Phospholipase A 2 and antioxidant enzyme activities in normal and PSE pork

Abstract

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 1 h and 24 h 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.