Mathematical modelling of the effect of gas composition and storage temperature on the gas exchange rate of soft cheese

Soft and semi-soft farm cheeses made from pasteurized milk and having high moisture content are common craft products in Ireland. Theses cheeses have limited shelf-life and need to consider the release of CO2 and consumption of O2 for packaging design. The objective of this work was to analyze the effect of the storage temperature (4, 12 and 20 °C) and different gas compositions (O2 and CO2) on the gas exchange rate of whole soft cheese (camembert-type). The O2 consumption rate was found to be 26.21 ml kg−1 h−1 at 4 °C when stored in 19% O2 and 10% CO2 gas composition. It increased to 91.03 ml kg−1 h−1 when temperature increased to 20 °C at the same gas composition. A Pareto analysis showed that the temperature and O2 concentration have a significant effect on the gas exchange rate, whereas the effect of CO2 concentration was negligible. The effect of O2 concentration on the gas exchange rate was found to be well described by a Michaelis–Menten equation whereas an Arrhenius equation was used to fit the effect of temperature. Combining the effect of O2 and temperature, a global model was developed and validated which provided a good fit to the experimental data, explaining 94% of the variance of the data.