High pressure treatment of reduced-fat Mozzarella cheese: Effects on functional and rheological properties

A study was undertaken to determine the effects of high pressure (HP) treatment on the rheological and cooking properties and appearance of reduced-fat Mozzarella cheese (RFMC). RFMC of approx. 10.7% fat was manufactured at pilot-scale. A portion of the cheeses (HP) were tempered at 21 °C for 16 h on day 1, high pressure-treated at 400 MPa for 5 min at 21 °C and then stored at 4 °C for 35 days. The remainder of the cheeses (C) were also tempered at 21 °C for 16 h and then stored at 4 °C for 35 days. There was a significant interactive effect of HP treatment and storage time on non-expressible serum per gram protein (NESP, i.e., an index of protein hydration in the cheese), the levels of which were significantly higher in HP than in C cheeses at day 2 of storage. HP treatment also significantly decreased the L* (reduced whiteness), a* (increased greenness) and b* (reduced yellowness)-values after storage for 1 day, but no effect was observed after 75 days storage. However, HP treatment did not significantly effect composition, pH, proteolysis, rheological properties of the unheated cheese or flowability and stretchability of the heated RFMC.