Abstract:

The aim of this study was to explore the effect of oxidation on the activity and autolysis of calpain in beef duringpostmortem ageing. The longissimus dorsi was excised from the carcass immediately after exsanguination. Then oxidizingagent with different concentrations (0 mmol/L H2O2 + 5 mmol/L NaCl; 50 mmol/L H2O2 + 5 mmol/L NaCl; 200 mmol/LH2O2 + 5 mmol/L NaCl; 500 mmol/L H2O2 + 5 mmol/L NaCl) was injected. The samples were vacuum packaged, andstored at 4 ℃ for 0, 1, 3, 7 and 14 days, respectively. Then, casein zymography and Western blotting were used to analyzethe samples. The results showed μ-calpain activity was reduced as a result of enhanced autolysis while m-calpain activityunderwent minor change with increasing oxidation level. Therefore, oxidation can inhibit the activity of μ-calpain andincrease its autolysis during beef postmortem ageing.

Key words: oxidation, calpain, activity, autolysis