Rheological Analysis of the Effect of Gelatinization of Starch Added to Fish-Meat Gel Based on Volume Changes

Abstract

The influence of adding starch on the elastic properties of fish-meat gel was studied by measuring its compression property and dynamic viscoelasticity. Samples with pregelatinized starch and with and without raw starch were used. Starch samples were used, as well. The results of the compression test were plotted using an equation obtained by substituting for volume changes as a function of β and μ directly into the original Mooney-Rivlin equation, ƒ=C₁(2λ-4βμ)+C₂(4β²λ-4β²μ-4β³μ), where ƒ is the stress, λ is the draw ratio, and C₁ and C₂ are constants. Fish-meat gels showed higher C₁ and C₂ values at 80°C than at 90°C, but the modulus of surimi showed a higher value at 90°C than at 80°C. Therefore we hypothesized that the gelatinization of starch was prevented by the surimi protein in the fish-meat gel at 90°C; the sample heated at 90°C showed lower packing effect than the sample heated at 80°C. And we also hypothesized the presence of the optimum heating temperature indicated a higher packing effect on the surimi protein.