Effects of rate of pH fall, time of deboning, aging period, and their interaction on veal quality characteristics.

Abstract

Three groups of veal carcasses were selected on the basis of their pH in the longissimus lumborum muscle at 3 h postmortem (pH3) to study the effects and interaction with time of deboning on quality characteristics of veal. The following groups of 10 calves each were selected: 1) fast pH fall, pH3 < 6.2; 2) intermediate pH fall, 6.2 < pH3 < 6.7; and 3) slow pH fall, pH3 > 6.7. Longissimus thoracis et lumborum (LTL) muscles of sides of the selected carcasses were randomly assigned to be excised at either 24 or 48 h postmortem. Color, water-holding capacity, and shear force measurements were determined after an aging period of 2, 3, 4, 7, and 14 d, respectively. Color of longissimus muscle samples from veal calves with similar preslaughter blood hemoglobin values becomes significantly lighter with a faster pH fall. Muscle color was not affected by time of deboning and overall color of all longissimus samples remained stable during storage and was not affected by rate of pH fall and time of deboning. Cooking losses increased with both a faster rate of pH fall and by deboning at 24 h postmortem. Drip losses during vacuum storage were higher for muscles excised at 24 rather than 48 h postmortem. Both when deboned at 24 and 48 h, postmortem veal carcasses with a lower rate of pH fall had higher shear force (SF) values than did carcasses with a higher rate of pH fall. Deboning at 24 h postmortem resulted in higher SF values than deboning at 48 h postmortem. Differences in SF between 24- and 48-h deboning were larger in slower glycolyzing carcasses. Aging improved tenderness but did not fully reduce the difference in SF values between 24- and 48-h deboning. The results suggest that deboning of veal carcasses before the ultimate pH has been reached may result in muscle contraction, which may exert negative effects on tenderness and water-holding capacity of veal. Effects of time of deboning can, at least partly, be explained by differential effects on shortening of the muscle fibers.