Characteristics and Purification of Soybean Milk Curdling Enzyme-Producing Yeast Saccharomyces bayanus SCY003

• Published in: FOOD SCIENCE AND TECHNOLOGY RESEARCH Vol. 20; no. 5; pp. 927 - 938
• Main Authors: Hatanaka, Sakiko, Maegawa, Machiko, Kanauchi, Makoto, Kasahara, Shin, Shimoyamada, Makoto, Ishida, Mitsuharu
• Format: Journal Article
• Language: English; Japanese
• Published: Tsukuba Japanese Society for Food Science and Technology 2014; The Japanese Society for Food Science and Technology; Japan Science and Technology Agency
• Subjects: alkaline protease; curdling; Degradation; enzyme; Foods; Milk; Protease; Proteins; purification; Saccharomyces bayanus; soybean milk; Soybeans; Strain
• ISSN: 1344-6606; 1881-3984
• DOI: 10.3136/fstr.20.927

Soybeans and the processed food, soybean milk, have important health functions. A cheese-like food produced from soybean milk resembles casein protein in its mouthfeel and physical properties. The intracellular soybean milk curdling enzyme-producing Saccharomyces bayanus SCY003 strain was screened. The curdling enzyme is an intracellular protease, a 45 kDa monomer protein that degrades soy protein subunits, produced by this strain. The optimum temperature and pH of enzyme activity are 50°C and pH 7.5, respectively. The protease degrades β-conglycinin and parts of glycinin in soy protein to α’, α and β subunits. The rheological characteristics of the resultant curd were assessed, and revealed that elasticity differed from curd produced by glucono δ-lactone, which is used in tofu production. A new soy protein food having health-supporting functions will be developed using this protease.