THE INFLUENCE OF COOKING TEMPERATURE, ETHNIC GROUP AND AGEING PERIOD ON COOKING LOSSES AND TEXTURE OF BEEF

Steaks of longissimus thoracis muscle (LT) of 6 hypertrophied Piemontese (PH), 6 hypertrophied Piemontese x Friesian crossbred (PHxF) and 6 Friesian (F), were randomly assigned to 1, 3, 7 or 14 days of ageing. For each ageing period, two steaks were cooked to an end-point cooking temperature of 50 and 70°C, respectively. Cooking losses (CL) Warner-Bratzler shear force (WBsf), toughness (T) and total energy (E) were investigated. At 50°C endpoint cooking temperature, F had lower WB, T and E (P<0.01) than PH and PHxF. When meat is cooked at 70°C end-point cooking temperature, PHxF and PH showed the lowest and the highest CL, respectively (P<0.01). At d1 and d14 the lowest and the highest CL were observed (P <0.01). In comparison with d3 and d1, d14 showed a lower WB, T and E, while the same parameters resulted lower at d7 than at d1. At 50°C, the meat toughness depended on the strength of connective tissue and allowed to detect differences due to ethnic group. On the contrary, the temperature of 70°C, inducing the collagen solubilisation, highlighted the toughness depending on myofibrillar tissue. This end-point cooking temperature allowed to observe differences in CL both among ethnic groups and ageing periods.