Amino acid profile in the ripening of Grana Padano cheese: a NMR study

Among typical Italian cheeses, Grana Padano is the most famous, with the biggest production. The final step in the cheesemaking is the natural ripening, which involves many modifications of high complexity. In the present work, thermoanalytical and spectroscopic techniques are applied to Grana Padano cheese as a new analytical approach. These are thermogravimetry (TG) and derived thermogravimetry (DTG) to determine different types of water present in the cheese matrix, low-resolution nuclear magnetic resonance (NMR) to provide information on the water localization and displacements within the foodstuff and high-resolution nuclear magnetic resonance (NMR) to evaluate all the amino acids present in the cheese. Modifications in both water and free amino acid contents are observed, as a function of the ripening time and of the distance from the centre of the cheese wheel.