Evaluating the behavior of Staphylococcus aureus and Bacillus cereus in dairy- and non-dairy-based aqueous slurries during manufacturing of table spreads

High moisture slurries used in production of table spreads may permit growth of Staphylococcus aureus and Bacillus cereus and subsequent production of heat stable enterotoxin. Compliance with the Food Safety Modernization Act (FSMA), specifically 21 CFR Part 117, Subpart B and Section 117.8 (c)(2) and (c)(3) requires a hazard analysis to determine if preventive controls are needed. In this study, growth of S. aureus and B. cereus in different dairy- and non-dairy based slurries during extended storage and use. Mathematical models were used to screen which slurries might support the growth of S. aureus and B. cereus . Samples were individually inoculated with multiple strains of S. aureus and B. cereus to achieve a target level of 10 2 -10 3 CFU/g. Inoculated and uninoculated slurry samples were incubated at typically holding temperatures of 35°C (95°F), 46.1°C (115°F) and 54.4°C (130°F). Samples were removed and tested following inoculation (time zero), after 4 and 12 hours, and after 1, 2, 3, 4, 5, 6, 7 and 10 days of incubation at the target temperatures. All experiments were repeated in triplicate. Samples were analyzed for S. aureus and B. cereus using Baird-Parker agar and mannitol yolk polymyxin agar, respectively. Neither S. aureus nor B. cereus exceeded (P<0.05) proposed food safety limits (10 5 CFU/g) at the evaluated experimental conditions. The study highlights the role of multiple hurdles (e.g. pH, potassium sorbate and sodium benzoate, and salt and other ingredients) in assuring safety of in-process dairy- and non-dairy based slurries used in the production of table spreads. This study found that mathematical models can help risk managers make informed decisions during product development. Finally, the study findings indicate no significant risk of growth of the target pathogens associated with the dairy- and non-dairy based aqueous slurries used in manufacturing of table spreads.

Keywords: S. aureus, B. cereus, table spreads, risk assessment, FSMA, predictive modeling.