INRA, UE1117 Vigne et Vin, UMT Vinitera, F-49070 Beaucouzé, France.
Anal Chim Acta. 2012 Jun 30;732:91-9. doi: 10.1016/j.aca.2012.02.013. Epub 2012 Feb 27.
Phenolics are responsible for important sensory properties of red wines, including colour, astringency, and possibly bitterness. From a technical viewpoint, the harvest date and the maceration duration are critical decisions for producing red wine with a distinctive style. But little is known about the evolution of phenolics and of their extractability during ripening to predict the composition of the wine and related sensory properties. The aim of this study was to understand the relationship between the sensory profile of the wines and (i) the ripening stage of the berries (harvest date) and (ii) the extraction time (maceration duration). Phenolic acids, flavonols, anthocyanins and proanthocyanidins of Vitis Vinifera var. Cabernet franc were measured in grapes and in wines from two stages of maturity and with two maceration durations. Phenolic composition was analysed by high performance liquid chromatography, after fractionation and thiolysis for proanthocyanidins. The distinctive style of wines was investigated by descriptive analysis (trained panel), Just About Right profiles and typicality assessment (wine expert panel). Relationships between phenolics and sensory attributes were established by multidimensional analysis, and phenolics were classified according to sensory data by ANOVA and PLS regressions. Astringency, bitterness, colour intensity and alcohol significantly increased with ripening and astringency and colour intensity increased with maceration time. Grape anthocyanins increased and thiolysis yield significantly decreased with ripening. In wine, proanthocyanidins increased, and mean degree of polymerisation and thiolysis yield decreased with longer extraction time. The high impact of harvest date on the sensory profiles could be due to changes in anthocyanin and sugar contents, but also to an evolution of proanthocyanidins. Moreover, proanthocyanidin composition was affected by maceration time as suggested by the decrease of thiolysis yield. Our results suggest that the wine sensory quality established by the expert panel, is linked as expected to grape quality at harvest, reflected by sugar and anthocyanin contents, but also by thiolysis yield, which requires elucidation.
酚类物质是红葡萄酒重要感官特性的成因，包括颜色、涩味和可能的苦味。从技术角度来看，采摘日期和浸渍时间是生产具有独特风格的红葡萄酒的关键决策。但是，对于酚类物质在成熟过程中的演变及其可提取性知之甚少，无法预测葡萄酒的成分和相关感官特性。本研究的目的是了解葡萄酒的感官特征与（i）浆果成熟阶段（采摘日期）和（ii）提取时间（浸渍时间）之间的关系。测定了赤霞珠葡萄和两种成熟度的葡萄酒中的酚酸、黄烷醇、花青素和原花青素。采用高效液相色谱法，对原花青素进行了分离和硫解分析。通过描述性分析（训练有素的小组）、恰到好处的轮廓和典型性评估（葡萄酒专家小组）研究了葡萄酒的独特风格。通过多维分析建立了酚类物质与感官属性之间的关系，并通过方差分析和 PLS 回归，根据感官数据对酚类物质进行了分类。涩味、苦味、颜色强度和酒精含量随成熟度的增加而显著增加，涩味和颜色强度随浸渍时间的增加而增加。葡萄中的花青苷含量增加，硫解产率显著降低。在葡萄酒中，原花青素增加，聚合度平均值和硫解产率随提取时间的延长而降低。采摘日期对感官特征的高影响可能是由于花青素和糖含量的变化，但也可能是由于原花青素的演变。此外，正如硫解产率降低所表明的那样，浸渍时间对原花青素的组成有影响。我们的结果表明，专家小组建立的葡萄酒感官质量与葡萄质量相关，反映在糖和花青素含量上，但也与硫解产率有关，这需要进一步阐明。
