Abstract:In this paper, the effects of excitation media (GasA: 10% O2: 50% N2: 40% CO2, GasB: 22% O2: 78% N2, GasC: 30% O2: 30% N2: 40% CO2) on lipid oxidation and enzyme activity of tilapia fillets treated with cold plasma during cold storage were evaluated based on the changes in lipid primary and secondary oxidation products and the activities of lipoxygenase (LOX), lipase, acid lipase, neutral lipase, and phospholipase. The results showed that cold plasma treatment could promote lipid oxidation in tilapia fillets and reduce the activities of lipid oxidation-related. During cold storage, the peroxide value and thiobarbituric acid value of tilapia fillets in the 10% O2 treatment group were 0.49 meq/kg and 1.05 mg/kg, which were significantly lower than those of the 21% and 30% O2 treatment groups (P<0.05). The enzyme activities of LOX, lipase, acid lipase, neutral lipase, and phospholipase all showed a trend of iniital increase then decrease during cold storage, reaching their maximum on the second day. The degree of inactivation of the above five enzymes increased with the increase in O2 content in the treatment group, with the enzyme activity being the lowest at a 30% O2 content and the highest at a 10% O2 content. Therefore, a low O2 content in cold plasma excitation medium is conducive to delaying lipid oxidation in tilapia fillets and maintaining the activities of oxidation-related enzymes. The results of this study provide a theoretical basis and technical support for regulating the lipid oxidation of tilapia by cold plasma treatment.
