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Nonisothermal heat resistance determinations with the thermoresistometer Mastia
Author(s) -
Conesa R.,
Andreu S.,
Fernández P.S.,
Esnoz A.,
Palop A.
Publication year - 2009
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.1365-2672.2009.04236.x
Subject(s) - isothermal process , heat resistance , thermodynamics , materials science , chemistry , escherichia coli , biochemistry , composite material , physics , gene
Aims: To design and build a thermoresistometer, named Mastia, which could perform isothermal and nonisothermal experiments. Methods and Results: In order to evaluate the thermoresistometer, the heat resistance of Escherichia coli vegetative cells and Alicyclobacillus acidoterrestris spores was explored. Isothermal heat resistance of E. coli was characterized by D 60°C = 0·38 min and z = 4·7°C in pH 7 buffer. When the vegetative cells were exposed to nonisothermal conditions, their heat resistance was largely increased at slow heating and fast cooling rates. Isothermal heat resistance of A. acidoterrestris was characterized by D 95°C = 7·4 min and z = 9·5°C in orange juice. Under nonisothermal conditions, inactivation was reasonably well predicted from isothermal data. Conclusions: The thermoresistometer Mastia is a very suitable instrument to get heat resistance data of micro‐organisms under isothermal and nonisothermal treatments. Significance and Impact of the Study: The thermoresistometer Mastia can be a helpful tool for food processors in order to estimate the level of safety of the treatments they apply.