EFFECT OF STUNNING TIME AND POLYPHOSPHATES ON QUALITY OF COOKED CHICKEN BREAST MEAT

Authors: YOUNG, LOUIS; NORTHCUTT, JULIE - UGA; LYON, CLYDE

Submitted to: Journal Of Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/8/1996
Publication Date: N/A
Citation: N/A

Interpretive Summary: There continues to be a problem with the color of commercially cooked poultry meat. Even though the meat may be fully cooked, it can exhibit a pink discoloration which consumers associate with under cooking. In this study, the effects if common slaughter practices - electrical stunning for humane slaughter and a marinade solution which increases meat juiciness - on meat acidity, color and tenderness were determined. It was found that, while no single condition is likely to cause fully cooked poultry to appear under cooked, certain combinations might. It is important for food processors to be aware of that possibility and to select processing conditions which avoid the problem.

Technical Abstract: The objective of this research was to determine effects of stunning time and polyphosphates on color, pH, and texture of chicken breast meat. Sixty broiler chickens were electrically stunned for 2 to 10 s in 2 s intervals and then conventionally slaughtered. Left and right Pectoralis major muscles were excised one h post-mortem. The left muscles (treated) were treated with a sodium tripolyphosphate salt solution, and the right(controls) were treated with a salt solution alone. All muscles were cooked to an endpoint temperature of 72 C in a 95 C water bath. Measurements of muscle pH were taken on the meat 1 h post-mortem, after treating, and after cooking. Color values and Warner-Bratzler shear values were evaluated on each cooked meat sample. As stunning time increased, pH increased at 1 h post-mortem but treating with either of the solutions eliminated this trend. Muscle pH also increased upon cooking except in the polyphosphate-treated muscles because the latter muscles achieved maximum pH prior to cooking. Stunning had no apparent effect on color values of the cooked meat; however, polyphosphate treatment resulted in meat that was darker and less red than controls. Longer stunning times resulted in greater shear values but polyphosphates did not affect Warner-Bratzler results. Taken together, these data suggest that processing variables which affect muscle pH also affect quality attributes.