KINETIC-PARAMETERS FOR PRESSURE-TEMPERATURE INACTIVATION OF BACILLUS-SUBTILIS ALPHA-AMYLASE UNDER DYNAMIC CONDITIONS

Pressure-temperature inactivation kinetics of two enzymatic model syst ems based on Bacillus subtilis alpha-amylase (BSA), previously determi ned under isobaric-isothermal conditions, were studied under more real istic, i.e. dynamic, process conditions. The proposed kinetic model wa s found to accurately describe non-isobaric/non-isothermal inactivatio n of BSA in absence as well as in presence of 15% glycerol. Furthermor e the effect of pressure cycling on the inactivation of BSA (in absenc e of glycerol) was investigated. Multiple application of pressure seem ed to exert a more pronounced inactivation effect as compared to a sin gle-cycle process of the same total time. This additional effect, howe ver, could be completely attributed to the more extensive temperature variation occurring during pressure cycling.