Résumé
The oxidation of ascorbic acid was chosen as a case study to investigate the effect of experimental errors and their propagation on the identification of the parameters of a kinetics law involving both ascorbic acid and oxygen content, on a typical food storage temperature range (8-33 degrees C) and under conditions representing anaerobic storage (0% O-2) to storage under air (21% O-2). A nonlinear method was used to identify kinetic parameters, both by incremental identifications of intermediate parameters and by direct identification of relevant parameters. Confidence intervals on all these identified parameters were evaluated using Monte Carlo simulations. The propagation error during the incremental stages of parameters identification induced a high uncertainty on the values obtained, thus a direct identification was preferred. The accuracy of the identified parameters was also shown to be strongly dependent on the experimental procedure carried out to obtain experimental data, but the time required to perform an ideal procedure is unrealizable. A methodology based on Monte Carlo simulations was proposed to optimize a priori the experimental procedure and data treatment to improve the characterization of such a kinetics law.