ABSTRACT
The soybean is an important food resource. It contains abundant protein, carbohydrate, and fat. It is a high-protein food and a good source of nitrogen for humans because the amino acid composition of protein in the soybean has the equivalent nutritional value as animal protein. The soybean contains some useful minor components such as isoflavone, saponin, lecithin, and phytosterol. The protein was the first soybean component recognized to have specified health uses. The soybean contains many protein components, which have many physical and physiological functions. Phytosterol is another soybean component used for lowering cholesterol. Phytosterol enters the micelle and competes with cholesterol when it is digested and absorbed. Carbohydrates account for about 28% of soybean. Soybean contains very few starches, unlike other legumes. The soybean also contains isoflavone, a kind of polyphenol, mainly in the germ. Soy isoflavone is effective at maintaining bone density.
