Molecular drivers of structural development in Mozzarella cheese

Mozzarella cheese undergoes significant structural rearrangement during maturation. This evolution in structure is critical to the product's functional performance. Understanding the driving forces responsible for these changes is of significant importance for manufacturers as it allows them to tailor their product and processes to optimise functionality. This investigation took a hierarchical approach to examine structural change and component mobility that occurs following manufacture. This brings together microscopy techniques with both 1H and 31P nuclear magnetic resonance. This enabled the observed structural evolution to be coupled with molecular mobility with regards to both water and phosphorous. Two primary drivers for change were proposed from which the other processes cascaded: changing strength in hydrophobic interactions and proteolytic breakdown. Initially the development of the cheese structure was driven primarily by a relaxation in protein matrix (caused by weakening hydrophobic interactions), resulting in the moisture equilibration processes. Further structural changes occurred as a result of the proteolytic breakdown of the casein and a possible relaxation in the protein structure. These proteolytic mechanisms dominated maturation behaviour after the moisture equilibration processes were substantially completed (typically >20 days).