The study was conducted to evaluate the pasting and rheological measurements of four different starches (wheat, rice, corn and chickpea) using starch pasting cell of the hybrid rheometer. The experiment was planned to initially record the pasting behavior of starches in the starch cell using heating, holding and cooling program. The cooked gels were then subjected to steady shear and dynamic rheological measurements in the same cell. The highest peak and the final and setback viscosities were recorded for chickpea starch while the lowest values were obtained for the rice starch. The pasting curves of different starches represented the typical curve as observed using the traditional visco-analyzer or visco-amylograph. All the studied starches represented shear-thinning non-Newtonian behavior (n was less than 1) when studied for their steady shear properties. The starches could be classified from less to more pseudoplastic as rice>corn>wheat>chickpea. The activation energy of rice starch was highest (142719 J/mol) while the activation energy of chickpea starch was lowest among all the starches (13291 J/mol). The storage moduli, loss moduli and tan ? were increased with increasing the frequency, and the crossover was also observed in corn, rice and wheat starch at the higher frequency. It is well evident from all the studied parameters that starch cell can be conveniently used to study the pasting and rheological properties of starches.
Pasting and Rheological Properties of Different Starches Using Starch Cell of Discovery Hybrid Rheometer
