청국장에 관한 연구(Ⅰ) : 청국장 제조과정에 있어서 콩단백질의 변화에 대하여 On the changes of soy - bean protein in manufacturing Chung - Kook - Jang = Studies on Chung - Kook - Jang(Part Ⅰ)

다국어 초록 (Multilingual Abstract)

As a series on the soy-bean protein and their related substances 9 samples were collected from 9 places such as straws (Rice) to obtain bacterial strains which produce protease. From these samples total of 23 strains were isolated by the use of dilution pour plate method.
For all isolated strains primary screening of productivity of protease was performed and useful straines with regard to protease productivities were identified.
Optimum conditions for enzyme action of protease from isolates D_9, F_(20) strains were pH 7.5 and 40℃.
Chung-Kook-Jang is one of the characteristic foods in Korea made from soy-bean by fermentation. The chief bacterium is Bacillus subtilis and the chief change which takes place in soy-bean during fermentation is degradation of protein.
Three kinds of Chung-Kook-Jang were prepared using three different strains of Bacillus natto, D_9 and F_(20) from isolated. Water soluble-N, TCA soluble-N, amino-N and peptide-N were measured about the steamed soybean, Chung-Kook-Jang prepared with three strains of bacteria. Water soluble-N decreased very largely in steamed soybean, but in Chung-Kook-Jang it increased to 85% of raw soy-bean.