Enumeration of coliforms and Salmonella in food prepared by blending and stomaching
Andrews, W.H.; Wilson, C.R.; Poelma, P.L.; Romero, A.; McClure, F.D.; Gentile, D.E.
Journal - Association of Official Analytical Chemists 61(6): 1324-1327
1978
ISSN/ISBN: 0004-5756 PMID: 365854 Document Number: 124786
The efficiencies of the Waring blender, the Stomacher 400 and the Stomacher 3500 were compared for preparing food samples for enumerating coliforms and Salmonella. Comparative most probable number (MPN) determinations were performed on 289 samples, representing 12 categories of nonfatty foods and 2 categories of fatty foods. Total coliforms were enumerated in 9 categories of nonfatty foods, and the geometric means of MPN in samples prepared by the Stomacher 400 and the Stomacher 3500 were not statistically different from those means of MPN of samples prepared by the blender in 100 and 89% of the categories, respectively. In the 3 categories of nonfatty foods in which fecal coliforms were enumerated, geometric means of the MPN of samples prepared by the Stomacher 400 and the Stomacher 3500 were not statistically different from those means of MPN of samples prepared by the blender in 3 and 2 of the food categories, respectively. Of the 3 categories of nonfatty foods in which Salmonella was enumerated, geometric means of the MPN of samples prepared by the Stomacher 400 and the Stomacher 3500 were not statistically different from those means of MPN of samples prepared by the blender in 3 and 2 of the categories, respectively. Adding Tween 80 to 2 categories of fatty foods at final concentrations of 0.5, 1.0 and 2.0% did not result in a consistent increase in coliform MPN obtained after stomaching with either model.