raw and germinated barley parts were recorded to be between 97.61 (foliole) and 164.44 mgGAE/100 g (radicle) to 38.93 (germinated barley grain) and 371.07 mg/100 g (radicle), respectively. Antioxidant capacity results (DPPH and ABTS assays) were recorded between 3.37 (germinated barley grain) and 4.82 mmol kg−1 (radicle) to 0.79 (germinated barley grain) and 2.28 mmol kg−1 (radicle), respectively. The highest total phenol and flavonoid content as well as antioxidant capacity values were detected in radicle. Catechin and kaempferol values of raw and germinated barley parts (radicle, foliole and germinated barley grain) were recorded between 5.85 (germinated barley grain) and 19.71 mg/100 g (radicle) to 3.91 (germinated barley grain) and 4.62 mg/100 g (foliole), respectively. Gallic acid results of barley samples varied between 0.72 (germinated barley grain) and 10.95 mg/100 g (radicle). The phenolic compounds detected in the highest amounts in raw and germinated barley parts were catechin, kaempferol and gallic acid. P and K results of raw (control) and germinated barley parts were recorded to be between 727.64 (foliole) and 2078.10 mg kg−1 (control) to 955.40 (germinated barley grain) and 3982.63 mg kg−1 (control), respectively. As a micro elements, Fe and Zn results of barley samples were identified between 2.95 (foliole) and 14.30 mg kg−1 (control) to 6.26 (foliole) and 24.84 mg kg−1 (control), respectively. Significant decreases in macro and micro element contents were observed during the germination of barley grain compared to the control. [ABSTRACT FROM AUTHOR]

Bacterial diseases caused by pathogenic bacteria are one of the health problems in recent times. The continuous use of antibiotics and increased hospitalization increased drug resistance. The increased drug resistance has led to the development of novel lead molecules. Hence, alternate medicine or secondary metabolites from plant sources is a possible therapeutic option to treat bacterial infection alone or with existing drugs. The present study aimed to evaluate the antimicrobial property of green tea extract, catechin, benzoyl peroxide and a combination of antibiotics against acne-causing Staphylococcus epidermidis, Staphylococcus aureus, and Propionibacterium acnes isolated from the skin surface of the clinical subjects. The aqueous and solvent extract of green tea showed antibacterial activity against the screened bacteria and it was further improved by combing with existing drugs. The Minimum Inhibitory Concentration (MIC) was performed using the broth dilution method and showed the least MIC value (

The aims of this study were to determine the polyphenolic profile, to estimate the total phenolic and flavonoid contents, and to evaluate the antioxidant and antidiabetic activities of the extract of Pistacia lentiscus leaves, and the hydroacetonic mixture was employed as an alternative for common solvents in the extraction process. In order to explain the antidiabetic activity, molecular docking has been performed on the main constituents of the leaf extract. The characterization of the extract has been performed by high-performance liquid chromatography (HPLC) leading to the detection of 20 compounds of which gallic acid, ellagic acid, catechin, kaempferol, and quercetin 3-glucoside were identified using authentic standards. The total phenolic and flavonoid contents, assessed using the Folin–Ciocalteu and quercetin methods, were 394.5 ± 0.08 mg gallic acid equivalent/g dry extract (mg GAE/g DE) and 101.2 ± 0.095 mg quercetin equivalent/g dry extract (mg QE/g DE), respectively. On the other hand, the antioxidant activity of leaf extract, quantified by determining the ability to neutralize the free radical DPPH and β-carotene/linoleate model system, reached the values of 0.0027 ± 0.002 mg/mL and 0.128 ± 0.04 mg/mL, respectively. Regarding the antidiabetic activity, based on the inhibition of pancreatic α-amylase activity, a significant inhibition of about 68.20% with an IC50 value of 0.266 mg/mL had been observed. This finding is consistent with the molecular docking study of the main phenolic compounds of the extracts, where a remarkable binding affinity against α-amylase was observed, with values of −7.631 (kcal/mol), −6.818 (kcal/mol), and −5.517 (kcal/mol) for the major compounds catechin, quercetin-3-glucoside, and gallic acid, respectively. [ABSTRACT FROM AUTHOR]

In peach, which is a climacteric fruit species, the fruit deteriorates rapidly at post harvest with the increase in ethylene production and respiration rate during ripening, and significant changes occur in quality properties and antioxidant activity. In the study, the effect of melatonin applications at different doses (0, 0.10, 0.25, 0.50 and 1.00 mM) at postharvest on fruit quality characteristics and biochemical content during cold storage was determined. The increased weight loss and decay rate with the prolongation of the cold storage period were lower in melatonin-treated fruit and varied depending on the application concentration. Melatonin application was effective in maintaining fruit flesh firmness, but application concentration had no effect. An increase in soluble solids content (SSC) ratio and a decrease in acidity occurred during storage, and changes in SSC and titratable acidity ratios were lower with melatonin application. In general, melatonin application was effective in maintaining the concentration of organic acids, but this effect varied depending on the concentration and compound. As a result, it was concluded that 0.25 mM melatonin application can be used to maintain the postharvest fruit quality of peach. [ABSTRACT FROM AUTHOR]

The leaves of the Camellia sinensis plant are used to produce many different types of teas, and green tea is particularly noted for its health promoting properties which are attributed to high concentrations of phenolic compounds known as catechins. Green tea is available in forms such as bagged, gunpowder (rolled leaf), and matcha, a fine powder. This study evaluated the phenolic content, catechin composition, caffeine concentration, and antioxidant properties of fifteen commercially-available green teas with an emphasis on identifying differences between ceremonial and culinary matcha. Gunpowder and bagged green teas had higher total phenolic contents and greater CUPRAC (cupric ion reducing antioxidant capacity) and ORAC (oxygen radical absorbance capacity) antioxidant capacities than matcha teas. Among matcha samples, less expensive culinary teas had greater total phenolic contents and higher antioxidant capacities than ceremonial products. Hierarchical cluster analysis was used to determine similarities and differences in catechin composition and revealed that bagged and gunpowder green teas had the highest levels of the stereoisomers epi/catechin gallate, which correlated with their strong antioxidant properties. Bagged and gunpowder teas were the lowest cost products in this study, indicating that they are an economical choice for consumers who want a green tea beverage with high catechin content, although they generally had lower caffeine levels than matcha. [ABSTRACT FROM AUTHOR]

Tapeworm infections cause insidious and irreversible effects in the infected individuals and some of them have already shown resistance to available drugs. A search for alternative treatment is urgently required. Phenolic compounds are amongst the most researched natural substances for their medicinal use. The present study aims to determine anthelmintic efficacy of two polyphenols Gallic acid and Catechin against the zoonotic rat tapeworm Hymenolepis diminuta. Both compounds are potent anti-oxidants and play major roles in combating pathogens, while their anthelmintic property according to our knowledge is yet to be explored. The parasite model H. diminuta was procured from intestine of infected rats raised in our laboratory. Two sets of parasites were treated in vitro with 5, 10, 20 and 40 mg/ml concentrations of each Gallic Acid and Catechin separately, another set of parasites were treated with standard dose of Praziquantel in RPMI 1640, while still another set of worms were kept in RPMI 1640 at 37 ± 10C with 1% Dimethyl sulfoxide as control. Motility and structural alterations were the parameters assessed for anthelmintic efficacy of the compounds. After paralysis the worms were processed for morphological, histological, and ultrastructural study and observed under light and electron microscope. Dose-dependent efficacy was observed in both compounds. Shrinkage of suckers, deformed proglottids and architectural alteration of the tegument were observed throughout the body of treated parasites compared to control. Although in terms of time taken for paralysis and mortality Gallic acid was more effective than Catechin, the degree of morphological aberrations caused were almost similar, except histological alteration was more in Catechin treated worms than in Gallic acid. Nevertheless, both Gallic acid and Catechin are suggested to possess anthelmintic efficacy besides other health benefits but extended studies are required to compare their efficacy. [ABSTRACT FROM AUTHOR]

This study investigated the assistance of ultrasound and Viscozyme L in the extraction of alkaloid and phenolic compounds from cocoa bean (Theobroma cacao L.) shells (CBS). Four variables including ultrasound temperatures (25–75oC), ultrasonic durations (25–65 min); enzyme concentrations (Viscozyme L, 0.5–2.5%), and enzymatic incubation times (10–180 min) were studied separately. As temperature and duration of sonication increased, total phenolic content (TPC), total flavonoid content (TFC) and antioxidant capacity (AC) were enhanced. TPC, TFC, AC ranged from 2.35 to 4.15 g gallic acid equivalents/100 g dry weight (DW); 6.45–10.76 g rutin equivalents/100 g DW; and 14.91–26.19 mol Trolox equivalents/100 g DW, respectively. Sonication at 55oC and 55 min were effective to obtain those polyphenols. Data of Ultra High Performance Liquid Chromatography showed that although amounts of theobromine, catechin, and caffeine extracted from CBS were significantly higher from control samples, however there has been little improvement when high heat and prolonged durations of sonication were employed. Those contents ranging from 1.01 to 1.05 g, 0.59–0.72 and 0.19–0.20 g/100 g DW for theobromine, catechin and caffeine, respectively, were improved with 1.5% Viscozyme L. Meanwhile, incubating the shells with 2.0–2.5% Viscozyme L yielded higher TPC and TFC. Overall, caffeine, AC, TFC, and TPC required 10 min of enzymatic incubation to reach their peak, while 40–50 min were required to achieve the highest theobromine and catechin concentrations. [ABSTRACT FROM AUTHOR]

This study evaluated the changes caused by cooking presoaked aged carioca beans in the autoclave steam, focusing on its bioactive components, antioxidant activity, and nutritional compounds. Additionally, to identify which carioca bean cultivar could preserve the most quantity of bioactive compounds in cooked flour. The cooked flours from Imperador had the highest antioxidant activity (DDPH: 10.58 µmolTrolox·g-1, ABTS: 18.71 µmolTrolox·g-1), anthocyanins (8.08 µg·g-1), and total phenolic content (TPC) (36.69 mg·g-1). The cultivar Gol also retained part of these compounds after cooking. The phenolic and saponin profiles of cooked flours revealed a reduction in phenolic compounds such as catechin, epicatechin, and kaempferol and an increase in soyasaponin-Ba and Bb. The samples Notavel, Dama, and Madreperola, presented the highest amount of soyasaponin-A0. Thus, the cooked flours from Imperador and Gol stood out due to their retention of part of their bioactive compounds, such as polyphenols and group B saponins. [ABSTRACT FROM AUTHOR]

Syzygium zeylanicum L. (DC) (SZL) has been used in antidiabetes treatment for ages. However, the scientific evidence of active agents that have antidiabetic activity and response against biological activities is limited. In this study, the active components of SZL trunk‐bark extract (SZL extract) were identified using principal component analysis (PCA), and their antidiabetic activities were assessed. The results indicated that the ethyl acetate fraction (EAF) had the highest concentration of phenolic compounds, antioxidants, and antihyperglycemic activities in the postprandial zebrafish model. The major antioxidant contributors were gallic acid, catechin, epicatechin, ellagic acid, quercetin, caffeine, and apigenin, and their concentrated levels reduced α‐amylase inhibitory activity, whereas rutin and ethyl gallate influenced the α‐glucosidase inhibitory activity. This study showed the bio‐functional properties of active phenolic compounds present in the SZL extract, potentially serving as a functional food to control hyperglycemia. [ABSTRACT FROM AUTHOR]

Glaucoma is the leading cause of irreversible blindness and visual impairment, affecting more than 80 million individuals worldwide. Oxidative stress and inflammation-induced neurodegenerative insults to retinal ganglion cells are the main pathogenesis of glaucoma. Retinal ganglion cells, the retinal neurons transmitting the visual signals to the visual cortex in the brain, have very limited regeneration or recovery capacity after damages. Apart from intraocular pressure-lowering treatments, there is still no clinically effective treatment to rescue the degeneration of retinal ganglion cells in glaucoma. Dietary antioxidants are easily accessible and can be applied as supplements assisting in the clinical treatments. Catechins, a chemical family of flavonoids, are the phenolic compounds found in many plants, especially in green tea. The anti-oxidative and anti-inflammatory properties of green tea catechins in vitro and in vivo have been well proven. They could be a potential treatment ameliorating retinal ganglion cell degeneration in glaucoma. In this review, the chemistry, pharmacokinetics, and therapeutic properties of green tea catechins were summarized. Research updates on the biological effects of green tea catechins in cellular and animal experimental glaucoma models were reviewed. In addition, clinical potentials of green tea catechins for glaucoma treatment were also highlighted. [ABSTRACT FROM AUTHOR]

The impact of key classes of compounds found in wine on protein removal by the ion-exchange resin, Macro-Prep® High S, was examined by adsorption isotherm experiments. A model wine system, which contained a prototypical protein Bovine Serum Albumin (BSA), was used. We systematically changed concentrations of individual chemical components to generate and compare adsorption isotherm plots and to quantify adsorption affinity or capacity parameters of Macro-Prep® High S ion-exchange resin. The pH (hydronium ion concentration), ethanol concentration, and prototypical phenolics and polysaccharide compounds are known to impact interactions with proteins and thus could alter the adsorption affinity and capacity of Macro-Prep® High S ion-exchange resin. At low equilibrium protein concentrations (< ~0.3 (g BSA)/L) and at high equilibrium protein concentrations in model wines at various pH, the adsorption behavior followed the Langmuir isotherm, most likely due to the resin acting as a monolayer adsorbent. The resulting range of BSA capacity was between 0.15-0.18 (g BSA)/(g Macro-Prep® High S resin). With the addition of ethanol, catechin, caffeic acid, and polysaccharides, the protein adsorption behavior was observed to differ at higher equilibrium protein concentrations (> ~0.3 (g BSA)/L), likely as a result of Macro-Prep® acting as an unrestricted multilayer adsorbent at these conditions. These data can be used to inform the design and scale-up of ion-exchange columns for removing proteins from wines.

Peanut sprout is a high-quality healthy food, which not only has beneficial effects, but also a higher phenol content than peanut seed. In this study, peanut sprout was treated with five cooking methods, namely boiling, steaming, microwave heating, roasting, and deep-frying, and the phenol content, monomeric phenol composition, and antioxidant activity were determined. The results showed that, compared with unripened peanut sprout, the total phenol content (TPC) and total flavonoid content (TFC) decreased significantly after the five ripening processes, and the highest retention of phenols and flavonoids was associated with microwave heating (82.05% for TPC; 85.35% for TFC). Compared with unripened peanut sprout, the monomeric phenol composition in germinated peanut was variable after heat processing. After microwave heating, except for a significant increase in the cinnamic acid content, no changes in the contents of resveratrol, ferulic acid, sinapic acid, and epicatechin were observed. Furthermore, there was a significant positive correlation of TPC and TFC with 2,2-diphenyl-1-picrylhydrazyl scavenging capacity, 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) scavenging capacity, and ferric ion reducing antioxidant power in germinated peanut, but not with hydroxyl free radical scavenging capacity, in which the main monomer phenolic compounds were resveratrol, catechin, and quercetin. The research results indicate that microwave heating can effectively retain the phenolic substances and antioxidant activity in germinated peanuts, making it a more suitable ripening and processing method for germinated peanuts. [ABSTRACT FROM AUTHOR]

• MWCNTs application in vitro increased the proliferation of callus biomass in Thymus daenensis. • Using MWCNTs has caused the plant tissues to accumulate secondary metabolites including rosmarinic acid, ferulic acid, caffeic acid, catechin, vanilin and hesperedin. • Transmission electron microscopy revealed carbon nanotubes in contact with the cell walls. • Findings report how plants respond phytochemically and physiologically to MWCNTs. Carbon nanotubes (CNTs) as novel promising nanomaterials have attracted considerable interest with excellent potential to boost the production of bioactive substance in plants. In the present study, we assessed morphological, physiological and phytochemical properties of Thymus daenensis callus culture upon exposure to various concentrations of multi-walled CNTs (MWCNTs) in vitro. Aseptic explants were cultured on 2, 4-dichlorophenoxy acetic acid (2, 4-D) and benzyl amino purine (BAP) containing Murashige and Skoog (MS) media. Results showed that callus exposure to MWCNTs may stimulate cells to absorb more water, grow faster and ultimately assist T. daenensis callus in accumulating higher fresh and dry biomass (maximum 100 µg ml−1). The application of MWCNTs resulted in higher values of antioxidant capacity, total flavonoids and phenolic compounds. High-Performance Liquid Chromatography (HPLC) analysis revealed that MWCNTs at specific concentration stimulate rosmarinic acid (25.25 mg g−1 DW), ferulic acid (1.97 mg g−1 DW), caffeic acid (1.02 mg g−1 DW), catechin (1.99 mg g−1 DW), vanilin (0.91 mg g−1 DW) and hesperedin (2.83 mg g−1 DW) biosynthesis. This increase followed a dose-dependent manner and was associated with changes in phenylalanine ammonia lyase enzyme activity (PAL). Maximum levels of antioxidant enzymes were obtained in callus grown on MS media supplemented with 500 and 1000 µg ml−1 of MWCNTs. Transmission electron microscopy (TEM) and optical microscopy micrographs revealed that MWCNTs entered the cell wall, cytoplasm and chloroplast, thereby increasing the cell size through mechanisms of action. The results revealed that MWCNTs can cross cell walls, enter the cytoplasm and other cellular organelles and facilitate water absorption. More biomass production and antioxidant biosynthesis were associated with higher levels of secondary metabolite production. Overall, the results indicated that MWCNTs can be used as a valuable elicitor in vitro for producing the highest economic values of rosmarinic acid, ferulic acid, caffeic acid, catechin, vanilin and hesperedin for pharmaceutical, therapeutic and food purposes. [ABSTRACT FROM AUTHOR]