Effect Of Electrical Stimulation And Delay Chilling On Myofibrilllar Microstructure Of Beef

Tenderness is the most important beef palatability attribute to consumer(Savell,J.W.,et al,1987;Savell,J.W.,1989).Many studies show that processing moders after slaughter such as electrical simulation and chilling system all play important roles in meat tenderizition.A series of studies on this fields has been conducted for many foreign academicians recent years,but systematic study has seldom been reported.To date,the mechanism of beef aging is not absolutely understood.Based on prevenient researches,the purpose of this research is to study the effect of electrical stimulation and delay chilling on tenderness of beef by analysis of carcass temperature,pH and shear force value and tenderizing effect of delay chilling.The major testing results are as follows:Four gropes crossbred yellow cattle are slaughted according to standard slaughting practices.Temperature decline and pH decline are determined during chilling.The results show that delay chilling has significant effect on pH and temperature decline (P<0.05);Electrical simulation has no significant effect on temperature decline (P<0.05),but fasts pH decline signigicantly (P<0.05).The shear force value of major beef cuts-longissimus is studied.The results show that electrical stimulation and delay chilling fasts beef aging process signigicantly (P<0.05).However,after 10d aging delay chilling has no significant effect on meat tenderness.Electrical stimulation induces contracture band in myofibril,then destroies myofibrilllar structure.Furthermore,electrical stimulation improves tenderness because of appearance of MFI at 3d.At 0d and 3d,sarcomere length of delaying chilling treatment is longer than sarcomere longth of conventional chilling significantly (P<0.05),but the significance disappeared at 7d,10d.The result of the ES&DC treatment shows that the effect of electrical stimulation on meat tenderisation is concerned to the chilling system.