Survival of Salmonella in a high sugar, low water-activity, peanut butter flavored candy fondant

This study examined the survival of a two strain mixture of Salmonella serovar Typhimurium in peanut butter flavored candy fondant during ingredient mixing and after storage up to 7 weeks. The sample was further tested for the presence or absence of Salmonella after six and twelve months of storage. Fondant ingredients mixed with inoculated peanut butter at a starting temperature of 70 °C led to 2.2 and 2.9 log cfu reduction in level of surviving Salmonella after 10 and 20 min of mixing respectively. A lower mixing temperature (65 °C) resulted in 1.2 log cfu reduction at both 10 and 20 min. Flavored fondant from both mixing temperatures were then stored at room temperature. During storage for up to 7 weeks, there was reduction in the level of surviving salmonellae by an average of 0.58 log cfu/week. The combination of heated mixing and storage for 5 weeks resulted in a 5-log reduction in the colony counts of salmonellae. In comparison, the average reduction of the inoculum in peanut butter was 0.45 log cfu per week totaling 3.16 log cfu after 7 weeks of storage. This study suggests that common candy industry mixing temperatures will not lead to a significant lethality of Salmonella in this product. Although the heated mixing followed by storage of flavored fondant for five weeks at room temperature provided a 5-log reduction in Salmonella survival, there was a presence of Salmonella in samples for up to twelve months of room temperature storage. Therefore, the need for good sanitation practices exists.

► Salmonella introduced in peanut butter can survive in processed peanut-butter flavored candy fondant.
► Samples in this study reached a 5-log reduction of Salmonella after 5 weeks.
► There was a presence of Salmonella in samples even after a year of storage.