Cold Plasma Pretreatment of Bee Pollen: Effects on Lipid Oxidation, Bioactivity, and Enzyme Activities During Storage

Lipid stability and functional activity deterioration during storage significantly compromise the quality of bee pollen. In this study, we applied a combined ethanol and cold plasma pretreatment to bee pollen either before drying (75%E-ACP) or after drying (D-75%E-ACP), and investigated its effects during eight weeks of accelerated storage at 50°C. The results showed that D-75%E-ACP pretreatment significantly inhibited lipid oxidation, reducing malondialdehyde (MDA) content by 43.24% compared to the control at the end of storage. Meanwhile, the activities of antioxidant enzymes such as superoxide dismutase (SOD) and phenylalanine ammonia-lyase (PAL) increased by 25.43% and 36.74%, respectively, while those of oxidases, including polyphenol oxidase (PPO), peroxidase (POD), and lipoxygenase (LOX) decreased by 12.5%, 47.62%, and 30.48%, respectively. These changes helped preserve key bioactive compounds, including phenolic compounds and carotenoids, and sustained high antioxidant activity. Additionally, D-75%E-ACP pretreatment inhibited browning without altering protein or sugar levels. In summary, this strategy shows promise for improving bee pollen storage and broader food preservation.