Dietary vegetable oils and alpha-tocopherol reduce lipid oxidation in rabbit muscle

This experiment was conducted to study the effect of dietary vegetable oil on lipid oxidation in rabbit muscle. A control diet with no added fat and two diets with olive or sunflower oil (30 g/kg) were used. Within each treatment, one group was fed a low level of alpha-tocopheryl acetate (10 mg/kg diet), and the other a supplemental level (200 mg/kg). Rabbits were fed experimental diets from weaning (20 d) to slaughter (69 d). The supplemental level of dietary alpha-tocopheryl acetate produced higher alpha-tocopherol concentration in muscle (P < 0.006) and lower lipid oxidation (P < 0.004). Rabbits that received sunflower oil had higher concentrations of thiobarbituric acid reactive substances than rabbits that consumed olive oil (P < 0.05). Moreover, a significant effect due to fat inclusion in the diet was found. Muscles from rabbits fed diets not enriched with fat had higher susceptibility to lipid oxidation (P < 0.005) and higher concentration of (n-3) fatty acids in polar lipids (P < 0.04) than those from rabbits fed fat-enriched diets. A second experiment was conducted and confirmed the higher lipid oxidation in the muscle of rabbits fed diets not enriched with fat than in that of rabbits fed diets containing sunflower oil (28 g/kg) (P < 0.003) as well as in diets with identical digestible energy. In this experiment, alpha-tocopheryl acetate was at the lower level (10 mg/kg feed). Inclusion of oils rich in oleic (olive oil) or linoleic acid (sunflower oil) in rabbit diets reduces lipid oxidation in muscles.