On the Viscoelasticity of Denatured Ovalbumin Gel by Alkali

Abstract

Measurements of creep on 10% denatured ovalbumin gel by alkali (OG) and 3% gelatin gel (GG) were carried out and compared with each other to elucidate some properties of OG, as one of the fundamental problems of Pidan making.
Mechanical models of OG and GG were expressed with 4 elements and 3 elements respectively. Creep compliance of OG was analysed to three compliance of instantaneous modulus, one retardation modulus and viscosity in permanent flow. Although instantaneous modulus (3.2_??_3.3×10⁴) of GG and OG were almost the same, retardation time and retardation modulus of OG (162, 3.2×10⁴) were lower than those of GG. Rigidity and viscosity of OG gradually decreased with the increase of temperature. Increased rigidity and extended distribution of retardation spectrum were obserbed in addition of 0.1M NaCl. Addition of 2M urea increased viscosity and produced mechanism in short retardation time. Although both rigidity and viscosity of OG increased in addition of 0.1M Na₂SO₃, in 0.2_??_0.5M the former decreased again to the value in 0.5M NaCl, the latter to the value in control, and almost no change of retardation spectrum was shown. From these results the structure having the characteristic fluidity of OG was discussed.