Factors influencing sensory quality in red wines of the variety Aghiorghitiko (Vitis vinifera L.) from Nemea

Sensory quality in wines from the indigenous Greek cultivar Aghiorghitiko of Nemea, in 2 years, was studied with multivariate modelling. The appearance, aroma and oral attributes were assessed separately using rank-rating in 13 red Nemea wines, dominated (10 of 13) by Aghiorghitiko, and headspace congeners (51) quantified by solid phase microextraction with gas chromatography. Partial least squares regression (PLS) and discriminant PLS studied relationships between sensory data and congeners, viticultural and oenological data, producers and influence of wood maturations, respectively. Principal component analysis (PCA) spaces for aroma (11 attributes; 64% variance, 3 PCs), congeners (51; 72%, 7 PCs) and oral characters (13 attributes; 77%, 3 PCs) showed similarities in product clustering. Modelling showed clear relationships between sensory character and plant density, wood maturation and producer, respectively. Sensory characters in Aghiorghitiko wines were primarily differentiated by oak maturation and producer influences. A part of the results of this work was presented at the Second International Symposium on the Evaluation and Exploitation of Grapes of Corresponding Terroir through Winemaking and Commercialisation of Wines, 1–3 June 2006, Santorini.     

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.     

成熟度对红地球葡萄品质的影响

目的比较不同成熟度对红地球葡萄(VitisviniferaL.)品质的影响。方法采用国家标准方法,对不同成熟度(盛花后88～123d)红地球葡萄的外观品质和内在营养品质进行比较分析。结果红地球葡萄的外观品质随着采摘期变化而变化,但是果形指数均维持在1.13以上,组间差异不显著(P0.05)。红地球葡萄果实中纤维、灰分、可溶性固形物(soluble solids, SS)、还原糖、蔗糖、抗坏血酸(ascorbic acid, ASA)和磷含量随采摘期延长而增加(P0.05),而水分和总酸的含量显著下降(P0.05)。Ca、Fe、Mg和K含量呈现先降后升趋势,组间均存在显著性差异(P0.05)。过熟期葡萄Ca、Fe含量显著低于始熟期(P0.05),而Mg、P、K含量则显著低于始熟期(P0.05)。矿物质的含量顺序为:KPMgCaFe; P、Ca、Fe含量均与单果重、总酸之间具有较强的线性关系。水分、纤维、灰分、可溶性固形物、还原糖、蔗糖、总酸和抗坏血酸两两间也具有较强的线性关系。结论不同成熟度红地球葡萄外观品质变化不显著(P0.05),但组间内在营养差异显著(P0.05)。研究结果可为红地球葡萄的开发使用提供理论参考。     

A study of antioxidant properties of some varieties of grapes (Vitis vinifera L.)

Grapes (Vitis vinifera L.) are a major fruit crop in the world. Grapes seem to confer health benefits due to their antioxidant activity. We have evaluated the antioxidant potential of 11 grapes varieties from India and nearby Asian countries. The assays employed involve different levels of antioxidant action like ferric reducing antioxidant power, radical scavenging by 1,1-diphenyl-2-picrylhydrazyl, ferrylmyoglobin/2,2'-azobis-3-ethylbenzthiazoline-6-sulfonic acid, oxygen radical absorbance capacity (ORAC), and inhibition of lipid peroxidation. The total phenolic and flavonoids contents were also estimated. Our study indicates that cv. Mango is the most potent followed by Sharad Seedless. Ethanolic extracts were found to be more effective than aqueous extracts. Cv. Sharad Seedless, Mango, and Manikchaman also had high ORAC values. Their HPLC analysis showed the presence of various antioxidant polyphenols. In conclusion our studies identified some varieties of grapes with high antioxidant activities and showed that their high antioxidant potential may be due to their phenolic and flavonoid contents.     

Determination of certain quality characteristics,thermal and sensory properties of ice creams produced with dried Besni grape (Vitis vinifera L.)

In this study, the effect of adding dried Besni grape (BG) at different concentrations on the physico‐chemical characteristics, colour values, total phenolic and flavonoid contents, glass transition (), melting (), freezing (T_f) and melting (T_m) point temperatures, and sensory properties of ice creams was investigated. Generally, the addition of BG caused a statistically significant (P < 0.01) increase in total solids, ash, fat, viscosity, first dripping times, complete melting times and a* colour values, while it decreased protein, pH, overrun, L*, b*, , , T_f and T_m values. The colour scores of ice cream samples showed a statistically significant increase (P < 0.05) with the increment of BG concentration, while the effects of BG addition on texture, resistance to melting, flavour, gumming structure and overall acceptability scores were not statistically significant.     

Antioxidant and antimicrobial potentials of Serbian red wines produced from international Vitis vinifera grape varieties

BACKGROUND: Antioxidant and antimicrobial potentials of Serbian red wines produced from different international Vitis vinifera grape varieties and their correlation with contents of phenolic compounds were studied by spectrophotometric and chromatographic methods. The antioxidant activity of red wines was estimated through their ability to scavenge 2,2′‐diphenyl‐1‐picrylhydrazyl free radical (DPPH^?). The red wines, gallic acid, (+)‐catechin and quercetin were screened in vitro for antimicrobial activity against Gram‐positive and Gram‐negative strains using microdilution and disc diffusion techniques. RESULTS: Excellent correlations between the contents of quercetin‐3‐glucoside (R² = 0.9463) and quercetin (R² = 0.9337) and DPPH^?‐scavenging ability of the red wines were found. Serbian red wines exhibited significant activity against Staphylococcus aureus, Listeria inocua, Micrococcus flavus, Sarcina lutea, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Salmonella enteritidis and Shigella sonnei strains, which was in correlation with their phenolic composition and antioxidant activity. The compounds gallic acid, quercetin and (+)‐catechin showed high activity against B. subtilis, S. aureus, S. lutea and M. flavus Gram‐positive and S. enteritidis and P. aeruginosa Gram‐negative strains. CONCLUSION: The results show that quercetin‐3‐glucoside and quercetin concentrations can be used as markers for the determination of antioxidant and antimicrobial potentials of red wines. Copyright © 2012 Society of Chemical Industry     

吡效隆和赤霉素对红双味葡萄果实膨大及品质的影响

以四川地区栽培的红双味葡萄为试材,在盛花期进行一次处理,研究不同浓度毗效隆(CPPU)和赤霉素(GA3)对其果实膨大和品质的影响.结果表明:经药剂处理后红双味葡萄果拉大小和品质都发生了一定程度的变化,各处理都能使其果粒得到显著膨大.从综合性状来看,红双味葡萄药剂处理的最佳浓度为CPPU l0mg/L + GA3 100m/L.     

Sensory and chemical characterisation of the aroma of Prieto Picudo rosé wines: The differential role of autochthonous yeast strains on aroma profiles

This study evaluates the specific impact of isolated yeast strains on the aromatic profile of fermented musts from Prieto Picudo, an autochthonous Castilla y León (Spain) red grape variety with an increasing demand in the local marketplace. For this purpose, the aroma profiles of wines elaborated from Prieto Picudo grapes have been studied by sensory analysis, gas chromatography–olfactometry (GC–O) and gas chromatography–mass spectrometry (GC–MS), with the aim of determining the potential of each strain to generate distinctive varietal and fermentation-derived aromatic compounds. The results have shown that the yeast strain exerts a critical influence on the levels of some fermentative (linear and branched ethyl esters, fatty acids, ethyl phenylacetate) and varietal compounds (4-mercapto-4-methyl-2-pentanone, 3-mercaptohexylacetate, β-damascenone), thus inducing a deep influence on the final aroma of the wine. Combination of both sensory and chemical data arises as a major tool to monitor the different patterns of aroma release and formation from selected yeast strains during the winemaking process.     

Susceptibility of 44 grapevine (Vitis vinifera L.) varieties to downy mildew in the field

Background and Aims: Downy mildew, which occurs worldwide, is one of the most destructive of all grapevine diseases. Several authors have examined the host–pathogen interaction in different Vitis species, crosses and hybrids, but only a few studies comparing this in true V. vinifera varieties have been undertaken. The aim of the present study was to examine the in‐field susceptibility to infection by Plasmopara viticola, the causal agent of downy mildew, of 44 grapevine varieties, all belonging to the collection of the Misión Biológica de Galicia. Methods and Results: Over a period of 2 years, the incidence and severity of downy mildew on the leaves and clusters of all 44 varieties was determined using a visual scale. Some of those examined showed high susceptibility (Chenin Blanc, Albariño and Prieto Picudo), others showed low susceptibility (Silveiriña, Caiño Bravo, Follajeiro and Brancellao Blanco), and still others showed intermediate susceptibility. Some varieties showed high disease incidence but low disease severity and vice versa. No significant correlation was detected between disease incidence and severity in either leaves or clusters, nor indeed between leaves and clusters. Neither berry colour, cluster compactness nor any other studied variable bore any clear relationship with susceptibility. Conclusion: The different grapevine varieties examined showed great variation in terms of their susceptibility to downy mildew. The susceptibility of most varieties was the same in both study years. Significance of the Study: The results of this work could help provide new material that might be of use in grapevine genetic improvement programs, and in the study of resistance to downy mildew. The selection of old varieties from the Iberian northwest may contribute towards the growth of organic viticulture in this area and even other winemaking regions around the world.     

Characterization of Polish Wines Produced from the Multispecies Hybrid and Vitis vinifera L. Grapes

Phenolic profile, antioxidant activity, and color parameters of Polish wines, produced from the multispecies hybrid and Vitis vinifera L. grapes were analyzed. A principal component analysis was applied, in order to differentiate the investigated wines in terms of content of phenolic compounds. The white wines turned out to be similar to each other in terms of color parameters and the results of principal component analysis, while the red wines strongly differed in this respect. However, the white wine produced from the multispecies hybrid grapes contained a higher level of phenolic acids and flavonoids, as compared to the white wines obtained from the hybrid cultivars. Out of the red wines, Rondo wine, produced from the multispecies hybrid grapevine was the richest in total phenolic and phenolic acids content. Caffeic acid and quercetin were the predominant phenolics in majority of the wines tested.     

Effects of mechanical thinning on fruit and wine composition and sensory attributes of Grenache and Tempranillo varieties (Vitis vinifera L.)

Background and Aims: Cost-effective yield control is required by the wine industry in order to reduce the existing worldwide wine surplus and to improve grape quality. The object of this study was to evaluate the chemical and sensory effects on the resulting wines of mechanical cluster thinning performed at different intensities on Grenache, and at different timings (pea size and veraison) on Tempranillo. Methods and Results: The experiments were conducted with a machine harvester in 2007 on two commercial vertical shoot-positioned vineyards in Spain's Rioja region. In both varieties, mechanical thinning was effective in yield reduction and resulted in more ripened fruit, and wines with higher alcohol and pH values, more intense colour and increased phenolic content. Regardless of the thinning intensity, sensory changes were less noticeable in Grenache than in Tempranillo wines. Of the latter, those from vines thinned during veraison were less aromatic and sour, but had increased astringency. Conclusions: Yield management through mechanical thinning induced changes to the chemical composition of fruit and wines as well as to the wines' aroma, taste and mouthfeel. The extent of the sensory implications seems to depend on several factors such as the variety and timing of thinning application. Significance of the Study: This is one of the first studies addressing the effects of mechanical thinning on the sensory properties of the resulting wine and has implications for viticultural management practices.     

Quality response of table grapes (Vitis vinifera L.) during cold storage to postharvest cap stem excision and hot water treatments

Berry quality, total phenol, sensory characteristics and decay incidence of grapes (V. vinifera cvs. Mü?küle and Red Globe) as affected by prestorage hot water immersion with or without cap stem excision treatments were investigated with 7‐day interval during storage at 1 °C for 21 days. Weight loss occurred mainly up to the second week and was more pronounced for the untreated control samples subjected to the stem excision. In Mü?küle, the least weight loss value was obtained from hot water–treated grapes (0.62%), while the highest loss occurred in control grapes of stem‐excised berries (0.96%). Immersion of stem‐retained grapes in hot water was the best applications for maintenance of overall storage quality for both cultivars. According to panellist scores, it is evident that hot water has positive effect on maintaining the minimally processed table grapes without altering the flavour and taste of the commodity. Stem‐retained berries of hot water treatment had the highest score for both Mü?küle and Red Globe, with their values 3.8 and 4.2, respectively, while the least values were obtained from stem‐excised berries of untreated control group of both the cultivars (1.9 and 3.0, respectively). At the end of three‐week storage, the least decay rates were determined in stem‐retained berries that received hot water treatment (5.3% for Mü?küle and 1.1% for Red Globe). Attenuate influence of brief high temperature exposure on ripening parameters (SSC, TA, MI, pH) was also observed. Postharvest hot water treatment may be used as a nonchemical means to extent storage life of minimally processed grapes with its alleviating effect on physiological disorders. Cap stem retaining in minimal processing can be recommended to maintain the quality of grapes.     

Effects of defoliation on quality attributes of Nero di Troia (Vitis vinifera L.) grape and wine

Field studies were conducted in Puglia (Italy) to evaluate the influence of defoliation around cluster zones on grape and wine quality. Nero di Troia grapes were subjected to four different treatments: N: no leaf removal; E: leaf removal in the area of the clusters along the east side (at complete veraison); E/W: leaf removal in the area of the clusters along the east and west side (at complete veraison); and F: almost complete leaf removal along the west side (at complete veraison) and at pre-harvest also along the east side. Grapes of defoliated vines generally showed higher sugar content, lower titratable acidity, total flavonoids, flavonoids different from anthocyanins, and total phenolic content than grapes from non-defoliated vines while their total anthocyanin concentration was not affected by defoliation at a significant level. Concerning wines, alcohol content, residual soluble solids, different forms of anthocyanins but also volatile acidity were generally higher in samples from defoliated vines. Differences were also highlighted among the defoliation treatments: the best results in terms of dry matter, sugar and alcohol content were observed in the samples submitted to the more severe defoliation as a consequence of the higher light availability and berry temperature. Concerning the concentration of the individual phenolics, significant differences were highlighted for: caffeic and caftaric acids, peonidin- and malvidin-3-p-coumaroylglucoside, which were higher in the E wines; quercetin-3-glucoside, galactoside, and rhamnoside, and procyanidins, which were higher in F wines.