Changes in sugar, organic acid contents and characteristics of kaki-shibu during fermentation

• Published in: Engei Gakkai zasshi Vol. 70; no. 1; pp. 95 - 101
• Main Authors: Imai, K. (Osaka Prefectural Univ., Sakai (Japan). Coll. of Agriculture), Shiozaki, S, Tsuda, T, Nakao, Y, Ogata, T, Horiuchi, S
• Format: Journal Article
• Language: Japanese; English
• Published: THE JAPANESE SOCIETY FOR HORTICULTURAL SCIENCE 01.01.2001
• Subjects: CARBOHYDRATES; DIOSPYROS KAKI; FERMENTATION; Japanese persimmon; kaki-shibu; organic acid; ORGANIC ACIDS; soluble tannin; sugar; TANNINS
• ISSN: 0013-7626; 1880-358X
• DOI: 10.2503/jjshs.70.95

Kaki-shibu is a fermented product made from the juice of immature Japanese persimmon fruit ; it has been traditionally used for painting and dyeing in Japan. Recently, it has attracted much interest as a deproteinizer during the brewing of sake. The properties of the kaki-shibu extracted from 'Tamura' and 'Tennou' persimmon and changes in the course of fermentation were studied, focusing largely on the non-tannic components. The soluble tannin content in the extract from immature fruit of 'Tennou' was 1.3 times higher than that of 'Tamura' ; the colloidal titration value and Baume degree were also higher 6 months after preparation. In both cultivars, the fructose content in the kaki-shibu, 3 days after the preparation, was higher than that of glucose. Sucrose was barely detected in the extracts of both cultivars. Sugars decreased rapidly during fermentation and disappeared 8 and 15 days after preparation of kaki-shibu from 'Tennou' and 'Tamura', respectively. Glycerin was detected in the 'Tennou' extract only 8 days after the preparation, but that from 'Tamura' persisted for 6 months after its preparation. Fermentation, which is an essential aging process for kaki-shibu, proceeded most actively from 3 to 29 days after the juice was extracted in both cultivars. The involatile acids, succinic and lactic, and the volatile acids, acetic, butyric and propionic, were formed during organic acid fermentation. Succinic and lactic acid contents rose rapidly for 3 days, whereas acetic acid increased for 15 to 29 days after the juice were extracted in both cultivars. Butyric acid was detected only in 'Tennou' 8 to 15 days after the samples were prepared. The total acid content, 6 months after the samples were prepared was 1.4 times higher in 'Tamura' than it was in 'Tennou'. These results indicate that kaki-shibu extracted from 'Tennou' contains an abundance of tannins, whereas that from 'Tamura' had greater organic acid content.