Modified atmosphere packaging delays enzymatic browning and extends the shelf life of fresh-cut lotus root by maintaining membrane lipid homeostasis.

Fresh-cut lotus root (FCLR) is prone to rapid browning and microbial growth after processing. Although modified atmosphere packaging (MAP) can inhibit browning in FCLR, the optimal gas composition and the physiological basis of browning inhibition remain unclear. In this study, a principal component analysis-assisted multi-index evaluation was employed to identify the optimal gas composition (MAP1: 1% O2, 15% CO2, 84% N2), followed by analyses of membrane lipid metabolism and untargeted metabolomics. After 15 d, MAP1 reduced browning by 72% and lowered mold/yeast counts and total aerobic counts by 1.0 and 1.4 log CFU·g-1, respectively, compared with the control. Furthermore, MAP1 significantly suppressed polyphenol oxidase activity (35.9% decrease) and peroxidase activity, slowed phenolic oxidation, alleviated membrane lipid peroxidation, and reduced malondialdehyde content and electrolyte leakage. Importantly, metabolomics analysis suggested that MAP modulated phenylpropanoid-related metabolites, altered GABA and proline-associated pathways, and maintained membrane lipid homeostasis, which may collectively contribute to browning suppression.