Effect of low voltage electrical stimulation on myofibrillar proteolysis of different parts of yak meat

After being treated by electrical stimulation in yak meat,changes in microstructure and myofibrillar proteolysis were studied.The raw materials were yaks slaughtered with electrical stimulation within 5min( 21 V,50Hz,90s),and then chilled( 0~4℃,wind speed 0.5m / s).Taking front triceps( TB),central longissimus muscle( ML) and posterior semimembranosus( SM) as material,respectively,then determined sarcomere length,muscle fiber diameter,MFI value,muscle fiber microstructures and SDS- PAGE electrophoresis after postmortem 0,1,3 and 5d.The results indicated that after electrical stimulation,sarcomere length of different parts of yak meat changed significantly( p < 0.05); the average diameter of the muscle fibers shortened 6%,5% and 9% repectively,MFI values increased by 54%,55% and 92% significantly,tenderness of SM increased significantly( p < 0.05).Share of different parts of yak meat myofibrillar ultrastructure contracture were 23.9%,26.3% and 31.2%. Myofibrillar ultrastructural changed significantly. The view of the SDS- PAGEphotograph,TB,ML and SM Myofibrillar protein degradated completely between 48~75ku. In a conclusion,electrical stimulation could shorten the aging time,and improve tenderness of yak meat,especially,make a significant difference to poorer SM part( p < 0.05).