Correlation between quality change and hydrogen sulfide in aquatic product: Detection of hydrogen sulfide and its potential applications using bigeye tuna (Thunnus obesus) model during cold storage.

Hydrogen sulfide (H2S) is an metabolic product of tuna during the spoilage, and relationship between H2S and tuna quality has not been specifically studied. This study detected changes in H2S content, H2S precursor substances, and related enzymes based on the formation pathway of H2S. H2S content increased of tuna resulted in significant increases in contents of cystathionine β-synthase, cystathionine γ-lyase, 3-mercapto pyruvate sulfotransferase, cysteine aminotransferase and methionine, while content of cysteine decreased which provided H2S formation. Cysteine and methionine metabolism, sulfur metabolism and histidine metabolism were metabolic pathways to assess H2S accumulation. Canonical correlation analysis showed that H2S content was significantly correlated with total volatile base nitrogen, total viable count (p < 0.05). This study elucidates the universality of H2S as an index for assessing seafood quality, utilizing quality indicators and modeling. Our findings offer a theoretical foundation and potential practical applications for improving the quality control of aquatic products.