Impact of polyphenols from black tea and red wine/grape juice on a gut model microbiome

Food and beverage products derived from fruit and vegetables contain polyphenols, which have been associated with various health benefits. Polyphenols may influence health through direct uptake in the intestine but also upon interaction with the gut microbiota for example by modification of the microbial composition or by conversion of the polyphenols to further bioactive compounds. So far, there are limited studies of complex polyphenols on the human gut microbiota especially using modern molecular technologies. Most studies investigating effects of dietary polyphenols have focused on single molecules or bacterial strains. In the current study, an in vitro gut microbial ecosystem, namely simulator of the intestinal microbial ecosystem (SHIME), was challenged with either a black tea or a red wine grape extract (RWGE), both containing complex dietary polyphenol mixtures. Within the context of the model system, the effects of these interventions on both microbial numbers and composition as well as metabolite levels were assessed. Antimicrobial effects, largely confined to unculturable members of the ecosystem, were revealed by complementary microbiological techniques. Pyrosequencing analysis showed a shift in the Firmicutes:Bacteroidetes ratio for both interventions. Black tea stimulated Klebsiella, enterococci and Akkermansia and reduced bifidobacteria, B. coccoides, Anaeroglobus and Victivallis. RWGE promoted growth of Klebsiella, Alistipes, Cloacibacillus, Victivallis and Akkermansia while bifidobacteria, B. coccoides, Anaeroglobus, Subdoligranulum and Bacteroides were decreased.The study shows that these complex polyphenols in the context of a model system can modulate select members of the human gut microbiota. These members represent novel targets of polyphenol degrading or resistant microbes to be validated under physiological conditions in vivo and further investigated for polyphenol metabolism or resistance mechanisms.     

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     

Simple determination of main organic acids in grape juice and wine by using capillary zone electrophoresis with direct UV detection

An accurate, simple and rapid capillary zone electrophoresis (CZE) method with direct UV detection has been set up for the determination of main organic acids in grape juice and wine. The determination of tartaric, malic, and citric acids in grape juices and tartaric, malic, succinic, acetic, lactic and citric acids in wines can be achieved in less than 3 min with only a simple dilution and filtration treatment of the sample. Validation parameters of the method as detection and quantification limits, linearity, precision (intraday and interday analysis) and recovery were also studied in grape juice, white wine, rose wine and red wine, separately. The proposed method decreases the analysis times of the previous reported CZE methods and allows the rapid control of the grape maturity, the winemaking processes and the detection of wine alterations and/or illnesses.     

High-performance liquid chromatography-diode array detector determination and availability of phenolic compounds in 10 genotypes of walnuts

Walnuts contain signi?cant amounts of bioactive compounds such as polyphenols. The aim of the present study was to determine the differences in phenolic composition and polyphenolic in vitro availability of 10 genotypes of walnuts. All analyzed genotypes showed high flavonoid and non-flavonoid phenolic compounds, especially Eureka and Tehama genotypes. Ellagic acid and syringic acid were the mayor non-flavonoids. Regarding flavonoids, catechin and procyanidin B₂ were the most abundant, covering about 98% of total flavonoids. The in vitro digestion showed flavonoids as the most available polyphenols, especially catechin, gallocatechin, and epigallocatechin gallate.     

葡萄与葡萄酒中总酚测定方法的研究进展

酚类物质是葡萄酒的骨架成分,也是葡萄酒保健功能的主要作用物质,所以准确测定酚类物质总量对评判葡萄酒的保健功能和判断葡萄酒品质有重要的意义。文章综述高锰酸钾法、福林酚法、普鲁士蓝法、香草醛—盐酸(硫酸)法、高效液相色谱法、蛋白质沉淀法在酚类物质测定中的应用情况,并分析其优缺点,为筛选和优化葡萄与葡萄酒总酚测定方法的研究工作提供参考。     

Mousy off-flavour production in grape juice and wine by Dekkera and Brettanomyces yeasts

The ability of four known species of Dekkera and Brettanomyces yeasts to produce mousy off-flavour in grape juice and wine was investigated for the first time. Using a sensory assessment technique the twelve type strains of Dekkera and Brettanomyces , representing four species, were found to grow and to be capable of producing mousy off-flavour in a grape juice medium; however, differences between strains were apparent. Four strains representing the two species of Dekkera (D. bruxellensis and D. anomala ) known to be associated with the spoilage of wine and other fermented beverages were further investigated for mousy off-flavour production in a red and white wine supplemented with nutrients. D. anomala and only one of the three D. bruxellensis strains tested grew in both wines and generally produced a moderate level of off-flavour, whereas the remaining two strains of D. bruxellensis , despite slowly losing viability (10- to 100-fold) over the 52–55 day period, produced detectable off-flavour. This work demonstrates the general ability of Dekkera and Brettanomyces yeasts to produce mousy off-flavour and confirms the importance of these yeasts for off-flavour production in grape juice and wine.     

葡萄酒中多酚及多酚氧化酶研究现状与展望

葡萄酒富含多种营养与保健成分,具有预防心脑血管疾病、抗氧化、抗菌、抗癌、助眠等保健功效,葡萄酒中多酚类物质因具有极强的抗氧化、抗菌与预防心脑血管疾病等生理药理活性而倍受人们推崇,但多酚氧化酶会氧化破坏葡萄酒中的多酚,不仅会使葡萄酒变色变质变味,还会使其营养和保健价值明显降低。对葡萄酒中的多酚以及多酚氧化酶进行深入研究不仅有利于优质葡萄酒的研发与生产,还将为相关食品药品与果酒科学的研究提供借鉴。该文主要对目前国内外对葡萄酒中多酚及多酚氧化酶的种类、制备方法、酶活测定方法、酶活的影响因素等内容的研究现状进行了概述,并对有待加强的研发内容及其前景进行了展望。     

BDI-GS体系评价干红葡萄酒营养健康效应及 食品安全性探讨

目的通过食品BDI-GS新体系评价干型红葡萄酒的营养健康效应,探讨食品安全性问题。方法以生长期ICR小鼠为研究对象,分组给予饮用水、5%、10%和20%干红稀释液,同时均给予玉米低营养饲料,共喂食12 d。解剖并统计9项脏器组织重量、系数及其损益指数(benefit damage index,BDI)和累计积分(general score,GS),并进行血清生化指标测试。结果除胰腺以外,3组干红对其他脏器组织均显示一定的营养健康效应,突出体现在胸腺、脾脏和性腺的重量及系数BDI值明显高于1.0;累计GSW值均明显高于9.0的基本值,而累计GSI值各剂量较接近,也均高于9.0。然而,连续摄取干红可以显著升高血糖(P0.05),轻度升高血脂水平。结论干红葡萄酒对机体脏器组织的总体营养及健康效应良好,不存在明显的健康损害。同时,与普通甜型红葡萄酒相比,干红葡萄酒的营养和健康效应更佳,拥有更好的内在质量和安全性。     

Effects of resveratrol and purple grape juice on nucleotide hydrolysis by adult rat serum

ATP, ADP and AMP (adenosine tri, bi and mono-phosphate, respectively) hydrolysis in rat serum were assessed in vitro in the presence of certain flavonoids: resveratrol, quercetin and rutin. Also, the effects of purple grape juice (PGJ) and the effect of PGJ before arginine treatment were observed on serum nucleotide hydrolysis. The in vitro nucleotide hydrolysis by rat serum was increased in the presence of resveratrol for ATP and ADP hydrolysis. There was a decrease of nucleotide hydrolysis in the presence of other flavonoids tested in vitro. The effects of PGJ treatment after 15 days showed that nucleotide hydrolysis increased for ATP, ADP and AMP. We also investigated whether animals that had received injections of arginine and presented reduction of nucleotide hydrolysis activities, would present a retrieval of this reduction by receiving PGJ before injections were administered. Evidently resveratrol may increase nucleotide hydrolysis by serum and PGJ may be capable of preventing the decrease in nucleotide hydrolysis caused by arginine treatment.     

Detection of ochratoxin A in tropical wine and grape juice from Brazil

BACKGROUND: Ochratoxin A (OTA) is the main mycotoxin found in grapes, wines and grape juices and is considered one of the most harmful contaminants to human health. In this study, samples of tropical wines and grape juices from different grape varieties grown in Brazil were analysed for their OTA content by high‐performance liquid chromatography. RESULTS: The detection and quantification limits for OTA were 0.01 and 0.03 µg L^?1 respectively. OTA was detected in 13 (38.24%) of the samples analysed, with concentrations ranging from < 0.03 to 0.62 µg L^?1. OTA was not detected in any of the grape juice samples. Most of the red wine samples proved to be contaminated with OTA (75%), while only one white wine sample was contaminated. However, the OTA levels detected in all samples were well below the maximum tolerable limit (2 µg L^?1) in wine and grape juice established by the European Community and Brazilian legislature. CONCLUSION: The results of this study indicate a low risk of exposure to OTA by consumption of tropical wines and grape juices from Brazil. © 2012 Society of Chemical Industry     

The fate of fungicide and insecticide residues in Australian wine grape by-products following field application

Pesticides applied to grape vines before harvest may concentrate in the grape seed due to their high oil solubility. Twenty-four samples of grape marc, representing a range of red and white wine grape varieties, were collected and analysed for selected fungicides and insecticides. Fifteen of the 24 samples were matched with insecticide and fungicide application diaries. Residue concentrations of the fungicides, procymidone, iprodione, cyprodinil, fenhexamid, fludioxinil, pyrimethanil and trifloxystrobin, and the insecticides, indoxacarb and tebufenozide, were higher in grape seed oil and grape seed meal than in the fruit and the marc. The relative concentrations were approximately proportional to the octanol to water partition coefficients, log K_ow. A range of other fungicides and insecticides were detected but were not significantly concentrated in the oil and seed meal relative to fruit and marc. The presence of pesticide residues in grape seed oil and grape seed meal will impact on the possibility of producing these wine by-products.     

Influence of whey-based fruit juice containing Lactobacillus rhamnosus on intestinal well-being and humoral immune response in healthy adults

The ability of probiotics to balance intestinal microbes and to modulate gut immune system has been reported for several probiotic strains. In the present study, Lactobacillus rhamnosus strain VTT E-97800 (E800) or L. rhamnosus Lc705 (the latter in combination with Propionibacterium freudenreichii ssp. shermanii JS) were separately administered to healthy adult volunteers (n=11 in both study groups) in a whey-based fruit juice. Survival of the potentially probiotic L. rhamnosus strains in the GI-tract and their effect on intestinal well-being and peripheral immune parameters were assessed. Both L. rhamnosus strains were recovered in high numbers in faecal samples during the consumption period and with few exceptions they were not detected after the 2 weeks follow-up period. Consumption of the juice supplemented with either of the L. rhamnosus strains did not have significant effect on faecal consistency or defecation frequency. No changes were observed in the immunological parameters (number or immunoglobulin A-, G- and M-secreting cells, expression of Fcα-receptor or complement receptors 1 and 3), except for a slight decrease in the number of IgA secreting cells during ingestion of the juice supplemented with L. rhamnosus Lc705 and P. freudenreichii ssp. shermanii JS. The results indicate that L. rhamnosus strains E800 and Lc705 had good survival ability in the GI-tract when administered in a whey-based fruit juice matrix. No adverse effects on intestinal function or on studied immunological parameters were observed during consumption of the whey based juice drink supplemented with the potential probiotic strains.     

葡萄多酚的保健作用及其在酿酒葡萄成熟度判定中的应用

葡萄酒含有极其复杂的物质,其中葡萄多酚对葡萄酒品质具有决定性的作用。本文综述了当前葡萄多酚的研究成果以及在酿酒葡萄成熟度判定中的应用。通过实验证明,酿酒葡萄中葡萄多酚含量的测定值可以用于判断葡萄成熟度,对酿酒葡萄的适时采收具有普遍的指导意义。     

Tart Cherries and health: Current knowledge and need for a better understanding of the fate of phytochemicals in the human gastrointestinal tract

Tart cherries are increasingly popular due to purported health benefits. This Prunus cesarus species is cultivated worldwide, and its market has increased significantly in the last two decades due to improvements in agricultural practices and food processing technology. Tart cherries are rich in polyphenols, with a very specific profile combining anthocyanins and flavonols (berries-like) and chlorogenic acid (coffee-like). Tart cherries have been suggested to exert several potentially beneficial health effects including: lowering blood pressure, modulating blood glucose, enhancing cognitive function, protecting against oxidative stress and reducing inflammation. Studies focusing on tart cherry consumption have demonstrated particular benefits in recovery from exercise-induced muscle damage and diabetes associated parameters. However, the bioconversion of tart cherry polyphenols by resident colonic microbiota has never been considered, considerably reducing the impact of in vitro studies that have relied on fruit polyphenol extracts. In vitro and in vivo gut microbiota and metabolome studies are necessary to reinforce health claims linked to tart cherries consumption.     

Determination of mepiquat chloride in grape, wine and juice by liquid chromatography with electrospray tandem mass spectrometry

A simple and rapid method was developed for the analysis of mepiquat chloride in grape, wine and juice by high-performance liquid chromatography with electrospray tandem mass spectrometry (LC/MS/MS). Mepiquat chloride was extracted with water-methanol (1:1). Extracted solution was adjusted to pH 10 with ammonia solution. A part of the extracted solution was cleaned up on a styrenedivinylbenzene (SDVB) cartridge for LC/MS/MS. The LC separation was performed on a C18 column (50 mm x 2 mm i.d.) using 0.1% IPCC-MS7-methanol (60:40) as the mobile phase at a flow rate of 0.2 mL/min. The mass spectral acquisition was done in the positive ion mode by applying selected reaction monitoring (SRM). The recoveries of mepiquat chloride from fresh grape, wine and juice fortified at 5 microg/kg and 50 microg/kg were 84.5-96.1%. The lower limit of quantification was 1 microg/kg. Fourteen fresh grape samples, 14 wines (white), 36 wines (red) and 11 juice samples were analyzed by this method. Mepiquat chloride was detected in 5 fresh grape samples, 3 wines (white) and 1 wine (red) at the level of 12.8-199 microg/kg, 5.7-47.7 microg/kg and 24.1 microg/kg, respectively.     

乙醇传感器法测定葡萄酒和黄酒中乙醇的含量

建立了生物传感器法测定葡萄酒和黄酒中乙醇含量的分析方法。结果表明:乙醇含量在2~80μL/100mL浓度范围内线性关系良好,相关系数为0.9997;加标回收率(n=3)在99.22%~101.59%之间;精密度和重复性(n=4)的RSD%低于1%。与国标酒精计法测定结果对比,两种方法无显著差异。该法具有无需样品前处理、特异性好、灵敏度高、测定速度快等优点,适用于企业对发酵过程控制和产品的质量检测。