Phospholipase A2 and antioxidant enzyme activities in normal and PSE pork

In order to reveal the relationship between phospholipase A(2) and antioxidant enzymes and drip loss in pork, the study was designed to examine the effects of phospholipase A(2) 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 A(2) (tPLA(2,) cPLA(2)+sPLA(2) and iPLA(2)), superoxide dismutase (SOD) and GSH-Px, and acid phospholipase. The results showed that pH(1 h) and pH(24 h) from PSE pork were lower (p<0.01) than for normal pork (RFN), but the L* value at 1h and 24h postmortem, TBARS content, drip loss at 48 h and 96 h, cooking loss, tPLA(2) activity and iPLA(2) were higher (p<0.01) than of normal pork. Correlation analysis indicated that drip loss at 48 h was negatively related to pH(1 h) (p<0.01) and pH(24 h) (p<0.01) but positively to T(1 h) (p<0.01) and the activities of total phospholipase A(2) (p<0.05) and calcium-independent phospholipases A(2) (p<0.01). The tPLA(2) and GSH-Px play important roles in drip loss.