PEPTIC AND PANCREATIC DIGESTIBILITY OF RAW AND HEAT-COAGULATED HEN'S EGG WHITE PROTEINS

Abstract

Raw and heat-coagulated hen's egg white proteins were evaluated for their peptic and pancreatic digestibility by the methods of SDS-PAGE and immunoblot analysis using antibodies against ovalbumin (OA) and ovomucoid (OM). Digestibility of OA was resistant to both peptic and pancreatic digestions in raw egg white, but this resistance was almost lost in heat-coagulated egg white. OM and ovotransferrin (OT) were easily digestive proteins against pepsin in both raw and heat-coagulated egg white and against pancreatin in heat-coagulated egg white, but these proteins were resistant to pancreatic digestion in raw egg white. These results indicate that peptic and pancreatic digestibility in hen's egg white proteins differ between raw and heat-coagulated egg white, and suggest that digestive ability in the stomach may be key for sufficient digestion of OM and OT when raw egg white is taken, because of both proteins being easily digestive to pepsin but being resistant to pancreatin.