An MRI method for monitoring the ripening of Grana Padano cheese

In this paper, we propose a magnetic resonance imaging (MRI) method for assessing the ripening stage of Grana Padano, one of the most appreciated long-ripened hard cooked Italian cheeses. The method is based on a combination of MRI analysis with a study of multi-component transverse relaxation (T2) distributions. Three different ripening stages (12, 16 and 20 months) were considered and, for each stage, three samples were investigated (for a total of nine samples). The relaxation profiles of differently ripened Grana Padano cheeses varied in terms of area fraction relative to the three observed components of T2 relaxation. In particular, a good linear relationship was observed between the area fraction of the first T2 population (mainly constituted by water protons in chemical exchange with labile protein protons) and the months of ripening. The proposed method might have a general validity for different kinds of cheese.