Protein Quality of Cheddar Cheese Compared with Casein and Fabricated Cheese in the Rat

ABSTRACT The protein quality of freeze‐dried cheddar cheese, spray‐dried cheddar cheese, freeze‐dried fabricated cheddar cheese (with casein as the main protein source), and sodium caseinate was evaluated in rats using the protein efficiency ratio (PER) assay (AOAC procedures) in two feeding experiments with casein as the control. Biological evaluation of the products showed that PER values for freeze‐dried cheddar cheese were significantly higher than casein (3.7 vs 2.5). Freeze‐dried cheddar also had a PER value significantly higher than spray‐dried cheddar cheese (3.7 vs 3.0). Freeze‐dried fabricated cheddar cheese and sodium caseinate had PER values not significantly different from the casein control.