Inhibiting browning in ready-to-eat oysters: The efficacy and mechanism of L-cysteine combined with light-proof nitrogen-filled packaging during accelerated storage

Ready-to-eat (RTE) oysters experience rapid and pronounced color deterioration, mainly attributable to lipid oxidation, phenolic oxidation, and Maillard/Maillard-like reactions. RTE oysters were treated with a combination of different color protection agents and packaging strategies to delay browning during storage. The color and associated color-change reactions of RTE oysters were evaluated to identify the optimal color-protection combination and elucidate its regulatory mechanisms. Results indicated that L-cysteine combined with light-proof nitrogen-filled packaging constituted the optimal color-protection strategy. This combination mitigated browning during storage by directly suppressing oxidation and the Maillard reaction. Furthermore, it indirectly inhibited both the Maillard reaction and lipid-mediated Maillard-like reactions by reducing the formation of free radicals and reactive carbonyl compounds. In summary, this study demonstrated that the integration of chemical color-protective agents with cost-effective physical methods effectively delayed the decline in color quality of RTE oysters throughout storage via multiple protective mechanisms.