Oxygen transfer in foods using oxygen luminescence sensors: Influence of oxygen partial pressure and food nature and composition

Abstract

A rapid and easy to handle (on-line monitoring) method to achieve oxygen sorption kinetics was developed and tested on a large range of food products. Measurements were performed using luminescence sensors placed into of a thin layer of food material exposed to increasing oxygen contents in the atmosphere. From oxygen sorption kinetics diffusivity values could be calculated using a mathematical model based on Fick’s second law. A large range of model and real food were studied: water, agar gel, orange juice, mashed apple, mashed tomato, miglyol, olive oil and copra oil. Luminescence sensors allowed accurate measurements since they are no-oxygen consuming. Oxygen diffusion through food obeyed to Fick’s second law and was found to be independent of oxygen partial pressure. Oxygen diffusivity was shown to be higher in aqueous products than in oils. Diffusivities obtained at 20 °C were varying from 0.22 ± 0.01 × 10 −9 m 2/s for copra oil to 2.48 ± 0.07 × 10 −9 m 2/s for water.