Identification of polyphenolic compounds in red and white grape varieties grown in R. Macedonia and changes of their content during ripening

The composition of polyphenols in the skin, seed and pulp extracts of the grapes of Vranec and Smederevka varieties, and Merlot and Chardonnay as well, was analyzed by liquid chromatography-diode array detection-mass spectrometry (HPLC-DAD-MS) and MS/MS techniques. Thirty-one phenolic compounds, including anthocyanins, flavonols and flavan-3-ols, as well as phenolic acids derivatives, have been identified in the extracts prepared from the grapes at physiological maturity, by mass spectrometry applying electrospray ionization operated in alternating ion mode and by performing tandem MS experiments in the ion trap mass analyzer. Grapes were analyzed at three different phases: (i) veraison, (ii) physiological ripeness and (iii) late harvest, in order to follow the evolution of polyphenolic content during berry development, applying spectrophotometric methods. Vranec had a higher polyphenolic content compared to Merlot due to the higher levels of total phenolics and flavonoids in the skins and seeds as well as a higher content of flavan-3-ols and anthocyanins in the skins, allowing discriminating the varieties. HPLC-DAD-MS analysis presented significantly higher relative amounts of anthocyanin monoglucosides and p-coumaroylglucosides in Vranec grapes. Smederevka seeds had a higher amount of flavan-3-ols than Chardonnay, while a higher content of total phenolics and flavonoids was found in the skins of the Chardonnay variety. Anthocyanin content in both red varieties increased during the berry ripening, while flavan-3-ols in seeds were mainly accumulated in the veraison phase followed by decrease of the content with ripening.     

Polyphenolic content of Vranec wines produced by different vinification conditions

Macedonian Vranec wines were analysed by HPLC coupled with DAD and MS detections and by spectrophotometric methods. ESI-IT MS and MS–MS methods with alternating ionisation polarity were used for identification of the phenolic compounds. Both, nonflavonoids (stilbens, hydroxybenzoic and hydroxycinnamic acids and derivatives) and flavonoids (flavonols, flavan-3-ols and anthocyanins) were detected in the samples. Vranec wines were produced under different fermentation conditions: maceration time of 3, 6 and 10 days, two doses of SO₂ (30 and 70 mg l⁻¹) and two yeasts for fermentation, in order to examine their effects on the extraction of phenolic compounds from grapes into the wine.     

Determination of flavan-3-ols and trans-resveratrol in grapes and wine using HPLC with fluorescence detection

Concentrations of trans-resveratrol, catechin and epicatechin were analyzed in musts and wines produced from seven red and four white grape cultivars from various wine growing regions of Turkey. Phenolics were quantified using an HPLC method optimized for the separation of wine phenolics. Wine samples contained higher phenolics levels than the corresponding musts. With the exception of Semillion, white wines and musts contained lower concentrations of phenolics than red wines and musts. However, the white cultivar Semillion had the highest concentrations of catechin and epicatechin among all wine and must samples. Semillion wine catechin and epicatechin were 13.7 and 11.8 mg/L, respectively. The highest level of trans-resveratrol among the white cultivars was found in Narince wine (1.93 mg/L). Within the red wine and must cultivars, Bo?azkere, Öküzgozü, and Cabernet contained the highest concentrations of flavan-3-ols and trans-resveratrol. Catechin was the major phenolic in all wines and most musts. Epicatechin was the major phenolic in 6 of the 11 must samples, but none of the wine samples. trans-Resveratrol was generally found in lowest concentrations in both wines and musts.     

High hydrostatic pressure treatment: An artificial accelerating aging method which did not change the region and variety non-colored phenolic characteristic of red wine

The effect of high hydrostatic pressure (HHP) treatment on the region and variety non-colored phenolic characteristics of red wine was investigated in this study. After HHP treatment, many changes occurred in the non-colored phenolic compounds in red wines. Changes in total phenolic acids and the contents of eleven phenolic acids among different regions and varieties varied and showed an overall upward trend, while chlorogenic acid decreased in several wines. The total flavan-3-ols and five flavan-3-ols largely decreased among the different regions and different varieties, while EGC slightly increased. In addition, HHP treatment did not change the grape variety and grape geographic origin discrimination based on phenolic acids and flavan-3-ols, which suggests that HHP treatment had no effect on the region and variety of non-colored phenolic characteristics of red wine. These results could expedite the use of HHP processing in the wine industry.Industrial relevanceHHP is an important technology which could simulate the traditional aging process in wine industry and could shorten a lot of time and save great economic costs. However, no HHP-treated wine has been introduced in the market throughout the world so far. This is due, in large part, to the lack of correlation studies. In this study, we proved that HHP didn't change grape variety and grape geographic origin phenolic characteristics, hence it could be used in geographic indication wines and varietal wines. With these results, we hope HHP technology could be successfully used in wine industry as early as possible.     

产地与品种对葡萄酒中酚类物质含量的影响

选取同一产地(天水)3 个葡萄品种：“西拉(Shiraz)”、“蛇龙珠 (Carbernet Gernischet)”、“赤霞珠(Cabernet Sauvignon)”所酿制的新鲜干红葡萄酒以及5 个不同产地(天水、和硕、玛纳斯、延庆和怀来)赤霞珠葡萄酒,采用高效液相色谱(HPLC)法分析葡萄酒中11 种酚酸、5 种黄烷-3- 醇、10 种黄酮醇和2 种黄酮的含量。结果表明：同一产地不同品种和同一品种不同产地间的葡萄酒中酚类物质的含量都存在显著差异。其中,赤霞珠葡萄酒是3 个葡萄品种中酚类物质含量最高的品种;在5 个不同产地中,延庆赤霞珠葡萄酒中酚酸含量最高,黄烷-3- 醇含量最高的为和硕赤霞珠葡萄酒,而怀来赤霞珠葡萄酒中所含黄酮醇含量最高。     

Influence of the temperature and oxygen exposure in red Port wine: A kinetic approach

Although phenolics are recognized to be related with health benefits by limiting lipid oxidation, in wine, they are the primary substrates for oxidation resulting in the quinone by-products with the participation of transition metal ions. Nevertheless, high quality Port wines require a period of aging in either bottle or barrels. During this time, a modification of sensory properties of wines such as the decrease of astringency or the stabilization of color is recognized to phenolic compounds, mainly attributed to anthocyanins and derived pigments.The present work aims to illustrate the oxidation of red Port wine based on its phenolic composition by the effect of both thermal and oxygen exposures. A kinetic approach toanthocyanins degradation was also achieved. For this purpose a forced red Port wine aging protocol was performed at four different storage temperatures, respectively, 20, 30, 35 and 40 °C, and two adjusted oxygen saturation levels, no oxygen addition (treatment I), and oxygen addition (treatment II). Three hydroxycinnamic esters, three hydroxycinnamic acids, three hydroxybenzoic acids, two flavan-3-ols, and six anthocyanins were quantitated weekly during 63 days, along with oxygen consumption. The most relevant phenolic oxidation markers were anthocyanins and catechin-type flavonoids, which had the highest decreases during the thermal and oxidative red Port wine process. Both temperature and oxygen treatments affected the rate of phenolic degradation. In addition, temperature seems to influence mostly the phenolics kinetic degradation.     

The impact of high voltage electrical discharge plasma on the chromatic characteristics and phenolic composition of red and white wines

The cold plasma is an emerging electrotechnology for the improvement of food safety without loss of physicochemical or sensory properties. The purpose of this study was to evaluate the effects of plasma treatments on the chromatic characteristics and phenolic composition of red and white wines. The red wine Cabernet Sauvignon and white wine Graševina were treated with high voltage electrical discharge plasma considering the variations in frequency (60, 90 and 120 Hz) and processing time (3, 5 and 10 min). Total phenolics, total anthocyanins, total tannins and chromatic characteristics were analyzed by spectrophotometry while free anthocyanins, phenolic acids and flavan-3-ols by the HPLC-UV/Vis. Obtained results illustrated that plasma treatments have influenced the stability of phenolic compounds in wines without major changes in color parameters. Also, among two different processing parameters, the duration time was the most significant factor inducing changes on wines.Industrial relevanceHigh voltage electrical discharge plasma has been shown to affect the stability of wine phenols without any significant change in the color. An increase in the concentration of certain phenolic compounds in white wine suggest that this technique could be used in the wine industry as an alternative technique for enhancing the oxidative stability of wine and consequently the wine quality during the aging process.     

The influence of pectolytic enzyme addition and prefermentative mash heating during the winemaking process on the phenolic composition of Okuzgozu red wine

The effects of pectolytic enzyme addition and mash heating prior to fermentation on the phenolic component of Okuzgozu red wine during the winemaking and ageing processes were investigated. In general, the highest concentration of total phenolics was found in the mash-heated wines, whereas the total flavan-3-ol and total anthocyanin contents in all of the wines, decreased notably during the winemaking and ageing processes. As determined by HPLC, hydroxycinnamic acids were the major phenolic acids in the red wines. After 6 months in the bottle, the enzyme-treated wines had lower phenolic acid concentrations than had the control and mash-heated wines, but no significant (p < 0.05) differences were found in the concentration of total phenolic acids between the control and mash-heated wines. All of the phenolic acid levels decreased with the winemaking and ageing processes whereas only gallic acid increased. The wines treated by the pectolytic enzyme addition had a lower monomeric flavan-3-ol content than had the other wines, and the amount of monomeric anthocyanins extracted did not increase with the addition of enzymes.     

Monitoring of chemical parameters of oxygen-treated musts during alcoholic fermentation and subsequent bottle storage of the resulting wines

The effect of hyper-oxygenation of Airén white wines on color characteristics, phenolic composition, and volatile profile has been evaluated in different processing steps, not previously reported in conjunction: musts, musts during the alcoholic fermentation, resulting young wines and after 1 year of bottle storage. Hyper-oxygenation treatment achieved a positive effect on color stabilization by means of significantly lower contents of most important phenolic compound families (hydroxycinnamic acid derivatives, benzoic acids, flavonols, and flavan-3-ols) in oxygen-treated musts in fermentation, young wines, and one-year-stored white wines. Therefore, browning was avoided in wines elaborated from hyper-oxygenated musts and their values of a* (green–red component of color) were maintained, in contrast to what occurred in control wines. With regard to volatile profile, the concentration of the majority of individual volatile compounds was significantly higher in wines derived from hyper-oxygenated musts, even after 1 year of bottle storage, especially those derived from alcoholic fermentation (alcohols: 2-methyl-1-butanol and 3-methyl-1-butanol, polar esters: ethyl lactate and ethyl glutarate, C₆ alcohols: 3-methyl-1-pentanol, and acetates: 2-phenylethyl acetate). This study enhances knowledge regarding the effects of hyper-oxygenation process during and after alcoholic fermentation and 1 year of bottle aging, especially as there is scarce literature available on the subject.     

Phenolic profile in Czech white wines from different terroirs

Grapevine cv. Riesling is a traditional variety of cool climate viticulture regions to which the Czech Republic belongs too. In total 35 wine samples from 9 different terroirs of wine-growing regions in the Czech Republic were evaluated for the content of 20 phenolic compounds comprising hydroxybenzoic acids, hydroxycinnamates, stilbenes, and flavan-3-ols. Phenolic compounds were evaluated by an HPLC method. Methods of multivariate statistical analysis were used to discriminate wine samples on the basis of their geographical origin. Canonical variate analysis proved that it is possible to differentiate wines according to their geographical origin by following authenticity markers: gallic acid, caffeic acid, caftartic acid, p-coutaric acid, ferulic acid ethylester, p-coumaric acid ethylester, (+)-catechin, and (?)-epicatechin. On the basis of statistical analyses, 100% wine samples were correctly classified. The results indicate that, for the case of white wines, mainly hydroxycinnamates and flavan-3-ols can be used for differentiation of their geographical origin.     

Antioxidant properties and phenolic profiles of four Chinese Za wines produced from hull‐less barley or maize

As an ancient low‐alcohol beverage, Za wine (ZW) is very popular in the Qiang ethnic minority areas of China. Za wine has been claimed to possess health‐promoting effects, which may be associated with its antioxidant (AO) activity in vivo. In this study, the total AO capacity, DPPH radical and hydroxyl radical scavenging activity, and reducing capacity for two traditional Za wines (TZW‐L and TZW‐W) produced from hull‐less barley and two commercial Za wines (CZW‐H and CZW‐M) produced from hull‐less barley and maize, respectively, were determined. Total phenolics (TP) and total flavonoids (TF) of ZW were measured, and the phenolic compounds were identified and quantified by high‐performance liquid chromatography (HPLC). A Chinese yellow wine (YW) produced from rice and wheat was used as a reference. The results indicated that ZW had effective antioxidant activity, with CZW‐H exhibiting the greatest AO activity amongst the wines analysed. Significant differences were also observed between TZW‐L, TZW‐W, CZW‐M and YW in some of the AO assays (p < 0.05). The results also showed that TP (TF) content varied from 137.15 µg gallic acid equivalent/mL (34.12 µg/ mL; CZW‐M) to 177.85 µg gallic acid equivalent/mL (56.38 µg/mL; CZW‐H), and that TP positively correlated to AO activity, suggesting that phenolic compounds could be major contributors to the AO activity of ZW. HPLC results indicated that protocatechuic acid and ferulic acid were the major phenolic compounds in TZW‐L, TZW‐W and CZW‐H, whereas syringic acid and p‐hydroxybenzoic acid were the dominant phenolic compounds in CZW‐M. Copyright © 2013 The Institute of Brewing & Distilling     

Thermovinification of grapes from the Cabernet Sauvignon and Pinot Noir varieties using immobilized yeasts

This study examined the thermovinification technique using yeasts immobilized on calcium alginate for microvinification of the Cabernet Sauvignon and Pinot Noir grape varieties grown in Diamantina, Minas Gerais, Brazil. The wines obtained by thermovinification were characterized by their chemical and sensory aspects. The varietal wines from Cabernet Sauvignon and Pinot Noir had an alcohol content of 9.3 and 10.9 % (v/v), respectively. The total acidity, volatile acidity and the alcohol/reduced dry extract ratio were consistent with the Brazilian standards established for identity and quality of wines. There was a significant reduction in the levels of anthocyanins, flavonoids and total phenolic compounds after aging in the bottle. The sensory evaluation presented an acceptability exceeding 60 % for both wines.     

Antioxidants in spring leaves of Oxalis acetosella L.

Oxalis acetosella L. is a common, edible wild plant native to the northern hemisphere. The contents of selected antioxidants, and the antioxidant capacity of young and old spring leaves of O. acetosella, were evaluated. The present study reports foliar contents of ascorbic acid, tocopherols, carotenoids, chlorophyll, flavonoids, phenolic acids and total phenolics, and compares the nutritional value of O. acetosella with other cultivated and wild plants. The composition of foliar antioxidants was found to depend on leaf age. On the other hand, the antioxidant capacity of old leaves were in the same range as young leaves. A comparison between O. acetosela with lettuce analysed in our study, and with numerous cultivated and wild edible plants from other studies, showed that O. acetosella is very rich in β-carotene, ascorbic acid, tocopherols and xanthophylls, and that it is one of the best sources of flavonoids (flavonol glycosides and flavan-3-ols), especially rutin. Therefore, O. acetosella is a potentially important dietary source of antioxidants.     

Phenolic compounds and antioxidative properties of selected wines from the northeast of Thailand

The phenolic contents and antioxidative properties of selected wines, produced in the northeast of Thailand, were evaluated and compared, particularly those produced at Suranaree University of Technology (SUT) Farm as a case study. Nine wine varieties were used to evaluate their total phenolic content (TPC) by Folin–Ciocalteu method, free radical scavenging efficacy by DPPH method and reducing power by ferric reducing-antioxidant power (FRAP) method. The red wines had significantly higher (p < 0.05) amounts of total phenols, flavonoids and antioxidant activities (AA) compared to white wines. Capillary electrophoresis (CE) was used as a powerful and high performing tool for analysis of principal phenolic compounds in the wines. t-Resveratrol was found in Shiraz, Zinfandel and blended wine varieties. (+)-Catechin was found in all wine varieties, except in Chasselar Dore. (+)-Catechin was present in wines at a higher level than (−)-epicatechin. In red wine, gallic acid was the dominant phenolic acid found.     

Phenolic constituents in major fractions of tropical rapeseed

Phenolic constituents in major fractions such as seed, cotylendons and hulls of commercial rapeseed varieties Ganyou-5, Westar, Raya-brown and Raya yellow grown under tropical conditions in Pakistan, were determined. Quantitative determination in percentage of sinapine, catechin, tannic acid and total phenolics as well as in absorption units at 550 nm of procyanidine, proanthocyanidine and flavan-4-ols in relation to different extractants such as methanol, methanol-HCl and their totals, were made. These varieties and their fractions widely varied in different phenolic constituents in respect of extractants used. Hulls of all cultivars contained higher levels of catechin, procyanidine, pronanthocyanidine and flavan-4-ols while lower amounts of sinapine, tannic acid and total phenols than the cotylendons. Cotylendons and hulls in seeds of raya-brown were exceptionally high in procyanidine.     

Comparing the effects of exogenous abscisic acid on the phenolic composition of Yan 73 and Cabernet Sauvignon (Vitis vinifera L.) wines

Phenolic compounds from red wines exert a strong influence on wine quality. Abscisic acid (ABA) is essential for the physiological and biochemical function of plants, but few investigators have thoroughly researched its effects on phenolic compounds in dyer grape varieties. The effects of exogenous ABA treatment on the phenolic composition and individual anthocyanin and non-anthocyanin phenolic contents of Yan 73 and Cabernet Sauvignon wines from the ABA-treated grapes, including anthocyanins, flavan-3-ols, flavonols, phenolic acids, and stilbenes were compared. The phenolic compounds in the Yan 73 wine were different from those in the Cabernet Sauvignon wine. The phenolic content (anthocyanins and non-anthocyanins) of the Yan 73 wine was significantly higher than that of the Cabernet Sauvignon wine. The concentrations of the individual phenolic compounds were enhanced by the ABA treatment for the two different wine varieties. The effects on the compositions varied, a similar trend was observed for the ratios of Cy-derivative and Dp-derivative pigments from the two wine varieties, and all non-acylated pigments were enhanced. The stilbene content was enhanced, the ratios of flavan-3-ol dimers and dimer-glucosides were reduced, and the effects on the composition of other compounds varied between the two grape varieties.     

Polyphenols,anthocyanins, and trans-resveratrol in red wines from the Hungarian Villány region

Epidemiological data indicate that moderate red wine consumption leads to less coronary heart disease and shows anti-carcinogenic effects. Especially, red wine phenolics have been linked to these effects. Sixty-seven red wines from the Hungarian Villány region, of vintages from 1996 to 2003 were analysed for their polyphenolic and anthocyanin composition by means of RP-HPLC/UV–Vis. Varieties with generally high concentrations of polyphenols are Kékfrankos, Merlot and Zweigelt, while anthocyanin content was highest in Shiraz, Oportó, Kékfrankos and Zweigelt. In agreement with other authors, our results show that trans-resveratrol content is mainly dependent on variety and vintage year. Principal component analysis (PCA) revealed that flavan-3-ols and delphinidin- and petunidin-3-glucosides are mainly responsible for the separation of wines according to polyphenolic composition. We could not discriminate between varieties or wineries based on polyphenol content, but could for vintage years.     

Influence of phenolics in finger millet on grain and malt fungal load,and malt quality

Phenolic type, fungal load, germinative energy (GE) and malt quality of finger millet grain types of varied kernel colour and phenolic content were analysed, to determine if phenolics in finger millet grain influence its malt quality. The fungal load (total fungal count (TFC) and infection levels) of the unmalted grain and malt were negatively correlated (p < 0.05) with total phenolics (TP) and amount of phenolic type (condensed tannins, anthocyanins and flavan-4-ols). High-phenol finger millet types had much higher malt quality than the low-phenol types, with respect to diastatic power (DP), and α- and β-amylase activities. GE, DP and α-amylase activity were positively correlated with TP and amount of phenolic type (p < 0.05) and negatively correlated with TFC (p < 0.01). Phenolics in finger millet grain influence its malt quality positively by contributing to attenuation of the fungal load on the germinating grain.     

Nutritional composition of commercial pickled garlic

The effect of pulp treatment on the qualitative and quantitative changes to polyphenol compounds, such as anthocyanins and flavanols, in musts and wines from blackcurrant and cherries was investigated. The following variants of pulp treatment were used: hot maceration, hot maceration and pulp pectinolysis with Rohapect MA Plus and Pectopol PM preparations, and also pulp pectinolysis with Rohapect and Pectopol preparations. The method of treatment affected the content of anthocyanins and flavan-3-ols in the musts. Different types of phenolic compounds reacted differently under must-making conditions. Wines made with different treatments presented statistical differences with the control wine and between them for the parameters studied.As a result of the analysis of cherry musts and wines by HPLC, the following flavan-3-ols were identified: catechin, epicatechin, dimer B₂ and trimer C₁. In the cherry wines studied, in the variants subjected to pectinolysis and fermentation in the pulp, epicatechin occurred in a smaller amount than catechin, while in the wines subjected to thermal treatment it was predominant. In the blackcurrant musts and wines the following flavanols were identified: gallocatechin, catechin, epigallocatechin, dimer B₂, epicatechin and trimer C₁. In the cherry musts and wines the following anthocyanin pigments have been identified: cyanidin 3-glucoside, cyanidin 3-rutinoside and cyanidin 3-glucosylrutinoside, the amount of which was the greatest. Anthocyanins identified in the blackcurrant musts and wines were delphinidine and cyanidine glycosides: delphinidin 3-glucoside, delphinidin 3-rutinoside, cyanidin 3-glucoside and cyanidin 3-rutinoside; their aglycones were also found.     

Comparative study of 11 phenolic acids and five flavan-3-ols in cv. Vidal: impact of natural icewine making versus concentration technology

Background and Aims:  In an effort to protect the development of the icewine production industry, this study aimed to find indicators to distinguish between authentic and non-authentic icewines.
Methods and Results:  Fully ripened berries were used to prepare three types of high-sugar grape juices: naturally frozen juice, refrigerator-frozen juice and concentrated juice. The content of phenolic acids and flavan-3-ols in the samples before and after fermentation was assayed. Significant differences were found in the individual level of most phenolic acids and flavan-3-ols except chlorogenic acid, sinapic acid and (−)-epicatechin among the three types of high-sugar juices. At the end of fermentation, there were significant differences in the wines, not attributable to the influence of yeasts.
Conclusions:  Vanillic acid, caffeic acid, (−)-epigallocatechin gallate, gentisic acid and syringic acid may be used as indicators of authentic icewine.
Significance of the Study:  This work provides a basis for distinguishing authentic icewine and controlling icewine quality.