Abstract

The extraction, refining and evaluation of fish oil from Sardinella fimbriata by Traditional method has been conducted in this work. The total percentage oil yield was 13.5% and the yield after purification was 58%. The analytical properties of the crude and the refined oil were evaluated and it was observed that the crude oil consist from: specific gravity 0.9036, refractive index 1.461, moisture content 0.7%, free fatty acid value 2.9 mg/KOH, iodine value 188 I₂/100g, peroxide value 2.18 mEq/kg, saponification value 202.7 mgKOH/g  and  slight brownish colour.

The refined oil was also evaluated as follows: specific gravity 0.8987, refractive index 1.465, moisture content 0.32%,free fatty acid value 2.1 mg/KOH, iodine value 181 I₂ /100g, peroxide 1.21 meq/kg, saponification value 174.8 mg KOH/g, and bright yellow colour. The predominant fatty acids found in crude and refined oil were C14:0, C15:0, C16:0, C17:0, C18:0, C23:0, C14:1ω-4, C18:1ω-9, C18:2ω-6, C18:3ω-3, C20:4ω-6, C20:5ω-3, C22:5ω-3 and C22:6ω-3. The total n-3 fatty acid content of the purified catfish oil was 13.361 mg/g of oil. The purified oil contained 5.009 mg/g DHA and 1.173 mg/g EPA. All the essential amino acids were present in the crude fish oil ranged from 1.907 to 0.067µg/g. After purification the major amino acid present was Valine (2.07µg/g) and Threonine (1.26µg/g). The vitamins present were in minor quantities; 0.06, 0.005 and 0.002µg/g of vitamin A, D and E, respectively in crude fish oil. In refined fish oil; 0.04 and 0.003µg/g of vitamin A and D were present.