THE EFFECT OF INCUBATION-TEMPERATURE ON RECOVERY OF MESOPHILIC BACTERIA FROM BROILER CHICKEN CARCASSES SUBJECTED TO TEMPERATURE ABUSE

The optimum temperature to recover mesophilic organisms from temperatu re-abused broiler chicken carcasses was determined. Twenty broiler car casses were collected from a commercial processing plant in each of th ree trials. Ten carcasses were sampled immediately (Day 0 control); 8 carcasses were sampled after holding at 3 C for 3 d, temperature abusi ng at 25 C for 12 h, and holding them at 3 C for an additional 3 d (te mperature abused); and the remaining 2 carcasses were sampled after ho lding at 3 C for 7 d (Day 7 control). Whole carcass rinses were analyz ed using total aerobic plate counts (TPC) and impedimetric detection t imes (DT) at incubation temperatures of 41, 42, 43, and 44 C. Total pl ate counts decreased (P < .05) and DT increased (P < .05), at all incu bation temperatures tested, for carcasses held under refrigeration (Da y 7 control). This demonstrates that mesophilic bacteria, rather than psychrotrophic bacteria, are being enumerated, because psychrotrophs i ncrease on chicken skin upon cold storage. Total plate count was great er (P < .05) and DT was significantly lower for temperature-abused vs Day 7 control birds (5.7 vs 3.6 log10 cfu/mL and 3.7 vs 6.5 h), respec tively. These results indicate that temperature-abused carcasses can b e microbiologically distinguished from nonabused controls at all incub ation temperatures tested. Recovery of mesophiles was optimal at 41 an d 42 C for TPC and 41, 42, and 43 C for DT. Because there were no diff erences between DT at 41, 42, and 43 C, and because 42 C has been succ essfully used in the past, either 42 C or 43 C can be used when determ ining DT.