Abstract
Experimental model glass chambers and a large apparatus to handle about ten tons of fruit at a time were constructed to study the removal of astringency from persimmon fruits (Diospyros kaki Thunb. cv. Hiratanenashi) by using ethanol and carbon dioxide together or alone.
Results with glass chambers revealed that astringency was removed slightly faster because more ethanol and acetaldehyde accumulated in the fruit flesh when the treatment combined ethanol and carbon dioxide rather than with either reagent alone. The loss of astringency was almost entirely due to the effects of carbon dioxide. When fruits were treated with either ethanol or carbon dioxide before the other reagent was used, the loss of astringency was mainly due to the effects of carbon dioxide. Flesh firmness decreased slightly during treatment more so in fruits treated with both reagents than in those treated with carbon dioxide alone.
Our results with large apparatus showed that the removal of astringency was again mainly due to the effects of carbon dioxide and the rate of flesh softening was somewhat hastened when ethanol was added before the carbon dioxide treatment, as was observed with small glass chambers.
