Effect of slaughter weight and aging time on the quality of meat from Awassi ram lambs

Thirty Awassi ram lambs were used to investigate the effects of live weight at slaughter (SW) and aging time (AT) on meat quality attributes of Mm. Semitendinosus, Semimembranosus, Biceps femoris and Longissimus. Lambs were slaughtered at 20, 30 or 40 kg live weight, and muscles of each lamb carcass were aged for either 24 h or 7 days. Warner–Bratzler shear force values increased (P < 0.01) with increasing live weight and decreased (P < 0.01) by increasing AT in both M. Semimembranosus and Biceps femoris. Lightness (L*) of the four muscles decreased (P < 0.001) with increasing weight but was not affected by AT. Aging time increased (P < 0.05) redness (a*) in Mm. Semitendinosus and Longissimus. Cooking loss was reduced (P < 0.001) by increased AT in M. Longissimus and by increasing (P < 0.001) live weight in M. Semitendinosus. Aging time had no effect on expressed juice of all muscles but it was improved (P < 0.001) with increasing live weight in M. Semimembranosus. pH values were significantly influenced for Mm. Semimembranosus and Biceps femoris and values were higher for lighter weight and decreased with increasing weight. Aging time did not influenced pH. In conclusion, meat quality for lambs slaughtered up to 30 kg was better than for lambs slaughtered at 40 kg with quality being improved by increasing aging time.