(2020) Physicochemical, pasting, and rheological properties of pearl millet starches from different cultivars and their relations

Abstract

Physicochemical, pasting, and rheological properties of pearl millet starches were studied and correlations among these properties were calculated. Amylose content, swelling power, and solubility of starches varied from 11.57 to 21.93%, 11.11 to 17.91 g g ⁻¹ and 12.20 to 15.20%, respectively. Volume% of starch granule size less than 10 µm varied from 36.23 to 48.34%, and 12.16 to 18.75% for above 20 µm size of granule. Peak viscosity of starches varied from 1291 to 1853 mPa·s, cv. RHB-173 had the highest value. Frequency sweep measurement of starch pastes revealed higher magnitude of G′ as compared to G″ with increase in to, indicating visco-elastic behaviour. Yield stress (σ o ), consistency index (K), and flow behaviour index (n) were observed as 40.73 to 115.72 Pa, 0.729 to 3.998 Pa·s, and 0.604 to 0.964, respectively. Starch pastes from cultivars studied showed shear thinning behaviour.