ICMSF methods studies. I. Comparison of analytical schemes for detection of Salmonella in dried foods

Twenty-six low-moisture food samples naturally contaminated with salmonellae were analyzed to compare the efficiency of sixty 25-g, fifteen 100-g, and three 500-g subsamples in recovery of salmonellae. In addition, the efficacy of wet compositing in recovery of salmonellae was studied by pooling in groups of five, the pre-enrichment broths from the 25-g and 100-g subsamples. Eighteen of the samples were positive by all sampling procedures. Four of the samples were negative when sixty 25-g subsamples were analyzed, four were negative by the fifteen 100-g sub-samples, and two were negative by the three 500-g subsamples. Wet-compositing results indicate the method is as sensitive in detecting salmonellae as the analysis of individual subsamples. The overall results indicate samonellae may be detected with equal facility by any of the sampling and analytical methods tested.