A higher decimal reduction time means higher resistance towards H2O2.
Physicochemical property ranges of freshly squeezed and processed juices, and a previously established decimal reduction times of Escherichia coli O157 H7 at different heating temperatures were used in establishing a Central Composite Design of Experiment that determined the combinations of product and process variable used in the model building.
To verify the performance of the disinfectant against an organism on a specific surface, the decimal reduction time (D-value) should be investigated, taking into consideration the resistance of the same organism in direct contact with the biocide.
The equation for the line is log10 D = a - bt, where D is the decimal reduction time in s, a the intercept, -b the slope and t the treatment temperature in °C.
Also a theoretical calculation of the logarithmic decimal reduction of Salmonella is presented.
The resistance value (death kinetics) of a BI was characterized in terms of decimal reduction time, D-value, which is the exposure time required, under specified set of conditions, to cause one log10 or 90% reduction of the initial population (N0, bioburden) of viable BI in the suspension [ 7, 8].
These curves were properly described by a (primary) model deduced from the Weibull distribution, whose parameters, first decimal reduction time (Dβ) and shape, were expressed as a function of sorbic acid concentrations (secondary model).
During the pressure hold, as expected, the associated decimal reduction times (D values) decreased with an increase in pressure.
Survivor curves were fitted from plate count data by means of a two-phase linear model to determine lag times and slopes of the curves, from which decimal reduction times (D-values) and times to a 4-log10 inactivation (t4D) were calculated.
