Abstract
In order to control blackening of pericarp during removal of astringency in kaki fruits y ethanol treatment, super-absorbent polymer sheets were applied, using Hiratanenashi, ne of the principal varieties of astringent cultivars in Japan.
1. By adding 38%(V/V) ethanol solution to the super-absorbent polymer sheet B that had igh absorbing ability, both the rate and the degree of blackening of pericarp were arkedly reduced, compared with the control treatment, spraying of 38%(V/V) ethanol olution alone. However, the blackening of pericarp of the highest kaki fruits was not educed.
2. Blackening of pericarp was not reduced by employing the super-absorbent polymer heet hat had a lower absorbing ability or spraying 38%(V/V) ethanol solution to the uper-absorbent polymer sheet B that had a high absorbing ability.
3. Blackening was not prevented by employing the super-absorbent polymer sheet B in a ase of corrugated cardboard that was closed up more tightly than the ordinary one.
4. When 38%(V/V) ethanol solution was absorbed into the super-absorbent polymer sheet, he astringency disappeared slowly, compared with ordinary spraying.
5. It was suggested that the effect of the super-absorbent polymer sheet B having a igh bsorbing ability on the control of blackening of pericarp was due both to the proper oncentration of gaseous ethanol, so that 38%(V/V) ethanol solution came in contact with he pericarp of persimmon, and to the prevention of high humidity conditions in the orrugated cardboard.
