Cereulide in Powdered Infant Formula: Microbial Ecology, Detection, and a Supply-Chain Perspective on Risk Management

Abstract

Powdered infant formula (PIF) is a low-water-activity food in which microbial growth is not expected; however, contamination with heat-stable toxins may still represent a food safety concern. Cereulide, a cyclic dodecadepsipeptide produced by emetic strains of Bacillus cereus, presents a particular challenge because toxin production can occur during upstream wet-processing stages, while the molecule remains chemically stable during thermal treatment, spray drying, and storage. Consequently, finished PIF may contain biologically active cereulide even in the absence of detectable viable B. cereus cells. This review synthesizes current knowledge on the microbiology, genetics, and ecological niches of cereulide-producing B. cereus within dairy and ingredient supply chains. Particular attention is given to the ces gene cluster located on the megaplasmid pCER270, the environmental conditions that promote toxin biosynthesis, and the analytical strategies used for cereulide detection in complex food matrices. Advances in detection methods, including LC–MS/MS-based toxin quantification and molecular screening of emetic lineages, are discussed in relation to their application in food safety monitoring. A central practical finding of this review is that fermentation-derived lipid ingredients—particularly microbially produced arachidonic acid (ARA) and docosahexaenoic acid (DHA) concentrates—represent the principal upstream supply-chain driver of cereulide risk in PIF, and are therefore the priority target for ingredient-level surveillance and control. Finally, we propose a supply-chain-oriented surveillance framework integrating microbial enumeration, ces-gene screening, and targeted cereulide analysis to support risk-based management of cereulide hazards in PIF production systems.