The effect of different extraction methods on the oil quality and quantity of rainbow trout (Oncorhynchus mykiss)

The effects of different fat extraction methods include Bligh and Dyer (BD), Smeds (SM), Bligh and Dyer used dichloromethane (BDD), Folch (FO), Roese-Gottible (RG), Soxhlet used petroleum ether (wet and dry samples) (SOX-WET, SOX-DRY) and Soxhlet used n-hexane (SOX-N) on total fat quantity and quality of Rainbow trout (Oncorhynchus mykiss) were investigated. Chemical properties including total fat, free fatty acid, peroxide value, conjugated diene and triene, tiobarbitoric acid, anisidine value, brown color factor, and color assessment were evaluated. According to the results, the amount of total fat was higher in Bligh and Dyer toward Soxhlet with wet sample, modified Bligh and Dyer and Roese-Gottible methods. The lowest primary lipid oxidation products were found in Bligh and Dyer and Soxhlet used petroleum ether. Comparison of tiobarbitoric acid value, showed higher secondary lipid oxidation products in Roese-Gottible toward Soxhlet and Folch methods. The highest amounts of conjugated triene, free fatty acids and TOTOX were also found in Roese-Gottible method. The results of this study showed that Smeds and Bligh and Dyer used dichloromethane extraction methods had proper fat quality, low cost and short time, as well.