Résumé
This study focuses on CO2 diffusivity, which is one of the most important factors impacting eye growth in semi-hard cheese, but yet has scarcely been investigated in literature. The effect of compositional and ripening parameters on experimental CO2 diffusivity in semi-hard cheese was studied. CO2 diffusivity in semi-hard cheese showed a complex relationship with temperature in the range 4 to 25 °C, represented by a quadratic curve with the highest diffusivity at 13 °C. Salt was found to impact CO2 diffusivity, with a decrease of about 60% for 0 to 2.7% w/w salt addition, which may be ascribed to viscosity increase of the cheese matrix and “salting in” effect of protein. CO2 diffusivity was found to increase with moisture content from 39 to 42% w/w, then it decreased from 42 to 48% w/w. Inevitable changes in protein content of the three cheese variants may be responsible for the complex behaviour observed.