Ca ²⁺ ‐Induced Gelation of Pre‐heated Whey Protein Isolate

Abstract

ABSTRACT Addition of CaCl 2 to pre‐heated whey protein isolate (WPI) suspensions caused an increase in turbidity when pre‐heating temperatures were ≥ 64°C. Pre‐heating to ≥ 70°C was required for gelation. WPI suspensions which contained CaCl 2 became turbid at 45°C and formed thermally induced gels at 66°C. Thermally and Ca 2+ ‐induced gels showed significant time/temperature effects but the penetration force values in the Ca 2+ ‐induced gels were always lower. However, Ca 2+ ‐induced gels were higher in shear stress at fracture. The Ca 2+ ‐induced gels had a fine‐stranded protein matrix that was more transparent than the thermally induced gels, which showed a particulate microstructure.