Drying technologies are often evaluated on their efficiency to remove moisture and impact on sensory quality of products. The decontamination effect against foodborne pathogens, however, is rarely investigated. This study investigated the inactivation of foodborne pathogens and surrogates on basil leaves during drying, from characterizing thermal resistance of strains in a_w-adjusted basil to collecting decontamination data under various drying processes. Salmonella Senftenberg was the most resistant pathogenic strain tested during heating on basil leaves. A treatment of 20 min at 60 °C reduced S. Senftenberg by 4.7 and 3.7-log on basil leaves at water activity of 0.99 and 0.95, respectively. The pronounced increase in strains’ thermal resistance at reduced water activity was also observed during dynamic hot-air drying. Overall, more than 4-log reduction of S. Senftenberg was achieved after 90 min, 40 min and 20 min drying in a laboratory oven at 60 °C, 80 °C and 100 °C, respectively. Upscaling experiments in a pilot dryer using surrogate strains provided additional confirmation on the decontamination efficiency and effect of product moisture content during drying. Results from surrogate strains suggested that Escherichia coli P1 showed to be a more suitable surrogate for hot-air drying processes of basil leaves than Enterococcus faecium.

干燥技术通常会评估其去除水分的效率以及对产品感官质量的影响。然而，很少研究对食源性病原体的去污效果。这项研究调查了干燥过程中罗勒叶上食源性病原体和替代物的失活，从表征经过_w调整的罗勒中菌株的耐热性到收集各种干燥过程中的去污数据。沙门氏菌（Salmonella Senftenberg）是在罗勒叶上加热期间测试的最抗病原性菌株。在60°C下处理20分钟可降低S.Senftenberg在罗勒叶上分别以4.7和3.7对数的水分活度分别为0.99和0.95。在动态热风干燥过程中，还观察到在水活度降低时菌株的耐热性显着增加。总体而言，超过4-log减少S. Senftenberg的90分钟，40分钟和在60℃，80℃和100℃下，分别烤箱实验室20分钟干燥后达到了。在使用替代菌株的中试干燥机中进行的放大试验进一步证实了去污效率和干燥过程中产品水分含量的影响。替代菌株的结果表明，与粪肠球菌相比，大肠杆菌P1更适合罗勒叶的热风干燥过程。