This study was conducted to validate a simulated commercial baking process for plain muffins against E. coli O121 (isolated from the recent illness outbreak associated with flour), and compare the thermal inactivation parameters (D- and z-values) of cocktails of four isolates of E. coli O121 and three serovars of Salmonella (Newport, Typhimurium, and Senftenberg) in muffin batter. Flour samples were spray inoculated with the E. coli O121 or Salmonella cocktails, dried back to the pre-inoculation weight to achieve ~7 log10 CFU/g, and used to prepare muffin batter. For the muffin baking validation study using E. coli O121, muffin batter was baked at 375 °F (190.6 °C) oven temperature for 21 min followed by 30 min of ambient cooling. The E. coli O121 population decreased by >7 log10 CFU/g in muffins by 17 min of baking, and was completely eradicated after 21 min of baking and ambient cooling. The D-values of E. coli O121 and Salmonella cocktails in muffin batter at 60, 65 and 70 °C were 42.0 and 38.4, 7.5 and 7.2, and 0.4 and 0.5 min, respectively; whereas the z-values of E. coli O121 and Salmonella were 5.0 and 5.2 °C, respectively.

中文翻译：

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松饼中大肠杆菌O121和沙门氏菌的存活率和耐热性比较。

进行了这项研究，以验证针对普通松饼的模拟商业烘焙过程，以抵抗大肠杆菌O121（从近期与面粉有关的疾病暴发中分离），并比较四种分离物的混合物的热失活参数（D值和Z值） O121和三个沙门氏菌沙门氏菌（纽波特，鼠伤寒和Senftenberg）在松饼面糊中的含量。将面粉样品用大肠杆菌O121或沙门氏菌鸡尾酒进行喷雾接种，干燥至接种前重量，达到〜7 log10 CFU / g，并用于制备松饼面糊。对于使用大肠杆菌O121进行的松饼烘烤验证研究，将松饼面糊在375°F（190.6°C）的烤箱温度下烘烤21分钟，然后在室温下冷却30分钟。烘烤17分钟后，松饼中的O121大肠杆菌种群下降了> 7 log10 CFU / g。并在烘烤21分钟和环境冷却后完全消除。在60、65和70°C的松饼面糊中，大肠杆菌O121和沙门氏菌鸡尾酒的D值分别为42.0和38.4、7.5和7.2，以及0.4和0.5分钟。而大肠杆菌O121和沙门氏菌的z值分别为5.0和5.2°C。