Efecto de la alimentación sobre la calidad de la carne de vacuno en la IGP "Carne de Ávila"

With the aim on one side to achieve an attractive product, differentiated and guaranteed quality of the label ‘PGI Carne de Ávila’ for the consumer, and on the other side, to optimize and maximize profitability for the farmer, 24 males of the breed Avileña-Negra Ibérica have been used. Half of the animals were fed a mixture of silage (70 per cent) and concentrate (30 per cent) (SILO batch) and the other half concentrate and cereal straw (PIENSO batch) during the fattening period to assess the effect of feeding, the effect of ageing (7, 14 and 21 days) and the effect of packaging (modified atmosphere, MAP, and vacuum packaging) on nutritional, sensory and instrumental meat quality of three muscles longissimus dorsi (LD), semitendinosus (ST) and pectoralis profundus (PP). The use of corn silage as an alternative to conventional concentrate during the fattening period did not alter production parameters concerning average daily gain, carcass yield and fatness, although there is a trend to a lower conformation of the carcass of animals receiving corn silage. The chemical composition, intramuscular fat and lipid oxidation were similar in both diets in the three muscles, except for a minor oxidation in the meat of SILO after 7 days of display in MAP for LD and PP. Regarding the fatty acid profile of LD muscle, the silo improves meat content in the n-3 fatty acids, conjugated linoleic acid (CLA) and the ratio n-6-n-3, but decreases monounsaturated fatty acids (MUFA) increasing saturated fatty acids. An the same time, silo improves the content in n-3 fatty acids, polyunsaturated fatty acids and the ratio n-6-n-3 but decreases MUFA without affecting the CLA in the PP and ST muscles. In the meat colour of LD and ST muscles, the silage increases the lightness (36.92 vs. 35.95), reduces redness (9.36 vs. 10.39) and tends to reduce the Chroma. The type of diet does not affect the texture and water holding capacity of meat for ST and PP muscles, but the LD of animals in SILO has lower toughness and load at 20 per cent compression, with a tendency to increase cooking losses. In relation to the sensory quality, corn silage improved tenderness and flavour in the three muscles, extending one day the visual acceptability of the LD at purchasing. Meat exposed in MAP has a better colour resulting in better visual acceptability, but the texture is adversely affected in the ST, the same as the lipid oxidation in LD piece if stored for more than 7 days. Therefore, tenderness and taste acceptability by consumers are altered. Although the meat in vacuum packaging stabilizes oxidation and provides a proper atmosphere for the tenderizing process, it does not show an attractive colour for the consumer.