DIETARY VEGETABLE-OILS AND ALPHA-TOCOPHEROL REDUCE LIPID OXIDATION INRABBIT 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. Wi thin 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/k g). Rabbits were fed experimental diets from weaning (20 d) to slaught er (69 d). The supplemental level of dietary alpha-tocopheryl acetate produced higher a-tocopherol concentration in muscle (P < 0.006) and l ower lipid oxidation (P < 0.004). Rabbits that received sunflower oil had higher concentrations of thiobarbituric acid reactive substances t han rabbits that consumed olive oil (P < 0.05). Moreover, a significan t effect due to fat inclusion in the diet was found. Muscles from rabb its fed diets not enriched with fat had higher susceptibility to lipid oxidation (P < 0.005) and higher concentration of (n-3) fatty acids i n polar lipids (P < 0.04) than those from rabbits fed fat-enriched die ts. A second experiment was conducted and confirmed the higher lipid o xidation 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 e xperiment, alpha-tocopheryl acetate was at the lower level (10 mg/kg f eed). Inclusion of oils rich in oleic (olive oil) or linoleic acid (su nflower oil) in rabbit diets reduces lipid oxidation in muscles.