North American Fruit Explorers mailing list at ibiblio

["Thomas Olenio" <tolenio@sentex.net>]

Hello,

 

Interesting article on astringency;

 

http://www.blackwell-synergy.com/doi/abs/10.1111/j.1365-2621.1993.tb06191.x

 

Temperature Affects Astringency Removal and Recurrence in Persimmon

RUTH BEN-ARIE¹ and LILLIAN SONEGO¹

 ABSTRACT

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% CO₂ 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 CO₂ treatment. Astringency also recurred in CO₂-treated non-astringent fruit, when exposed to high temperatures. The disappearance and recurrence of astringency correlated with amount of methanol-soluble tannins.