Lipid oxidation was studied in M. longissimusdorsiand M. semimembranosusin 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 ˚С until 6th dayand -20 ˚С until 90th day. The way of the rearinghad signific antin fluence (Р<0.01; 0.001) onthelipidoxidationinthe musclesduringthe storageinbothlambsofNortheastern Bulgarian Fine Wool Breed and the cross.The lipid oxidation waslowerintheanimalsrearedonpasture. Themuscle 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. پرونده مقاله

Protein oxidationM.longissimus dorsi andM. semimembranosuswas studied in ram lambs of Northeastern Bulgarian Fine Wool Breed and cross of this breed with Ile de France, reared and in doors and on pasture.The degree of protein oxidation is determined by measuring the content of carbonyls, formed during the storage of the investigated muscles at low temperatures(4˚С till6thday and -20˚С till90thday). Protein oxidation was lower in pastured animals. Differences between the groups were significant at4th(P<0.05) and90thday (P<0.001)for the animals of Northeastern Bulgarian Fine Wool Breed and at 24h (P<0.05), 6th and 90thday(Р<0.01)in crossbred lambs.Differences were reported in protein oxidation in the muscles at 48h (P<0.01) and the 4thday (P<0.05) as well as at 48h (P<0.05) and the 90thday(Р<0.001), for the lambs of Northeastern Bulgarian Fine Wool Breed and the cross, respectively. The dynamic of changes of the carbonyls in the muscles shows that storage duration influences protein oxidation. The carbonyl contents in M. longissimus dorsi were significantly higher the 90th day of the storage, compared to the other intervals in both indoor reared lambs of Northeastern Bulgarian Fine Wool Breed and the crossbred animals, as well as in pastured crossbred lambs. In M. semimembranosus differences between the contents of the carbonyls in the intervals of measurement and the 90th day of the storage were significant in both animals of Northeastern Bulgarian Fine Wool Breed and the cross, reared indoors. پرونده مقاله