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

Abstract

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. Industrial relevance Mozzarella cheese has become one of the most prominent cheese varieties. Low fat cheeses are desirable and sought after but fat reduction adversely effects texture and cooking properties. Since HP treatment of milk has shown to improve texture of low fat cheeses it was relevant to investigate the impact of HP treatment on appearance and on rheological and cooking behaviour of reduced-fat Mozzarella cheese. Although time dependent changes were observed no clear trends or advantages could be attributed to HP treatment.