Characterization of the gelation and resulting network of a mixed-protein gel derived from sodium caseinate and ovalbumin in the presence of glucono-δ-lactone.

We investigated mixed-protein gels made from sodium caseinate and ovalbumin at different ratios with use of the acidification agent glucono-δ-lactone. Dynamic viscoelastic measurements revealed that increasing the ovalbumin content decreased the mechanical properties of the gel but accelerated onset time of the phase transition. Ultrasound spectroscopy during gelation revealed that the relative velocity gradually decreased, whereas the ultrasonic attenuation increased during the whole acidification process until gelation was complete, although these changes were much smaller than those observed with heat-induced gelation.