Presence and Significance of Bacillus cereus in Dehydrated Potato Products

Abstract

Dehydrated potato contains Bacillus cereus at a prevalences of 10 to 40% and at numbers usually less than 103 CFU g−1. B. cereus in dehydrated potato is likely to be present as spores that are able to survive drying of the raw vegetable and may represent a significant inoculum in the reconstituted (rehydrated) product where conditions favor germination of, and outgrowth from, spores. Holding rehydrated mashed potato alone, or as part of another product (e.g., potato-topped pie), at temperatures above 10°C and below 60°C may allow growth of vegetative B. cereus. Levels exceeding 104 CFU g−1 are considered hazardous to human health and may be reached within a few hours if stored inappropriately between these temperatures. Foods incorporating mashed potato prepared from dehydrated potato flakes have been implicated in B. cereus foodborne illness. This review is a summary of the information available concerning the prevalence and numbers of B. cereus in dehydrated potato flakes and the rate at which growth might occur in the rehydrated product.