Lipid changes and volatile compounds formation in different processing stages of dry-cured Spanish mackerel

Abstract Objectives This study delves into the alterations in lipids and major flavor compounds occurring throughout various drying stages (raw fish, dry-cured for 4, 8, and 12 d) of dry-cured Spanish mackerel (DCSM) and elucidates the mechanism underlying their formation. Materials and Methods In this paper, we used Thin Layer Chromatography and Headspace Gas Chromatography-Ion Mobility Spectrometry to determine the changes in lipid and volatile substances during the drying process of Spanish mackerel. Results The phospholipid, triacylglycerol, heptanal, t-2-hexenal, and dimethyl disulfide contents were notably lower in the samples collected 4 d before processing. The peroxide value and thiobarbituric acid reactive substances significantly increased after 4–8 d, concomitant with the generation of numerous volatile compounds, including alcohols, aldehydes, and ketones. Substantial quantities of 2-methylbutyraldehyde, thiazole, butyl acetate, and trimethylpyrazine emerged during the 8–12 d processing phase. Furthermore, C18:1n-9, C20:5n-3, and C22:6n-3 demonstrated noteworthy correlations with the development of 21 compounds. Principal component analysis, grounded in lipid and volatile compound content, adeptly classified the DCSM drying process into lipolysis and flavor preparation (0–4 d), lipid oxidation and flavor formation (4–8 d), and maturation (8–12 d). The ripening stage played a crucial role in shaping the comprehensive flavor profile. Conclusion This study offers valuable insights to enhance traditional DCSM flavor processing and regulation.