MODELING OF DISSOLVED-OXYGEN CONCENTRATION DURING STORAGE OF PACKAGEDLIQUID FOODS

A mathematical model that combines oxygen uptake from the outside envi ronment with oxygen consumption by oxidative reactions, in a liquid pa cked food during storage, was developed. The model was applied to oran ge juice aseptically packaged in Tetra Brik Aseptic cartons, during st orage of up to 5 months at 4, 8, 20, 30, 40 and 50 degrees C. The para meters of the model, the oxygen mass transfer coefficient and the rate constant of consumption reactions, were estimated by fitting the mode l to the experimental data. The value of the rate constant estimated f or the system tested in this work, was three orders of magnitude great er than the value of the oxygen mass transfer coefficient. The influen ce of temperature on the reaction rate was well described by art Arrhe nius type equation, with an activation energy of 46 kJ/mole. This mode l was further tested with data reported in literature and it was found that it adequately describes the dissolved oxygen concentration chang es during storage. (C) 1998 Elsevier Science Limited. All rights reser ved.