The evolution of an a parameter with treatment time can be fitted to both zero and first order reactions (Fig. 2).
However, with increasing temperature, the experimental data were better fitted to first order kinetics.
This finding was consistent with many previous studies (Avila & Silva, 1999; Garza et al., 1999; Ibarz et al., 1999).
The values of the kinetic constants increased with treatment temperature. This supported the theory that an increase in heating temperature induced the color shift to red.