Development of an analyser to determine the oxygen and carbon dioxide levels in the head‐space of packages

This paper describes the development of an analyser intended to measure the concentrations of CO₂ and O₂ present as part of the gas mixture in the head‐space of food packages. The efficiency of the measuring device was evaluated by analysing the atmosphere of packages containing the following food products: grated Parmesan cheese, milk powder and fresh pasta. A comparison between the results of the analysis performed with the newly developed analyser and those obtained by gas chromatography showed good correlation between the two methods. The O₂ and CO₂ analyser presented satisfactory accuracy (absolute error smaller than 2.5%, v/v) and precision (relative standard deviation varying from 0.2% to 8.5%). In addition, final results of the levels of both gas types present in the atmosphere submitted to analysis are obtained after about 2 min. The proposed analyser constitutes an alternative solution for the analysis of gases present in the head‐space of packages, especially when gas samples of very small volumes—about 200 μl—are to be used. Copyright © 1999 John Wiley & Sons, Ltd.