Effects of Heat Treatment and Endogenous Enzymes on Flavor Formation during the Processing of Dried Sea Bass

Dried sea bass samples were prepared with endogenous enzymatic transformation + light heat treatment (S1), endogenous enzymatic transformation + high-intensity heat treatment (S2), light heat treatment (S3) and high-intensity heat treatment (S4), and their flavor was analyzed by sensory evaluation, solid phase microextraction combined with gas chromatography-mass spectrometry (GC-MS). The correlation between volatile components and sensory attributes was investigated by partial least squares regression (PLSR). Sensory analysis showed that there were significant differences in flavor profiles between samples S1, S2, S3, and S4. The results of GC-MS showed that n-hexanal, nonanal, n-octanal, butyl phenol, 1-octene-3-ol, 2,3-octanedione, caryophyllene, and 2,6-di-tert-butyl-p-cresol were the major volatile components in dried sea bass. The volatile components of S1, S2, S3, and S4 were significantly different, and the content of volatile components in S1 and S2 was significantly higher than that in S3 and S4. PLSR analysis showed that benzaldehyde, kunienal, n-octanal, acetophenone, heptanol, and 2-ethyl hexanol were correlated with the sensory properties of dried sea perch. The contents of these substances were significantly different among the four samples. The comparison revealed that hexanal, acetophenone, and benzaldehyde in S1 and S2, enhancing the grassy and sweet aroma, were produced by the reaction between fat and amino acids under the action of endogenous enzymes. In S3 and S4, heat treatment promoted the oxidative degradation of triglycerides to produce octanal, 2-ethylhexanol, decenal and trans-2-octenal, enhancing the orange and fatty aroma. In addition, the enzymatic activity of cathepsin B was much higher in S1 and S2 than in S3 and S4. The results of this study provide a theoretical reference for optimizing the preparation process of dried sea bass and further understanding of the mechanism of the flavor formation of aquatic foods.