Viscoelastic Changes of Rice Starch Suspensions During Gelatinization

Abstract

Dynamic rheometry was utilized to characterize viscoelastic changes during heat-induced gelatinization of 2 domestic rice starch suspensions, 1 from waxy and the other from indica rice. Gelatinization included 4 stages: suspension into sol, sol transition to gel, network destruction, and network strengthening. Increase in storage modulus (GЈ) was observed as early as about 47 ЊC. For indica rice, the maximum value (GЈ max ) was higher, and the decrease afterwards was slower, owing to its higher amylose content. The effects of heating time and temperature were found additive. Sealing samples with oil affected the accuracy of measurement. Finally, the network of starch gels had a larger fractal dimension than that of soy protein isolates previously investigated, suggesting firmer food texture.

Thermal and Rheological Properties of Mung Bean Starch Blends with Potato, Sweet Potato, Rice, and Sorghum Starches

“…concluded three factors accounting for the initial increase to G′ max : a closely packed network created by progressive swelling of starch granules, solubilized amylose molecules realized during heating, and increased gel volume. Low molecular weight amylopectin could also interact with the amylose matrix to strengthen the continuous phase or network, contributing to an increase in G′ (Hsu et al 2000). T G′max of various starches did not differ much and ranged from 72.0 (PT) to 77.4 (R), while G′ max had great variation ranging from 4303 (PT) to 12,200 (MB).…”

“…During controlled heating, G′ and G″ of all starches remained constant before 60°C. With amylose molecules dissolved from swollen starch particles, the starch suspension transformed into a "sol" as a result of a slight increase in G′ (Hsu et al 2000), before a steep increase to a maximum (G′ max ) with increasing temperature (65 to 70°C). concluded three factors accounting for the initial increase to G′ max : a closely packed network created by progressive swelling of starch granules, solubilized amylose molecules realized during heating, and increased gel volume.…”

Functional and physicochemical properties of pulse starch

“…) in G9 and G0 to a maximum value. These changes have been attributed to the formation of a network of swollen starch granules (Hsu et al, 2000). The moduli started decreasing after reaching a maximum value that indicates destruction of the gel structure (Tsai et al, 1997).…”

Effect of various plant starches on the quality characteristics of starch-based sweetened cow milk yoghurt

“…The brabender visco-amylograph, rapid visco-analyser and rotational viscometers have been used for measuring starch paste viscosity. Many scientists have also used the dynamic rheometer for studying the viscoelastic or rheological properties of starches (Hsu, et al, 2000;Lii, et al, 1996).…”