Simulation of E-coli inactivation by carbon dioxide under pressure

Published isobaric semilogarithmic survival curves of E. coli were fitted with logS(t) = -b(P)t(n(P)) where b(P) and n(P) are pressure dependent coefficients. Pressure profiles, P(t), were generated with a double logistic model and the corresponding inactivation rate Is only a function of the momentary CO2 pressure and survival ratio, then dlogS(t)/dt = -b(t).n(t).{-logS(t)/b(t)}((n(t)-1)//n(t)). This differential equation was solved numerically to produce nonisobaric survival curves, which demonstrated the effects of the pressure level, treatment duration, and the come up time. They also enabled theoretical comparison of processes consisting of single and multiple compression-decompression cycles of equivalent duration.