Yoshio Makino*, Yoshihiro Tanigawa*, Itsuko Takegami* and Takeshi Shirakawa*

* Kagawa Prefectural Fermentation and Food Experimental Station

+ Correspondence should be addressed to Yoshio Makino:
(1351-1, Koh, Nohma, Uchinomi-cho, Shozu-gun, Kagawa 761-4421 Japan)

Abstract

Crude soya-sauce mash, which is treated as an industrial waste produced in soya-sauce factories, was desalted and dried at a pilot scale plant which treats 100kg of soya-sauce mash per process. The finished product was dried and its components were analyzed in order to discuss the application methods of the product. 95% of the salt in the crude soya-sauce mash was extracted by dipping the crude mash in water which outweighed the mash in a 3:1 ratio. The yield of the finished product was 60.1%. C/N ratios and contents of salt and nitrogen in the product were 9.3, 0.44% and 6%, respectively. These values indicate that the product can be used as fertilizer or as soil conditioner. The product includes 34.2% crude protein. This suggests that the product also includes nutrients needed by domestic animals. The amount of standard plate counts, thermostable bacteria, lactic-acid bacteria or coliform groups in the product was less than 300CFU/g. The amount of fungi in the product is less than 100CFU/g. Water activity in the product was 0.540. These factors support the stability of the product during storage.

Key words: soya-sauce, industrial waste, desalting, dry, analysis