Abstract: Purpose: To predict the shelf life of milk powder based on the change of oxygen concentration in the packaging headspace. Methods: The relative oxygen consumption rate was used to characterize the oxidation characteristics of whole milk powder, and the oxygen consumption threshold was determined by analyzing several oxidation indexes. Oxygen permeability of the packaging materials and oxidation characteristics of milk powder were integrated to characterize the change of headspace oxygen concentration, and a shelf life prediction model of milk powder was established based on the total oxygen consumption. The model was verified by accelerated storage test of polyethylene terephthalate/polyethylene packaged whole milk powder at 45 ℃. Results: The oxygen consumption threshold of whole milk powder was 0.041 47 mg/g. The experimental data of oxygen concentration in the packaging headspace during accelerated storage was consistent with the predicted data, and the relative deviation between the experimental and theoretical shelf life was 6.06%. Conclusions: The shelf life of whole milk powder can be predicted by the change of oxygen concentration in the packaging headspace.

Key words: shelf life; packaging; whole milk powder; relative oxygen consumption rate; oxygen consumption threshold