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Flavan-3-ols are the most found flavonoid compounds in the human diet. Polymeric and monomeric flavan-3-ols reach the colonic region intact, where the gut microbiota utilizes them as substrates. In this research work, we investigated the pattern of colonic metabolites associated with flavan-3-ols, conducting a comprehensive analysis that combined (un)targeted metabolomics and in vitro colonic models. Firstly, the proposed flavan-3-ol metabolic pathway was investigated in-depth using a static in vitro model inoculated with different fecal donors. An apple, (−)-epicatechin, and procyanidin C1 were employed as feeding conditions. Small phenolic acids, such as phenylpropanoic acid and 3,4-dihydroxybenzoic acid, were positively associated with the apple feeding condition. In contrast, 5-(3ʹ,4ʹ-dihydroxyphenyl)-γ-valerolactone and other specific early intermediates like phenylvaleric acids were positively associated with (−)-epicatechin. Secondly, by employing a dynamic in vitro simulator model of the human digestion system (SHIME), we reconstructed the flavan-3-ol metabolic pathway regionally. In the proximal colon region, we localized catabolites, such as 5-(3ʹ,4ʹ-dihydroxyphenyl)-γ-valerolactone, while in the distal region, we identified mainly small phenolics. Combining static and dynamic in vitro models, we observed differences in the release of flavan-3-ol catabolites, influenced by both the food structure (isolated compounds and a food matrix) and the colonic region. This study sheds light on the colonic catabolism of one of the main dietary (poly)phenols and localizes microbial metabolites. [Display omitted] • The dynamic in vitro model revealed spatiotemporal production of flavan-3-ols. • Flavan-3-ol catabolism was expanded considering proximal and distal colonic regions. • Flavan-3-ol catabolites differed between epicatechin and apple conditions. • 5-(3′,4′-dihydroxyphenyl)-γ-valerolactone may be released in the proximal colon. [ABSTRACT FROM AUTHOR]

[Display omitted] • Substitution patterns significantly affect the copigmentation ability of monomeric flavan-3-ols. • Hydroxy group addition to the B ring slightly enhanced copigmentation. • Esterification of the C3 hydroxyl group with gallic acid markedly enhanced copigmentation. • Substitution effects are closely linked to stereoisomeric configurations. Monomeric flavan-3-ols are important copigments in red wines, due to their superior copigmentation ability and high concentration. In this work, a systematic study was conducted on the copigmentation effects of eight common monomeric flavan-3-ols with malvidin-3- O -glucoside, using experimental and theoretical methods. The results revealed that the addition of a hydroxy group to the B ring and the attachment of a galloyl group at the 3- O position of monomeric flavan-3-ols both contributed to enhance copigmentation, with the latter exerting a more pronounced effect. Regarding stereoisomerism, it was observed that the cis -configuration of the B ring and 3- O -hydroxy group favored copigmentation. However, the cis -configuration of the B ring and 3- O -galloyl group was disadvantageous due to steric hindrance, in contrast to when these moieties occupied opposing sides (i.e., the 2,3- trans configuration). These results highlight the crucial role played by both substitution patterns and conformational arrangements in determining the copigmentation ability of monomeric flavan-3-ols. [ABSTRACT FROM AUTHOR]

[Display omitted] • Flavan-3-ol-rich apple juices were made with the emerging spiral filter technology. • Novel insights into flavan-3-ol reactions with sugars and other carbonyl compounds. • Ascorbic acid had a protective and destabilizing effect on flavan-3-ols. • Storage of apple juice as concentrates accelerated flavan-3-ol degradation. • New UHPLC- and HILIC-ESI(−)-QTOF-HR-MS/MS data on flavan-3-ol degradation products. Potentially health-promoting concentrations of flavan-3-ols were previously shown to be retained in apple juices produced with the emerging spiral filter press. Due to the novelty of this technology, the factors governing the stability of flavan-3-ol-rich apple juices have only scarcely been studied. Therefore, we produced flavan-3-ol-rich apple juices and concentrates (16, 40, 70 °Brix) supplemented with ascorbic acid (0.0, 0.2, 1.0 g/L) according to common practice. Flavan-3-ols (DP1-7) and twelve flavan-3-ol reaction products were comprehensively characterized and monitored during storage for 16 weeks at 20 and 37 °C, employing RP-UHPLC- and HILIC-DAD-ESI(−)-QTOF-HR-MS/MS. Flavan-3-ol degradation followed a second-order reaction kinetic, being up to 3.5-times faster in concentrates (70 °Brix) than in single strength juices (16 °Brix). Furthermore, they diminished substantially faster compared to other phenolic compounds. For instance, after 16-weeks at 20 °C, the maximum loss of flavan-3-ols (−70 %) was greater than those of hydroxycinnamic acids (−18 %) and dihydrochalcones (−12 %). We observed that flavan-3-ols formed adducts with sugars and other carbonyls, such as 5-(hydroxymethyl)furfural and the ascorbic acid-derived L-xylosone. Increased degradation rates correlated particularly with increased furan aldehyde levels as found in concentrates stored at elevated temperatures. These insights could be used for optimizing production, distribution, and storage of flavan-3-ol-rich apple juices and other foods and beverages. [ABSTRACT FROM AUTHOR]

Background Coffee consumption is associated with a reduced risk of several chronic diseases in a dose-dependent manner. Chronic intake results in the transient appearance of bioactive phenolic metabolites in the circulatory system. However, there is a lack of information on the impact of different patterns of coffee consumption on plasma and urinary profiles of phenolic metabolites. Objectives Plasma and urinary phenolic metabolites were investigated following regular consumption of different daily dosages of coffee or cocoa-based products containing coffee (CBPCC) under a real-life setting. Methods A repeated-dose, randomized, crossover human intervention was conducted with 21 healthy volunteers. For 1 mo, participants consumed 1) 1 cup of coffee (1C), 2) 3 cups of coffee (3C), or 3) 1 cup of coffee + 2 CBPCC twice daily (PC). Plasma and urine samples were collected over a 24-h period after each treatment. The nutrikinetics and urinary excretion of native, human phase II, and colonic metabolites were assessed. Results A total of 51 (poly)phenolic metabolites were quantified, with 41 metabolites being strictly related to coffee consumption. Significant differences were observed among treatments for most of the metabolites. The metabolites present in the highest amounts were the hydroxycinnamate, phenylpropanoic acid, benzaldehyde, and benzene classes, along with (–)-epicatechin and phenyl-γ-valerolactone derivatives after PC treatment. Daily average concentrations did not exceed 200 nmol/L and were <100 nmol/L for most of the metabolites. The excretion of coffee phenolics ranged from 40% to 70% of intake, indicating that coffee hydroxycinnamates are notably more bioavailable than previously thought. Interindividual variability was also investigated. Conclusions The absorption, metabolism, nutrikinetic profile, and bioavailability of coffee phenolics were established for different patterns of coffee consumption under real-life conditions. This work provides the basis for further nutritional epidemiology research and mode-of-action cell-based studies. This study was registered at clinicaltrials.gov as NCT03166540. [ABSTRACT FROM AUTHOR]

Background Flavonoids are a diverse group of plant constituents with demonstrated neuroprotective and anti-tumor effects. Flavonoid intake may decrease the risk of glioma, but the possibility of an association has not yet been investigated in humans. Objectives We evaluated the association between dietary flavonoid consumption and the risk of glioma. Methods We followed participants in the female Nurses' Health Study (1984–2014; n  = 81,688) and Nurses' Health Study II (1991–2017; n  = 95,228) and the male Health Professionals Follow-Up Study (1986–2014; n  = 49,885). We used multivariable-adjusted Cox proportional hazards regression models to evaluate the associations between average long-term (up to 30 years) or recent (up to 12 years) dietary flavonoid intake (total flavonoids and each of 6 subclasses) and risks of incident glioma. Flavonoid intake was derived from validated quadrennial FFQs. Incident glioma was self-reported and confirmed by a medical record review or was determined by a medical record review after death. Results We documented 536 incident cases of glioma across 5,936,386 person-years of follow-up. Long-term total flavonoid, flavan-3-ol, and polymeric flavonoid (polymer) intakes were associated with decreased glioma risks in pooled analyses comparing the highest to lowest quintiles of consumption [HR, 0.79 (95% CI, 0.59–1.05; P -trend = 0.04) for total flavonoids; 0.76 (95% CI, 0.57–1.01; P -trend = 0.04) for flavan-3-ols; and 0.82 (95% CI, 0.61–1.09; P -trend = 0.05) for polymers]. Associations with recent intake were weaker. There were no associations with other flavonoid subclasses. After additional adjustment for tea consumption, there were no associations between flavan-3-ol or polymer consumption and glioma. Conclusions Increased dietary intakes of flavan-3-ol and polymeric flavonoids, especially those predominant in tea, were associated with decreased glioma risks in a prospective cohort of men and women. [ABSTRACT FROM AUTHOR]

Background Although available data suggest that some dietary flavan-3-ol sources reduce cardiometabolic risk, to our knowledge no review has systematically synthesized their specific contribution. Objective We aimed to examine, for the first time, if there is consistent evidence that higher flavan-3-ol intake, irrespective of dietary source, reduces cardiometabolic risk. Methods MEDLINE, Cochrane Central, and Commonwealth Agricultural Bureau abstracts were searched for prospective cohorts and randomized controlled trials (RCTs) published from 1946 to March 2019 on flavan-3-ol intake and cardiovascular disease (CVD) risk. Random-effects models meta-analysis was used. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach assessed the strength of evidence. Results Of 15 prospective cohorts (23 publications), 4 found highest compared with lowest habitual intakes of flavan-3-ols were associated with a 13% reduction in risk of CVD mortality and 2 found a 19% reduction in risk of chronic heart disease (CHD) incidence. Highest compared with lowest habitual intakes of monomers were associated with a reduction in risk of type 2 diabetes mellitus (T2DM) (n  = 5) and stroke (n  = 4) (10% and 18%, respectively). No association was found for hypertension. Of 156 RCTs, flavan-3-ol intervention resulted in significant improvements in acute/chronic flow-mediated dilation (FMD), systolic (SBP) and diastolic blood pressure (DBP), total cholesterol (TC), LDL and HDL cholesterol, triglycerides (TGs), hemoglobin A1c (HbA1c), and homeostasis model assessment of insulin resistance (HOMA-IR). All analyses, except HbA1c, were associated with moderate/high heterogeneity. When analyses were limited to good methodological quality studies, improvements in TC, HDL cholesterol, SBP, DBP, HOMA-IR, and acute/chronic FMD remained significant. In GRADE evaluations, there was moderate evidence in cohort studies that flavan-3-ol and monomer intakes were associated with reduced risk of CVD mortality, CHD, stroke, and T2DM, whereas RCTs reported improved TC, HDL cholesterol, SBP, and HOMA-IR. Conclusions Available evidence supports a beneficial effect of flavan-3-ol intake on cardiometabolic outcomes, but there was considerable heterogeneity in the meta-analysis. Future research should focus on an integrated intake/biomarker approach in cohorts and high-quality dose–response RCTs. This review was registered at www.crd.york.ac.uk/PROSPERO/ as CRD42018035782. [ABSTRACT FROM AUTHOR]

Highlights • Lab-scale cocoa bean fermentation is made to reproduce large-scale fermentation. • Yeasts and acetic acid bacteria alone can influence cocoa bean biochemistry. • Formation of flavour precursors in cocoa is pH-induced. • A peptide in fermented beans can potentially lead to cocoa-specific flavour. Abstract This study encompassed the lab-scale fermentation of cocoa beans in 300-g heaps under controlled laboratory conditions, in order to replicate the microbial dynamics and metabolomic changes that usually occur in large-scale spontaneous fermentations. Growth profiles of yeast and acetic acid bacteria (AAB) with the native assortment of microbes as well as with the use of a starter culture were very similar to those observed in literature. Greater production of acetic acid by AAB not only led to more acidic-tasting liquor but also contributed to bitterness, due to polyphenol preservation. It also brought about a drastic drop in pH leading to greater proteolytic activity. Peptides generated through proteolysis also showed incredible similarity to those reported in literature, in particular, those speculated to be involved in cocoa-specific flavour. A closer look at the naturally occurring peptide repertoires of our fermentation trials, generated by the breakdown of cocoa storage protein, pointed to a potential peptide responsible for cocoa-specific aroma. [ABSTRACT FROM AUTHOR]

[Display omitted] • Comparing decanter (DEC) and spiral filter press (SPF) production of apple juices. • Mass spectrometric identification of flavan-3-ols using doubly-charged ions. • Flavan-3-ol quantification in apple juice by HILIC and a NIST standard. • Flavan-3-ol levels (DP1-7) 7- to 20-fold higher after SPF than after DEC. • Total phenolic compound levels 3- to 10-fold higher after SPF than after DEC. The retention of flavan-3-ols and other phenolic compounds during apple juice production at pilot plant scale (200 kg, cv. Boskoop) was investigated. An oxygen-excluding spiral filter press and a conventional decanter were used with and without pectinase mash treatment. Phenolic compounds were comprehensively identified and quantitated by RP-UHPLC and HILIC, both coupled to DAD-FLD and DAD-ESI(-)-QTOF-HR-MS/MS. These techniques combined with using a NIST cocoa flavan-3-ol standard allowed for the first time an individual quantification of flavan-3-ol fractions (DP 1–7) in apple juices. Spiral filter-pressed juices were exposed to less oxidation and exhibited four times higher total phenolic compound levels than decanter-made juices (1016 vs. 262 mg/L). Apple juices derived from pectinase-treated mashes had lower total phenolic compound levels than their non-treated counterparts. However, those made by spiral filter press still retained significantly higher concentrations (780 vs. 104 mg/L). Flavan-3-ols were especially well retained by spiral filter press processing, reaching unprecedentedly high concentrations of up to 713 mg/L. A 280 mL serving of non-treated spiral filter-pressed juice would therefore suffice to provide the daily intake of 200 mg flavan-3-ols, equaling the dose of cocoa flavan-3-ols associated with an authorized European health claim for healthy blood flow. [ABSTRACT FROM AUTHOR]

Highlights • Synergic effect of bPRPs and aPRPs on the interaction with flavanols is observed. • 30 soluble aggregates flavanol-PRPs (molecular weight 4680–35,851 Da) were detected. • Catechins bind preferentially bPRPs than aPRPs. • aPRPs seem to interact preferentially with medium size aggregates flavanol-bPRPs. Abstract In this study, we have evaluated by HPLC-DAD, DLS and MALDI-TOF a synergic effect of the coexistence of two salivary-PRP fractions (basic-PRPs and acidic PRPs) on the interaction with flavanols. Results obtained showed noticeable enhancement of the interaction between (epi)catechin and PRPs when both types of proteins are blended. Up to 30 soluble aggregates have been tentatively identified with molecular weight from 4680 to 35,851. (epi)Catechins seem to bind preferentially bPRPs than aPRPs, although the medium size aggregates flavanol-bPRPs formed could favour the interaction with aPRPs giving rise to soluble mixed aggregates. [ABSTRACT FROM AUTHOR]

Abstract The aim of the present study was to establish the profiles of soluble free phenolics (SFPs) and bound phenolics (BPs) in high molecular weight (HMW) melanoidin fractions isolated from raw and roasted beans of two Theobroma cacao L. varieties. Samples were prepared using three methods (saline treatment and acidic and alkaline hydrolysis) to obtain different forms of phenolic compounds. A total of fifteen phenolics, including three flavan-3-ols, seven phenolic acids, one phenolic aldehyde, and four N -phenylpropenoyl-L-amino acids (NPAs), were identified using ultra-high-performance liquid chromatography coupled to diode array detection and electrospray ionization high-resolution mass spectrometry (UHPLC-DAD-ESI-HR-MSn). In HMW fractions from both studied cocoa types, the main SFPs were N -caffeoyl-L-Asp and procyanidin B2, whereas the main BPs were catechin, epicatechin, ellagic acid, protocatechualdehyde, and N -caffeoyl-L-Asp. The concentrations of individual BPs were much higher than the content of total SFPs. It was also found that, as compared to alkaline hydrolysis, acid hydrolysis released a significantly higher amount of BPs from HMW melanoidin fractions. A comprehensive quantitative analysis indicated significant variation in the investigated phenolic compounds depending on the cocoa type and roasting conditions. An increase in treatment temperature from 110 to 150 °C led to a decline in SFPs and an increment in BPs. The HMW fractions of unroasted Criollo beans exhibited the highest content of SFPs and the lowest content of BPs. The highest BP concentrations were obtained for both cocoa bean varieties roasted at 150 °C. The present study revealed that HMW melanoidin fractions from cocoa beans of different varieties roasted at higher temperatures are a good source of phenolic compounds that can be released under both acidic and alkaline conditions. Graphical abstract Unlabelled Image Highlights • A total of 15 phenolics were identified by UHPLC-DAD-MSn in melanoidins of two cocoa types. • The bound phenolics level in the HMW cocoa melanoidins was higher than free forms • The soluble free phenolic of the HMW cocoa samples decreased after roasting. • Roasting causes increase in bound phenolics of all of the HMW cocoa melanoidins. • The changes of both phenolics forms depend on the cocoa type and roasting conditions. [ABSTRACT FROM AUTHOR]

Two series of compounds showing mass signals at m / z 605 and 893 (negative ionization mode) have been detected in fermented cocoa beans. This study objective is to identify these mass signals and characterize their structure in fermented cocoa samples. Our hypothesis is that these signals may correspond to ethyl-bridged flavan-3-ols resulting from flavan-3-ol condensation with acetaldehyde which is a microbial metabolite. Mass spectrometry was used to compare the retention times and mass fragmentation patterns between a model solution using epicatechin and procyanidin dimer B2, the major flavan-3-ols of cocoa, as precursors and extracts of fermented cocoa. Their identification was confirmed: four isomers of ethyl-linked epicatechin as well as several isomers of epicatechin-ethyl-procyanidin B2, in which B2 was mostly linked through its upper unit, were characterized in cocoa. This study demonstrates the presence of flavan-3-ol acetaldehyde condensation products in fermented cocoa beans and provides the first report of epicatechin-ethyl-procyanidin B2. [ABSTRACT FROM AUTHOR]

Quinces are attracting interest due to their health and nutritional benefits. Drying kinetics, bioactive compounds, antioxidant activity, and the main sensory parameters were determined in dried quinces, cultivar Leskovač , as affected by the drying method. The highest total polyphenols content was observed in dried samples obtained after freeze drying and convective drying at 50 °C. The best drying treatment, considering only sensory attributes, was vacuum-microwave drying at 480 W, because it led to intermediate dark color and high intensities of basic tastes and key flavor attributes. The studied parameters were finally used to recommend convective drying at 60 °C as the most appropriate drying method for quinces, because it had a high content of total phenolic compounds (2nd best treatment out of 10), a good sensory profile, was cheap, and caused no negative effects on nutritional or sensory parameters; the only disadvantage was its long drying time. [ABSTRACT FROM AUTHOR]

This paper reviews pioneering human studies, their limitations and recent investigations on the absorption, metabolism, distribution and excretion (aka bioavailability) of (–)-epicatechin. Progress has been made possible by improvements in mass spectrometric detection when coupled to high performance liquid chromatography and through the increasing availability of authentic reference compounds of in vivo metabolites of (–)-epicatechin. Studies have shown that [2- 14 C](–)-epicatechin is absorbed in the small intestine with the 12 structural-related (–)-epicatechin metabolites (SREMs), mainly in the form of (–)-epicatechin-3′- O -glucuronide, 3′- O -methyl-(–)-epicatechin-5-sulfate and (–)-epicatechin-3′-sulfate, attaining sub-μmol/L peak plasma concentrations ( C max ) ∼1 h after ingestion. SREMs were excreted in urine over a 24 h period in amounts corresponding to 20% of (–)-epicatechin intake. On reaching the colon the flavan-3-ol undergoes microbiota-mediated conversions yielding the 5C-ring fission metabolites (5C-RFMs) 5-(hydroxyphenyl)-γ-valerolactones and 5-(hydroxyphenyl)–γ-hydroxyvaleric acids which appear in plasma as phase II metabolites with a C max of 5.8 h after intake and are excreted in quantities equivalent to 42% of the ingested (–)-epicatechin. Other catabolites excreted in 0–24 h urine in amounts equivalent to 28% of intake included 3-(3′-hydroxyphenyl)hydracrylic acid, hippuric acid and 3′-hydroxyhippuric acid. Overall (–)-epicatechin is highly bioavailable with urinary excretion indicating that 95% is absorbed and passes through the circulatory systems as a diversity of phase II metabolites. Rats produce a very different profile of SREMs than that of humans. These findings demonstrate that ex vivo studies investigating the mechanisms underlying the protective effects of (–)-epicatechin on human health should make use of physiological concentrations human of SREMs and 5C-RFMs, and not the parent (–)-epicatechin, with model systems derived from human cells. In epidemiological studies 5-(4′-hydroxyphenyl)-γ-valerolactone-3′-sulfate and 5-(4′-hydroxyphenyl)-γ-valerolactone-3′- O -glucuronide, the principal 5C-RFMs in both plasma and urine, could serve as key biomarkers of (–)-epicatechin intake. [ABSTRACT FROM AUTHOR]

Cluster thinning is a common practice for regulating vine yield and grape quality. The effects of cluster thinning on vine photosynthesis, berry ripeness and flavonoid composition of V. vinifera L. Cabernet Sauvignon were evaluated during two seasons. Half of the clusters were removed at pea-size and veraison relative to two controls, respectively. Both cluster thinning treatments significantly increased pruning weight and decreased yield. No effects of cluster thinning on berry growth, ripeness and flavonol composition were observed. Early cluster thinning decreased the photosynthetic rate at pea-size, but the effect diminished at post-veraison. Early cluster thinning significantly promoted the biosynthesis of anthocyanins but decreased the proportion of 3′5′-hydroxylated and acylated anthocyanins at veraison. Late cluster thinning decreased the proportions of 3′5′-hydroxylated and acylated anthocyanins. Additionally, Cluster thinning showed inconsistent effects on flavan-3-ol composition over the two seasons. [ABSTRACT FROM AUTHOR]

In the present study, 27 barley genotypes (Hordeum vulgare L.) grown in two geographic origins (Czech Republic and Spain) were analysed for their contents of β-glucan, tocols and phenolic compounds (free and bound). The samples included hulled, hull-less and coloured genotypes. The results showed that concentrations of β-glucan range from 2.40 to 7.42 g/100 g. Total tocol content of the barley samples ranged between 39.9 and 81.6 μg/g. A total of 64 compounds were identified in the barley samples. These included 19 phenolic acids and aldehydes, 9 flavan 3-ols, 9 flavone glycosides, and 27 anthocyanins. The results showed a wide range of phenolic concentrations in the barley samples, highlighting the presence of considerable amounts of anthocyanins in purple barley genotypes. In synthesis, barley should be considered a good source of bioactive components, especially because of the broad spectrum of phytochemicals with potential health benefits besides the soluble fibre (β-glucan). [ABSTRACT FROM AUTHOR]

[Display omitted] • A tetrameric condensed tannin of (epi)catechin-(epi)gallocatechin was described for the first time in the barks from Stryphnodendron pulcherrimum. • Condensed tannins have many potentials to avoid human diseases. • Metabolized products (e.g., OPAC, DHAA, DHPA, and DHPV) from condensed tannins could be associated with the gut well-functional. Stryphnodendron pulcherrimum is a plant found in the Brazilian Amazon and contains high content of catechin/(epi)catechin (flavan-3-ol) derivatives. The polymerization of this kind of flavan-3-ol generates condensed tannins, often associated to plant-based diets and gut microbiota. Thus, the discovery of condensed tannins from plants is a valuable approach once it enhances their availability from natural sources. Herein, we described a tetrameric condensed tannin (Molecular Mass 1,170 a.m.u.) tentatively identified for the first time in the barks from S. pulcherrimum. Condensed tannins-derived (flavan-3-ols units) are likely degraded in the gut, and their degradation products such as 3-hydroxyphenylacetic acid (OPAC), 3,4-dihydroxyphenylacetic acid (DHAA), 3-(3,4-dihydroxyphenyl)-propionic acid (DHPA), and 5-(3′,4′-dihydroxyphenyl)-γ-valerolactone (DHPV) could present benefits to gut microbiome metabolism. Therefore, this observational study represents a new insight into S. pulcherrimum , its molecules, and their potential benefits to avoid different diseases and gut well-functional. [ABSTRACT FROM AUTHOR]

Flavonoids, proanthocyanidins (PAs) and salicylic alcohol derivatives are the main groups of ingredients in Salix needed as defensive tools and signal molecules, but have also pharmaceutical importance. The present study investigated total PA content, complete PA pattern, the oligomeric/total PAs quotient and the contents of catechin and epicatechin during one growing-season for the leaves and this year's sprouts in ten willows ( Salix pentandra L. ♂, S . alba L. ♂, S. fragilis L. ♀, S. caprea L. ♂ & ♀, S. cinerea L. ♂, S. caprea x cinerea ♂, S. daphnoides Vill. ♂ & ♀ and S. purpurea L. ♀; all Salicaceae). Comparison of the different species revealed distinct seasonal fluctuations of the oligomeric and polymeric PA fractions, but the contents of both groups always developed in the same direction. All willows prefer the synthesis of PAs with DP-2 - DP-4 within the oligomeric fraction (DP-2 – DP-10) and species with rather low PA contents like S. purpurea (0.1–2.6 mg/g) as well as species with rather high PA contents like S. alba (3.8–14.7 mg/g) were found. Only slight gender specific differences could be observed for both sexes of S. daphnoides and S. caprea. The PA pattern of the hybrid S. caprea x cinerea seems to be influenced by both parents. Thus, the accumulation of the oligomeric PAs accorded to S. caprea and the polymeric PAs matched S. cinerea resulting in an overall depression of PAs in the sprouts and a varying seasonal trend in the leaves. In contrast, the content of catechin remained high and seemed to be not influenced in the hybrid. Although only one individual of each Salix species could be considered in this screening study, the present results demonstrate the variability of the flavan-3-ol pattern within the genus Salix but also some preliminary correlations could be observed. Future studies with more Salix species will provide more insights into chemotaxonomic correlations. [ABSTRACT FROM AUTHOR]

Flavan-3-ols are the most abundant flavonoids in diet and the analysis and quantification of flavan-3-ol metabolites could report valuable information to assess their absorption mechanisms and bioavailability. In our research, we have studied the feasibility of the determination of three flavan-3-ols metabolites (3-hydroxyphenylacetic acid, 4-hydroxyphenylacetic acid and syringic acid) in urine samples using parallel factor analysis of fluorescence excitation emission matrices. In the optimised conditions, urine samples were directed analysed after diluting in water, centrifuged and filtered. The procedure was successfully applied to quantify the concentration of the selected flavan-3-ols catabolites in urine samples with recoveries ranging between 85 and 93%. For instance, multivariate analytical figures of merit show low sensitivity and selectivity and LOD between 39 μg/L and 53 μg/L. The proposed procedure is fast, simple, reliable and cheap method to quantify flavan-3-ols metabolites in urine and constitutes a powerful tool for screening their abundance in different food matrices after consumption. [ABSTRACT FROM AUTHOR]

[Display omitted] • Procyanidins were extracted from grape seeds and purified by HSCCC. • The antimicrobial activity of flavan- 3 -ols was highly selective. • Activity increased in the order EC < EGC, oligomeric procyanidins < EGCG. • Strict anaerobes were 10 – 100 times more sensitive than facultative anaerobes. • Inhibition of intestinal amylases increased in the order EC, oligomers < EGC < EGCG. This study aimed to determine structure–function relationships of monomeric and oligomeric flavan- 3 -ols (procyanidins) with respect to their antimicrobial activity and their inhibition of digestive enzymes. Monomeric flacan- 3- ols were purchased as reference compounds; oligomeric procyanidins were extracted from grape seeds, separated by high-performance counter-current chromatography and characterized by LC-MS/MS. The antimicrobial activity against a broad range of intestinal microorganisms increased in the order catechin = epicatechin > epigallocatechin and oligomeric procyanidins > epigallocatechin gallate. Facultative anaerobes were highly resistant while strict anaerobes including Allobaculum sp. and Ruminococcus gnavus were 10 – 100 times more sensitive. The inhibition of digestive enzymes from the rat small intestine increased in the order catechin < epicatechin and oligomeric procyanidins < epigallocatechin < epigallocatechin gallate. Trimeric and polymeric procyanidins were more inhibitory than dimeric procyanidins. Both the antimicrobial and enzyme-inhibitory activities of procyanidins and flavan- 3- ols likely relate to their microbiome-modulating and health beneficial properties. [ABSTRACT FROM AUTHOR]

Uncariols A ( 1 ) and B ( 2 ), two new phenylpropanoid-substituted flavan-3-ols, and (±)-uncariols C ( 3a / 3b ) and D ( 4a / 4b ), two pairs of new phenylpropanoid-substituted flavonol enantiomers, together with nine known compounds ( 5 – 13 ), were isolated from the leaves of Uncaria rhynchophylla . The structures of 1 – 4 were established primarily by NMR and HRESIMS experiments. The absolute configurations of the new ones were deduced via the circular dichroism (CD) and quantum chemical calculations of the electronic circular dichroic (ECD) spectra. In addition, all of the isolated compounds showed potent antioxidant activity in the DPPH radical scavenging test. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the effect of different dying methods, such as convective drying (CD: 50, 60, 70 °C), vacuum-microwave drying (VMD: 120, 480, 480–120 W), a combination of convective pre-drying and vacuum-microwave finish drying [(CPD (60 °C)-VMFD (480–120 W)], and freeze-drying (FD) on key quality parameters of dried jujube fruits (cv. “ GAL ”, “ MSI ”, and “ PSI ”). The parameters studied included bioactive compounds (flavan-3-ols and flavonols, identified by LC-PDA-MS, and vitamin C), antioxidant capacity (ABTS and FRAP), and sensory attributes (e.g. hardness, jujube-ID, and sweetness). The best quality of the dried product (high contents of bioactive compounds and high intensity of key sensory attributes) was found in fruits treated by FD and VMD 480–120 W. The best cultivars were “ PSI ” and “ GAL ” from the point of view of bioactive content and sensory quality, respectively. [ABSTRACT FROM AUTHOR]

Background: Prospective cohort studies have shown that the consumption of cocoa and tea is associated with lower risk of cardiovascular diseases (CVDs), and cocoa and tea have been shown to improve CVD risk factors in randomized controlled trials. Cocoa and tea are major dietary sources of the flavan-3-ol epicatechin. Objective: We investigated the associations of dietary epicatechin intake with 25-y CVD mortality in elderly Dutch men. Design: We used data from the Zutphen Elderly Study, which was a prospective cohort study of 774 men aged 65-84 y in 1985. Epicatechin intake was estimated 4 times in 15 y with the use of the crosscheck dietary history method. Time-dependent Cox proportional hazards models were used to investigate repeated measures of epicatechin intake in relation to 25-y CVD mortality. Results: Mean intake of epicatechin was 15.2 ± 7.7 mg/d, and the major dietary sources were tea (51%), apples (28%), and cocoa (7%). During 25 y of follow-up, 329 men died from CVD, 148 died from coronary heart disease (CHD), and 72 men died from stroke. Risk of CHD mortality was 38% lower in men in the top tertile of epicatechin intake than in men in the bottom tertile of epicatechin intake (HR: 0.62; 95% CI: 0.39, 0.98). Epicatechin intake was also significantly associated with 46% lower risk of CVD mortality in men with prevalent CVD (HR: 0.54; 95% CI: 0.31, 0.96) but not in men who were free of CVD. Conclusions: We show, for the first time to our knowledge, that epicatechin intake is inversely related to CHD mortality in elderly men and to CVD mortality in prevalent cases of CVD. More studies are needed before conclusions can be drawn. [ABSTRACT FROM AUTHOR]

The interest in Ziziphus jujube is growing because it is an excellent source of nutrients and phytochemicals, and can contribute to a healthy diet. Nutritional compounds (phenolic compounds and l -ascorbic acid), and antioxidant capacity of 4 Spanish jujube cultivars were studied. Polyphenols were identified by LC–MS–QTof and quantified by UPLC–PDA–FL. A total of 25 polyphenolic compounds were identified and classified as 10 flavan-3-ols, 13 flavonols, 1 flavanone, and 1 dihydrochalcone. The content of total polyphenols (TP) ranged from 1442 to 3432 mg/100 g dry matter (dm) in fruits of the cultivars ‘ DAT ’ and ‘ PSI ’, respectively. Flavan-3-ols, the major group of polyphenols in jujube represented ∼92% of the TP content, whereas flavonols only amounted for about ∼8% each. The content of l -ascorbic acid was very high and took values in the range of 387–555 mg/100 g fresh weight (fw). Some Spanish jujube cultivars, especially ‘ PSI ’ and ‘ MSI ’, may be selected to promote the growth of cultivars with valuable nutritional and phytochemical beneficial effects on human health. [ABSTRACT FROM AUTHOR]

This work aimed at providing some novel aspects pertaining to flavan-3-ols, flavonols and stilbenes extraction from grape stems using high voltage electrical discharges (HVED). Treatment time, pH and ethanol concentration affecting the extractability of these compounds were optimized through response surface methodology. The results from the optimized extraction technique (pH = 2.5; Time = 4.0 ms: Ethanol = 50%) were compared to a conventional hydro-alcoholic extraction. HVED improved significantly the extraction of flavan-3-ols and flavonols but was less efficient on stilbenes. The efficiency of HVED is directly correlated with the other processing conditions (pH, ethanol concentration). Prolonged HVED treatment at low pH value was a positive combination for flavan-3-ols. The proposed procedure (pH = 2.5; Time = 4.0 ms; Ethanol = 50%) allowed the release of almost 35% of additional phenolic compounds, which can be attributed to a better extractability of flavan-3-ols (+ 21%) and of flavonols (+ 12%), compared to conventional hydro-alcoholic extraction. [ABSTRACT FROM AUTHOR]

Jambolan fruit has been used in traditional Indian medicine and has recently attracted interest as a functional food. The comprehensive study by HPLC–DAD-ESI-MS/MS has revealed the occurrence of around 74 individual phenolic compounds in the edible parts of jambolan, including 9 anthocyanins (mainly based on delphinidin, petunidin and malvidin), 9 flavonols (myricetin, laricitrin and syringetin glycosides), 19 flavanonols (dihexosides of dihydromyricetin and its methylated derivatives), 8 flavan-3-ol monomers (mainly gallocatechin), 13 gallotanins and 13 ellagitanins, together with some proanthocyanidins (highly galloylated prodelphinidins) and free gallic and ellagic acids. No hydroxycinnamic acid derivatives were detected. The skin of the jambolan fruit accumulated great amounts of phenolic compounds, almost all of the non-tannin phenolics. In contrast, condensed tannins (proanthocyanidins) and hydrolyzable tannins (gallotannins and ellagitannins) were present in both edible parts, accounting for greater amounts in the skin. Overall, the main phenolics of jambolan were anthocyanins and hydrolyzable tannins (similar amounts of gallotannins and ellagitanins), followed by flavanonols, flavonols and flavan-3-ols. [ABSTRACT FROM AUTHOR]

Markets of different countries have proposed guava tea infusions as a drink that can modulate the glycaemic index in blood. This property has been attributed to the phenolic compounds contained in guava leaves. However, phenolic profile of guava leaves is still not well-known. Based on this information, different ethanol/water mixtures were used to extract the phenolic compounds in guava leaves. Phenolic identification was carried out by HPLC-ESI-QTOF-MS in guava leaves from pomifera and pyrifera varieties; moreover, the antioxidant activities of the ethanolic extracts were determined by TEAC and FRAP methods. To sum up, seventy-two phenolic compounds were identified. To our knowledge, twelve of them were determined for the first time in guava leaves. The highest amount of phenolic compounds was found in EtOH/H 2 O 80:20 (v/v) mixture. Furthermore, pyrifera var. showed higher concentration of phenolic compounds than pomifera var. (113.34 vs. 86.12 mg/g leaf d.w.) and also greater antioxidant capacity. [ABSTRACT FROM AUTHOR]

Analytical techniques, such as liquid chromatography coupled to mass spectrometry (LC-MS) or nuclear magnetic resonance (NMR), are widely used for characterization of complex mixtures of (isomeric) proteins, carbohydrates, lipids, and phytochemicals in food. Food can contain isomers that are challenging to separate, but can possess different reactivity and bioactivity. Catechins are the main phenolic compounds in tea; they can be present as various stereoisomers, which differ in their chemical properties. Currently, there is a lack of fast and direct methods to monitor interconversion and individual reactivity of these epimers (e.g. epicatechin (EC) and catechin (C)). In this study, cyclic ion mobility mass spectrometry (cIMS-MS) was explored as a potential tool for the separation of catechin epimers. Formation of sodium and lithium adducts enhanced IMS separation of catechin epimers, compared to deprotonation and protonation. Baseline separation of the sodium adducts of catechin epimers was achieved. Moreover, we developed a fast method for the identification and semi-quantification of cIMS-MS separated catechin epimers. With this method, it is possible to semi-quantify the ratio between EC and C (1:5 to 5:1, within 50–1200 ng mL−1) in food samples, such as tea. Finally, the newly developed approach for cIMS-MS separation of flavonoids was demonstrated to be successful in separation of two sets of positional isomers (i.e. morin, tricetin, and quercetin; and kaempferol, fisetin, luteolin, and scutellarein). To conclude, we showed that both epimers and positional isomers of flavonoids can be separated using cIMS-MS, and established the potential of this method for challenging flavonoid separations. [Display omitted] • Adduct formation used as a tool to enhance resolution in ion mobility. • Extremely fast separation of four catechin epimers in green tea. • Accurate semi-quantification of catechin epimer ratio in green tea. • cIMS-MS has potential for real-time monitoring of individual isomers in mixtures. [ABSTRACT FROM AUTHOR]

Bioactives are food constituents that, while not essential to human life, can affect health. Thus, there is increased interest in developing dietary recommendations for bioactives. Such recommendations require detailed information about the long-term association between habitual intake and health at population scale, and these can only be provided by large-scale observational studies. Nutritional epidemiology relies on the accurate estimation of intake, but currently used methods, commonly based on a 2-step process involving self-reports and food composition tables, are fraught with significant challenges and are unable to estimate the systemic presence of bioactives. Intake assessments based on nutritional biomarkers can provide an advanced alternative, but there are a number of pitfalls that need to be addressed in order to obtain reliable data on intake. Using flavan-3-ols as a case study, we highlight here key challenges and how they may be avoided. Taken together, we believe that the approaches outlined in this review can be applied to a wide range of food constituents, and doing so will improve assessments of the dietary intake of bioactives. [ABSTRACT FROM AUTHOR]

Our food supply contains a range of essential and non-essential food components. There are substantial epidemiologic findings and additional clinical data to support the health benefits for some non-essential food components – these compounds are often referred to as bioactives. While there is a well-established process in place to make science-based dietary recommendations for essential nutrients, this is not the case for bioactive food components. This manuscript reviews the evolution of the RDAs and the transition to a DRI framework for establishing requirements for essential nutrients. Then, the potential of development of public health recommendations for bioactives will be explored and the benefits and challenges of making recommendations will be presented. The scientific support for case studies for lutein and flavan-3-ols, will be made. Finally, suggestions for frameworks that might be considered by authoritative policy-making bodies when evaluating the efficacy and safely of proposed bioactives will be discussed. [ABSTRACT FROM AUTHOR]

Understanding the fate of ingested polyphenols is crucial in elucidating the molecular mechanisms underlying the beneficial effects of a fruit and vegetable-based diet. This review focuses on the colon microbiota-mediated transformation of the flavan-3-ols and the structurally related procyanidins found in dietary plant foods and beverages, plus the flavan-3-ol-derived theaflavins of black tea, and the post-absorption phase II metabolism of the gut microbiota catabolites. Despite significant advances in the last decade major analytical challenges remain. Strategies to address them are presented. [ABSTRACT FROM AUTHOR]

[Display omitted] • Soluble polysaccharides from white (PSW) and red (PSR) grape skins were obtained. • The usefulness of PSW and PSR to modulate red wine astringency was evaluated. • Flavan-3-ol–polysaccharide interactions were characterized by ITC and HPLC–MS. • Polysaccharide size and composition affect polysaccharide-flavan-3-ols interactions. • PSR decreased noticeably wine astringency causing a great flavan-3-ol loss. Soluble polysaccharides from white (PSW) and red (PSR) grape skins were obtained to be evaluated as potential modulators of the unbalanced astringency of a Tempranillo red wine. The modulation of astringency was evaluated by a sensory panel and it seemed to be related to the changes in the polyphenolic profile. Isothermal Titration Calorimetry (ITC) studies, employed to characterize flavan-3-ol–polysaccharide interactions, showed that PSR decreased noticeably wine astringency causing a great flavan-3-ol loss (ca. 40 %), since they interacted more spontaneously with the flavan-3-ols (ca. ΔGtotal = −2.14 × 104 cal/mol) than PSW (ca. ΔGtotal = −1.32 × 104 cal/mol). The strength of these interactions seems to be related to the polysaccharide molecular size and to the presence of arabinogalactans in the structure. On the contrary, PSW showed no relevant effects on wine astringency. Furthermore, potential variations of color were also assessed and no deleterious effect was observed after the addition of any polysaccharide. [ABSTRACT FROM AUTHOR]

Medicinal plant materials are not usually analysed for condensed tannins (CT). Thirty commercially available European medicinal plants and herbal products were screened for CT and fourteen CT samples were analysed in detail. This is also the first comprehensive CT analysis of pine buds, walnut leaves, heather flowers and great water dock roots. Acetone/water extracts contained between 3.2 and 25.9 g CT/100 g of extract, had CT with mean degrees of polymerisation of 2.9 to 13.3, procyanidin/prodelphinidin ratios of 1.6/98.4 to 100/0 and cis / trans flavan-3-ol ratios of 17.7/82.3 to 97.3/2.7. The majority of samples contained procyanidins, four contained A-type linkages (blackthorn flowers, heather flowers, bilberry leaves and cowberry leaves) and one sample also had galloylated procyanidins (great water dock roots). [ABSTRACT FROM AUTHOR]

Numerous clinical studies have found that ingestion of chocolate reduces the risk of metabolic syndrome, however, the mechanisms were remain unclear. We have reported that a single dose of a flavan-3-ol fraction derived from cocoa (FL) enhanced energy expenditure (EE) and increased the mRNA expression levels of uncoupling proteins (UCPs) and peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α), and the protein level of phosphorylated AMP-activated protein kinase (AMPK)α in tissues, along with plasma adrenaline level. In the present study, we examined whether the EE enhancing activity of FL is mediated by adrenergic effect using several adrenalin receptor (AR) blockers. In the first study, mice were butoxamine, as β2AR blocker, with vehicle or 10 mg/kg FL orally. We found that pretreatment with butoxamine prevented the increases of EE, the mRNA expression of UCP-3, and phosphorylated AMPKα that were induced in the gastrocnemius muscle of mice by 10 mg/kg FL. Secondly, mice were given SR52930, as β3AR blocker. Pretreatment with SR52930 prevented the increases of EE, the mRNA expression of UCP-3, and phosphorylated AMPKα that were induced in the gastrocnemius muscle of mice by 10 mg/kg FL. Pretreatment with a combination of both blockers also reduced the increments in mRNA expression levels of UCPs and PGC-1α, however, phosphorylated AMPKα in skeletal muscle was rather increased. These results suggest that the ability of a single oral dose of FL to enhance metabolic activity is mediated by sympathetic nerve system (SNS). [ABSTRACT FROM AUTHOR]

The impact of high hydrostatic pressure (HHP) treatments on the phenolic compounds composition of a red wine was studied after storage in order to evaluate the potential of this technology as an enological practice. Red wines pressurized at 500 and 600 MPa at 20 °C for 5 and 20 min, respectively, showed a lower content of monomeric anthocyanins (13 to 14%), phenolic acids (8 to 11%), and flavonols (14 to 19%) after 5 months of storage, when compared to the unpressurized wine. These results, together with the different degree of tannin polymerization and flavan-3-ol content in the pressurized wines led to propose an effect of HHP in the increase of polymerization and cleavage reactions of proanthocyanidins. The sensorial analysis of pressurized wines showed lower astringency, a higher intensity of cooked fruit aroma and lower intensity of fruity notes, when compared with the unpressurized wine. These effects are associated to those observed during wine aging. Industrial relevance During the last decade, the use of high hydrostatic pressure (HHP) as a non-thermal technology for food preservation and modification has increased substantially. Recently, pressure treatments have shown to influence long term red wine physicochemical and sensorial characteristics, leading to aged wine-like characteristics. Therefore, the use of HHP technology to modify wine composition could benefit the wine industry, especially to improve wines with low aging potential. This work shows that HHP can be potentially used as enological practice, modulating the organoleptic properties of wine by decreasing astringency and increasing pleasant aromas. It seems possible to exploit commercially the production of young red wines with distinct characteristics using this technology, addressing the market and consumer demand. [ABSTRACT FROM AUTHOR]

Flavonoids, as plant secondary metabolites, are widespread throughout the plant kingdom and involved in many physiological and biochemical processes. Drought resistance is attributed to flavonoids with respect to protective functions in the cell wall and membranes. The flavanone 3-hydroxylase ( F3H ) gene which encodes flavanone 3-hydroxylase, is essential in flavonoids biosynthetic pathway. Lycium chinense ( L. chinense ) is a deciduous woody perennial halophyte that grows under a large variety of environmental conditions and survives under extreme drought stress. A novel cDNA sequence coding a F3H gene in Lycium chinense ( LcF3H , GenBank: KJ636468.1 ) was isolated. The open reading frame of LcF3H comprised 1101 bp encoding a polypeptide of 366 amino acids with a molecular weight of about 42 kDa and an isoelectric point of 5.32. The deduced LcF3H protein showed high identities with other plant F3Hs, and the conserved motifs were found in LcF3H at similar positions like other F3Hs. The recombinant protein converted naringen into dihydrokaempferol in vitro. Since studies have shown that amongst flavonoids, flavan-3-ols (catechin and epicatechin) have direct free radical scavenging activity to maintain the normal physiological function of cells in vivo, these data support the possible relationship between the oxidative damage and the regulation of LcF3H gene expression in L. chinense under drought stress. In order to better understand the biotechnological potential of LcF3H , gene overexpression was conducted in tobacco. The content of flavan-3-ols and the tolerance to drought stress were increased in LcF3H overexpressing tobacco. Analysis of transgenic tobacco lines also showed that antioxidant enzyme activities were increased meanwhile the malondialdehyde (MDA) content and the content of H 2 O 2 were reduced comparing to nontransformed tobacco plants. Furthermore, the photosynthesis rate was less decreased in the transgenetic plants. These results suggest that LcF3H plays a role in enhancing drought tolerance in L. chinense , and its overexpression increases tolerance to drought stress by improving the antioxidant system in tobacco. [ABSTRACT FROM AUTHOR]

Background: Flavonoids inhibit the growth of colon cancer cells in vitro. In a secondary analysis of a randomized controlled trial, the Polyp Prevention Trial, a higher intake of one subclass, flavonols, was statistically significantly associated with a reduced risk of recurrent advanced adenoma. Most previous prospective studies on colorectal cancer evaluated only a limited number of flavonoid subclasses and intake ranges, yielding inconsistent results. Objective: In this study, we examined whether higher habitual dietary intakes of flavonoid subclasses (flavonols, flavones, flavanones, flavan-3-ols, and anthocyanins) were associated with a lower risk of colorectal cancer. Design: Using data from validated food-frequency questionnaires administered every 4 y and an updated flavonoid food composition database, we calculated flavonoid intakes for 42,478 male participants from the Health Professionals Follow-Up Study and for 76,364 female participants from the Nurses' Health Study. Results: During up to 26 y of follow-up, 2519 colorectal cancer cases (1061 in men, 1458 in women) were documented. Intakes of flavonoid subclasses were not associated with risk of colorectal cancer in either cohort. Pooled multivariable adjusted RRs (95% CIs) comparing the highest with the lowest quintiles were 1.04 (0.91, 1.18) for flavonols, 1.01 (0.89, 1.15) for flavones, 0.96 (0.84, 1.10) for flavanones, 1.07 (0.95, 1.21) for flavan-3-ols, and 0.98 (0.81, 1.19) for anthocyanins (all P values for heterogeneity by sex >0.19). In subsite analyses, flavonoid intake was also not associated with colon or rectal cancer risk. Conclusion: Our findings do not support the hypothesis that a higher habitual intake of any flavonoid subclass decreases the risk of colorectal cancer. [ABSTRACT FROM AUTHOR]

Total phenolic, flavonoid and anthocyanin contents of dichloromethane, ethyl acetate, ethanol, and aqueous extracts of branches, leaves and fruits from Prunus spinosa were quantified by spectrophotometrical methods and the results showed solvent and botanical organ dependence. In order to detect antioxidant activity, a method based on the reduction of DPPH was carried out. Activity of ethanol, ethyl acetate and aqueous extracts of branches demonstrated a higher scavenging capacity compared to other analysed extracts. Phytochemical analysis allowed detecting flavonoids, coumarins, phenolic acids and flavan-3-ols. Ethanolic extract of branches was subjected to an in vitro digestion. Buccal and gastric digestion had no substantial effect on any of the phenolic compounds. However, these compounds were significantly altered during intestinal digestion. The results showed that a significant proportion of these compounds would be transformed into other unknown and/or undetected structural forms. Furthermore, three phenolic acids, two coumarins, fourteen flavan-3-ols, and six flavonols were identified using HPLC-DAD-ESI-MS. [ABSTRACT FROM AUTHOR]

This study investigated the separate and combined anthelmintic (AH) effects of different phenolic compounds, including condensed tannins and flavonoids, all of which are known to occur in willow leaves, a potentially valuable dry season feed. A range of contrasting model tannins, which span the whole range of willow tannins, were isolated from tilia flowers, goat willow leaves, black currant leaves and red currant leaves. All together, the tested compounds represented the major tannin types (procyanidins and prodelphinidins) and flavonoid types (flavonols, flavones and flavanones). The larval exsheathment inhibition assay (LEIA) was used to assess their in vitro effects on Haemonchus contortus third stage larvae. Arbutin, vanillic acid, and taxifolin proved to be ineffective whereas naringenin, quercetin and luteolin were highly effective at 250 μM concentrations. Procyanidin (PC) tannins tended to be less active than prodelphinidin tannins (PD). Experiments with combinations of tannins and quercetin or luteolin revealed for the first time the existence of synergistic AH effects between tannins and flavonoid monomers. They also provided evidence that synergistic effects appear to occur at slightly lower concentrations of PC than PD. This suggests that the AH activity of condensed tannins can be significantly enhanced by the addition of quercetin or luteolin. This information may prove useful for plant breeding or selection and for designing optimal feed mixtures. [ABSTRACT FROM AUTHOR]

Poor absorption and bioavailability of procyanidins from the upper gastrointestinal tract result in the majority of the dose reaching the colon. During colonic transit, progressive microbial metabolism likely produces gradients of procyanidins and microbial metabolites along the length of the colon, suggesting that proximal and distal regions are exposed to different profiles of procyanidins and metabolites. However, previous studies have largely treated the colon as a single organ or looked at fecal profiles, and differences in the profiles of native and metabolite compounds between regions have not been observed. The metabolism kinetics of procyanidins larger than trimers and formation of metabolites in the colon have not been well characterized. Therefore, the objective of this study was to determine the kinetics of delivery and microbial metabolism of monomeric, dimeric and oligomeric procyanidins in the cecum and proximal, mid and distal colon. Sprague-Dawley rats were gavaged grape seed extract and sacrificed over 18 h. Analysis of luminal contents showed distinct native and metabolite profiles for each region. Procyanidins had maximum concentrations at approximately 3h postgavage for all sections. Metabolites reached maximum concentrations from 3 to 18 h postgavage. The appearance of metabolites was highly dependent on species: larger metabolites were found at earlier times in the more proximal segments, and smaller metabolites were found at later times in more distal regions. This study allowed for the observation of regions in the lower gastrointestinal tract, giving insight into the distribution and delivery of procyanidins and their microbial metabolites throughout the colon. [ABSTRACT FROM AUTHOR]

In this study, potential interactions of alginate-proteins and proteins-polyphenols were utilized for the formulation of microparticles encapsulating green tea flavan-3-ols and caffeine. Electrostatic assisted extrusion of alginate-protein (whey proteins, bovine serum albumine, calcium caseinate, soy proteins, hemp proteins) formulations was performed for the production of microparticles and the effect of chitosan or pectin coating was evaluated. Employing alginate in combination with soy or hemp proteins provided large and hard particles, while reinforcement with whey proteins and bovine serum albumin provided the most spherical and softer particles (lower hardness and elasticity), with average diameters around 700–800 μm. The combination of alginate and calcium caseinate or whey proteins enabled to retain the highest content of polyphenols and caffeine in the formulated particles (up to 80%). Chitosan or pectin coating did not improve the physical and morphological properties or the encapsulation efficiency, but conferred better (prolongued) release profile of polyphenols from the particles. The release studies in water and simulated gastric and intestinal fluids revealed burst release of polyphenols (over 50% in first 5–10 min) followed by sustained release up to 120 min. An artificial neural network designed based on all physical and bioactive parameters of the formulated particles, revealed that the combination of alginate with calcium caseinate or bovine serum albumin as the delivery formulation and pectin coating would provide particles with the maximum loading efficiency of green tea polyphenols and proteins as the functional components, which may facilitate their functional properties when delivered to specific target media in the organism. [ABSTRACT FROM AUTHOR]

Dietary intervention studies suggest that flavan-3-ol intake can improve vascular function and reduce the risk of cardiovascular diseases (CVD). However, results from prospective studies failed to show a consistent beneficial effect. Associations between flavan-3-ol intake and CVD risk in the Norfolk arm of the European Prospective Investigation into Cancer and Nutrition (EPIC-Norfolk) were investigated. Data were available from 24,885 (11,252 men; 13,633 women) participants, recruited between 1993 and 1997 into the EPIC-Norfolk study. Flavan-3-ol intake was assessed using 7-day food diaries and the FLAVIOLA Flavanol Food Composition database . Missing data for plasma cholesterol and vitamin C were imputed using multiple imputation. Associations between flavan-3-ol intake and blood pressure at baseline were determined using linear regression models. Associations with CVD risk were estimated using Cox regression analyses. Median intake of total flavan-3-ols was 1034 mg/d (range: 0–8531 mg/d) for men and 970 mg/d (0–6695 mg/d) for women, median intake of flavan-3-ol monomers was 233 mg/d (0–3248 mg/d) for men and 217 (0–2712 mg/d) for women. There were no consistent associations between flavan-3-ol monomer intake and baseline systolic and diastolic blood pressure (BP). After 286,147 person-years of follow-up, there were 8463 cardiovascular events and 1987 CVD related deaths; no consistent association between flavan-3-ol intake and CVD risk (HR 0.93, 95% CI: 0.87; 1.00; Q1 vs Q5) or mortality was observed (HR 0.93, 95% CI: 0.84; 1.04). Flavan-3-ol intake in EPIC-Norfolk is not sufficient to achieve a statistically significant reduction in CVD risk. [ABSTRACT FROM AUTHOR]

Interactions between polyphenols and macromolecules may impact polyphenol stability and bioavailability from foods. The impact of milk on tea flavan-3-ol stability to thermal treatment was investigated. Single strength (36.2 protein per L), quarter strength (9.0 g protein per L) milk, and control model beverages were incubated with epigallocatechin gallate and green tea extract at 62 or 37 °C for 180 min. Intact flavan-3-ols and select auto-oxidation products [theasinesins (THSNs) and P-2 dimers] were quantified by LC–MS. Generally, greater polyphenol to protein ratios increased first order degradation rates, consequently decreasing formation of oxidation products. The presence of galloyl and hydroxy moieties was associated with higher stability of monomeric flavan-3-ols with increasing protein concentrations suggesting potential for protein affinity to stabilise flavan-3-ols to thermal treatment. Absence of these moieties led to no observable improvements in stability. These results suggest that protein interactions may be useful in stabilising flavan-3-ols through thermal processing. [ABSTRACT FROM AUTHOR]

Phytochemical profiles of 24 quince liquors were studied as the combination of technologically variant. Liquors were obtained after macerating quinces from three varieties ( Vranja , ALM3 and ZM2 ), with or without skin, at two ratios of quince:ethanol (50:50 and 25:75), and at two alcohol content (60% and 30%). Polyphenols were identified by LC-PDA-QTOF/MS and quantified by UPLC-PDA and UPLC-FL. A total of 18 polyphenolic compounds were identified and classified as 5 flavan-3-ols, 5 phenolic acids, and 8 flavonols. Flavan-3-ols were the most abundant group followed by hydroxycinnamates and flavonols. The highest contents of total polyphenols (∼1000 mg/100 mL) and antioxidant activity (37.1 mmol Trolox/100 mL) were found in the liquors prepared using fruits with skin and 50:50 quince:ethanol ratio. The skin of quinces was the main source of phenolic acids and especially flavonols. The high antioxidant activity and polyphenolic content of quince liquor may be deemed as a promising new alcoholic beverage. [ABSTRACT FROM AUTHOR]

Catechin and epicatechin are the health beneficial flavan-3-ols in tea and many fruits. However, their extreme hydrophilicity renders drawbacks for them to pass through the bio-membranes. We prepared lipophilic flavan-3-ol derivatives by acetylation or by acetone-conjugation. The structures of these derivatives were determined based on their NMR and MS spectra. The 3,5- and 3,7-diacetyl derivatives showed radical scavenging activity slightly weaker than catechin and epicatechin, but showed significantly enhanced capacity to penetrate into living cells. Moreover, the diacetyl derivatives released flavan-3-ols inside cells, while catechin or epicatechin themselves could not penetrate into the cells. The acetone conjugates showed strong antioxidant activity and were able to enter into living cells in the intact form. The acetylated and acetone-conjugated derivatives protected H 2 O 2 -induced erythrocyte hemolysis more effectively than catechin and epicatechin. These results indicated that acetylated and acetone-conjugated flavan-3-ols are promising compounds with less hydrophilicity and better bioactivities in biological systems. [ABSTRACT FROM AUTHOR]

The aim of the present work was to evaluate the effect of the main factors conditioning accelerated ageing processes (oxygen dose, chip dose, wood origin, toasting degree and maceration time) on the phenolic and chromatic profiles of red wines by using a multivariate strategy based on experimental design methodology. The results obtained revealed that the concentrations of monomeric anthocyanins and flavan-3-ols could be modified through the application of particular experimental conditions. This fact was particularly remarkable since changes in phenolic profile were closely linked to changes observed in chromatic parameters. The main strength of this study lies in the possibility of using its conclusions as a basis to make wines with specific colour properties based on quality criteria. To our knowledge, the influence of such a large number of alternative ageing parameters on wine phenolic composition and chromatic attributes has not been studied previously using a comprehensive experimental design methodology. [ABSTRACT FROM AUTHOR]

Aims Previous epidemiological studies have suggested that ingestion of chocolate reduces the risk of cardiovascular disease. In the present study, we examined the effects of flavan-3-ols derived from cocoa on blood pressure, lipolysis, and thermogenesis in rats fed a high-fat diet and that showed early signs of metabolic syndrome. Main methods The rats were divided into three groups, and fed either normal diet (normal), 60% fat high-fat diet (HFD), or HFD containing 0.2% flavan-3-ols (HFD-flavan) for 4 weeks. At the end of the feeding period, blood pressure was measured and animals were sacrificed under anesthesia. Lipolysis and thermogenesis-related protein levels were measured in several tissues by Western blotting, and mitochondrial DNA copy number was measured by RT-PCR. Key findings Mean blood pressure and epididymal adipose tissue weight of HFD-flavan were significantly lower compared with those of HFD. Uncoupling protein (UCP)1 in brown adipose tissue and UCP3 in gastrocnemius of HFD-flavan were significantly increased compared with those of HFD group. Carnitine palmitoyltransferase (CPT) 2 levels in liver and medium-chain acyl-CoA dehydrogenase (MCAD) levels in gastrocnemius and liver were significantly increased by the supplementation of flavan-3-ols. Significance In addition to having hypotensive effects, flavan-3-ols enhance thermogenesis and lipolysis and consequently reduce white adipose tissue weight gain in response to high-fat diet feeding. [ABSTRACT FROM AUTHOR]

Highlights: [•] Eight novel 8-C N-ethyl-2-pyrrolidinone substituted flavan-3-ols were identified. [•] The metabolic pathway of theanine and catechins were clarified. [•] These compounds showed great antioxidant activities. [Copyright &y& Elsevier]

Highlights: [•] Eleven quince cv. as a good sources for their industrial processing into high-quality juices. [•] The results of ANOVA and cluster analysis indicate that the quality of quince juices was affected by cultivars. [•] Flavan-3-ols have the greatest influence on the antioxidant. [•] Quince juices are richer in bioactive compounds and more attractive than the available other commercial products. [•] These results indicate the potential uses some cultivars of quince fruits for juice industry. [Copyright &y& Elsevier]

Highlights: [•] Conjugates of flavan-3-ols with cysteine or acetylcysteine were prepared. [•] The preparation was simple, and all of the reagents were edible. [•] The conjugates had greater radical-scavenging activity than the flavan-3-ols. [•] The flavan-3-ol-cysteine conjugates were active against α-glucosidase. [Copyright &y& Elsevier]

Highlights: [•] RNAi in this study was finished through instantaneous conversion, laying the foundation for the complete conversion to gain a transgenic strawberry for the future. [•] FaDFR is one of the key genes in the anthocyanin biosynthesis pathway in strawberry fruit. [•] Metabolites were shunted to the quercetin-glycoside biosynthesis pathway after silencing of FaDFR. [ABSTRACT FROM AUTHOR]