Submitted to: International Dairy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 16, 1996
Publication Date: N/A
Interpretive Summary: American consumers want reduced fat Mozzarella cheese with the same texture and melting properties as the original cheeses, which contain more than 16% fat. Manufacturing reduced fat Mozzarella requires some changes in certain steps, but the exact effects of these changes have to be known so that the best possible product can be made. Mozzarella containing around 10% fat was studied to learn if the arrangement of proteins affects the cheese. The results show that molecules of casein, which is the major protein in cheese, come together in Mozzarella to form clusters while the cheese is stored in the refrigerator. This appears to improve textural properties of the cheese. These results will give cheesemakers a better idea about changes in the structure of Mozzarella and how to take advantage of these changes when manufacturing a high quality product.
Technical Abstract: In an attempt to gain a better understanding of textural changes in Mozzarella cheese during storage, transmission electron microscopy was used to compare ultrastructure of the cheese on the day of stretching and after 6 weeks of storage at 4øC. Low- fat and full-fat cheeses were prepared from nonhomogenized milk and from milk homogenized at 10.3 and 17.2 MPa. Measurements of electron density distribution in the protein matrix revealed that casein submicelles became more aggregated during storage, but did not decrease in number. Submicelles appeared to be part of a new membrane formed around the fat globules in the Mozzarellas made from homogenized milk, which has been previously observed. Changes in submicelle structure could explain the differences in texture properties between fresh and stored Mozzarella cheeses, and between Mozzarellas made from homogenized and nonhomogenized milk.