Degradation Kinetics of Myosin Heavy Chain of Pacific Whiting Surimi

摘要

Pacific whiting surimi paste was ohmically heated to investigate degra- dation of myosin heavy chain (MHC) caused by endogenous proteinase over a range of 40-85℃ and 0.5-35 min. Degradation was best de- scribed with an apparent reaction order of 1.4. Changes of degradation rate increased with temperature and reached a maximum at 57℃. Then, rate of MHC degradation decreased with higher temperature and reached a minimum at 75℃. Ea values of activation and inactivation zone were 142.3 and 83.1 KJ/mol, respectively. Generally, failure shear stress and shear strain increased linearly with MHC content. Proteolytic degrada- tion of actin exhibited the same trend as that of MHC but at a slower rate. The synergistic effect of actin in the gelation of whiting surimi was predominant at >75℃.