Effects of high pressure treatment on lipolysis-oxidation and volatiles of marinated pork meat in soy sauce

To investigate the effect of high pressure (HP) treatment (150 and 300 MPa for 15 min at 20 °C) on lipolysis-oxidation and volatile profile of marinated pork meat in soy sauce, the changes of lipase, phospholipase and lipoxygenase (LOX) activities, TBARS, free fatty acids and volatiles composition in control and HP treated samples were analyzed. Acid and neutral lipase activities and free fatty acids content decreased, while LOX activity and TBARS increased after HP treatment. Phospholipase had well stability under HP. The levels of volatile compounds from lipid oxidation and brine increased under HP and then contributed 73.16-78.25% of the typical aroma, while volatile compounds from carbohydrate fermentation, especially acetic acid, decreased with the pressure increasing. The decrease of free fatty acids during pressurization was probably attributed to the decline of lipase activity and the increase of LOX activity. These findings indicated that HP (150-300 MPa/15 min) promoted lipid oxidation and the permeation of brine, but inhibited carbohydrate fermentation.