Lipolysis and lipid oxidation in bacon during curing and drying–ripening

Dry-cured bacons were processed using pig bacon belly as material by dry-salting and drying–ripening. Lipolysis and lipid oxidation in intramuscular lipids were studied by evaluating the changes in lipid composition, lipolytic enzymes and lipoxygenase (LOX) activities, peroxide value (POV) and TBARS during processing. Lipid composition showed a significant decrease (p < 0.05) in phospholipids and an increase (p < 0.05) in free fatty acids (r = −0.85, p = 0.0004). All lipolytic activities decreased (p < 0.05) with increasing process time. Acid lipase showed higher activity than did neutral lipase (p < 0.05) throughout the processing. LOX activity increased significantly during salting (p < 0.01) and thereafter decreased. High salt content inhibited acid lipase and phospholipase activities but promoted LOX activity. Both POV and TBARS decreased (p < 0.05) with temperature rising during the last ripening period, suggesting that rising temperature in this period could lower oxidation indices in products. LOX was closely correlated with TBARS (r = 0.94) but not with POV (r = 0.36), indicating that LOX could facilitate lipid secondary oxidation.