Nutritional Status, Characterization and Fatty Acid Composition of Oil and Lecithin Isolated from Fresh Water Fish Shoul (<i>Channa striata</i>)

Abstract

Fishes are rich sources of different types of nutrients. Some species are found in marine water; on the other hand some varieties are available in fresh water. Consumption of fish is very beneficial to the health and development of the human body and fish becomes an integral part of the food culture of populations in many countries. They provide essential nutrients to the human. The aim of this study was to estimate the nutritional status of the selected fish species, to extract and characterize the fish oil and lecithin. Fish oil contains higher amount of polyunsaturated fatty acids which have significant effect in maintaining a healthy cardiac life. Biochemical composition of shoul (<i>Channa striata</i>) was determined. It was found that fishes are rich sources of protein and other nutrients. All the other parameters such as, moisture, protein, lipid, total sugar and ash were found in significant amount in shoul. Shoul fish oil was extracted using n-hexane by soxhlet apparatus. The percentage of oil from shoul fish powder was 12.64 (g% w/w). Lecithin was also extracted from this fish fleshes before and after oil extraction. Lecithin was 2.07 (g% w/w) and 3.10 (g% w/w) before and after oil extraction. It was found that percentage of lecithin was increased after oil extraction. The physicochemical properties of fish oil and lecithin were investigated. The higher saponification value and iodine value indicates that oil and lecithin contains shorter fatty acid chain length with lower molecular weight and the presence of higher amounts of unsaturated fatty acids in the samples. Low acid value and peroxide value indicate higher quality index of fish oil and lecithin. The oxidative stability of shoul fish lecithin was also measured by thiocyanate (TC) method and thiobarbituric acid (TBA) method. Shoul fish lecithin showed higher oxidative stability due to the presence of natural antioxidant. Fatty acid composition of shoul fish oil and lecithin was measured by gas chromatography (GC). The important polyunsaturated fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were found to be 0.49% and 1.37% in fish oil. But lecithin contains only 7.8% DHA and other monounsaturated fatty acids. This fish oil and lecithin also contain higher amount of monounsaturated fatty acid and average amount of polyunsaturated fatty acids. Fish oil and lecithin also act as sources of essential fatty acid. Therefore, we can use this fish oil and lecithin in edible purpose, food industry and pharmaceutical industry.