Differences of the Components of Tannin among Three Types of Persimmon Fruits and Characteristics of Tannin from ‘Luotian Tianshi’

A study was conducted to clarify the seasonal changes in components of tannin and the relationships between the differences in tannin and fruit astringency of cultivars. Pollination constant non astringent type cultivars had high level of catechin((+)-C)which declined rather slowly during fruit development compared with that in pollination variant nonastringent(PVNA)and pollination constant astringent(PCA)type cultivars. The contents in PCNA cultivars was as 3.89 times as that in other type cultivars toward late September. PCNA type cultivars contained only 28.7 mg·kg-1 FW gallic acid(GA)which was 6.70 and 3.23 times lower than PCA and PVNA type cultivars respectively on June 25. Gallcatechin(GC)changed in different type cultivars similarly with GA and trended to disappeared in PCNA type cultivars after late June.The ratio of the area of tannin cell to parenchymatous cell was only 0.044 in ‘luotian tianshi’ fruits which was almost the same as that in PCNA type cultivars while it reached 0 147 in PCA and 0.083 in PVNA type cultivars. At the same time ‘luotian tianshi’ had high level of both(+)-C and GA which reached 162 mg·kg-1 FW and 149 mg·kg-1 FW respectively instead of only(+)-C in PCNA or GA in PCNA type cultivars. The cotent of water soluble tannin(3.8 g·kg-1 FW)was remarkably lower than PCA type cultivars(31.5 g·kg-1 FW),but it was higher than PCNA type cultivars(0.65 g·kg-1 FW). These results showed that ‘luotian tianshi’ was different from Japanese PCNA type cultivars to some extent.