Ll. Young et al., Effect of polyphosphate treatment and electrical stimulation on postchill changes in quality of broiler breast meat, POULTRY SCI, 78(2), 1999, pp. 267-271
The objective of this study was to assess effects of treating electrically
stimulated broiler forequarters with polyphosphates after various aging per
iods on quality. Ninety-six mixed sex broilers were electrically stunned an
d slaughtered. Half the carcasses were electrically stimulated during bleed
ing and half were not. Forequarters were harvested immediately after chilli
ng and after 2, 4, and 6 h postchill. Left forequarters were marinated in s
alt solution and right forequarters in salt solution plus sodium tripolypho
sphate. After marination, the quarters were cooked. Yield and meat pH were
evaluated immediately after marinating; and color, yield, and cooking loss
were evaluated after cooking. Electrical stimulation resulted in a decline
in muscle pH for the 0 postchill group. The pH of muscles from unstimulated
and stimulated carcasses from the remainder of the postchill times were eq
uivalent. Phosphate treatment increased pH at all postchill times.
Electrical stimulation of the marinated quarters increased cooking loss and
decreased yield regardless of marinade composition. Both cooking loss and
yield were superior for forequarters harvested at 0 or 2 h postchill compar
ed to those harvested at 4 or 6 h postchill. The phosphate improved moistur
e binding regardless of electrical treatment or time of harvest. Color valu
es of cooked muscles were unaffected by marination time, but the phosphate-
treated muscles had higher b* (yellowness) values than controls. Shear valu
es of unstimulated carcasses that received phosphate treatment were 35% gre
ater than those that received no phosphate treatment. When the carcasses we
re electrically stimulated, the toughening effect of the phosphate was elim
inated.