Investigating the correlation between major taste substances and volatile flavor substances in Lateolabrax japonicus (sea bass) under bloodletting conditions

In this study, we assessed the effect of four bloodletting methods, namely head knocking to stun (Control), gill cutting and resting, room temperature gill cutting and swimming and low temperature gill cutting and swimming, on the flavor of sea bass (Lateolabrax japonicus). Among the four methods, the gill-cutting swimming method at room temperature consumed the least amount of glycogen (5.81g/100g) and adenosine triphosphate (ATP) (205.75 mg/100g) and caused the least stress to the fish. Bloodletting reduces bitter amino acids and increases sweet and salty substances. It also lowers heptanal, benzaldehyde, octanal, hexanal, and 1-octen-3-ol, reducing fishy odors. The results of orthogonal partial least squares discriminant analysis (OPLS-DA) (VIP>1) and Spearman's correlation analysis were combined to derive correlations between the main taste compounds and 27 major volatile flavor compounds. Among them, benzaldehyde exhibited a significant positive correlation with 1-octen-3-one (p < 0.05) and a highly significant positive correlation with 2-pentanol (p < 0.01). Meanwhile, 2-hexen-1-ol demonstrated highly significant positive correlations with trans-2,4-decadienal and 1-hexanol (p < 0.01). This suggests significant interactions between aldehydes and alcohols and ketones. This study adds a theoretical basis for the practical application of the bloodletting method and provides ideas for obtaining high-quality perch.