Effects of Different Drying Methods on Lipid Oxidation and Volatile Flavor Components of Spanish Mackerel (Scomberomorus niphonius)

To explore the effects of different drying methods on lipid oxidation and volatile flavor components of fishery products, the corresponding experimental groups were prepared by hot-air drying, cold-air drying and traditional natural drying using fresh Spanish mackerel (Scomberomorus niphonius) as raw material. The moisture content, pH value, lipid content, acid value (AV), peroxide value (POV), malondialdehyde (MDA), fatty acid composition and volatile flavor components of raw materials and different dried samples were measured. The results showed that the moisture content of dried samples prepared by three drying methods was about 30% with the pH value above 6. The AV, POV and the contents of MDA in the cold-air drying group were lower than the other groups (P<0.05). In the hot-air drying group, the lipid content decreased the most, and the AV was the highest, the POV and the content of MDA were significantly lower than those of natural drying group (P<0.05). The AV of the natural drying group represented the lowest, the POV and the content of MDA were significantly higher than those of other groups (P<0.05). The content of unsaturated fatty acid, especially the ω-3 polyunsaturated fatty acids decreased significantly (P<0.05), especially in the natural drying group. A total of 120 volatile flavor substances in 8 categories were detected from raw materials and drying samples, mainly composed of aldehydes, alcohols and esters. Principal component analysis revealed that the cumulative contribution rate of the 3 principal components to flavor was 99.9%, and the score of the natural drying group was the highest. The results indicated that the different drying methods had a great influence on the degree of lipid oxidation and flavor of Spanish mackerel, and the natural drying group had the best flavor. This research provides effective data support and development direction for the technological transformation of the traditional aquatic product processing industry.