嘉峪关地区不同成熟度‘佳美’葡萄理化成分的研究

Physic-chemical components of Gamay grape at different maturity stages in Jiayuguan

【目的】研究‘佳美’葡萄果实成熟期间葡萄皮和葡萄籽中理化成分及其相关性,为该地区‘佳美’葡萄成熟度的监控提供参考。【方法】以‘佳美’葡萄为试材,于不同的成熟度(采收日期08-19,08-26,09-02,09-09)采收取样,用模拟葡萄酒溶液分别提取葡萄皮和葡萄籽中的多酚,研究不同成熟度下葡萄皮和葡萄籽中的总酚、黄酮、总黄烷醇和单宁含量的差异,并对不同成熟度葡萄理化指标之间的相关性进行分析。同时利用主成分分析,对不同成熟度葡萄品质进行研究,确定嘉峪关地区‘佳美’葡萄的最佳采收期。【结果】随着成熟度的增加,‘佳美’葡萄的还原糖、糖酸比逐渐升高,总酸质量浓度逐渐降低。葡萄皮中的总酚、黄酮和总黄烷醇含量先上升后下降,单宁含量先下降后上升。葡萄籽中的总酚、黄酮、总黄烷醇和单宁含量均呈先下降后上升趋势。不同成熟度葡萄理化指标的相关性分析表明,葡萄皮中的总酚与总黄烷醇呈显著正相关,与葡萄籽总酚之间呈显著负相关,并且葡萄皮中的黄酮与葡萄籽中的黄酮、总黄烷醇和单宁之间均呈显著负相关,葡萄皮总黄烷醇与葡萄籽单宁含量之间呈显著负相关,葡萄籽黄酮、单宁和总黄烷醇含量之间呈极显著正相关。不同采收期葡萄果实品质排序为09-09>09-02>08-26>08-19。【结论】葡萄果皮多酚含量显著升高,而葡萄籽中多酚含量显著降低,且不同采收期葡萄籽中的多酚均高于葡萄皮。嘉峪关地区‘佳美’葡萄的最佳采收日期在09-09前后。

【Objective】The physic-chemical components and correlation between them were studied during ripening process of Gamay grape to provide reference for determining grape maturity.【Method】This work studied the differences in contents of total phenols,flavonoids,flavan-3-ols and tannins in skins and seeds of Gamay grape at different maturity stages（harvest dates 08-19,08-26,09-02,and 09-09）.The components were extracted with 12%ethanol solution.The correlations between components were studied,and the optimal harvest time was determined using principal component analysis.【Result】With the increase of maturity,contents of reducing sugar and reducing sugar/total acid increased,while content of total acid decreased.The contents of total phenols,flavonoids and flavan-3-ols in skins firstly increased before decreasing,while tannin content firstly decreased and then increased.The contents of total phenols,flavonoids,flavan-3-ols and tannin in seeds were firstly decreased and then increased.The total phenols hadapositive correlation with flavan-3-ols in skins and a negative correlation with total phenols in seeds.The flavonoids in skins had negative correlations with flavonoids,flavan-3-ols and tannin in seeds.There was a negative correlation between flavan-3-ols in skins and tannin in seeds.Flavonoids,tannin and flavan-3-ols in seeds also existed significantly positive correlations.The grape quality was in an order of 09-0909-0208-2608-19.【Conclusion】With the increase of maturity,phenols content in grape skins increased,while that in seeds decreased.The phenols content in grape seeds was higher than in skins.The optimal harvest date of Gamay was about 09-09.