1887

Abstract

A plot of the thermal resistance of var. spores (log value) against temperature was linear between 37 and 190 °C ( = 23 °C), provided that the relative humidity of the spore environment was kept below a certain critical level. The corresponding plot for spores was linear in the range 150 to 180 °C ( = 29 °C) but departed from linearity at lower temperatures (decreasing value). However, the value of 29 °C was decreased to 23 °C if spores were dried before heat treatment. The straight line corresponding to this new value was consistent with the inactivation rate at a lower temperature (60 °C). The data indicate that bacterial spores which are treated in dry heat at an environmental relative humidity near zero are inactivated mainly by a drying process. By extrapolation of the thermal resistance plot obtained under these conditions for var. spores, the value at 0 °C would be about 4 years.

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/content/journal/micro/10.1099/00221287-101-2-227
1977-08-01
2021-05-16
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