UNIQUE FEATURES OF TANNIN CELLS IN FRUIT OF POLLINATION CONSTANT NON-ASTRINGENT PERSIMMONS

Among the four types of persimmon, the fruit of pollination constant non-astringent (PCNA) cultivars has a different development pattern of tannin cells in the flesh than the other three (PVNA, PNA, and PCA) types.
The development of tannin cells in PCNA types seems to cease at early stages of fruit growth, so that tannin concentration in the flesh gradually decreases with fruit development by dilution.
In order to clarify this difference between PCNA and non-PCNA types, the tannin cell size of 42 cultivars was investigated at fruit maturity in this study.
Tannin cells were collected after EDTA maceration of the flesh, and the areas and both major and minor axes of 100 tannin cells were measured in each cultivar using computer imagery.
Among the 42 cultivars examined, tannin cell sizes of all 15 PCNA cultivars were much smaller than all 27 non-PCNA cultivars.
Even considering the density of tannin cells in the flesh, tannin cells of PCNA fruit occupied much smaller volumes (less than one-fifth on average) per weight of flesh than in non-PCNA cultivars.
These results clearly show that the dilution of tannins is the main cause of natural astringency-loss in PCNA persimmons.

II International Persimmon Symposium

K. Yonemori, A. Ikegami, S. Kanzaki, A. Sugiura

Diospyros kaki, tannin accumulation, Japanese persimmon

https://doi.org/10.17660/ActaHortic.2003.601.3