Re. Klont et al., Effects of rate of pH fall, time of deboning, aging period, and their interaction on veal quality characteristics, J ANIM SCI, 78(7), 2000, pp. 1845-1851
Three groups of veal carcasses were selected on the basis of their pH in th
e longissimus lumborum muscle at 3 h postmortem (pH3) to study the effects
and interaction with time of deboning on quality characteristics of veal. T
he 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 selecte
d carcasses were randomly assigned to be excised at either 24 or 48 h postm
ortem. Color, water-holding capacity, and shear force measurements were det
ermined after an aging period of 2, 3, 4, 7, and 14 d, respectively. Color
of longissimus muscle samples from veal calves with similar preslaughter bl
ood 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 duri
ng vacuum storage were higher for muscles excised at 24 rather than 48 h po
stmortem. 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 carcass
es with a higher rate of pH fall. Deboning at 24 h postmortem resulted in h
igher SF values than deboning at 48 h postmortem. Differences in SF between
24- and 48-h deboning were larger in slower glycolyzing carcasses. Aging i
mproved tenderness but did not fully reduce the difference in SF values bet
ween 24- and 48-h deboning. The results suggest that deboning of veal carca
sses before the ultimate pH has been reached may result in muscle contracti
on, which may exert negative effects on tenderness and water-holding capaci
ty of veal. Effects of time of deboning can, at least partly, be explained
by differential effects on shortening of the muscle fibers.