HTST Inactivation of Peroxidase in a Computer‐Controlled Reactor

Abstract

Computer control of the movement of a sample holder and thermocouple into a high temperature steam reactor was found to be an effective system for studying the HTST inactivation of peroxidase. For the kinetic analysis of the heat activation of peroxidase at temperatures above 100°C a fit of the remaining percent of activity to a pseudo-kinetic model which accounted for regeneration was found to give rate constants or D values with a temperature dependence (z value of 33.5'C) in good agreement to data reported earlier.

Model System for Aseptic Processing of Paniculate Foods using Peroxidase

“…4) was 48.4ЊC (r 2 ϭ 0.99). This is higher than that reported by Weng et al (1991a, b) (11.1ЊC) and Joffe and Ball (1962) (9.8ЊC), but closer to those reported by Vamos-Vigyazo (1981) (27-31.4ЊC), David and Shoemaker (1985) (33.5ЊC) and Lineback (1994) (42.2ЊC). These differences probably are due to the different sources of peroxidase and the differing amounts of individual components in the enzymes used.…”

Kinetic Parameters for Inactivation of Bacillus stearothermophilus at High Temperatures

“…Duplicate profiles for a given piston residence time and reactor temperature were virtually superimposable; typical profiles for a 1 set exposure are shown (1) ti for replicate profiles. F values less than 1.5% (David and Shoemaker, 1985).…”

“…Based on heat transfer analysis (David, 1985), corrections for heating and cooling lags should be very small (except for the capillary tube at 135°C) and were not incorporated in the calculations. At 13X, the capillary tube required 16 set to heat within O.l"C of the oil temperature.…”

“…Details are given by David and Shoemaker (1985). Timetemperature data were acquired at the rate of 60 points per second.…”

“…The reactor used in the present work was a modified design of the Pflug and Esselen (1953) resistometer and was fabricated with accurate computer control of heating times and time-temperature data acquisition (David, 1985;David and Shoemaker, 1985). A piston carried spore suspension on membrane discs into a high temperature steam chamber.…”