Phenolic compounds and antioxidant properties of different grape cultivars grown in China

Skins and seeds of 18 grape cultivars belonging to Oriental and North American Vitis Species/hybrids, and Vitis vinifera were analysed for health beneficial properties. Four phenolic compound parameters (total phenols, flavonoids, flavan-3-ols and anthocyanins) and three antioxidant property parameters (DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging, ABTS [2,2-azino-di-(3-ethylbenzothialozine-sulphonic acid)] radical scavenging and FRAP (ferric reducing antioxidant power)) were measured. Principal component analysis (PCA) was used for this evaluation and results showed that both phenolic compounds and antioxidant properties in the seeds and skins varied among the cultivars investigated. V. vinifera “Cabernet Sauvignon” had the highest values of phenolic compounds and antioxidant properties in seeds followed by Muscadines, while the lowest appeared in the Oriental Vitis species. As expected, these values of the Euro-Asian or Euro-American hybrids fell between the parents. However, far less variation of these values was observed in the skins among different grape cultivars investigated. Interestingly, even the total phenolic contents in the berries of two cultivars are similar, distributions of phenolic compounds in seeds and skins varied greatly among them. Additionally, significant correlations among different antioxidant assays in both seeds and skins were observed. These antioxidant properties were also found highly correlated to the main phenolic compounds.     

Headspace-based techniques to identify the principal volatile compounds in red grape cultivars

The control of the raw material has a great influence on the final quality of wine. Nowadays, wineries have practically not incorporated an effective quality control of grape juice on their production process. Although wine aroma has been widely analysed, grape juice aroma for wine-making has been poorly studied. In this study, two headspace-based technique methodologies have been proposed to characterise the aroma of grape juice: static headspace (SHS) and headspace solid phase microextraction (HS-SPME). Both techniques were applied on the samples from three maturation stages of two red grape cultivars: Tempranillo and Bobal, ranked first in Spanish and in Valencian Community cultivars, respectively. This study identifies the principal volatile compounds of grape juice: C₆ compounds, especially alcohols and aldehydes, using both techniques. It was confirmed that SHS and HS-SPME techniques could be incorporated into the process of the grape quality control in wineries as a result of its operational simplicity, low cost and reduced ecological impact compared with other conventional organic solvent-based techniques.     

HPLC-DAD detection of changes in phenol content of red berry skins during grape ripening

With increasing concern for a demand from consumers for natural products, there is a wide interest in bioactive substances. The new frontier of dietary quality is the study and promotion of functional foods. Phenols are among the most important functional molecules. Red grape and red wine contain bioactive products as phenols. Changes occurring in the concentrations of phenols, such as hydroxycinnamic tartaric acids (hctas), flavonols, and anthocyanins in berry skins, were measured during growth and ripening of four red grape cultivars, Alicante, Black Malvasia, Nerello, and Prunesta (Vitis vinifera L.), cultivated in a coastal location of the Reggio Calabria Province (Southern Italy). These cultivars are the most popular and are considered to be the most suitable grape cultivars for cultivation in the Tyrrhenian side of the Reggio Calabria Province. Fractioning of three phenolic classes was conducted through the adsorbing resin Serdolit XAD-2. Each single phenolic fraction was analyzed by liquid chromatography with diode array detector (HPLC-DAD). Each cultivar presented a different chromatographic profile particularly for anthocyanins. The cultivar Nerello was distinguished from other for its high content of anthocyanins. The rate, at which the concentration of hctas, flavonols and anthocyanins increased, varied greatly among the cultivars. The hydroxycinnamic tartaric acid profile varied in the studied cultivars, in fact in Alicante, Black Malvasia and Prunesta cultivars, the predominant was trans-coumaroyl tartaric acid, while in Nerello cultivar, trans-caffeoyl tartaric acid was the most abundant. In addition, the results showed that amounts of phenolic compounds contained in grape skin changed throughout the grape ripening process.     

Aroma characterization of red wines from cv. Bobal grape variety grown in La Mancha region

Bobal is an indigenous Spanish cultivar, principally grown in the region of Valencia. The volatile composition of young red wines made from the cv. Bobal grape variety grown in the La Mancha region of Spain has been studied over five vintages by instrumental analysis to determine the influence of grape variety on the aroma of wine. Free and glycosidically-bound aroma compounds were isolated by solid phase extraction (SPE) using dichloromethane and ethyl acetate respectively to later be analyzed using gas chromatography-mass spectrometry (GC/MS). One hundred and twelve (112) free aroma compounds and ninety-six (96) bound aroma compounds were identified and quantified in Bobal wines oven this five year period. Based on the result, Bobal wine presents a complex chemical profile with a wealth of aromas in its aromatic composition.     

Morphology, anatomy and development of the pericarp after anthesis in grape, Vitis vinifera L.

Studies of the structure and cytological development of the pericarp of the grape berry are reviewed and further studies conducted using contemporary methods of histology, histochemistry, electron microscopy and traditional methods of proximate analysis to investigate post-anthesis pericarp morphology, anatomy, fine structure and tissue composition. The observations are presented within a biological and ecological context in which the pericarp, in its primary role, serves as an aid to seed dispersal, as indicated by the developmental changes it undergoes in composition and structure after anthesis. It is concluded that the pericarp embodies a broad spectrum of evolutionary responses to natural selection exerted both by biotic and abiotic factors in wild populations of grapevines. The presently used cultivars have retained these characteristics, as they have not been exposed for thousands of years, and are still not exposed, to natural selection.     

Freeze-dried grape skins by-products to enhance the quality of white wines from neutral grape varieties

Wastes generated by the wine industry (grape marc), mainly residues from white wine vinifications, are an important source of aroma and phenolic compounds. However, grape marcs are highly perishable and seasonal products, so they require an adequate conservation method. In this respect, freeze-drying, versus conventional drying methods, is a good alternative since this technique preserves the quality of the raw material. Specifically, freeze-drying hardly caused losses of characteristic grape variety volatiles, such as terpenes and C₆ compounds, neither increases in the concentration of furan compounds. Furthermore, freeze-dried grape skins obtained from residues did not presented changes in the amounts of phenolic compounds with respect to the fresh skins. On the other hand, skin-contact treatment with Muscat freeze-dried skins enhanced the aroma of white wines made from Airén grapes, a variety considered neutral, without affecting negatively their color. Skin-contact treatment preserved the wine fruity notes, although the only wine that conserved floral notes in its flavor profile was that macerated with freeze-dried skins. Also, these wines were better rated by the assessors than those macerated with Muscat fresh skins.     

Effect of co-winemaking in phenolic composition, color and antioxidant capacity of young red wines from La Mancha region

The influence of co-winemaking technique on the phenolic profiles, color and antioxidant capacity of wines made from red grape varieties cultivated in La Mancha region (Spain) was investigated. Co-winemaking red wines were obtained by pre-fermentative blend of grapes (1:1, w/w) from the predominant Cencibel (Tempranillo) variety in this region and the minor varieties Bobal, Moravia Agria, Moravia Dulce, Tortosí and Rojal, together with a three varieties blend (1:1:1, w/w/w) of Cencibel, Bobal and Moravia Agria grapes. The phenolic profiles obtained in co-winemaking wines showed more quantity of different compounds than single-variety wine of Cencibel used as reference. The best results were obtained using Bobal, Moravia Agria and Moravia Dulce varieties for co-winemaking, especially an improvement of color characteristics. All co-winemaking wines significantly increased the total resveratrol content as compared to the Cencibel reference wine, although cis-isomers largely predominated in all wines. Moravia Agria and Rojal varieties produced co-winemaking wines with decreased antioxidant capacity, whereas Bobal and Moravia Dulce varieties increased it, even when the co-winemaking wine from Moravia Dulce contained less total polyphenols than Cencibel reference wine. Co-winemaking technique can be suggested as a way to widen the offer of wines to consumers, incorporating characteristic properties of minor grape varieties. In addition, this enological technique has the benefit of avoiding the disappearance of native species, thus improving the biodiversity of La Mancha region.     

Phenolic fortification of yogurt using grape and callus extracts

In this study, acidified ethanol extracts of four different grape varieties (Cabernet sauvignon, Chardonnay, Shyrah, and Merlot) and grape callus were supplemented into yogurt as functional ingredients. The total phenolic substances, total anthocyanin content, and antioxidant activity of the yogurts were measured using chemical analyses. Yogurts inoculated with red grape and callus extracts displayed high phenolic - anthocyanin content and thus exhibited higher antioxidant power compared to yogurts containing chardonnay extracts and control samples. The storage time significantly affected the free radical scavenging capacity of the yogurts. The yogurts supplied with grape callus extract displayed the greatest antioxidant power on the first day of storage compared to all the assayed samples. The Gas Chromatography (GC) analysis revealed the presence of at least 10 individual bioactive phenolic compounds in the callus yogurt. The results obtained from this investigation shows that grape callus culture has a potential to be used as a food supplement to play a role in reducing the risk of developing chronic diseases such as cancer and cardiovascular disease.     

酿酒和鲜食葡萄酿造起泡葡萄酒品质差异研究

选用陕西地区的鲜食葡萄品种户太八号、夏黑和酿酒品种爱格丽、嘉年华、玫瑰香为原料,酿制小容器起泡葡萄酒,并对不同品种葡萄酿造的起泡葡萄酒进行酚类物质、香气物质及感官指标进行定量描述分析（QDA）比较。结果表明：不同品种葡萄果实及起泡葡萄酒总酚含量存在显著差异（P＜0.05）,鲜食葡萄品种的总酚含量高于酿酒葡萄品种,夏黑葡萄果实中的总酚含量最高,为（97.95±2.93） mg/g,5种起泡葡萄酒的基本指标均符合国家标准,其中酿酒品种中嘉年华及鲜食品种里户太八号起泡葡萄酒的酚类物质含量较高;5种起泡葡萄酒共检测出香气物质50种,其中玫瑰香起泡葡萄酒香气物质种类最多（33种）;QDA分析结果表明,爱格丽及夏黑起泡葡萄酒感官品质较佳,分别得分75.99分和81.80分。     

葡萄对SO2伤害的敏感性与吸收SO2途径的探讨

用不同用量的SO2对8个葡萄品种进行处理,研究了葡萄对SO2伤害的敏感性与吸收SO2的途径。结果表明,不同品种葡萄对SO2的敏感性及伤害部位不同,8个待测品种按对SO2敏感性的不同可被分为四类;果实中SO2具有累积效应,葡萄对SO2的敏感性不同,吸收SO2的途径和能力也不同。     

葡萄砧木及酿酒品种抗寒性比较

利用电解质外渗率法和恢复生长法对11个葡萄砧木品种(3309C、5BB、河岸、110R、Fercal、SO4、1103P、8B、贝达、MRH20、Beaument)和5含酿酒葡萄品种(霞多丽、西拉、赤霞珠、梅鹿辄、香百川)的抗寒性进行了鉴定。结果表明:葡萄砧木的抗寒性明显强于酿酒品种。不同砧木及酿酒品种的抗寒性也存在着明显差别,砧木抗寒性强弱依次为贝达>MRH20、5BB>110R>3309C>SO4>Fercal>河岸葡萄、8B>Beaumont、1103P;酿酒葡萄品种抗寒性强弱依次为香百川>霞多丽、赤霞珠>西拉>梅鹿辄。     

Effect of cofermentation of grape varieties on aroma profiles of la mancha red wines

The effect of winemaking using blends of red grape varieties cultivated in La Mancha region (Spain) on the aroma profile of wines was researched by chemical characterization. Free and glycosidically bound aroma compounds were isolated by solid phase extraction using dichloromethane and ethyl acetate, respectively, as solvents in elution and then analyzed by gas chromatography-mass spectrometry. Free and bound volatile compounds were analyzed in Cencibel, Bobal, and Moravia Agria monovarietal wines, and in 3 wines obtained with the blending of grapes: Cencibel (50%) + Bobal (50%); Cencibel (50%) + Moravía Agria (50%); Cencibel (33%) + Bobal (33%) + Moravía Agria (33%). Aroma compounds were studied in terms of odor activity values (OAVs). Ninety free aroma compounds and sixty-five bound aroma compounds were identified and quantified. The odor activity values for the different compounds were classified into 7 odorant series. The fruity and sweet series contributed most strongly to the aroma profile of all wines, independently of the winemaking technique used. In general, co-winemaking wines present a more complex chemical profile than monovarietal wines. Practical Application: Some grape varieties could benefit from this process with the presence of other varieties that might have an excess of aroma compounds. In this study, the wines were elaborated by blending different grape varieties together; this process implies co-maceration and co-fermentation steps. The co-winemaking technique could benefit from additional molecules provided by the other varieties, which results in a more complex formation than in the case of monovarietal wines. This technique provides a viable alternative to traditional winemaking methods for improving and enhancing the sensory profile of elaborated wines.     

Oak extract application to grapevines as a plant biostimulant to increase wine polyphenols

Oak extract is a mixture of compounds including phenolics (volatiles and non volatiles), which could act as plant biostimulant if they are able to modulate plant physiological response. It is known that it can modify grape volatile composition after the application over grapevines, impacting on wine aroma, but no studies have been carried out on phenolic composition. So, the aim of this work was to evaluate the phenolic composition of wines elaborated from Monastrell grapevines treated with a commercial oak extract in order to study its biostimulant activity. Several families of polyphenols were studied, including phenolic acids, stilbenes, flavanols, flavonols and anthocyanins, which were analyzed by HPLC-DAD-MS. Results showed oak extract could be considered like an important biostimulant of grape polyphenols, since it affected grape composition, producing less alcoholic and acid wines with higher colour intensity, lower shade and so a more stable colour and higher content of polyphenols such as gallic acid, hydroxycynnamoyltartaric acids, acylated anthocyanins, flavanols and stilbenes.     

Polyphenolic composition of Spanish red wines made from Spanish Vitis vinifera L. red grape varieties in danger of extinction

Phenolic composition, chromatic characteristics, and antioxidant activity of young wines made from three minority red grape varieties (Moravia Dulce, Rojal and Tortosí) cultivated in the Spanish region of Castilla-La Mancha were studied over two vintages. Phenolic contents were affected by both grape variety and vintage, whereas phenolic profiles were mainly affected by grape cultivar, thus allowing their differentiation The anthocyanin profiles of Moravia Dulce and Tortosí wines were dominated by malvidin 3-glucoside, whereas peonidin 3-glucoside was in Rojal wines. The flavonol profile of Rojal and, in a lesser extent, Tortosí wines were dominated by B-ring di-substituted flavonols (mainly quercetin-type flavonols). In contrast, B-ring tri-substituted flavonols (mainly myricetin-type) predominated in Moravia Dulce wines. All studied wines had high quantities of total resveratrol, especially Rojal and Moravia Dulce wines, although they mainly occurred as cis-isomers. Rojal wines always appeared as the most different single-cultivar wines in all parameters in this study, being characterized by the lowest content of almost all families of phenolic compounds. With regard to the colour characteristics, all the studied wines had normal values to be considered young red wines except for Rojal wines, which should be considered as rosé wines. Finally, all wines showed remarkable antioxidant activity, closely connected with their phenolic content. The results suggest that Moravia Dulce and Tortosí grape cultivars could be appropriate raw materials for the elaboration of quality young red wines, whereas Rojal grapes could be for rosé wines.     

Effect of heating conditions of grape seeds on the antioxidant activity of grape seed extracts

This study was carried out to evaluate the effect of heating and physical conditions of grape seeds on the antioxidant activity of their extracts. Two forms of grape seeds, whole and powdered forms, were heated at four different temperatures −50, 100, 150 and 200 °C. After heating, grape seeds were extracted with 70% ethanol (0.1 g grape seed/10 mL of 70% ethanol), and total phenol contents (TPC), radical scavenging activity (RSA) and reducing power of the extracts were determined. Thermal treatment of grape seed increased the antioxidant activity of extracts. The maximum TPC and RSA of whole grape seed extract (WGSE) were achieved when the seeds were heat-treated at 150 °C for 40 min, while that of powdered grape seed extract (PGSE) were at 100 °C for 10 min, and were greater than that of the non-treated control. Also, the reducing powers of WGSE and PGSE slightly increased at the conditions. According to the GC-MS analysis, several low-molecular-weight phenolic compounds such as azelaic acid, 3,4-dihydroxy benzoic acid, and o-cinnamic acid were newly formed in the WGSE heated at 150 °C for 40 min. There were slight differences in the kinds of phenolic compounds between non-heated and heated GSE. In HPLC analysis, the contents of gallocatechin gallate and caffeine in GSE significantly increased by heat treatment. These results indicated that antioxidant activity of GSE was affected by heating conditions (temperature and time) and physical conditions of grape seeds at the time of heat treatments.     

Antioxidant activity and phenolic content of 16 raisin grape (Vitis vinifera L.) cultivars and selections

Six raisin grape cultivars and 10 new raisin grape selections were analyzed for antioxidant activity (ABTS assay) and for total and individual phenolic compounds. Samples were freeze–dried and values are reported on a dry weight basis. Antioxidant activity across the 16 samples ranged from 7.7 to 60.9 μmol Trolox/g DW, with A95-27 exhibiting the greatest activity. Total phenolic content, determined in gallic acid equivalents using the Folin–Ciocalteau assay, ranged from 316.3 to 1141.3 mg gallic acid/100 g DW and was strongly correlated (r = 0.990) with antioxidant results. Concentrations of individual phenolics were determined by HPLC. trans-Caftaric acid was the predominant compound in all samples. A95-15 contained the lowest concentration (153.5 μg/g DW) of caftaric acid, while Fiesta contained the highest concentration (598.7 μg/g DW). Selections A56-66, A95-15, and A95-27 had much higher levels of catechin (86.5–209.1 μg/g DW) and epicatechin (126.5–365.7 μg/g DW) than the other samples.     

Impact of Processing Parameters on the Phenolic Profile of Wines Produced from Hybrid Red Grapes Maréchal Foch,Corot noir,and Marquette

Phenolic extraction in hybrid and interspecific wine grape cultivars is poorly understood, especially in terms of the impact of fermentation and enological conditions on condensed tannins and anthocyanins. Following fractionation via solid‐phase extraction and high‐performance liquid chromatography, phenolic profiles of must and wine from red hybrid grape cultivars Maréchal Foch, Corot noir, and Marquette were examined to assess the impact of enzyme and tannin addition, cold soak, and hot press during vinification. Across cultivars, hot press treatments resulted in the greatest extraction of condensed tannin, anthocyanin, and other monomeric phenolic compounds in musts, and treatments that increased skin contact time or cellular degradation during fermentation produced higher concentrations of tannins, anthocyanins, and flavonols. However, these increases were transient, evincing incomplete carryover into finished wines. Depending on initial must extraction, diglucoside forms of anthocyanins were either selectively extracted or selectively retained throughout fermentation when compared to their monoglucoside counterparts. Typical of hybrid grapes, tannin concentrations across cultivars were low, even under hot press conditions. For condensed tannins and anthocyanins, a cultivar‐specific, stable‐state concentration and phenolic profile emerged regardless of fermentation conditions. Due to the high levels of diglucoside anthocyanins and low levels of condensed tannins, it is expected that the color development and profile in these wines produced from hybrid grape cultivars will be dictated by the monomeric anthocyanins and their potential role in copigmentation processes involving other monomeric phenolic species, as opposed to the formation of polymeric color pigments.     

Varietal differences among the phenolic profiles and antioxidant properties of four cultivars of spine grape (Vitis davidii Foex) in Chongyi County (China)

Spine grape (Vitis davidii Foex) is an important wild plant species in South China. To provide sufficient experimental evidence for the strong antioxidant activity of spine grapes, four cultivars from Chongyi County, China, including three red varieties (Junzi #1, Junzi #2, and Liantang) and one white variety (Baiyu) were evaluated. The Junzi #1 had the highest phenolic content (total phenolic, flavonoids, flavanols, and anthocyanins) and the strongest antioxidant capacity (DPPH radical-scavenging capacity, cupric-reducing capacity and hydroxyl radical-scavenging activity) among the four varieties. HPLC analysis of spine grapes revealed that the (+)-catechin was the most abundant phenolics and the hydroxycinnamic acids were the major phenolic acids in the four varieties. Hierarchical cluster analysis showed that the Junzi #1 belongs to the group with high phenolic content and strong antioxidant power. The results suggest the Junzi #1 has the best health promoting properties, and the higher utilization value and potential for development.     

Relationship between wine composition and temperature: Impact on Bordeaux wine typicity in the context of global warming—Review

Weather conditions throughout the year have a greater influence than other factors (such as soil and cultivars) on grapevine development and berry composition. Temperature affects gene expression and enzymatic activity of primary and secondary metabolism which determine grape ripening and wine characteristics. In the context of the climate change, temperatures will probably rise between 0.3°C and 1.7°C over the next 20 years. They are already rising and the physiology of grapevines is already changing. These modifications exert a profound shift in primary (sugar and organic acid balance) and secondary (phenolic and aromatic compounds) berry metabolisms and the resulting composition of wine. For example, some Bordeaux wines have a tendency toward reduced freshness and a modification of their ruby color. In this context it is necessary to understand the impact of higher temperatures on grape development, harvest procedures, and wine composition in order to preserve the typicity of the wines and to adapt winemaking processes.     

Screening of bioactive components in grape and apple vinegars: Antioxidant and antimicrobial potential

Vinegars contain several bioactive compounds that are characterized according to the type of the raw material, such as grape vinegars and apple vinegars. Liquid chromatography coupled to diode array detection and electrospray ionization tandem mass spectrometry was used for identification and quantification of phenolic compounds. Antioxidant properties of vinegars were determined by 2,2‐diphenyl‐1‐picrylhydrazyl and 2,2′‐azino‐bis‐3‐ethylbenzthiazoline‐6‐sulphonic acid assays. Antimicrobial activities of vinegars were examined with an agar disc diffusion method with Staphylococcus aureus , Escherichia coli and Pseudomonas aeruginosa . Gallic acid and chlorogenic acid were found to be the major phenolic acids accounting for the largest proportion of the total phenolic acid contents in grape vinegars and apple vinegars. Within the flavonols, quercetin‐3‐O‐galactoside and quercetin were detected as the major compounds in grape vinegars. Apple vinegars were characterized by phloridzin, phloretin and high chlorogenic acid content. Antimicrobial activity results indicated that grape vinegars exhibited higher antimicrobial activity against tested bacterial strains correlated with their higher antioxidant capacity. Copyright © 2017 The Institute of Brewing & Distilling