LC-MS-based non-targeted metabolomics analysis of sea urchin during frozen storage under different packaging methods

Non-targeted metabolomics was employed to investigate key metabolites and metabolic pathways influencing sea urchin quality during frozen storage (−18 °C) under different packaging methods (normal, nitrogen, and vacuum). Comparative analysis revealed significant metabolic variations between frozen and fresh samples. KEGG enrichment analyses demonstrated that the metabolism of the normal packages was more disturbed, while there was a significant accumulation of polyunsaturated fatty acids (linolenic and α-Linolenic acid). Nitrogen packaging partially mitigated oxidation, but polyunsaturated fatty acids (linolenic and eicosapentaenoic acids (EPA)) still accumulated. Vacuum packaging had the best metabolic stability, minimal changes in amino acid metabolism, and effectively inhibited the production of polyunsaturated fatty acids, thereby substantially reducing off-flavor formation. This study provides a crucial theoretical foundation for controlling quality deterioration in frozen-stored sea urchins and offers valuable insights for optimizing commercial transportation and marketing strategies.