Science and Education Publishing Journal of Food and Nutrition Research 2333-1240 3 9 2015 11 17 Influence of Feeding System on Lipids and Proteins Oxidation, and Antioxidant Enzymes Activities of Meat from Aberdeen Angus Steers 581 586 EN A. Terevinto M.C. Cabrera A. Saadoun Fisiología & Nutrición, Facultad de Ciencias, Universidad de la República. Calle Igua 4225. Montevideo. Uruguay JFNR2015394 10.12691/jfnr-3-9-4 2015 7 19 2015 9 15 2015 11 15 Three feeding system were investigated to determine if any of them is more suitable to ensure a better antioxidant protection to meat. Animals were produced on pasture, pasture supplemented with corn grain, or feedlot. TBARS, protein carbonyls and antioxidant enzyme activities have been determined in fresh ad aged meat from Biceps femoris of Aberdeen Angus steers. No feeding system showed clear protection against lipids and protein oxidation in fresh meat. However, aged meat suffer always lipids and protein oxidation independently of the feeding system. There is not a clear pattern of the action of the catalase antioxidant enzyme (no significant main effect). However, pasture based feeding system present a lower SOD (0.96 UI) and GPx (9.22 nmoles/min/mg protein) activity, versus feedlot (1.12 UI and 11.48 nmoles/min/mg protein, respectively). Based on the results of the present investigation, it seems difficult to conclude about the best feeding system advised to minimize the lipids and protein oxidation of meat.