Unlocking the effects of cold plasma on enhancing the stabilization of oat flour: Insights from storage characteristics, lipidomics, and flavor analysis

Abstract

Cold plasma (CP) treatment, as a non-thermal stabilization strategy, is a promising alternative to heat technology for improving the storage stability of oat flour. In this study, the efficacy of CP treatment on enhancing the storage stability of oat flour was evaluated and the underlying mechanism of lipid oxidation and flavor evolution was explored via lipidomics and GC-MS analysis. Results showed that oats were treated under varying CP conditions, and 40 kV for 90 min was determined as the optimal parameter, which resulted in the inhibition rates of lipase, lipoxygenase, and peroxidase activities reaching 45.6%, 34.8%, and 56.0%, respectively. Furthermore, during 28-day accelerated storage, the activities of three enzymes in CP-treated oat flour were continuously inhibited, and their fatty acid value (9.3%), peroxide value (32.8%), and malondialdehyde content (17.9%) were significantly reduced when compared with the control group. The total phenolic content of oat flour was also remarkably retained by CP treatment. Untargeted lipidomics showed that CP inhibited lipid hydrolysis at the diacylglycerol and lysophosphatidylcholine stages, blocking free fatty acid release. Although CP transiently increased aldehydes, it ultimately reduced the off-flavor markers and promoted the accumulation of certain pleasant esters during storage. These findings demonstrated that CP enhanced the storage stability of oat flour by modulating lipid metabolic flux through irreversible enzyme inactivation.