Abstract: In order to study the relationship between the texture traits of perch and energy metabolism-related enzymes and protein oxidation during superchilled storage, we investigated the influence of three different packaging treatments (air packaging, vacuum packaging, and tea polyphenols combined with vacuum packaging) on the shear stress, microstructure, differential scanning calorimetric (DSC), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), total sulfhydryl content and energy metabolism-related enzyme (lactate dehydrogenase, Ca2＋-ATPase, and Mg2＋-ATPase) activities of perch during superchilled storage at ?2 ℃. The results showed that for all three groups, the shearing force, total thiol content and energy metabolism-related enzyme activities were significantly decreased with prolonged storage (P < 0.05), and a significant increase in these parameters was recorded for the third group compared with the two other groups (P < 0.05), indicating that tea polyphenols could preserve the quality of perch during superchilled storage. The SDS-PAGE and DSC analysis showed that myosin was slightly denaturated during superchilled storage for 21 days. The activities of three energy metabolism-related enzymes were positively correlated with the content of sulfhydryl groups (P < 0.05, r = 0.99), indicating that ATPase and lactate dehydrogenase activities are closely related to the degradation of myofibrillar protein, and there was also a significant positive correlation between the total content of thiol and ATPase activity and shear force (P < 0.01, r = 0.92), suggesting that myofibrillar protein oxidation could cause texture deterioration in perch.

Key words: superchilling, perch, shear stress, energy metabolism-related enzyme