Enhancement of the Nutritional Value and Eating Quality of Beef

Abstract

Consumer interest in the nutritional aspects of health has increased interest in developing methods to manipulate the fatty acid composition of ruminant products. Ruminant meats such as beef and lamb are often criticised by nutritionists for having high amounts of saturated fatty acids (S) and low polyunsaturated fatty acids (P).The P:S ratio in beef is approximately 0.1, the ideal being about 0.4. This project is part of a larger EU-supported project entitled Healthy Beef (Enhancing the content of beneficial fatty acids in beef and improving meat quality for the consumer: QLRT-CT-2000-31423). The Teagasc contribution, which was a collaboration between Grange Research Centre and The National Food Centre, focussed on nutritional manipulation of beef cattle. In particular, on exploiting grazing and fishoil as tools to enhance the concentration of “healthy” fatty acids in beef. The conclusions were: • The beneficial effect of a grazed grass-based diet on the fatty acid composition of beef was confirmed • The scale of this beneficial effect is strongly dependent on the duration of grazing • The optimum concentration of beneficial fatty acids was not achieved suggesting that feeding management prior to grazing is important • Grazing influenced beef colour and drip-loss in a durationdependent manner • Animals finished off grass for 40 or 98 days produced meat that was tougher than that from animals finished on silage and concentrates or fed grass for the last 158 days. • Fish oil supplementation enhanced the concentration in beef, of fatty acids that are beneficial to human health • The linear response to increasing level of fish oil consumption indicates scope to further enhance the concentrations of beneficial fatty acids in beef Wilting of grass prior to ensiling did not impact negatively on the overall content of n-3P in muscle, but it increased the concentration of conjugated linoleic acid • Dietary inclusion of fish oil or wilting of grass prior to ensiling did not affect muscle appearance • Fish oil seemed to increase tenderness but only at the high level of inclusion. This merits further study • There was some evidence that wilting of grass prior to ensiling enhanced meat tenderness. This needs to be confirmed.