柿单宁研究进展

Research progress of Kaki tannin

概述了柿单宁的定义、分类和功能作用.阐述了柿单宁的特性、主要组成、分子结构及柿果在生长成熟、脱涩和加工过程中单宁的存在方式和运动变化规律的研究进展.柿单宁主要由儿茶素、儿茶素-3-酸、儿茶素和儿茶素-3-酸四种单体组成,通过C-4、C-6或C-8位相连接可聚合成高聚物.涩柿果实在生长、成熟中单宁细胞体积变大,数量增多,单宁含量增加.脱涩中单宁细胞收缩,单宁由低聚物变成高聚物,涩味消失.在加工中返涩的主要原因是由于柿单宁从无涩味的高聚物水解变成了有涩味的低聚物.

The definition, classification and health function of kaki tannin were outlined and the properties, composition and molecular structure of kaki tannin were summarized in the article. The changing regularity and existence of kaki tannin in the persimmon fruit growing, removing astringency and processing were reviewed. The kaki tannin is composed of epiatechin, catechin-gaUate, gallocatechin and gallocatechin-gallate by C-4, C-6 or C-8 polymerizing high polymer. The volume of kaki tannin cells become bigger, the number of them increased and the content of kaki tannin rose during the growing and ripping of persimmon fruit. While removing the astringency, the tannin cells shrieked and the kaki tannin changed from oligomer into high polymer, then astringency disappeared; The reason of reastringency during the processing is that kaki tannin hydrolyzed from non-astringent high polymer to astringent oligomer.