Effect of the local microenvironment on survival and thermal inactivation of Salmonella in low- and intermediate-moisture multi-ingredient foods.

Multi-ingredient foods having low- or intermediate-moisture characteristics may pose a special challenge to process design and validation. Ingredients of these foods can create local microenvironments that may have a distinct impact on pathogen survival and processing requirements. In this study, two model systems, each consisting of 80% commercial peanut butter (P) and 20% nonfat dry milk powder (M), were formulated to be identical in composition, but different in the source of the Salmonella contamination as originating in either the ingredient P or M.