Abstract The knowledge of grapes phenolic content is proven to be critical for the vinification process and the improvement of wine quality. This study was undertaken to determine the phenolic composition and to employ the phenolic profile as a varietal discrimination tool in five Greek red grape varieties. Ninety grape samples from two seasons (2017 and 2018) were analyzed after extraction with organic solvents. Their proanthocyanidin profile, expressed as percentages of flavan-3-ols, was determined in both skins and seeds by employing phloroglucinolysis followed by HPLC-UV and MS detection, and anthocyanin profile was identified only in the skin extracts by HPLC-UV. Significant differences were observed in proanthocyanidin and anthocyanin profiles of skin extracts between the samples of different varieties, but not in seeds. (-)-Epicatechin was the main subunit in Mandilaria, Kotsifali, Agiorgitiko and Xinomavro grapes while (-)-epigallocatechin gallate in Mavrotragano. Malvidin-3-O-glucoside was the predominant pigment in all grape samples analyzed with the exception of Kotsifali skin extracts, where peonidin-3-O-glucoside was the most abundant anthocyanin. In addition, Mavrotragano skin extracts were the richest in delphinidin and petunidin-3-O-glucosides, while Agiorgitiko and Xinomavro contained the highest amount of malvidin-3-O-glucoside. The results underline the significance of the skin phenolic composition as a tool for the discrimination of the Greek red grape varieties.

中文翻译：

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根据果皮和种子的花青素和原花青素谱区分五种希腊红葡萄品种

摘要 葡萄酚含量的知识被证明对酿酒过程和葡萄酒质量的提高至关重要。本研究旨在确定酚类成分，并将酚类成分用作五个希腊红葡萄品种的品种鉴别工具。用有机溶剂提取后，对来自两个季节（2017 年和 2018 年）的 90 个葡萄样品进行了分析。它们的原花青素谱，以黄烷-3-醇的百分比表示，在皮肤和种子中通过使用间苯二酚分解法随后进行 HPLC-UV 和 MS 检测来测定，并且花青素谱仅在皮肤提取物中通过 HPLC-UV 进行鉴定。在不同品种的样品之间观察到皮肤提取物的原花青素和花青素谱存在显着差异，但在种子中没有观察到。(-)-表儿茶素是 Mandilaria、Kotsifali、Agiorgitiko 和 Xinomavro 葡萄的主要亚基，而 (-)-表儿茶素在 Mavrotragano 中是没食子酸。Malvidin-3-O-glucoside 是所有分析的葡萄样品中的主要色素，Kotsifali 皮提取物除外，其中 peonidin-3-O-glucoside 是最丰富的花青素。此外，Mavrotragano 皮肤提取物含有最多的花翠素和矮牵牛素-3-O-葡萄糖苷，而 Agiorgitiko 和 Xinomavro 含有最高量的 Malvidin-3-O-葡萄糖苷。结果强调了皮肤酚类成分作为区分希腊红葡萄品种的工具的重要性。Malvidin-3-O-glucoside 是所有分析的葡萄样品中的主要色素，Kotsifali 皮提取物除外，其中 peonidin-3-O-glucoside 是最丰富的花青素。此外，Mavrotragano 皮肤提取物含有最多的花翠素和矮牵牛素-3-O-葡萄糖苷，而 Agiorgitiko 和 Xinomavro 含有最高量的 Malvidin-3-O-葡萄糖苷。结果强调了皮肤酚类成分作为区分希腊红葡萄品种的工具的重要性。Malvidin-3-O-glucoside 是所有分析的葡萄样品中的主要色素，Kotsifali 皮提取物除外，其中 peonidin-3-O-glucoside 是最丰富的花青素。此外，Mavrotragano 皮肤提取物含有最多的花翠素和矮牵牛素-3-O-葡萄糖苷，而 Agiorgitiko 和 Xinomavro 含有最高量的 Malvidin-3-O-葡萄糖苷。结果强调了皮肤酚类成分作为区分希腊红葡萄品种的工具的重要性。