The effect of milk fat on cheddar cheese yield and its prediction, using modifications of the Van Slyke cheese yield formula

This study investigated the effect of milk fat content, in the range 0.54 to 3.33% (wt/wt), on rennet coagulation properties and the composition, actual yield, and predicted yield, as determined by the Van Slyke formula, of low-fat, half-fat, reduced-fat, and full-fat Cheddar cheeses. The yields predicted using the original Van Slyke formula were significantly lower than the corresponding actual yields for the low-fat, half-fat, and reduced-fat Cheddar cheeses. A more accurate prediction of cheese yield was obtained when the Van Slyke formula was modified to account for denaturation of whey protein on pasteurization and for the differences in fat recovery and content of nonfat, nonprotein cheese solids among cheeses of different fat contents. Increasing milk fat content resulted in cheese with significantly higher contents of fat, moisture in the nonfat substance, and salt-in-moisture and lower contents of moisture, protein, and ash. Both actual and dry matter cheese yields increased with milk fat content at rates of 1.16 +/- 0.15 and 0.93 +/- 0.10 kg/kg of fat, respectively. The milk fat content did not significantly influence the content of protein lost in the bulk cheese whey (i.e., whey expressed during draining and cheddaring). In contrast, fat losses in the bulk whey decreased significantly with increasing milk fat content in the range 0.54 to 2.00% (wt/wt). However, further increase in milk fat content to 3.33% (wt/wt) resulted in an increase in the proportion of milk fat lost to the cheese whey.