Yeast Starter Culture Identification to Produce of Red Wines with Enhanced Antioxidant Content

Grape variety, quality, geographic origins and phytopathology can influence the amount of polyphenols that accumulate in grape tissues. Polyphenols in wine not only shape their organoleptic characteristics but also significantly contribute to the positive impact that this beverage has on human health. However, during the winemaking process, the total polyphenol content is substantially reduced due to the adsorption onto yeast wall polymers and subsequent lees separation. Despite this, limited information is available regarding the influence of the yeast starter strain on the polyphenolic profile of wine. To address this issue, a population consisting of 136 Saccharomyces cerevisiae strains was analyzed to identify those with a diminished ability to adsorb polyphenols. Firstly, the reduction in concentration of polyphenolic compounds associated to each strain was studied by assaying Total Phenolic Content (TPC) and Trolox Equivalent Antioxidant Capacity (TEAC) in the wines produced by micro-scale must fermentation. A total of 29 strains exhibiting a TPC and TEAC reduction ≤ 50%, when compared to that detected in the utilized grape must were identified and the nine most-promising strains were further validated by larger-scale vinification. Physico-chemical analyses of the resulting wines led to the identification of four strains, namely ITEM6920, ITEM9500, ITEM9507 and ITEM9508 which showed, compared to the control wine, a TPC and TEAC reduction ≤ 20 in the produced wines. They were denoted by a significant (p < 0.05) increased amount of anthocyanin, quercetin and trans-coutaric acid, minimal volatile acidity (<0.2 g/L), absence of undesirable metabolites and a well-balanced volatile profile. As far as we know, this investigation represents the first clonal selection of yeast strains aimed at the identifying "functional" fermentation starters, thereby enabling the production of regional wines with enriched polyphenolic content.

Oxidation of Wine Polyphenols by Electrochemical Means in the Presence of Glutathione

The oxidation of wine may be beneficial or harmful to its quality. On the one hand, controlled oxidation can lead to the development of desirable sensory characteristics for red wine, such as enhanced color stability. Alternatively, oxidation can lead to white wine browning and a decrease in fruity aromas, and the development of an off flavor and wine polyphenols are also involved. The presence of glutathione (GSH) can help mitigate the negative effects of oxidation by acting as a protective antioxidant. In order to better understand the antioxidant role played by GSH, wine polyphenols oxidation experiments by electrochemical means in the presence of GSH were carried out. The oxidation behavior of polyphenols representing different phenolic classes commonly found in wines, including protocatechuic acid (PCA), caffeic acid (CAF), epicatechin (EC), and rutin (Ru), was investigated using cyclic voltammetry and bulk electrolysis. We identified the oxidation products and reaction pathways of these polyphenols using ultra-high-performance liquid chromatography coupled with mass spectrometry (UPLC-MS), in both the absence and the presence of glutathione (GSH). UPLC-MS was utilized to demonstrate that, in the presence of glutathione (GSH), the four molecules were subjected to electrochemical oxidation, resulting in the formation of mono- and bi-glutathione conjugates. A two-electron oxidation process combined with the removal of two protons is the first step in transforming polyphenol molecules. As a result, the corresponding quinone is formed. The quinone can then be reduced back to its original form by glutathione (GSH), or it can interact further with GSH to produce mono- and bi-glutathione conjugates. These results contribute to understanding and predicting the oxidative degradation pathway of polyphenols in wine. Understanding this process seems important for winemakers to control and optimize the sensory characteristics of their wines.

Intracellular Polyphenol Wine Metabolites Oppose Oxidative Stress and Upregulate Nrf2/ARE Pathway

Moderate wine consumption has been associated with several benefits to human health due to its high polyphenol content. In this study, we investigated whether polyphenols contained in a particular red wine, rich in polyphenols, can pass the cell membrane and switch the oxidant/antioxidant balance toward an antioxidant pattern of THP-1 cells and human cardiomyocytes through a gene regulatory system. First, we identified which metabolite polyphenols present in red wine extract cross cell membranes and may be responsible for antioxidant effects. The results showed that the wine metabolites in treated cells belonged mainly to stilbenes, flavan-3-ols derivatives, and flavonoids. Other metabolites present in cells were not typical wine metabolites. Then, we found that red wine extract dose-dependently lowered reactive oxygen species (ROS) induced by tert-butyl hydroperoxide (TBHP) up to 50 ± 7% in both cell lines (p < 0.01). Furthermore, wine extract increased nuclear Nrf2 of about 35 ± 5% in both cell lines (p < 0.01) and counteracted its reduction induced by TBHP (p < 0.01). The rise in Nrf2 was paralleled by the increase in hemeoxygenase-1 and glutamate-cysteine ligase catalytic subunit gene expression (both mRNA and protein) (p < 0.01). These results could help explain the healthful activity of wine polyphenols within cells.

Evaluation of Plant-Based Byproducts as Green Fining Agents for Precision Winemaking

Consumers are increasingly looking for foods, including wine, that are free of animal-derived proteins. This study seeks to evaluate patatin, a new, plant-based and allergen-free fining agent, by comparing it with the fining agents polyvinipolypyrrolidone, bovine serum albumin, and methylcellulose. Specifically, its effects on the phenolic profile of enological tannins were analyzed with four spectrophotometric assays: OD 280 nm, Folin−Ciocâlteu, Adams−Harbertson, and methylcellulose. In addition, changes in the polyphenol composition of Sangiovese red wine were determined by UV-Vis spectrophotometry and HPLC with adsorption trials, and the solid−liquid interaction in a wine solution was modeled by both Langmuir and Freundlich equations. Our findings highlight the occurrence of systematic proportional error between the selected spectrophotometric assays. As a result, direct comparisons of protein precipitation assays can be made only among results obtained with the same spectrophotometric method. However, it is clear that patatin has an impact on the phenolic profile of Sangiovese red wine: it removes simple phenolics (gallic acid, (+)-catechin, (−)-epicatechin, epicatechin gallate, syringic acid, fertaric acid, coutaric acid, and rutin) as well as both oligomeric and polymeric tannins to different extents. In concentrations of less than 1 g/L, the patatin isotherm showed a linear relation between the equilibrium concentration and the quantity absorbed, obeying the Freundlich model reasonably well (KF 1.46; 1/n 1.07; R2 0.996 with 1/n > 1). Thus, the adsorption process is strongly dependent on the fining dosage.

Effects of Wine and Its Microbial-Derived Metabolites on Intestinal Permeability Using Simulated Gastrointestinal Digestion/Colonic Fermentation and Caco-2 Intestinal Cell Models

This paper explores the effects of wine polyphenols on intestinal permeability in in vitro conditions. A red wine (2500 mg/L of gallic acid equivalents) was sequentially subjected to gastrointestinal and colonic digestion in the Dynamic Gastrointestinal Simulator (simgi^®) to obtain two simulated fluids: intestinal-digested wine (IDW) and colonic-digested wine (CDW). The two fluids were incubated with Caco-2 cell monolayers grown in Transwell^® inserts, and paracellular permeability was measured as transport of FITC-dextran. Non-significant decreases (p > 0.05) in paracellular permeability were found, which was attributed to the relatively low phenolic concentration in the solutions tested (15.6 and 7.8 mg of gallic acid equivalents/L for IDW and CDW, respectively) as quercetin (200 µM) and one of its microbial-derived phenolic metabolites, 3,4-dihydroxyphenylacetic acid (200 µM), led to significant decreases (p < 0.05). The expression of tight junction (TJ) proteins (i.e., ZO-1 and occludin) in Caco-2 cells after incubation with IDW and CDW was also determined. A slight increase in mRNA levels for occludin for both IDW and CDW fluids, albeit without statistical significance (p > 0.05), was observed. Analysis of the microbiome and microbial activity during wine colonic fermentation revealed relevant changes in the relative abundance of some families/genera (i.e., reduction in Bacteroides and an increase in Veillonella, Escherichia/Shigella and Akkermansia) as well as in the microbial production of SCFA (i.e., a significant increase in propionic acid in the presence of IDW), all of which might affect paracellular permeability. Both direct and indirect (microbiota-mediated) mechanisms might be involved in the protective effects of (wine) polyphenols on intestinal barrier integrity. Overall, this paper reinforces (wine) polyphenols as a promising dietary strategy to improve gut functionality, although further studies are needed to evaluate the effect on the intestinal barrier under different conditions.

Current and future experimental approaches in the study of grape and wine polyphenols interacting gut microbiota

Interactions between polyphenols and gut microbiota are indeed a major issue of current interest in food science research. Knowledge in this subject is progressing as the experimental procedures and analysis techniques do. The aim of this article is to critically review the more leading-edge approaches that have been applied so far in the study of the interactions between grape/wine polyphenols and gut microbiota. This is the case of in vitro dynamic gastrointestinal simulation models that try to mitigate the limitations of simple static models (batch culture fermentations). More complex approaches include the experimentation with animals (mice, rats, pigs, lambs and chicks) and nutritional intervention studies in humans. Main advantages and limitations as well as the most relevant findings achieved by each approach in the study of how grape/wine polyphenols can modulate the composition and/or functionality of gut microbiota, are detailed. Also, common findings obtained by the three approaches (in vitro, animal models and human nutritional interventions) such as the fact that the Firmicutes/Bacteroidetes ratio tends to decrease after the feed/intake/consumption of grape/wine polyphenols are highlighted. Additionally, a nematode (Caenorhabditis elegans) model, previously used for investigating the mechanisms of processes such as aging, neurodegeneration, oxidative stress and inflammation, is presented as an emerging approach for the study of polyphenols interacting gut microbiota. © 2020 Society of Chemical Industry.

Procyanidin C1 Inhibits Melanoma Cell Growth by Activating 67-kDa Laminin Receptor Signaling

SCOPE

Procyanidin C1 (PC1) is an epicatechin trimer found mainly in grapes that is reported to provide several health benefits. However, little is known about the molecular mechanisms underlying these benefits. The aim of this study is to demonstrate the molecular mechanisms by which PC1 operates.

METHODS AND RESULTS

A 67-kDa laminin receptor (67LR) is identified as a cell surface receptor of PC1, with a Kd value of 2.8 µm. PC1 induces an inhibitory effect on growth, accompanied by dephosphorylation of the C-kinase potentiated protein phosphatase-1 inhibitor protein of 17 kDa (CPI17) and myosin regulatory light chain (MRLC) proteins, followed by actin cytoskeleton remodeling in melanoma cells. These actions are mediated by protein kinase A (PKA) and protein phosphatase 2A (PP2A) activation once PC1 is bound to 67LR.

CONCLUSION

It is demonstrated that PC1 elicits melanoma cell growth inhibition by activating the 67LR/PKA/PP2A/CPI17/MRLC pathway.

Autochthonous Saccharomyces cerevisiae Starter Cultures Enhance Polyphenols Content, Antioxidant Activity, and Anti-Inflammatory Response of Apulian Red Wines

Several biotic and abiotic factors can influence the amount of polyphenols in grape tissues. During vinification, the temperature, presence of grape seeds and peel, and use of enzymes, can influence the extraction of polyphenols. However, little information is available on the effects of yeast strains used in the polyphenolic composition of wine. With this aim, two selected Saccharomyces cerevisiae strains, ITEM 14093 and ITEM 14077 were used to produce wine from two Italian grape cultivars, Primitivo and Negroamaro. At the end of the alcoholic fermentation, the content of total polyphenols and of particular classes of polyphenols (stilbenes, phenolic acids, flavonols, and flavanols) and the antioxidant activity were evaluated and compared in the obtained wines. We also examined the effects of red wine extracts in a culture model of vascular inflammation. The results obtained comparing wine extracts obtained by utilizing commercial or autochthonous yeast showed that wines obtained with selected yeast significantly inhibited vascular inflammation. The results are positively directed towards the healthy properties of wine drinking.

Inhibition of Oral Pathogens Adhesion to Human Gingival Fibroblasts by Wine Polyphenols Alone and in Combination with an Oral Probiotic

Several benefits have been described for red wine polyphenols and probiotic strains in the promotion of colonic metabolism and health. On the contrary, knowledge about their role in the management of oral health is still scarce. In this work, the antiadhesive capacity of selected red wine polyphenols and oenological extracts against the oral pathogens Porphyromonas gingivalis, Fusobacterium nucleatum, and Streptococcus mutans in an in vitro model of human gingival fibroblasts has been explored as well as their complementary action with the candidate oral probiotic Streptococcus dentisani. Results highlighted the antiadhesive capacity of caffeic and p-coumaric acids as well as grape seed and red wine oenological extracts. Both, caffeic and p-coumaric acids increased their inhibition potential against S. mutans adhesion when combined with S. dentisani. Additionally, UHPLC-MS/MS analysis demonstrated the oral metabolism of wine phenolics due to both, cellular and bacterial activity.

Oxidation of Wine Polyphenols by Secretomes of Wild Botrytis cinerea Strains from White and Red Grape Varieties and Determination of Their Specific Laccase Activity

Processing of Botrytis cinerea-infected grapes leads to enhanced enzymatic browning reactions mainly caused by the enzyme laccase which is able to oxidize a wide range of phenolic compounds. The extent of color deterioration depends on the activity of the enzymes secreted by the fungus. The present study revealed significant differences in the oxidative properties of secretomes of several B. cinerea strains isolated from five grape varieties. The presumed laccase-containing secretomes varied in their catalytic activity toward six phenolic compounds present in grapes. All strains led to identical product profiles for five of six substrates, but two strains showed deviating product profiles during gallic acid oxidation. Fast oxidation of caffeic acid, ferulic acid, and malvidin 3-O-glucoside was observed. Product formation rates and relative product concentrations were determined. The results reflect the wide range of enzyme activity and the corresponding different impact on color deterioration by B. cinerea.

Wine Flavonoids in Health and Disease Prevention

Wine, and particularly red wine, is a beverage with a great chemical complexity that is in continuous evolution. Chemically, wine is a hydroalcoholic solution (~78% water) that comprises a wide variety of chemical components, including aldehydes, esters, ketones, lipids, minerals, organic acids, phenolics, soluble proteins, sugars and vitamins. Flavonoids constitute a major group of polyphenolic compounds which are directly associated with the organoleptic and health-promoting properties of red wine. However, due to the insufficient epidemiological and in vivo evidences on this subject, the presence of a high number of variables such as human age, metabolism, the presence of alcohol, the complex wine chemistry, and the wide array of in vivo biological effects of these compounds suggest that only cautious conclusions may be drawn from studies focusing on the direct effect of wine and any specific health issue. Nevertheless, there are several reports on the health protective properties of wine phenolics for several diseases such as cardiovascular diseases, some cancers, obesity, neurodegenerative diseases, diabetes, allergies and osteoporosis. The different interactions that wine flavonoids may have with key biological targets are crucial for some of these health-promoting effects. The interaction between some wine flavonoids and some specific enzymes are one example. The way wine flavonoids may be absorbed and metabolized could interfere with their bioavailability and therefore in their health-promoting effect. Hence, some reports have focused on flavonoids absorption, metabolism, microbiota effect and overall on flavonoids bioavailability. This review summarizes some of these major issues which are directly related to the potential health-promoting effects of wine flavonoids. Reports related to flavonoids and health highlight some relevant scientific information. However, there is still a gap between the knowledge of wine flavonoids bioavailability and their health-promoting effects. More in vivo results as well as studies focused on flavonoid metabolites are still required. Moreover, it is also necessary to better understand how biological interactions (with microbiota and cells, enzymes or general biological systems) could interfere with flavonoid bioavailability.

An Integrated View of the Effects of Wine Polyphenols and Their Relevant Metabolites on Gut and Host Health

Over the last few decades, polyphenols, and flavonoids in particular, have attracted the interest of researchers, as they have been associated with the health-promoting effects derived from diets rich in vegetables and fruits, including moderate wine consumption. Recent scientific evidence suggests that wine polyphenols exert their effects through interactions with the gut microbiota, as they seem to modulate microbiota and, at the same time, are metabolized by intestinal bacteria into specific bioavailable metabolites. Microbial metabolites are better absorbed than their precursors and may be responsible for positive health activities in the digestive system (local effects) and, after being absorbed, in tissues and organs (systemic effects). Differences in gut microbiota composition and functionality among individuals can affect polyphenol activity and, therefore, their health effects. The aim of this review is to integrate the understanding of the metabolism and mechanisms of action of wine polyphenols at both local and systemic levels, underlining their impact on the gut microbiome and the inter-individual variability associated with polyphenols' metabolism and further physiological effects. The advent of promising dietary approaches linked to wine polyphenols beyond the gut microbiota community and metabolism are also discussed.

Faecal metabolomic fingerprint after moderate consumption of red wine by healthy subjects

Faecal metabolome contains information on the metabolites found in the intestine, from which knowledge about the metabolic function of the gut microbiota can be obtained. Changes in the metabolomic profile of faeces reflect, among others, changes in the composition and activity of the intestinal microorganisms. In an effort to improve our understanding of the biological effects that phenolic compounds (including red wine polyphenols) exert at the gut level, in this foodomic study we have undertaken a metabolome characterization of human faeces after moderate consumption of red wine by healthy subjects for 4 weeks. Namely, a nontargeted metabolomic approach based on the use of UHPLC-TOF MS was developed to achieve the maximum metabolite information on 82 human faecal samples. After data processing and statistical analysis, 37 metabolites were related to wine intake, from which 20 could be tentatively or completely identified, including the following: (A) wine compounds, (B) microbial-derived metabolites of wine polyphenols, and (C) endogenous metabolites and/or others derived from other nutrient pathways. After wine consumption, faecal metabolome was fortified in flavan-3-ols metabolites. Also, of relevance was the down regulation of xanthine and bilirubin-derived metabolites such as urobilinogen and stercobilin after moderate wine consumption. As far as we know, this is the first study of the faecal metabolome after wine intake.

Red wine polyphenols increase calcium in bovine aortic endothelial cells: a basis to elucidate signalling pathways leading to nitric oxide production

1. The present study investigates the mechanisms by which polyphenolic compounds from red wine elicit Ca(2+) mobilization in bovine aortic endothelial cells (BAECs). Two polyphenol-containing red wine extracts, red wine polyphenolic compounds (RWPC) and Provinols, and delphinidin, an anthocyanin were used. 2. RWPC stimulated a Ca(2+)-dependent release of nitric oxide (NO) from BAECs accounting for the relaxation of endothelium-denuded rat aortic rings as shown by cascade bioassay. 3. RWPC, Provinols and delphinidin increased cytosolic free calcium ([Ca(2+)](i)), by releasing Ca(2+) from intracellular stores and by increasing Ca(2+) entry. 4. The RWPC-induced increase in [Ca(2+)](i) was decreased by exposure to ryanodine (30 microM), whereas Provinols and delphinidin-induced increases in [Ca(2+)](i) were decreased by bradykinin (0.1 microM) and thapsigargin (1 microM) pre-treatment. 5. RWPC, Provinols and delphinidin-induced increases in [Ca(2+)](i) were sensitive to inhibitors of phospholipase C (neomycin, 3 mM; U73122, 3 microM) and tyrosine kinase (herbimycin A, 1 microM). 6. RWPC, Provinols and delphinidin induced herbimycin A (1 microM)-sensitive tyrosine phosphorylation of several intracellular proteins. 7. Provinols released Ca(2+) via both a cholera (CTX) and pertussis toxins (PTX)-sensitive pathway, whereas delphinidin released Ca(2+) only via a PTX-sensitive mechanism. 8. Our data contribute in defining the mechanisms of endothelial NO production caused by wine polyphenols including the increase in [Ca(2+)](i) and the activation of tyrosine kinases. Furthermore, RWPC, Provinols and delphinidin display differences in the process leading to [Ca(2+)](i) increases in endothelial cells illustrating multiple cellular targets of natural dietary polyphenolic compounds.