Characterization of the reaction–diffusion kinetic model: (A) Parametric optimization to find γ to best fit low temperature and high temperature experimental data, (γ=3×108 s−1), R2 = 0.84) (B) Zonal characterization of the reaction diffusional model - reaction-limited zone (Z1), transition zone (Z2) within the absolute temperature range of 437–507K (pink dashed lines), transition point temperature (TTR = 470 K, marked in blue dotted lines) and diffusion limited zone (Z3) (C) Tabulated criteria for zonal characterization, temperature range and inactivation time.