Abstract: In order to investigate the influence of the refining process on the quality and sensory properties of snakehead fish oil, the physicochemical properties, fatty acid composition and volatile flavor composition during the refining process of crude fish oil extracted from snakehead viscera were evaluated. The results showed that the physicochemical properties of snakehead fish oil were significantly improved; the acid value, peroxide value, moisture content, volatile content, anisidine value and unsaponifiable matter content were significantly reduced, and the iodine value was increased. In total, 27 fatty acids were detected in snakehead fish oil, the major ones being oleic acid, linoleic acid, and palmitic acid. During the refining process, the number of fatty acids was almost unchanged, the contents of monounsaturated and polyunsaturated fatty acids increased, while a reverse trend was observed for the content of saturated fatty acids. Additionally, a total of 99 volatile compounds were detected during the refining process of snakehead fish oil, among which 14 compounds including 1-octen-3-ol, hexanal, nonanal, 2-heptenal, (E,Z)-2,6-nonadienal, 2,4-decadienal, and trans-2,4-decadienal were the key flavor substances of snakehead fish oil. These findings provide a theoretical basis and technical support for the deep processing and high-value utilization of snakehead fish visceral oil.

Key words: snakehead fish oil; refining; physicochemical indexes; fatty acid composition; flavor substances