Survival of Clostridium botulinum in hot-fill meals

Sous-vide technology poses a risk of botulism. Twenty-six catering and retail cook-chill meals were challenged with non-proteolytic Clostridium botulinum (10³ spores/g) and incubated for 10 days at 10 °C. C. botulinum populations were enumerated on salicin tryptic soy agar and background microflora – on plate count agar. Botulinal toxin was detected using the enzyme-linked immunoassay. Only ten of the products supported the active growth of this pathogen. C. botulinum populations were static in another ten products which had a low pH except for two vegetable-based soups. In the remaining six products, C. botulinum populations reduced to undetectable levels. Although the predictive models described the general growth pattern of C. botulinum in the products supporting the active growth and the products with low pH values, they did not predict the spontaneous decline of this pathogen and the static populations in high pH vegetable soups.