This study investigated the use of extrusion technology and fat replacers to produce high protein, low fat Cheddar cheese. In chapter 3, four different fat replacers were tested at the highest concentration level of each, as recommended by the manufacturers for low fat cheese, to investigate the change in cheese texture and optimize extruder conditions. In addition, the press time/pressure combinations of the extruded cheeses were optimized. The fat replacers and extruder conditions that were effective in improving the texture of low fat cheese were then used in chapter 4. In chapter 4, three fat replacers were used at three different concentrations (lowest, middle and highest) as recommended by the manufacturers for replacing fat in cheese. The fat replacers were microcrystalline cellulose (MCC 1) (0.125%, 1.06% and 2%), whey protein concentrate (WPC 2) (0.50%, 0.75% and 1%) and whey protein concentrate (WPC 1) (0.40%, 2.20% and 4%). These fat replacers were effective in improving the texture of low fat cheese as determined from the results of chapter 3. The extruded cheese samples with and without fat replacers were analyzed for texture at three different time periods (1 day, 1 week, and 1 month). None of the fat replacers used were effective in improving the texture of low fat cheese significantly. Since none of the treatments statistically improved the texture of low fat cheese, in the next part of the study, extrusion alone and WPC 1 at the middle concentration were then used to produce low fat cheese with high protein content by blending low moisture aged Cheddar cheese and nonfat cheese. Extrusion of cheese blends with or without fat replacer yielded cheese with high protein level. It was concluded from the study that the fat replacers we used were not effective in improving the texture but extrusion of aged Cheddar cheese with nonfat cheese can yield high protein cheese.

This study investigated the use of extrusion technology and fat replacers to produce high protein, low fat Cheddar cheese. In chapter 3, four different fat replacers were tested at the highest concentration level of each, as recommended by the manufacturers for low fat cheese, to investigate the change in cheese texture and optimize extruder conditions. In addition, the press time/pressure combinations of the extruded cheeses were optimized. The fat replacers and extruder conditions that were effective in improving the texture of low fat cheese were then used in chapter 4. In chapter 4, three fat replacers were used at three different concentrations (lowest, middle and highest) as recommended by the manufacturers for replacing fat in cheese. The fat replacers were microcrystalline cellulose (MCC 1) (0.125%, 1.06% and 2%), whey protein concentrate (WPC 2) (0.50%, 0.75% and 1%) and whey protein concentrate (WPC 1) (0.40%, 2.20% and 4%). These fat replacers were effective in improving the texture of low fat cheese as determined from the results of chapter 3. The extruded cheese samples with and without fat replacers were analyzed for texture at three different time periods (1 day, 1 week, and 1 month). None of the fat replacers used were effective in improving the texture of low fat cheese significantly. Since none of the treatments statistically improved the texture of low fat cheese, in the next part of the study, extrusion alone and WPC 1 at the middle concentration were then used to produce low fat cheese with high protein content by blending low moisture aged Cheddar cheese and nonfat cheese. Extrusion of cheese blends with or without fat replacer yielded cheese with high protein level. It was concluded from the study that the fat replacers we used were not effective in improving the texture but extrusion of aged Cheddar cheese with nonfat cheese can yield high protein cheese.