Influence of salt content on eye growth in semi-hard cheeses studied using magnetic resonance imaging and CO2 production measurements

Eye growth in semi-hard cheeses was previously found to be subject to a strong spatial-dependency between the periphery and the core zone, and salt appeared to be a key factor to be studied to better understand the phenomenon of eye growth. An experiment was therefore designed to study salted and unsalted cheeses, by combining magnetic resonance imaging and a method for determining CO2 production based on gas pressure measurements. Chemical and rheological tests were also performed to make sure that only the salt content was modified between the two types of cheeses. It appeared that the presence of salt induced a delay in both bacterial development and CO2 production. The eyes in salted cheeses were found to be six times smaller, and their growth kinetics were slower. The combination of these two techniques thus made it possible to decorrelate factors and to quantify the influence of salt on eye development.