Impact of pre-enrichment broth on recovery of S. typhimurium and reformed water activity on dominance and endurance of Salmonella in Indian sweetmeat milk (doodh) peda

Food-borne outbreaks associated with low water activity (a w ) foods involve Salmonella contamination, and its control is a significant challenge. In India, milk (doodh) peda is a low a w traditional and popular food. Accordingly, it is essential to determine the prevalence and survival of Salmonella spp. in artificially spiked milk peda stored for an extended period at different a w . Salmonella spp. was not detected in any of the 25 indigenous peda samples. Salmonella did not grow in low a w . However, S. Typhimurium ATCC 25241, which was inoculated artificially at a level of 1.5x10 4 CFU/g, survived in the spiked peda sample at 0.75, 0.56, and 0.32 a w . Survival of S . Typhimurium ATCC 25241 was observed for a more extended period (19 days) at lower a w than higher a w . These results confirmed that even though Salmonella spp. was not detected in milk peda samples, but can survive for a long time in contaminated samples. Salmonella survived for a long time by the osmoadaptation mechanism. These results revealed that the survival of S. Typhimurium is influenced by a w , and the prevalence of Salmonella in the peda sample was inversely proportional to a w .