Temperature Affects Astringency Removal and Recurrence in Persimmon

Astringency was removed from‘Triumph’persimmons by immersion in water at 40°C for 5 hr or 60°C, for 1 hr. Similar treatments at 20° and 80°C, had no effect on astringency reduction. Subsequent application of 80% CO 2 for 48 hr was effective for 20°C‐treated fruit but not for 80° C‐treated fruit, which became nonastringent only after exposure to acetaldehyde. Extending the 60°C treatment beyond 2 hr resulted in recurrence of astringency, which was not reduced by subsequent CO 2 treatment. Astringency also recurred in CO 2 ‐treated non‐astringent fruit, when exposed to high temperatures. The disappearance and recurrence of astringency correlated with amount of methanol‐soluble tannins.