Factors affecting the pH decline in lamb after slaughter

Early postmortem pH has been linked to meat tenderness, especially in elect rical stimulation and/or rapid chilling applications. In order to evaluate factors that affect PH, a trial was carried out in which 96 lambs were slau ghtered over a period of 12 months. Carcass traits including age, sex and w eight were recorded and the pH of M. longissimus thoracis et lumborum was m easured at 0.5. 1.5, 4 and 24 h postmortem. Significant differences in pH w ere present over the 12 months but these differences could not be attribute d to seasonal or age factors. The sex of the animal had no effect on early pH (0.5 h, 1.5 h) or final pH (24 h), but the 4 h pH of female lambs was lo wer than that of male lambs (P < 0.001). Regression analysis, using 0.5 h p H and other measured traits. showed that individual male and female predict ion models were better (R-2 = 0.80 and RSD = 0.10) for predicting 4 h pH th an a combined model (R-2 = 0.74 and RSD = 0.11). (C) 2001 Elsevier Science Ltd. All rights reserved.