Abstract
Abstract. In order to study the effect of different amounts of concentrate feed and the effectiveness of natural antioxidants on
the fatty acid stability of intramuscular fat during the first days postmortem, 75 young bulls of the Retinta breed were divided in three groups: 30 were grazed, 30 were fed on medium concentrate diets, and 15 were fed on high-concentrate diets. Young bulls were slaughtered at commercial weight, around a 500 kg final body weight. Samples from
Longissimus lumborum muscle were assigned to two ageing periods (0 and 7 d) and were vacuum packaged in
vacuum bags (O2 permeability: 9.3 mL O2/m2 per 24 h at 0 ∘C)
using an EGARVAC® sealer. Beef from grass-fed bulls showed a higher polyunsaturated fatty acid
content than concentrate-fed bulls. During the first 7 d postmortem, no changes in the fatty acids profile
were observed, because α-tocopherol content was optimal to prevent lipid oxidation. The higher level of natural
antioxidants in grass than in grain resulted in the stability of the fatty acid profile. This study shows that the
anti-oxidative potential of natural antioxidants in meat plays an important role during the first 7 d postmortem.
Funder
Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria