Comparison of Soybean Varieties for Cyclitol Content in Soybean Curd Wastewaters

D-chiro-Inositol and its methylated form, pinitol, are major cyclitols of soybeans and play important roles in seed maturation. Cyclitols are often used as dietary supplements for acute type II diabetes. Process optimization was performed by varying grinding times, soaking times, and coagulants for the isolation of cyclitols from soybean curd wastewater. The optimal condition was 4 min of grinding, 5 h of soaking. was also employed as a coagulant. By using the optimal conditions, the highest amount of cyclitols was obtained from Shinpaldal among 12 varieties of Korean soybeans. Shinpaldal had about 24% more cyclitols than US No. 1 did.