Phospholipase A2 and antioxidant enzyme activities in normal and PSE pork

In order to reveal the relationship between phospholipase A2 and antioxidant enzymes and drip loss in pork, the study was designed to examine the effects of phospholipase A2 and antioxidant enzymes on the water-holding capacity of pork during postmortem chilling. Six PSE and RFN samples (longissimus muscle) were used to determine the activities of phospholipase A2 (tPLA2, cPLA2 + sPLA2 and iPLA2), superoxide dismutase (SOD) and GSH-Px, and acid phospholipase. The results showed that pH1 h and pH24 h from PSE pork were lower (p < 0.01) than for normal pork (RFN), but the L* value at 1 h and 24 h postmortem, TBARS content, drip loss at 48 h and 96 h, cooking loss, tPLA2 activity and iPLA2 were higher (p < 0.01) than of normal pork. Correlation analysis indicated that drip loss at 48 h was negatively related to pH1 h (p < 0.01) and pH24 h (p < 0.01) but positively to T1 h (p < 0.01) and the activities of total phospholipase A2 (p < 0.05) and calcium-independent phospholipases A2 (p < 0.01). The tPLA2 and GSH-Px play important roles in drip loss.