Manufacture of Cheddar cheese from high-pressure-treated whole milk

The cheese-making characteristics of high-pressure (HP)-treated milk were examined. The rennet coagulation time of pasteurised milk decreased after HP treatment at 400 MPa but increased after treatment at 600 MPa. The L-value (whiteness) of milk decreased directly after HP treatment but, over the course of coagulation, whiteness of HP-treated milk increased to the same level as in the control. Cheddar cheese was then manufactured from raw whole milk or whole milk treated by high-pressure (HP) at 400 MPa (HP400) or 600 MPa (HP600) for 10 min at 20 °C. HP treatment of raw milk at 600 MPa resulted in a 3.66 log reduction in the initial counts of non-starter lactic acid bacteria (NSLAB), decreased protein and fat content, as well as a lower pH compared to the control. Furthermore, higher treatment pressures resulted in increased incorporation of β-lactoglobulin into the cheese curd, with parallel increases in yield by 1.23% and 7.78% for HP400 and HP600 cheeses, respectively. Overall, this study showed that the effects of HP treatment on milk proteins increased rennet coagulation times and changes in cheese composition at day 1. Industrial relevance: High-pressure treatment is a novel technology which has been applied to a number of commercial food products. In this study, HP-induced changes in milk proteins resulted in increased cheese yields and increased cheese whiteness. In addition, HP treatment significantly reduced the microflora of raw milk cheese. Those attributes could be of interest for both industry and consumer.