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

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 t he brewing of sake. The properties of the kaki-shibu extracted from 'Tamura ' and 'Tennou' persimmon and changes in the course of fermentation were stu died, focusing largely on the non-tannic components. The soluble tannin content in the extract from immature fruit of 'Tennou' w as 1.3 times higher than that of 'Tamura';the colloidal titration value and Baume degree were also higher 6 months after preparation. In both cultivar s, the fructose content in the kaki-shibu, 3 days after the preparation, wa s higher than that of glucose. Sucrose was barely detected in the extracts of both cultivars. Sugars decreased rapidly during fermentation and disappe ared 8 and 15 days after preparation of kaki-shibu from 'Tennou' and 'Tamur a', 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 extra cted in both cultivars. The involatile acids, succinic and lactic, and the volatile acids, acetic,butyric and propionic, were formed during organic ac id fermentation. Succinic and lactic acid contents rose rapidly for 3 days, whereas acetic acid increased for 15 to 29 days after the juice were extra cted 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 afte r 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 c ontent.