Influence of Cooling Rate on Growth of Bacillus cereus from Spore Inocula in Cooked Rice, Beans, Pasta, and Combination Products Containing Meat or Poultry.
Juneja, Vijay K
Mohr, Tim B
Snyder, O Peter
J Food Prot
VKI Lecture Series, Progress in flow instability analysis and laminar-turbulent transition modeling
International Association for Food Protection
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Juneja, V. K., Mohr, T. B., Silverman, M., & Snyder, O. P. (2018). Influence of Cooling Rate on Growth of Bacillus cereus from Spore Inocula in Cooked Rice, Beans, Pasta, and Combination Products Containing Meat or Poultry.. J Food Prot https://doi.org/10.4315/0362-028X.JFP-17-397
The objective of this study was to assess the ability of Bacillus cereus spores to germinate and grow in order to determine a safe cooling rate for cooked rice, beans, and pasta, rice-chicken (4:1), rice-chicken-vegetables (3:1:1), rice-beef (4:1), and rice-beef-vegetables (3:1:1). Samples were inoculated with a cocktail of four strains of heat-shocked (80°C for 10 min) B. cereus spores (NCTC 11143, 935A/74, Brad 1, and Mac 1) to obtain a final spore concentration of approximately 2 log CFU/g. Thereafter, samples were exponentially cooled through the temperature range of 54.5 to 7.2°C in 6, 9, 12, 15, 18, and 21 h. At the end of the cooling period, samples were removed and plated on mannitol egg yolk polymyxin agar. The plates were incubated at 30°C for 24 h. The net B. cereus growth from spores in beans was <1 log after 9 h of cooling, but the pathogen grew faster in rice and pasta. In combination products, the net growth was as follows: 3.05, 3.89, and 4.91 log CFU/g in rice-chicken; 3.49, 4.28, and 4.96 log CFU/g in rice-beef; 3.50, 4.20, and 5.32 CFU/g in rice-chicken-mixed vegetables; and 3.68, 4.44, and 5.25 CFU/g in rice-beef-mixed vegetables after 15, 18, and 21 h of cooling, respectively. This study suggests safe cooling rates for cooling cooked rice, beans, pasta, rice-chicken, rice-chicken-vegetables, rice-beef, and rice-beef-vegetables to guard against the hazards associated with B. cereus.
European Research Council (259620)
External DOI: https://doi.org/10.4315/0362-028X.JFP-17-397
This record's URL: https://www.repository.cam.ac.uk/handle/1810/288101