Chemical Composition of Soybean Oil Extracted from Hypocotyle-Enriched Soybean Raw Material and Its Cholesterol Lowering Effects in Rats

Abstract

Soybean oil (termed Soybean-germ oil to distinguish it from normal soybean oil) was extracted from hypocotyle-enriched (37%) soybean raw material and its chemical composition was analyzed. The total sterol content in Soybean-germ oil was 1.7% which is higher than that in soybean oil (0.4%), corn oil (1.1%) and rice bran oil (1.0%). The ratio of Campesterol to the total sterols of Soybean-germ oil was 8.1% that was lower than those of soybean oil (20.2%), corn oil (20.5%) and rice bran oil (15.7%), respectively. The sum of Δ7-Stigmastenol, Δ7-Avenasterol and Citrostadienol in Soybean-germ oil was 517mg/100g which was higher than in corn oil (30mg) and rice bran oil (230mg), respectively. Its cholesterol lowering effects in rats were evaluated. Between the rats fed test feeds containing 0.5% cholesterol and 10% test oils, the increases in the serum and liver cholesterol levels were more suppressed in the rats fed Soybean-germ oil than in those fed soybean oil. The higher sterol content in Soybean-germ oil may be related to its enhanced cholesterol lowering effects.