Stress-adaptive responses by heat under the microscope of predictive microbiology.

Autor: Valdramidis, V. P., Geeraerd, A. H., van Impe, J. F.
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Zdroj: Journal of Applied Microbiology; Nov2007, Vol. 103 Issue 5, p1922-1930, 9p, 2 Charts, 4 Graphs
Abstrakt: Aims:  In previous studies the microbial kinetics of Escherichia coli K12 have been evaluated under static and dynamic conditions ( Valdramidis et al. 2005, 2006 ). An acquired microbial thermotolerance following heating rates lower than 0·82°C min−1 for the studied micro-organism was observed. Quantification of this induced physiological phenomenon and incorporation, as a model building block, in a general microbial inactivation model is the main outcome of this work. Methods and Results:  The microbial inactivation rate observed ( kobs) under time-varying temperature conditions is studied and expressed as a function of the heating rate (d T/ d t). Hereto, a model building block related to the microbial physiology ( kphys) under stress conditions is developed. Evaluation of the performance of the developed mathematical approach depicts that physiological adaptation is an essential issue to be considered when modelling microbial inactivation. Conclusions:  Consideration, at a mathematical level, of microbial responses resulting in physiological adaptations contribute to the reliable quantification of the safety risks during food processing. Significance and Impact of the Study:  By taking into account the physiological adaptation, the microbiological evolution during heat processing can be accurately assessed, and overly conservative or fail dangerous food processing designs can be avoided. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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