Death Kinetics of Escherichia Coli in a Combined Treatment With Heat and Monolaurin

A kinetic study was performed on the combined effect of monolaurin and heat on the death of Escherichia coli. The following results were obtained: (1) Monolaurin was about eleven times more active than that of sodium laurate; (2) Temperature enhanced the effect of monolaurin. True enthalpyentropy compensation effect was shown in this death reaction. The value of 341.9°K was obtained from the formula of ΔH*= T c ·ΔS*+ b and 331.5°K from Arrhenius plots as a compensation temperature; (3) The apparent minimum enhancing concentration of monolaurin ranged from 0.0056 mM to 0.013 mM, varying with the heating temperature. It may be concluded from the results of this study that the enhancing effect of monolaurin on the thermal death of E. coli corresponds to that of the amphoteric surfactant type (S type) agent defined in our previous report.