Strategies to improve nutritional and organoleptic quality of beef

Abstract

The aim of the present thesis was the study of the strategies to improve nutritional and organoleptic quality of beef. Two experiments were performed. The first experiment was undertaken to evaluate: i) the effects of supplementation of sunflower and linseed on growth performance and on nutritional and eating quality of meat from young bulls; ii) to test if a combination of linseed and sunflower seeds have a synergistic effect on fatty acids profile. Longissimus thoracis (LT) muscle from 32 Podolian x Limousine young bulls, aged for 8 days was used to evaluate the effect of oilseeds supplementation on nutritional and organoleptic quality of beef. The animals were fed with one four isoenergetic and isoproteic diets: control diet (CO) consisting of oat hay and concentrate and no supplemental fat; Linseed diet (LS): oat hay and concentrate with a supplementation of 10% linseed; Sunflower diet (SS): oats hay and concentrate with supplementation of 10%; Linseeds+Sunflowers seeds diet (LS+SS): oat hay and concentrate with supplementation of (1:1 w/w). The oilseeds supplementation diet increased the content of fatty acids n3 and decreased the ratio of n-6/n-3 in the muscle. The results demonstrate that the oilseeds supplementation is a nutritional strategy to improve the health n-3 fatty acid content in beef, also significantly improved the sensory properties of meat. The second experiment evaluated the effect of linseed supplementation and duration of feeding on fatty acids profile and on bioactive compounds of beef. 48 Friesian steers were randomly allocated during finishing period into six experimental treatments following a 3x2 factorial arrangement. The 6 treatments consisted of 3 different time of administration of diet: 40, 75 or 120 days before slaughter and 2 diet, control diet (CO) with no supplemental oilseeds and linseed diet (LS) containing 10% whole linseed. Linseed supplementation strongly affect the nutritional profile of meat, in particular meat from linseed group showed improvement the content of total monounsaturated (P<0.05), CLA (P<0.05), n3 polyunsaturated fatty acids (P<0.01) and bioactive substances such as creatine (P<0.05), carnosine and anserine (P<0.001). The duration of feeding and the interaction diet x duration significantly affected the proportions of fatty acids. The cholesterol content in meat was not affected by the dietary treatment while, significant differences (P<0.05) was found in meat after 75 days of linseed somministration.These results confirmed the better nutritional profile of meat from linseed group and demonstrated also that is not necessary to feed bovine for a long time to achieve a high increase of n3 polyunsaturated fatty acids, but 75 days of feeding is enough to obtain meat with beneficial characteristics.