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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 #411493
Research Project: Advanced Methods for Predictive Modeling of Bacterial Growth and Survival in Foods

Location: Microbial and Chemical Food Safety

Title: Evaluation of thermal inactivation kinetics of Escherichia coli O157:H7, uropathogenic E. coli (UPEC) and Salmonella spp. in ground meats by one-step dynamic analysis

Author
item Sheen, Shiowshuh - Allen
item Huang, Lihan

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/18/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Introduction: Thermal inactivation is one of the most effective and practical methods for eliminating foodborne pathogens in foods. This study aimed to evaluate and determine the thermal inactivation parameters of pathogens in ground meats using a one-step dynamic heating to minimize the residual errors globally. Methods: A multi-strain cocktail of Escherichia coli O157:H7, uropathogenic E. coli (UPEC), and Salmonella spp. were individually inoculated to irradiated ground meats. The samples, pressed to form a very thin layer, were heated to increase in temperature linearly from 30 to 70 degree C in a programmable water bath at 1.5 degree C per min. Samples taken when the water bath temperature reached 54, 57, 60, 63, and 67 degree C were evaluated for the survival counts, which were then used to determine the thermal resistance of each microorganism through non-linear regression, following the first-order inactivation kinetics. Each experiment was repeated three times randomly. Results:One-step dynamic analysis was used to analyze the dynamic survival curves. The z values obtained were 6.45, 5.40 and 5.82 degree C for E. coli O157:H7 (in ground beef), UPEC (in ground beef), and Salmonella spp. (in ground chicken), respectively. The estimated log(D0), representing thermal resistance at 0 degree C, was 11.4±0.4, 13.6±0.8, and 12.5±0.5 min for E. coli O157:H7, UPEC, and Salmonella spp., respectively, indicating the D value at 0 degree C is almost infinite. The D value (at temperature T) can be calculated using equation: log(D) = log(D0) – T/z. The results show that the D and z values obtained from this study are very similar to the values reported in the literature. Significance: The results of this study show that one-step dynamic analysis is an effective method to determine the thermal resistance of foodborne pathogens accurately and quickly in foods, while minimizing the residual errors globally.