Non-intrusive Measurements of Headspace Gas Composition in Liquid Food Packages Made of Translucent Materials

摘要

The increase in chilled food consumption requires enhanced food safety and quality assurance. Food deteriorating processes are affected by the presence of oxygen, combined with factors such as time and temperature. To slow down deterioration processes and prolong shelf life, traditional packaging methods are being replaced by modified atmosphere packaging, for example. Oxygen, which is naturally present in the headspace of most food packages, is then reduced and controlled. Many sensing techniques for food quality assurance have been developed; however, almost all are intrusive, increasing the complication level and causing sample waste. The purpose of this paper is to introduce a non-intrusive technique [gas in scattering media absorption spectroscopy (GASMAS)] for measuring gas composition in the headspace of liquid food packages. The GASMAS method uses diode laser absorption spectroscopy combined with diffuse light propagation to analyse gas located inside solids and liquids. By illuminating the package from the outside and analysing the scattered light that emerges, the absorption from the gas inside the headspace can be studied. The GASMAS technique was evaluated on a series of carton packages with a high-quality orange juice and a nitrogen headspace. A clear variation in oxygen content was measured for samples with different storage times. The results demonstrate the possibility of using the GASMAS method for non-intrusive quality measurements in food products and packaging. They also indicate the potential for the non-intrusive quality assurance applications without waste of samples. A further development of the technique could include 'inline' quality control of packed food items throughout the food packaging supply chain.