7 Pages

Soy Sterols

WithIkuo Ikeda

Soybean oil contains about 300 to 400 mg of plant sterols per 100 g. Major components of soy sterols are sitosterol (53 to 56%), campesterol (20 to 23%), and stigmasterol (17 to 21%). Soybean germ makes up 2% of whole soybean. Soybean-germ oil can be extracted from hypocotyl-enriched raw soybean. It comprises 1% of soybean oil. It was reported that soybean-germ oil contains relatively high amounts of plant sterols. The fatty acid composition of soybean-germ oil is similar to that of soybean oil. Therefore, the effective reduction of serum cholesterol concentration in soybean-germ oil may be ascribed to plant sterols in the oil. Stigmasterol has a double bond at the 22-23 position of sitosterol. Plant stanols, in which a double bond at the 5-6 positions in the steroid ring of plant sterols is saturated, are also contained in soybean oil in trace amounts.