Phospholipid Degradation Kinetics of Pork during Combined High-Pressure and Thermal Treatments

In order to explore the effect of combined high-pressure and thermal treatment on the lipolysis of phospholipids in pork, the phospholipid degradation kinetics of pork was studied in the 300 to 700 MPa pressure range and in the 20 to 60 ℃ temperature range. It was found that the lipolysis process followed first-order kinetics. The lipolysis rate constant (k) of polyunsaturated fatty acids (PUFA) was the highest, followed by total phospholipids (PL), and those of monounsaturated (MUFA) and saturated fatty acids (SFA) were relatively low. The average activation energies of SFA and MUFA were the highest, and the absolute values of the average activation volume were at a high level. Hence, the lipolysis rate constants of SFA and MUFA were sensitive to temperature and pressure. Kinetic models for PL lipolysis were established using the Arrhenius and Eyring equations. Both models had good fitness to the data and showed similar temperature-pressure contour curves. Accordingly, the lipolysis kinetics of different phospholipid components was different, but the lipolysis kinetics of PL was very similar to that of PUFA. The kinetic models could predict the degree of lipolysis of phospholipids under preset pressure, temperature and time conditions, which will be helpful in designing or optimizing high-pressure processing parameters to improve the quality of meat products.