Aged-beef quality and fatty acid profile of subcutaneous fat from Nellore and Nellore × Angus crossbred young bulls finished in the feedlot with a high-lipid diet

Abstract

Context Although beef consumption has been linked to increased blood cholesterol, it has positive impacts on human health and provides essential nutrients of high biological value. Aims This study investigated the effects of aging time on beef quality, the chemical composition of the Longissimus thoracis (LT) muscle, and the metabolite and fatty acid profile of the subcutaneous fat from young bulls finished in feedlot with a high-lipid diet. Methods Fifty young bulls were divided into groups following their breed composition, Nellore (n = 25) and Angus × Nellore crossbred (n = 25), and randomly assigned into four pens. The feedlot phase consisted of 105 days of feed, and the diet (80% concentrate) was formulated to meet or safely exceed the requirements of beef cattle to achieve an average daily gain of 1.6 kg/day. After slaughter, meat samples were collected between the 11th and 13th ribs 24 h postmortem. Steaks were aged for 1, 14, 28, and 42 days. Key results No differences were observed for total weight loss, drip loss, and cooking loss between the genetic groups (P > 0.05). An increase in lipid oxidation was observed for TBARS in the LT beef and subcutaneous fat (P < 0.01). Shear force was influenced by breed and aging time (P < 0.01). There was a significant interaction between aging time and the parameters L* a*, b* c*, and h* (P < 0.01). The crossbred animals had greater (P < 0.01) concentrations of collagen, and Nellore had greater (P < 0.01) concentration of moisture in their LT beef. In total, 33 metabolites were identified in beef extract, and differences were observed in beef from both groups. Nellore animals had higher concentrations of polyunsaturated fatty acids and conjugated linoleic acid. Conclusions The shear force, collagen concentration, and moisture were affected by breeds, while the aging time affected lipid oxidation, shear force, and colour parameters. Different breeds and a high-lipid diet modified the metabolite profile of meat and the profile of subcutaneous fat. Implications These findings suggest that genetic manipulation could potentially be used to improve beef quality.