Russell S M, Fletcher D L, Cox N A
Department of Poultry Science, University of Georgia, Athens 30602.
Poult Sci. 1994 May;73(5):739-43. doi: 10.3382/ps.0730739.
The effects of freezing on the recovery of mesophilic bacteria from broiler chicken carcasses were determined. Fifty fresh broiler carcasses were used in each of three independent trials. Ten carcasses were sampled at time of collection (Treatment 1: Day 0 control). The other 40 carcasses were sampled at Day 7 following one of four additional treatments with 10 carcasses each: held at 3 C (Treatment 2: 7-d control), frozen and then held at 3 C (Treatment 3: frozen control), temperature abused at 25 C for 12 h and held at 3 C (Treatment 4: temperature abused), and temperature abused at 25 C for 12 h, frozen, and held at 3 C (Treatment 5: temperature abused and frozen). Carcasses were sampled by rinsing, and total plate counts (TPC) expressed as log10 colony-forming units per milliliter and impedance detection times (DT) in hours were determined using incubation temperatures of 42 and 43 C, respectively. Results for TPC for Treatments 1 to 5 were 3.89, 3.52, 2.86, 6.53, and 5.57 log10 cfu/mL, respectively. Results for DT for Treatments 1 to 5 were 5.41, 6.50, 7.10, 2.55, and 3.42 log10 cfu/mL, respectively. Freezing reduced the ability to detect temperature abuse because of a significant reduction in the number of mesophiles recovered using either microbiological technique. Freezing appears to decrease, but may not completely eliminate, the ability of selective incubation to detect temperature abuse.
测定了冷冻对从肉鸡屠体中回收嗜温菌的影响。在三个独立试验中，每个试验使用50个新鲜肉鸡屠体。在采集时对10个屠体进行采样（处理1：第0天对照）。另外40个屠体在第7天进行采样，这40个屠体分别接受四种额外处理之一，每种处理10个屠体：保存在3℃（处理2：7天对照），冷冻后保存在3℃（处理3：冷冻对照），在25℃温度滥用12小时后保存在3℃（处理4：温度滥用），以及在25℃温度滥用12小时、冷冻后保存在3℃（处理5：温度滥用并冷冻）。通过冲洗对屠体进行采样，并分别使用42℃和43℃的培养温度测定以每毫升log10菌落形成单位表示的总平板计数（TPC）和以小时为单位的阻抗检测时间（DT）。处理1至5的TPC结果分别为3.89、3.52、2.86、6.53和5.57 log10 cfu/mL。处理1至5的DT结果分别为5.41、6.50、7.10、2.55和3.42 log10 cfu/mL。由于使用任一种微生物技术回收的嗜温菌数量显著减少，冷冻降低了检测温度滥用的能力。冷冻似乎会降低，但可能不会完全消除选择性培养检测温度滥用的能力。
