Effect of proteose-peptone on the heat gelation of whey protein isolates

Abstract

SUMMARY Whey proteins have been isolated from cheese whey by complex formation with carboxymethylcellulose. The protein preparations form stable gels and foams when reconstituted in water. A study has been made of the effect of concentration, pH and temperature on the gelling behaviour of the whey protein isolates, and the conditions necessary for a standard gelling test have been defined. Proteose-peptones (p-p) have been prepared from a whey protein isolate which showed a strong tendency to gel, and also from heated and unheated milk. The gelling behaviour of whey protein isolates, which showed either no tendency or a strong tendency to gel, has been studied in the presence and absence of added p-p. The quantities added varied from 0·05 mg isolated from unheated milk to 15 mg from heated milk. No change in gelling time was observed, and it was concluded that p-p were not responsible for the gelling behaviour exhibited by whey protein isolates.