Rheological Properties of Heat-Induced Ovalbumin Gels Prepared by Two-step and One-step Heating Methods

Ovalbumin gave a transparent solution, transparent gel, or opaque gel on heating at low ionic strength, but a turbid gel, or turbid suspension at high ionic strength (one-step heating). The ovalbumin solution, once heated at low ionic strength, gave a transparent gel with a second heating at high ionic strength (two-step heating). Textural parameters of hardness and adhesiveness, viscoelastic parameters from creep curves, breaking energy and water-holding capacity of these gels were measured. Transparent gels by the one- or two-step heating were firm and elastic and had high water-holding capacity. Turbid gels by one-step heating were soft and less elastic and had low water-holding capacity. The relationship between gel properties and structure was discussed.