Correlation analysis of enzymes associated with energy metabolism and quality of tilapia fillets during iced storage

Objective: To inquiry the correlation of partial enzyme activities associated with energy metabolism and quality of tilapia fillets during iced storage. Methods: The determination of changes of enzyme activities including Ca2 +- ATPase, Mg2 +- ATPase and lactate dehydrogenase ( LDH) of tilapia fillets over a period of iced storage was based on spectrophotometry.These variation trends containing p H and the content of myosin as well as actin with iced time were also determined. SPASS software was utilized for correlation analysis. Results: The value of p H of tilapia fillets on the whole presented a first descending and latter upgrade tendency during iced storage. Myosin degraded obviously and the content of actin showed a significant negative correlation with iced time ( p ≤0.05, r =-0.836) .Ca2 +- ATPase activity had reduced to 42.9% of the initial value on the iced 4th day.Mg2 +- ATPase activity dramatically increased on the iced 2nd day, and there was still a rising trend in the later stage.A highly significant positive correlation was observed between lactate dehydrogenase activity and iced storage period ( p ≤0.05, r =0.625) . Conclusions: Ca2 +- ATPase and lactate dehydrogenase activities of iced tilapia fillets met Karl Pearson linear relation with p H, presenting a significant correlation ( p ≤0.01) . ATPase and lactate dehydrogenase, to some extent, were associated with the degradation of myofibril protein.