Hydrolysis of Muscle Proteins by Actinidin (Kiwifruits Protease)

Abstract

Crude actinidin was prepared from kiwifruits. Both myosin and actin were hydrolyzed by crude actinidin. The hydrolyzation of skeletal myosin molecule by crude actinidin was similar to that by chymotrypsin. Actinidin also hydrolyzed collagen molecule. When the beef pieces were immersed in the crude actinidin solution at 4°C, the cutting strength for raw and cooked meats reduced gradually with time of soaking and they reached to the constant after about 6 hours. The samples prepared from beef pieces immersed in the crude actinidin solution for 22 hours were observed by scanning electron microscopy. It was confirmed that the ultrastructure of the meats treated with actinidin was fragiler than that of control. AS the results, it is clear that actinidin which is contained in kiwifruits may be successful as meat tenderizer.