The effect of pH, thiol reagent and time on properties of urea-induced whey protein gels

Solutions of whey protein isolate (11.0% by weight) in 6 mol/dm³ urea spontaneously formed gels at 25°C. The gelling rate increased exponentially, but the gels became less elastic and more fragile, as the pH was increased from 7 to 10. The addition of N-ethylmaleimide at <3 mmol/dm³ increased gel strength, whereas gelation was inhibited above 5 mmol/dm³. Gel strength increased by 25% during storage at 25°C for 7 days.