Abstract
It is known that soybean protein is not digested easily because of containing trypsin-inhibitor. When soybeans are not boiled but parched with heat, the trypsin-inhibitor is stable. Therefore, digestibility of protein of parched soybean-flour is low. This paper reports that the digestibility of soybean protein is high when soybean is parched before crushed, and it is low when parched after crushed. When whole soybeans were parched at 150°C for 20 minutes, for example, digestibility of their protein was high. However, digestibility of soybean flour protein was as low as that of soybean protein when soybeans were parched on the same condition after crushed. This suggests that trypsin-inhibitor is inactive in raw whole soybeans, but is active when they are crushed.
