title: Effect of acute heat stress and slaughter processing on poultry meat quality and postmortem carbohydrate metabolism.
abstract: This study investigated the effects of acute heat stress and slaughter processing on poultry meat quality and carbohydrate metabolism. Broilers (200) were randomly divided into 2 groups receiving heat stress (HS; 36°C for one h), compared to a non-stressed control (C). At slaughter, each group was further divided into 2 groups for slaughter processing (L = laboratory; F = commercial factory). L group breasts were removed immediately after bleeding without carcass scalding or defeathering, and stored at 4°C. F group broilers were scalded (60°C, 45 s) after bleeding and defeathering. Then the breasts were removed and cooled in ice water until the core temperature was ≤4°C. Rates of Pectoralis core temperature and pH decline were changed by slaughter processing, but only HS affected ultimate pH in group L. HS muscles had higher L* values (P < 0.05) than controls at 24 h postmortem. Laboratory processing "hot-deboning" increased drip loss, which resulted in a lower cooked loss (P < 0.05). Postmortem glycolysis was affected only by HS. The speed of lactic acid accumulation and glycogen degradation was faster in the HS group than controls at 5 min postmortem. During storage the glycolysis rates were not different (P > 0.05). Sarcoplasmic protein solubility was higher in F processed birds (P < 0.05). HS decreased the solubility of myofibrillar and total protein in the L-slaughtered birds. Thus, HS caused a higher frequency of accelerated muscle glycolysis than controls. Factory processing (chilling) could not completely eliminate the effects of accelerated glycolysis caused by pre-slaughter HS.
authors.forename: R H
authors.initials: RH
authors.lastname: Wang
authors.forename: R R
authors.initials: RR
authors.lastname: Liang
authors.forename: H
authors.initials: H
authors.lastname: Lin
authors.forename: L X
authors.initials: LX
authors.lastname: Zhu
authors.forename: Y M
authors.initials: YM
authors.lastname: Zhang
authors.forename: Y W
authors.initials: YW
authors.lastname: Mao
authors.forename: P C
authors.initials: PC
authors.lastname: Dong
authors.forename: L B
authors.initials: LB
authors.lastname: Niu
authors.forename: M H
authors.initials: MH
authors.lastname: Zhang
authors.forename: X
authors.initials: X
authors.lastname: Luo
mesh_terms: D000818:Animals; D050260:Carbohydrate Metabolism; D002645:Chickens; D005511:Food Handling / Q000592:standards*; D006358:Hot Temperature; D008297:Male; D008460:Meat / Q000032:analysis* / Q000592:standards*; D011897:Random Allocation; D013312:Stress, Physiological
keywords: carbohydrate metabolism; chicken meat quality; heat stress; slaughter processing