Comparison of insolubility of tannins induced by acetaldehyde vapor in fruits of three types of astringent persimmon

In relation to fruit development, we examined the differences in the degree s of insolubility of soluble tannins by acetaldehyde vapor treatment in the fruits of three types of astringent persimmon (Diospyros kaki Thunb.); pol lination-variant and astringent (PVA) type, pollination-constant and astrin gent (PCA) type, and pollination-variant and nonastringent (PVNA) type with a small number of seeds. Insolubilibed tannins in the flesh cubes of these three types of persimmon fruit after acetaldehyde vapor treatment at three stages of fruit development Similarly became soluble by extraction with HC l-MeOH, irrespective of the fruit type and maturity. These results confirm that the ease of removing astringency in all of the three types of astringe nt persimmon may depend on the amount of acetaldehyde accumulated in the fl esh.