Effects of ultrafiltration followed by heat or high-pressure treatment on camel and bovine milk cheeses

Abstract

The aim of this study was to assess the effects of ultrafiltration (UF) combined with high-pressure processing (HPP) or heat treatment on the quality of soft cheese produced from camel milk (CM) or bovine milk (BM). Milk was concentrated by UF (0, 1, and 2-fold) before treatment with HPP at 350 MPa or 550 MPa for 5 min at 4 °C or by pasteurization at 65 °C for 30 min or at 75 °C for 30 s. Cheeses were produced using starter cultures and camel chymosin and pH, yield, proximate composition, texture profile, rheological properties, and protein profiles were determined. The highest yield of BM cheese (26%) was observed under the treatment with 2-fold UF combined with HPP at 550 MPa. CM cheese had the highest storage and loss moduli as well as the total solid and protein content under this treatment. According to SDS-PAGE electrophoresis, CM cheeses were more susceptible to proteolysis and had a higher number of low-molecular-weight bands, indicating the involvement of some active enzymes compared with BM cheeses. In conclusion, UF combined with HPP can enhance the cheese total solid content and gel structure in CM cheese products compared with heat treatment.