红葡萄酒涩感研究进展

涩感是影响红葡萄酒感官质量及内在品质的关键因素。文章参考国内外研究结果,对比分析了红葡萄酒中的涩感物质、涩感产生机理、涩感强度及质量的影响因素、涩感的评价方法,为改善红葡萄酒质量提供参考。红葡萄酒中的涩感物质包括缩合单宁、水解单宁以及有机酸,涩感是由涩感物质和口腔作用引起的一种干燥的、粗糙的、褶皱的,收敛性的触觉,涩感的强度及质量主要取决于单宁的浓度、聚合度、结构特点,此外还受葡萄品种、产区、酿酒方式影响,涩感的评价方法主要有感官评价、化学分析这2大类,这2种方法往往结合使用以获取最佳分析结果。此外,合理选择葡萄原料及酿造方式也是提升红葡萄酒质量的有效方法。     

Red wine astringency: a review

The chemical and physical basis for red wine astringency is reviewed. Models describing the physiological foundation of astringency are presented and compared. The phenolic and other red wine components that evoke astringency are described, together with their sensory properties and the factors that affect their perception. The paper also presents a detailed account of the chemical properties of saliva and the possible modes of interaction between these and red wine phenolics that lead to the necessary physical changes in saliva required to elicit astringency. Reasons for differences in astringency perception across oral sites and amongst individual tasters are also discussed. It is concluded that whilst great advances have been made in the field of red wine phenolic chemistry in recent years, a better understanding of the effect of wine polyphenol-salivary protein interaction on the rheological properties of saliva is required in order to gain a comprehensive understanding of red wine astringency.     

New insight in characterization of red wine astringency using soft tribology method

The variation of friction coefficient (μ) of model wine and model saliva mixtures with entrainment speed (V_R) on simulated oral surfaces was evaluated by oral tribology. Combined with techniques of dynamic light scattering (DLS), atomic force microscopy (AFM), rheometer, and quartz crystal microbalance with dissipation monitoring (QCM-D), the correlation between characteristics of the model wine and model saliva mixtures (particle size and morphology, suspension viscosity, adsorption film thickness, and viscoelasticity) and the oral lubrication loss was established. The results showed that the higher the concentration of tannin in the model wine, the larger the size of the complexes with the model saliva, and the higher the thickness, viscoelasticity, and roughness of the adsorption film formed, which resulted in the increase of friction coefficient in the boundary lubrication regime. Different from previous results, it is found that the maximum value of the friction coefficient (μ_max) in the boundary regime has the best positive correlation with the astringency perception intensity of the model wine accordingly.     

Cabernet sauvignon red wine astringency quality control by tannin characterization and polymerization during storage

Cabernet Sauvignon wine grape variety is an emblematic cultivar of Bordeaux winegrowing region. Twenty-three vintages of Cabernet Sauvignon wines from chateau Mouton Rothschild were studied using chemical and sensory analysis. Total phenolic compounds, total anthocyanins, total tannins, hue, CI (colour intensity), titratable acidity, ethanol level and pH were evaluated. Percentage of galloylation (%G), of prodelphinidins (%P) as well as mean degree of polymerization (mDP) were also determined. Sensory analysis concerning astringency intensity using a 0–7 point scale was performed in parallel. Correlations between bottle wine ageing and mDP and astringency were obtained. Increasing age gave lower scores in astringency intensity (R ² = 0.598, p = 0.000) and inferior mDP values (R ² = 0.851, p = 0.000). In addition, we evidenced that mDP is an analytical parameter for estimating astringency (R ² = 0.556, p = 0.000) in red CS (Cabernet Sauvignon) wine from Pauillac denomination.     

Bitterness and astringency of grape and wine polyphenols

Extracts containing anthocyanins (ACN), and skin tannins (SKIN) and seed tannins (SEED) were prepared from Vitis vinifera cv. Cabernet Franc grapes grown in the Loire Valley, and characterised. Phenolic fractions from Cabernet Franc wines made from three Loire Valley locations were also isolated and characterised. Bitterness and astringency of ACN, SEED and SKIN as well as the wine extracts were evaluated by time intensity procedures in citric acid solution and in a base white wine. SEED and SKIN were equally astringent when tasted at the same concentration in spite of differences in tannin composition. The lower molecular weight (MW) of SEED was equal in astringency to larger MW SKIN which had a lower percentage of galloylation. The SEED fraction was slightly more bitter than the SKIN fraction in the citric acid solution, although no difference could be detected between samples in base white wine. Astringency of ACN alone was much lower than either SKIN or SEED. Addition of ACN to either tannin fraction produced very small sensory effects in citric acid. In wine, addition of ACN to either SEED or SKIN increased astringency significantly over either fraction alone, but had no effect on bitterness. The wine fractions differed only in astringency, which was correlated with tannin units as determined by thiolysis.     

Influence of the elimination and addition of seeds on the colour,phenolic composition and astringency of red wine

Several winemaking techniques have been developed to eliminate seeds to prevent the release of high amounts of very astringent proanthocyanidins, especially when the grapes are unripe. However, there is no scientific information on the effects of this practice. The aim of this paper is to study how the elimination and addition of seeds influence the colour, phenolic composition and astringency of red wine. The elimination of around 80% of the seeds led to a significant decrease of colour intensity and anthocyanin concentration. The addition of seeds originated wines with a greater concentration of total anthocyanin, but did not significantly affect the wine colour. These wines also presented significantly higher levels of proanthocyanidins, a greater proportion of epicatechin-3-gallate, a lower mean degree of polymerization, and, in particular, a drastic increase in astringency. Wines obtained with the elimination of seeds, on the other hand, had exactly the opposite characteristics.     

Integrated rural wine tourism: a case study approach

Using the Niagara Peninsula Appellation as the case study, qualitative research was employed through the use of interviews conducted with wineries and industry associations, in an attempt to answer two specific questions: (1) how does the wine industry and wine tourism aid in the development of Niagara’s rural area using the integrated rural tourism (IRT) concept, and (2) how can IRT aid in rural development through direct, experiential, conservation, development, and synergistic benefits. It is apparent that the seven components of IRT provide a reasonable framework to analyse the ability of IRT to realize benefits, although that the addition of marketing and future needs/desires as components improve its explanatory power. Using the modified IRT framework, this research found that wine tourism has derived direct, experiential, conservation, and synergistic benefits, with work still to be undertaken in order to improve upon tourism’s positive impacts in Niagara and peripherally rural areas more generally in the areas of community engagement and improved industry synergy.     

An assessment of the effects of wine volatiles on the perception of taste and astringency in wine

The objective of this work is measuring the effect of different volatile extract compositions on the perception of taste, astringency, global intensity and persistence of wine. Six Spanish wines, two from Chardonnay and four from Tempranillo grapes, all of them showing different chemical and sensory characteristics, were selected. Wines were separated into volatile and non-volatile fractions by solid phase extraction and lyophilisation and further liquid extraction, respectively. Eighteen “reconstituted wines” were prepared, combining different volatile extracts and different non-volatile matrices and adjusting ethanol content to 12% (v/v), and were further described by a specifically trained sensory panel. Taste attributes (sweetness, acidity, bitterness), astringency, aroma intensity, global intensity and persistence were assessed in both, original and “reconstituted” wines by using a numerical category scale. The sensory properties of the original wines were retained by their corresponding “reconstituted samples”. The sensory assessment of the “reconstituted wines” showed that the addition of volatile fruity extracts from white wines brought about a decrease in astringency and bitterness and an increase in sweet perception in all cases. While global intensity and persistence of white wine matrices were also increased, they did not change in red wine matrices, which suggests that the volatile fraction plays only a secondary role in these attributes of red wines. Similarly, the effects of replacing the volatile fraction of a red wine by volatile extracts from other red wines were small and inconsistent, which confirms that taste and astringency are primarily driven by non-volatile molecules in these wines.     

Measuring perceptions of quality in food products: the case of red wine

Perceived quality in food products is complex and is often operationalized by multi-dimensional constructs, whose measurement requires the designing of sufficiently validated scales. Since the intrinsic characteristics of each individual product are different and the extrinsic attributes can have an effect that differs from expectations, it is necessary to adapt the scale to each considered product. Using an empirical study, we demonstrate that perception of wine quality has a dimensional structure (7 dimensions) and can be measured using a 21-item scale that has been satisfactorily validated. Through the methodology proposed and the operationalization of the items as perceptions minus expectations, we suggest using two different scales for food and beverage products, one for intrinsic attributes and another for extrinsic attributes.     

Insights on the chemical basis of the astringency of Spanish red wines

The main goal of the present study is to provide an insight on the role played by non-volatile molecules on the different in-mouth attributes, particularly astringency. For achieving such goal, the main in-mouth sensory attributes of 34 oaked Spanish red wines were measured by a trained panel. The wine content in 30 sensory-active molecules was analysed by different HPLC based methodologies together with classical enological parameters and two proanthocyanidin indexes. Fourteen compounds (aconitic acids, polymeric proanthocyanidins, caftaric, caffeic and coutaric acids and seven quercetins) were found to be at concentrations above reported taste thresholds and to have a reasonably high range of occurrence. Two highly statistically significant models for astringency were built with those compounds. Even if the models could not be fully validated by sensory addition experiments, the research has demonstrated that wine astringency is driven by polymeric proanthocyanidins and by certain phenolic acids, the rate trans/cis-aconitic acid and flavonol profiles. The research has highlighted the existence of extremely complex interactions between non-volatile compounds on the in-mouth sensory perception. Particularly remarkable is the lack of additivity and potential antagonism found between the pairs cis/trans-aconitic acids, between aconitic and caffeic acids and between quercetin-3-O-galactoside and quercetin-3-O-glucoside. Also remarkable was the sweetness × astringent interaction and the matrix-dependence of the sensory responses elicited by flavonols. These results suggest the need for new paradigms and experimental procedures for fully decoding the real sensory relevance of individual non-volatile compounds in the overall wine flavour.     

葡萄酒中单宁涩感评价及结构分析研究进展

单宁是红葡萄酒中的重要成分,对红葡萄酒的口感、颜色、稳定性等都有着重要的影响。该文介绍了单宁的涩感评价方法（感官评价、蛋白质沉淀法、电子舌）及结构分析方法（色谱技术、核磁共振技术、质谱技术、基质辅助激光解吸附技术）的研究进展,并提出了今后的研究方向。     

Territorial identity as a competitive advantage in wine marketing: a case study

This article presents a case study on territorial identity as a competitive advantage in marketing fine wines. The study is centred on three renowned Tuscan local wine systems strongly oriented towards quality and well-established on international markets. The survey aimed at understanding difficulties faced by these local systems in the UK market. An explorative ‘case study’ approach was adopted, aimed at supplying analytical dimensions useful in ‘framing’ a marketing problem to be solved. Experts and key informants were interviewed about their opinions and perceptions on the case study both in the production area and in the UK. Most of the problems faced when marketing the wines considered in this study may be described as a failure to join with the conventional definition of quality that is relevant to the British market. According to the proposed interpretation, a strong territorial identity is a necessary ingredient, but alone is an insufficient condition to build a competitive advantage. The proposed interpretation suggested a set of possible actions at the territory level to exploit economies of concerning market intelligence, marketing approach and collective communication.     

分光光度法测葡萄酒的色度

本文探讨了用分光光度计葡萄酒色度的方法及注意的问题。红葡萄酒的色度可用其在420nm，520nm,620nm下的吸光值之和表示，但是直接测其吸光值和稀释液，其结果不同，应根据吸光值的范围来决定使用方法；另外，葡萄酒色度还受pH影响，随着pH增大，色度值也增大。     

菊花红葡萄酒的研制

用酿制的红葡萄酒与菊花浸提液、蔗糖及柠檬酸进行调配试验,制得一种既具有菊花药用和香味,又具有传统葡萄酒特色,营养及口感俱佳的新型葡萄酒。其配方为红葡萄酒70%,菊花液15%,蔗糖10%,柠檬酸0.15%。