Abstract: The lipids extracted from fresh pork were air-packaged with a polyethylene terephthalate/polyethylene (PET/PE) double-layer composite and thereafter treated by cold plasma cold sterilization. The effect of cold plasma cold sterilization processing time and voltage on lipid oxidation was investigated. To analyze the impact on the activation energy (Ea) for primary and secondary lipid oxidation, kinetic models were built. The results indicated that primary and second lipid oxidation were significantly promoted with increasing voltage up to 80 kV, processing time up to 80 s and storage time and the effect of voltage was greater than that of processing time. Furthermore, the increase in processing time and voltage could markedly reduce the Ea for secondary lipid oxidation. The Ea for primary lipid oxidation decreased with increasing voltage, while it followed a parabolic relationship with increasing processing time, which was fitted as follows: y = ? 0.005 3x2 + 0.464 1x + 20.684 (R2 = 0.974 4), and the maximum Ea for primary lipid oxidation of 30.84 kJ/mol was observed upon cold plasma cold sterilization processing for 43.8 s. The Ea for secondary oxidation was lower than that for primary oxidation under the conditions: voltage 30–80 kV and processing time 30.7–80.0 s, demonstrating that intramuscular fat is prone to secondary oxidation. The above findings lead to the conclusion that lipid oxidation in fresh pork is prone to occur when processed by cold plasma cold sterilization, making cold plasma cold sterilization potentially suitable for low-temperature short-time processing of pork products as a new technology to promote lipid oxidation.

Key words: cold plasma cold sterilization, lipid oxidation, voltage intensity, processing time, activation energy