Dipartimento Colture Arboree, Università di Torino, via L. da Vinci 44, 10095 Grugliasco (TO), Italy.
J Agric Food Chem. 2012 May 16;60(19):4931-45. doi: 10.1021/jf2045608. Epub 2012 May 4.
The diversity of berry skin flavonoids in grape genotypes has been previously widely investigated with regard to major compounds (nonacylated anthocyanins and flavonols), but much less with regard to acylated anthocyanins and hydroxycinnamoyl tartrates (HCTs). In this study, the composition of the phenolic fraction of the berry skin (free and acylated anthocyanins, flavonols, and HCTs) was assessed on 34 grapevine genotypes grown in a collection vineyard in northwestern Italy. The phenolic fraction was profiled on berries collected in the same vineyard, at the same ripening level across two successive vintages. The anthocyanin, HCT, and flavonol profiles were specific of each genotype, and the first two were relatively little affected by the vintage. A wide diversity in the polyphenolic fraction was shown among cultivars. Besides expected discriminatory effects of free anthocyanins and flavonol profiles, principal component analyses allowed a good discrimination of cultivars on the basis of coumaroylated anthocyanins and of the HCT profile. Anthocyanins were mostly acylated by aromatic acids, and acylation was independent from the anthocyanin substrate. HCTs were present mostly as coumaroyl and caffeoyl derivatives, and no correlation was observed between the same acylation patterns of tartrate and of anthocyanins. The results of this study are discussed in the light of new hypotheses on still unknown biosynthetic steps of phenolic substances and of the potential use of these substances in discrimination and identification of different grape cultivars in wines.
先前已经广泛研究了葡萄基因型浆果果皮类黄酮的多样性，主要涉及主要化合物（酰化的花青素和黄酮醇），但对酰化的花青素和羟基肉桂酰基酒石酸盐（HCTs）的研究则较少。在这项研究中，对意大利西北部一个收藏葡萄园种植的 34 个葡萄品种的浆果果皮酚类部分（游离和酰化的花青素、黄酮醇和 HCTs）的组成进行了评估。在两个连续年份的相同成熟度下，在同一葡萄园收集浆果时，对酚类部分进行了分析。花青素、HCT 和黄酮醇的图谱是每个基因型特有的，前两种图谱受年份的影响相对较小。品种间多酚部分表现出广泛的多样性。除了游离花青素和黄酮醇图谱的预期鉴别作用外，主成分分析还允许根据香豆酰化花青素和 HCT 图谱对品种进行很好的区分。花青素主要被芳香酸酰化，酰化与花青素底物无关。HCTs 主要以咖啡酰基和肉桂酰基衍生物的形式存在，并且在酒石酸盐和花青素的相同酰化模式之间没有观察到相关性。本研究的结果根据关于酚类物质未知生物合成步骤的新假设以及这些物质在葡萄酒中不同葡萄品种的鉴别和鉴定中的潜在用途进行了讨论。
