THE EFFECTS OF CACL2 ON AGGREGATION OF WHEY PROTEINS

Aggregation rates of calcium-containing whey protein isolate (WPI) or beta-lactoglobulin solutions were determined by measuring the rate of change in turbidity (O.D.(400)). Aggregation at 40-70 degrees C follow ed zero order kinetics and did not fit a simple Arrhenius relationship , suggesting different mechanisms above and below denaturation tempera ture. The stoichiometry of CaCl2 and protein concentrations had a grea ter effect on aggregation at 40 and 50 degrees C than calcium concentr ation. Maximum aggregation rates occurred when CaCl2 (mM)/protein (%w/ v) was between 3.3 and 23.3. Results suggest that aggregation occurrin g at sub-denaturation temperatures during whey processing may be contr olled by altering the calcium to protein ratio.