STRUCTURE AND DYNAMICS OF OVALBUMIN GELS .3. SOLVENT EFFECT

Solvent effects on dynamical and thermal behaviors of ovalbumin (OVA) gels induced by thermal denaturation at high temperature of 160 degree s C were studied from dynamic shear modulus measurement, shear creep a nd creep recovery measurement, and DSC measurement. Two organic solven ts, glycerin (G) and ethylene glycol (EG), and their mixtures with wat er (W)(G/W and EG/W) were used as solvent for preparation of gels. Sta ble gels formed in pure glycerin took a fractal structure at OVA conce ntration C range of 15-45 wt% at a temperature specific to respective C, whereas a fractal structure was not observed for gels prepared in E G, G/W, and EG/W. The results were consistent with thermal denaturatio n behaviors of OVA in these solvents. Morphologies of two gels prepare d in water and glycerin were explored using high resolution SEM, which showed that a basic unit responsible for formation of OVA gels was sp heres with a diameter ranging from 20 to 40 nm, being much larger than 5.6 nm of the diameter of native OVA, and a fractal structure was rel ated to network formation accompanied by melting of these spheres.