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Detergent and sanitizer stresses decrease the thermal resistance of Enterobacter sakazakii in infant milk formula.
T M Osaili1, R R Shaker, A N Olaimat
1Department of Nutrition and Food Technology, Faculty of Agriculture, Jordan University of Science and Technology, P.O. Box 3030 Irbid, 22110, Jordan. tosaili@just.edu.jo
Journal of Food Science
|April 5, 2008
Summary
Stressing Enterobacter sakazakii with common agents like acid, chlorine, or ethanol reduces its heat resistance in infant formula. This finding aids in developing safer thermal processing for powdered infant milk formula (PIMF).
Area of Science:
- Food microbiology
- Thermal processing
- Bacterial stress responses
Background:
- Enterobacter sakazakii is a pathogen of concern in infant milk formula.
- Thermal processing is crucial for eliminating microbial contamination in PIMF.
- Understanding stress effects on bacterial thermal resistance is vital for food safety.
Purpose of the Study:
- To determine the impact of various stresses (acid, alkaline, chlorine, ethanol) on the thermal inactivation of Enterobacter sakazakii.
- To evaluate the thermal resistance of stressed and unstressed E. sakazakii in infant milk formula.
- To provide data for optimizing thermal processing of PIMF to ensure infant safety.
Main Methods:
- Bacterial cells (Enterobacter sakazakii) were subjected to acid, alkaline, chlorine, and ethanol stresses.
- Stressed and unstressed cells were exposed to reconstituted powdered infant milk formula (PIMF) at temperatures ranging from 52-58°C.
- Alternative method involved mixing cells with PIMF before reconstitution with hot water (50-100°C).
- Decimal reduction times (D-values) and z-values were calculated using linear regression analysis.
Main Results:
- Detergent and sanitizer stresses generally decreased the thermal resistance of Enterobacter sakazakii.
- Specific stress conditions influenced the D- and z-values, indicating altered heat susceptibility.
- The study quantified the changes in thermal resistance under different stress scenarios.
Conclusions:
- Pre-stressing Enterobacter sakazakii can reduce its thermal resistance in infant milk formula.
- Findings are valuable for regulatory agencies and manufacturers in designing effective thermal inactivation processes.
- Optimized heating processes can enhance the safety of powdered infant milk formula against E. sakazakii contamination.
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