C perfringens in herbs and spices

Clostridium perfringens spores are able to persist under harsh conditions, and thus, are predestined as high risk hazards in the food category dried spices and herbs.

In the present study, C. perfringens spores were produced, and then, screened toward their susceptibility to the antimicrobial activity of nine condiments. While heat activation for induction of spore germination led to a significant increase in recovery by almost 1 log10 colony forming units, the supplementation of germinants was negligible. The enumeration of C. perfringens before heat treatment revealed no detrimental effects by potential antimicrobial active compounds of the condiments. However, after heat activation a significant reduced recovery was determined for cinnamon and allspice in comparison to the control but it was still higher than without treatment. Probably, the heat improved the extraction of compounds inhibiting the germination of the spore and/or the outgrowth of the cell.

Practical applications

This study contributes to the understanding of the production of C. perfringens spores and their recovery from artificially spiked condiments. For an efficient spore production the following four factors are essential with decreasing importance, namely (a) the strain selection, (b) the preparation via a two-step approach, (c) the heat activation, and (d) the supplementation of germination factors. The detection of the actual contamination is of major importance especially for food control institutions. Neglecting the heat activation poses a potential risk for underestimation and false-negatives during food control analyses. Consequently, it is recommended to enumerate before and after heat treatment to detect vegetative cells as well as spores.

Production of Clostridium perfringes spores and their recovery from artificially spiked spices and herbs

1 March 2018

Journal of Food Safety

Philipp Lins

DOI: 10.1111/jfs.12453