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ARS Home » Northeast Area » Wyndmoor, Pennsylvania » Eastern Regional Research Center » Microbial and Chemical Food Safety » Research » Publications at this Location » Publication #421417
Research Project: Development and Validation of Predictive Models and Pathogen Modeling Programs; and Data Acquisition for International Microbial Databases

Location: Microbial and Chemical Food Safety

Title: Effect of nisin and storage temperature on outgrowth of Bacillus cereus spores in pasteurized liquid whole eggs

Author
item GOSHALI, BINITA - University Of Georgia
item KAPOOR, HARSIMRAN - University Of Georgia
item KUMAR, GOVINDARAJ - University Of Georgia
item SHRESTHA, SUBASH - Cargill Corporation
item Juneja, Vijay
item MISHRA, ABHINAV - University Of Georgia

Submitted to: Foods
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/1/2025
Publication Date: 2/6/2025
Citation: Goshali, B.K., Kapoor, H.K., Kumar, G.D., Shrestha, S., Juneja, V.K., Mishra, A. 2025. Effect of nisin and storage temperature on outgrowth of Bacillus cereus spores in pasteurized liquid whole eggs. Foods. https://doi.org/10.3390/foods14030532.
DOI: https://doi.org/10.3390/foods14030532

Interpretive Summary: Bacillus cereus, a deadly bacterium, can cause food poisoning due to consumption of contaminated liquid whole eggs (LWE). Thus, there was a need to determine the time and temperature for LWE to remain pathogen-free and provide vital data for performing risk assessment on LWE. We investigated the growth of this pathogen in LWE supplemented with natural preservative, nisin, and developed a dynamic model to estimate the growth under different time/temperature scenarios. The model will assist retail food service establishments as well as the regulatory agencies to evaluate risk of B. cereus growth in LWE.

Technical Abstract: This study aimed to explore the effect of nisin on the growth kinetics of Bacillus cereus in liquid whole eggs. Samples supplemented with 0-6.25 ppm of nisin were inoculated with a four-strain cocktail of B. cereus spores (heat-shocked) and incubated at isothermal temperatures of 15-45C for growth studies. Baranyi model was fitted to all B. cereus isothermal growth profiles to generate maximum growth rate and lag phase duration (LPD). The statistical analysis showed that while the LPD of B. cereus was affected by both storage temperature and nisin concentration, growth rate was unaffected by nisin concentrations. Growth was considerably inhibited for 29 days on average in the sample containing 6.25 ppm at 15C. The extended Ratkowsky square-root model was fitted into the estimates of growth rate to analyze the effect of temperature on bacterial growth. A second-order polynomial model was generated to evaluate the effect of temperature and nisin on the LPD of B. cereus in LWE. A tertiary model was developed and validated using three dynamic temperature profiles, which showed that the model accurately predicted the growth rate but underpredicted the LPD, making it “fail-safe.” This disagreement was addressed by adjusting different h0 values for each experimental setup, which improved the model's LPD prediction accuracy. The findings indicate that nisin is effective in inhibiting the growth of B. cereus spores in LWE; thereby, enhancing food safety, and lowering the risk of illness.