Lipid Oxidation in M. longissimus dorsi and M. semimembranosus in Lambs Reared Indoors and on Pasture

Lipid oxidation was studied in M. longissimus dorsi and M. semimembranosus in male lambs of Northeastern Bulgarian Fine Wool Breed and cross of this breed with Ile de France, reared indoors and on pasture. The oxidation of the lipids was determined by quantification of thiobarbituric acid reactive substances (TBARS), formed during the storage of the muscles at 4 degrees C until 6th day and -20 degrees C until 90th day. The way of the rearing had significant influence (P<0.01; 0.001) on the lipid oxidation in the muscles during the storage in both lambs of Northeastern Bulgarian Fine Wool Breed and the cross. The lipid oxidation was lower in the animals reared on pasture. The muscle type also had significant effect on the amounts of TBARS, as they were higher in M. semimembranosus. The dynamic of changes in TBARS contents on the muscles in both groups of animals from the breed and the cross showed influence of the duration of the storage on the lipid oxidation, as the highest values were achieved on the 90th day of samples storage.