On the Foul Smell of Kaki-Shibu

Abstract

Kaki-shibu, the astringent extract from persimmon fruits which is used for the clarification of sake (rice wine), emits a kind of foul smell. In this study, the sources of this smell have been researched. The volatile organic acid was isolated by steam distillation and ether extraction. Eighteen acids, i.e. formic, acetic, propionic, butyric, isovaleric, valeric, caproic, enathic, pelargonic, and unknowns, were detected from the extract by the gas chromatography. Commercial kaki-shibu contained about 2% of total acid and most of it was volatile. Acetic acid was about 60%, propionic acid about 18%, and butyric acid about 4% of volatile acid. It was found that the volatile acids were produced from sugar in the press juice of persimmon fruits by the organic acid fermentation during early storage period.