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Modelling the effect of the redox potential and pH of heating media on Listeria monocytogenes heat resistance
Author(s) -
Ignatova M.,
Leguerinel I.,
Guilbot M.,
Prévost H.,
Guillou S.
Publication year - 2008
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1111/j.1365-2672.2008.03812.x
Subject(s) - redox , listeria monocytogenes , oxidizing agent , chemistry , thermal resistance , thermodynamics , inorganic chemistry , thermal , bacteria , biology , organic chemistry , genetics , physics
Aims: Study the effect of redox potential and pH of the heating media on Listeria monocytogenes heat resistance and model its action at fixed temperature. Methods and Results: The heat resistance of Listeria monocytogenes at 58°C was studied in Brain Heart Infusion broth as a function of pH (from 5·0 to 7·0) and redox potential ( E h7 ). The media redox was adjusted with nitrogen gas, potassium ferricyanide and dithiothreitol. A Weibull model was used to fit survival curves. The heat resistance parameter (δ 58°C ) was estimated from each inactivation curve. A major effect of pH was observed. Bigelow model was used to describe the effect of redox potential on the apparent L. monocytogenes heat resistance. The highest δ 58°C values have been obtained at pH 7·0 and oxidizing conditions. Conclusions: The developed model indicates that the E h7 has a significant effect and varied depending on the pH of the heating media. The z redox values, calculated from δ 58°C allowed quantifying the influence of heating media redox potential on L. monocytogenes thermal inactivation. Significance and Impact of the Study: The obtained model shows the action of redox potential on L. monocytogenes thermal destruction and might be useful to take into account in food thermal processes.