关键词: 葡萄, 种子, 代谢组学, 代谢物, 酚类, 脂类

Abstract:

【Objective】 Grape seeds have high bioactivity because they are rich in many metabolites. The objective of this study was to comprehensively identify the metabolite components in grape seeds, to compare and to analyze the differences of metabolites among different varieties, and to explore the relationship between metabolites in grape seeds and skin color and variety origin, so as to provide a reference basis for further development and utilization of grape seeds. 【Method】 The mature seeds of purple-skinned Kyoho (V. labruscana: V. labrusca × V. vinifera, JFS), pink-skinned Wink (V. vinifera, WKS), and yellow-skinned Italia (V. vinifera, YDS) were used for widely targeted metabolomics analysis by UPLC-MS/MS. The metabolites were identified and compared by multivariate statistical methods. 【Result】 The quality of metabolomics data was good, and the data of samples within groups was repetitive and the differences in the data of samples among groups were existed. A total of 514 metabolites were identified in the seeds of three grape varieties, including 6 primary metabolites, such as amino acids and lipids, and 20 secondary metabolites, such as proanthocyanidins and resveratrol. Among different varieties, the metabolite components were similar but the metabolite contents were significantly different. The relative contents of most metabolites were high in the dark variety Kyoho, followed by the light variety Wink, but low in the colorless variety Italy, indicating that the metabolite contents in grape seeds might be positively correlated with the skin color. The relative contents of metabolites in the seeds of Wink and Italia were similar, while they were greatly different from those of Kyoho, indicating that the metabolite contents in grape seeds might be related to the variety origin. The differential metabolites among different varieties were mainly involved in phenylpropane biosynthesis, anthocyanin synthesis, lipid metabolism, etc. pathway. There were many phenolic compounds in the differential metabolites and the metabolites with the large difference were mainly flavonoids. Grape seeds were rich in phenols and lipids. In addition to monomeric flavane-3-ols and their polymers, the relative contents of other phenolic compounds such as flavones and flavonols were also high. There was no significant difference in the relative contents of resveratrol among the three varieties. The relative contents of glyceryl phosphatide such as lysophosphatidylcholine were high, while those of linolenic acid were low. There was little difference in the relative contents of lipids among different varieties. 【Conclusion】 The metabolite components in grape seeds of different varieties were similar, while the metabolite contents were related to the skin color and the variety origin. Phenols and lipids were important components of metabolites in grape seeds and could be used as good sources for food and other processing industries.

Key words: grape (Vitis vinifera), seed, metabolomics, metabolite, phenol, lipid