typically associated with spray drying could not be counted on to supplant adequate pasteurization and postdrying sanitary procedures. Bradshaw et al. (1987), in studies of the thermal resistance of disease-associated Salmonella Typhimu-rium in milk, reported the organism did not survive pasteurization.

Doyle et al. (1985) studied survival of Listeria monocytogenes during manufacture and storage of nonfat dry milk. Concentrated (30% solids) and unconcen-trated skim milks were inoculated with 105-106 L. monocytogenes/mL. They reported reductions of 1.0-1.5 logw L. monocytogenes/g occurred during the spray drying process and that the organism progressively died during storage. The inoculated milks were not pasteurized before drying. Bradshaw et al. (1985) and Donnelly et al. (1987) reported that L. monocytogenes did not survive in milk during pasteurization. Earlier studies (Nichols, 1939; Higginbottom, 1944) also reported on destruction of microorganisms during drying and the fate of surviving organisms during storage.

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