Oxidative resistance, carotenes, tocopherols and lipid profile of liver oil of the ray Rhinoptera steindechneri

The liver oil of the tecolote ray (Rhinoptera steindechneri) was characterized in terms of its lipid by-class composition and fatty acid profile, natural antioxidants content, oxidative resistance and physicochemical properties. The liver oil content was considered high and fluctuated between 57% and 67% of the liver weight (w/w). The carotenes and α-tocopherols levels varied from 2.9 to 17.4 mg/100 g of oil and 3.0 to 15.2 mg/100 g of oil, respectively. The oxidative resistance reported as the induction period varied between 2.1 and 4.7 h, showing a very stable oil due to its level of natural antioxidants. The triglycerides were the major lipid by-class in the oil (703–790 mg/oil g), followed in a smaller proportion by sterol esters, polar lipids and free sterols. The liver oil of tecolote ray proved to be an adequate source of the n-3 polyunsaturated fatty acids EPA and DHA, similar to the traditional codfish liver oil.