17A-15 |
|
J. L. CHILDS, E. A. Foegeding, and C. R. Daubert. Dept. of Food Science, North Carolina State Univ., 238 Schaub Hall, Box 7624, Raleigh, NC 27695-7624 Shredding cheese allows it to melt more evenly and easily. A high quality shred would ideally be one that is uniformly cut. Some, but not all, factors affecting the shred quality are cheese composition, shredding temperature, shredding equipment and properties of the cheese including rheological and adhesive properties. Three mozzarella cheeses with varying levels of protein and fat and were evaluated to determine factors hat influence shred quality. A shred analysis was done by shredding blocks of cheese in a food processor under a 4 Kg load. The shredded cheese was then sieved to obtain a shred distribution of long, short and fine shreds. A probe tack test directly measured adhesion of the cheese to a stainless steel surface. Adhesion is related to surface energy and rheological properties. Surface energy was determined by measuring the contact angle when dimethyl sulfoxide and formamide are dropped on the cheese surface. Surface energy was determined by using contact angle values in equations derived from Young’s equation. Rheological characterization was done by creep and recovery tests. Creep and recovery data allowed for calculating the maximum compliance and percent recovery. All tests were done at 2, 7, 14, 21 and 28 days after cheese processing. A low quality cheese shred was represented by a large percentage of fines after shredding. The highest percentage of fines was from the cheese that had the highest percentage of fat and least amount of protein. This cheese also had the highest maximum compliance (i.e. the least firm) over the 28-day testing period. Surface energy did not vary over the three cheeses. Differences found in the tack test were not consistent with the differences from the shred test. Therefore, quality of shred was related to the rheological properties of the cheese. Shred quality can be maximized by alteration of rheological properties.
Session 17A, Dairy Foods: Cheese and microbiology
|