Kinetics of Clostridium sporogenes PA3679 Spore Destruction Using Computer‐Controlled Thermoresistometer

A modified version of a computer‐controlled thermoresistometer was used, with and without micropurge, to study the inactivation kinetics of Clostridium sporogenes PA 3679 spore destruction between 121–143°C in phosphate buffer (pH 7) and in mushroom extract acidified with citric acid. A shorter temperature come up time was observed with micropurge. The thermal death time (TDT) curve for spores in phosphate buffer with micropurge followed a straight line (z = 9.5°C). Without micropurge the curve could be described by two lines with z = 10.0 °C for temperatures up to 132.5 °C and z = 18.3 °C for higher temperatures. The spore heat resistance in mushroom extract was lower than in phosphate buffer. D T . values decreased exponentially as temperature increased, but acidification did not reduce thermal resistance at high temperatures.