LAUSR

Abstract A state diagram approach was used to compare heat stability among whey protein ingredients. Solutions were thermal processed and solubility, turbidity, and colloidal structure (sol, precipitate, or gel) were plotted against the variables of pH (3–7) and protein concentration (1–10%, w/w) to form state diagrams. Each of the whey protein ingredients produced state diagrams with unique patterns in the protein concentrations associated with colloidal structures and in heat stability regions. Relative heat stability among ingredients depended on the pH-thermal processing combination, in that patterns observed at pH ≤ 4.5 were not equivalent to patterns produced at pH > 4.5. Heating at temperatures of 100 °C for short times. State diagrams were able to differentiate among the whey protein ingredients, but absolute values were determined by the heating treatment.