James W O, Prucha J C, Brewer R L, Williams W O, Christensen W A, Thaler A M, Hogue A T
USDA Food Safety and Inspection Service, Washington, DC 20250.
J Am Vet Med Assoc. 1992 Sep 1;201(5):705-8.
In June and September 1988, the USDA Food Safety and Inspection Service sampled raw chicken carcasses at a federally inspected slaughter establishment in Puerto Rico to determine the effects of changing the scalding equipment on bacterial contents of raw poultry products. The scalding equipment was changed to a countercurrent configuration, with a postscald hot-water rinse cabinet that sprayed carcasses as they exited the scalder. Analysis of 250 carcass-rinse samples collected at preevisceration, prechill, and postchill sites over 7 days indicated that carcasses had mean aerobe plate counts of log(10)3.73 before evisceration, 3.18 before chilling, and 2.87 after chilling; Enterobacteriaceae counts of log(10)2.70 before evisceration, 2.25 before chilling, and 1.56 after chilling; and Escherichia coli counts of log(10)2.09 before evisceration, 1.61 before chilling, and 0.89 after chilling. Salmonellae were found on 24% of the carcasses before evisceration, on 28% before chilling, and on 49% after chilling. Although bacterial count reductions were significant at all 3 sites, the proportion of carcasses contaminated with salmonellae in this study was higher at the postchill than prechill site (49 vs 28%). This no doubt was caused by cross-contamination in the chiller. These percentages indicated that although simple scalder changes contributed substantially to the improvement of the bacterial quality of chicken carcasses, additional interventions in the chilling process (such as chlorination of chill water) are important to control cross-contamination and to preserve the positive effects obtained by the scalder changes.
1988年6月和9月，美国农业部食品安全与检验局在波多黎各一家接受联邦检查的屠宰场对生鸡胴体进行了抽样，以确定更换烫毛设备对生禽产品细菌含量的影响。烫毛设备改为逆流配置，配备了一个烫毛后热水冲洗柜，在胴体离开烫毛机时对其进行喷淋。对7天内从去内脏前、预冷和冷却后部位采集的250份胴体冲洗样本进行分析，结果表明，胴体在去内脏前的需氧菌平板计数平均为log(10)3.73，预冷前为3.18，冷却后为2.87；肠杆菌科计数在去内脏前为log(10)2.70，预冷前为2.25，冷却后为1.56；大肠杆菌计数在去内脏前为log(10)2.09，预冷前为1.61，冷却后为0.89。去内脏前24%的胴体检测出沙门氏菌，预冷前为28%，冷却后为49%。尽管在所有三个部位细菌计数的减少都很显著，但本研究中冷却后胴体被沙门氏菌污染的比例高于预冷部位（49%对28%）。这无疑是由冷却器中的交叉污染造成的。这些百分比表明，虽然简单地更换烫毛设备对提高鸡胴体的细菌质量有很大贡献，但在冷却过程中采取额外的干预措施（如冷却用水加氯）对于控制交叉污染和保持更换烫毛设备所取得的积极效果很重要。
