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-degrees-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-degrees-C). Without micropurge the curve could be described by two lines with z = 10.0-degrees-C for temperatures up to 132.5-degrees-C and z = 18.3-degrees-C for higher temperatures. The spore heat resistance in mushroom extract was lower than in phosphate buffer. DT values decreased exponentially as temperature increased, but acidification did not reduce thermal resistance at high temperatures.