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.