Salmonella is the pathogen mostly associated with feed and dry food safety incidents and is a cause of many foodborne outbreaks. In most feed mills conditioning and retentioning systems are installed to improve the pelleting process but also as a kill-step to reduce the microbial load of the feed material. As knowledge about the efficiency of this kill-step at different process conditions in specific feed matrices is lacking, a study was carried out to characterize the inactivation kinetics of Salmonella spp. in broiler feed treated with superheated steam in laboratory scale. First, Salmonella strains commonly associated with feed materials were identified through a literature review. Five Salmonella strains were screened for heat resistance allowing selection of Salmonella Agona as one of the most heat-resistant serotype. Screening of triplicate strains of this serotype allowed selection of S. Agona RA1052 (isolated from animal feed) as the most suitable strain to be used in determination of D- and z-values at selected moisture levels and temperatures in broiler feed. D-values for S. Agona strain RA1052 in broiler feed mash adjusted to 12% moisture, determined within a customized autoclave at 65°C and 85°C, were 178.2 s and 3.1 s, respectively. At 19% moisture, D-values were 81.1 s at 65°C and 0.7 s at 85°C. To perform on-site challenge tests, the surrogate Enterococcus faecium ATCC 8459 (NRRL B-2354) with an equivalent heat resistance to S. Agona RA1052 was selected. The collected data will serve as a basis for the validation of conditioning and retentioning as a Salmonella spp. kill step in pilot and industrial scale.

沙门氏菌是主要与饲料和干食品安全事件相关的病原体，并且是许多食源性疾病暴发的原因。在大多数饲料厂中，都安装了调节和保留系统以改善制粒过程，但同时也是减少饲料原料微生物负荷的重要步骤。由于缺乏有关特定饲料基质中不同工艺条件下该杀灭步骤效率的知识，因此开展了一项研究以表征沙门氏菌的失活动力学。在实验室规模用过热蒸汽处理过的肉鸡饲料中添加。首先，通过文献综述鉴定了通常与饲料原料相关的沙门氏菌菌株。五沙门氏菌筛选菌株的耐热性，从而选择沙门氏菌为最耐热的血清型之一。对该血清型一式三份菌株的筛选允许选择S. Agona RA1052（从动物饲料中分离）作为最合适的菌株，用于确定肉鸡饲料中选定的水分含量和温度下的D和z值。在定制的高压釜中于65°C和85°C下测定的，调节至12％水分的肉鸡饲料中的Agona S. RA1052菌株的D值分别为178.2 s和3.1 s。湿度为19％时，D值在65°C下为81.1 s，在85°C下为0.7 s。要进行现场挑战测试，需替代粪肠球菌选择了具有与S. Agona RA1052相同的耐热性的ATCC 8459（NRRL B-2354）。收集的数据将作为验证条件和保留沙门氏菌的基础。扼杀试点和工业规模。