Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 2, 1998
Publication Date: N/A
Interpretive Summary: Food manufacturers have recently tried to improve processing efficiency by centralizing food preparation as much as possible. In some cases, this has worked well, but in the case of poultry, a special problem has developed. Manufacturers have found that if the poultry is prepared for final cooking at the processing plant instead of at the retail outlet, it is sometimes tough. Previous research has shown that this toughening effect is related to use of a certain additive called "sodium polyphosphate" or "STPP". STPP is added to improve the moisture characteristics of the final product, but if it is added too soon after slaughter, it can interfere with biochemical reactions still taking place in the muscle fiber. This research shows that the rest period between slaughter and addition of STPP can be shortened significantly if the carcasses are electrically shocked immediately after slaughter to hasten the speed of the biochemical reaction. This information will provide economic benefits to the poultry industry by reducing the amount of space, equipment and personnel needed for processing the birds.
Technical Abstract: The objective of this study was to assess effects of treating electrically stimulated broiler forequarters with tripolyphosphates (TPP) after various post-chill aging periods on quality of the breast meat. Ninety six broilers were processed: 48 stimulated during bleeding & 48 not stimulated. Forequarters were harvested after chilling & after 2, 4, & 6 h post-chill. Left forequarters were marinated in salt solution & right forequarters in salt plus sodium TPP. After marination, quarters were cooked. Moisture binding, pH changes, color, & texture was observed. Stimulation resulted in a decline in muscle pH for the 0 post-chill group. Marination in TPP increased pH, & the effect was similar for muscles from forequarters at all post-chill times. Stimulation increased cooking loss & decreased cooked yield. Both cooking loss & yield were superior for forequarters harvested at 0 or 2 h post-chill compared to those harvested at 4 or 6 h post-chill. The TPP improved moisture binding regardless of electrical treatment or time of harvest. Color values were unaffected by marination time, but the TPP treated muscles had higher yellowness values than controls. Shear values of nonstimulated carcasses which received TPP treatment were 35% greater than those which received no TPP treatment. If the carcasses were stimulated, the toughening effect of the phosphate was eliminated.