Molds of the genus
Aspergillus and
Rhizopus were cultivated, respectively, on steamed rice and soybeans, and activities of several enzymes related to soybean protein hydrolysis in cultured products (
koji) were compared. Following results were obtained.
1.
Aspergillus koji and soybean koji were rich in glucosamine compared with Rhizopus one and rice one, respectively.
2. Activities of acid carboxypeptidase I, II-IV and leucine aminopeptidase I, II and III, as well as protease, produced by
Aspergillus showed a tendency to be affected by carbohydrate-protein ratio of the raw material.
3.
Aspergillus produced acid carboxypeptidase II-IV to some extent, whereas
Rhizopus scarcely. The difference was considered to be one of the reason why these two molds hydrolyzed soybean protein to different extent.
4.
Rhizopus indicated extremely weak activities of α- and glucoamylase in rice and soybean
koji.
5. Soybean
koji indicated higher activities of plant cell-macerating enzymes and cellulase than rice koji for all kinds of molds tested.
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