Here we developed an advanced reaction-diffusion model to predict the evolution of the myoglobin state in beef meat using numerous reactions with rate constants of different orders of magnitude. The initial scheme included 44 reactions from the literature. Sensitivity analysis proved that this initial scheme was equivalent to a simple 22reaction scheme. Results calculated with this scheme were compared against the spatial distributions of oxymyoglobin (MbO 2), metmyoglobin (MMb) and deoxymyoglobin (DMb) measured in meat cuts stored at 20 • C under air-permeable packaging. We found global agreement between measured and calculated distributions when adequate rate constant values were used, particularly for the formation of MbO 2 from DMb. The model was used to calculate evolutions in MbO 2 and MMb distributions under different situations (modified-atmosphere packaging, Fenton chemistry with or without water-soluble antioxidants, increased mitochondrial oxygen consumption). Results were used to discuss the underlying kinetics reaction mechanisms and the performances and limits of the model.