Cold plasma and honey synergistically inhibit polyphenol oxidase to enhance fresh-cut apple preservation.

Fresh-cut apple slices (FAS) are prone to browning and microbiological safety issues. This study investigated the synergistic effects of cold plasma (CP) treatment and honey coating (HC) on preserving FAS quality during storage. Among six honeys, 10 % jujube honey exhibited the strongest anti-browning effect. The optimized CP treatment condition was 51.5 W for 9.9 min. Compared to individual treatments, CP/HC synergistically reduced microbial growth, ensuring safety, while achieving the highest polyphenol oxidase (PPO, 60 %) and respiration inhibition, thereby reducing browning (ΔE < 5) and improving quality. Sensory evaluation confirmed that CP/HC-treated FAS retained better overall acceptability for up to 8 days. Mechanistically, it was proven that the proteins and polyphenols in honey inhibit browning by non-competitively inhibiting PPO activity, reversing browning products, and the synergistic effect of multiple components. Furthermore, CP treatment induced structural changes and aggregation of PPO, as evidenced by decreased α-helix content (8.6 %), increased particle size (146 %).