Rapid Fluorometric Analysis of Acid Phosphatase Activity in Cooked Poultry Meat

A new quantitative f1uorometric assay was used to determine poultry-muscle acid phosphatase (ACP) activity at five end-point temperatures (EPTs). Nonfrozen or frozen ground broiler and turkey breast and turkey dark meat (16 9) were packed in glass tubes (25 ×150mm) and heated to 62.8, 65.6, 68.3, 71.1 and 73.9°C in a water bath set 1.5°C above target EPT. After heating, samples were removed and immediately chilled (2-3°C). A 75 μl portion of an aqueous meat extract (1 meat/2 H₂O wt/wt) was added to 2.0 ml ACP substrate and the kinetic increase in fluorescence monitored at 38°C. The experiment was replicated three times. A curvilinear decrease in mean (N = 12) ACP activity occurred within each muscle type. Although freezing before cooking lowered ACP activity, it was not different (P>.05) from that of nonfrozen meat. Acid phosphatase activity (mU/kg) means (N = 12) with standard errors for EPTs between 68.3 and 71.1°C for broiler and turkey breast and turkey dark meat were as follows: 9270 ± 873 and 5548 ± 562; 9313 ± 665 and 6808 ± 521; and 4821 ± 398 and 3370 ± 281, respectively. This procedure provides a rapid (3 min instrument time), sensitive analytical method for quality-assurance process-control technicians or regulatory analysts to monitor EPT in cooked poultry.