Lamb meat quality of two breeds with protected origin designation. Influence of breed, sex and live weight.

Lamb meat quality of two Portuguese products was examined. The influences of slaughter weight, sex and breed on eating quality were evaluated. Data were obtained from 72 lambs of two different breeds with protected designation origin. In accord with the normal slaughter weight in the region three classes were considered: A: 9-14kg live weight; B: 14-19kg live weight and C: 19-24kg live weight. pH of M. longissimus thoracis et lumborum muscle (MTL) was measured 1h and 24h after slaughter. Meat colour was estimated in the M. longissimus thoracis et lumborum muscle (MTL) muscle on the 12th rib using the L*a*b* system. Shear force was evaluated 72h after slaughter. Sensorial analysis was assessed by a trained taste panel of 12 members. The pH values found could be considered within the normal pH range, between 5.5 and 5.9. When the pH measurement was made 24h after slaughter, the heavy lambs had significant higher value than the light lambs. In relation to colour variables, live weight, sex and breed had no effect on the red index (a*). Lightness (L) decreased with increasing live weight and the light lambs had higher yellow index (b*) than the heavier lambs. Shear force increased with live weight and the Bragançano breed had a greater mean shear force than the Mirandesa (7.8 vs. 6.8kg/cm(2)). The heavy carcasses had more flavour intensity than the light ones. Mirandesa lambs had significantly lower values for toughness, stringy and odour intensity than Bragançana lambs.