Physicochemical, functional, thermal and pasting properties of starches isolated from pearl millet cultivars

Physicochemical, functional, thermal and pasting properties of starches isolated from five cultivars of pearl millet (Pennisetum glaucum) were studied. Amylose contents of the starches varied from 15.64 to 19.46 g/100 g of starch. Swelling power of different starch samples was highly restricted as it varied from 2.03 to 14.5 g/g at a temperature range of 60 to 90°C. The solubility of starch samples ranged from 7.25 to 12.13 g/100 g at 90°C. Light transmittance value of cultivar ‘HHB-67’ starch suspension was significantly lower than the transmittance value of the starch suspensions from other pearl millet cultivars (p 0.05). Pasting temperature of starch suspensions ranged from 88.1 to 90.2°C being the lowest and the highest for ‘Pioneer 86M86’ and ‘HHB-67’ cultivars, respectively. The paste from Pioneer 86M86 starch showed highest stability to shear force whereas, starch paste from Varun 666 and Pioneer 86M86 cultivars showed the higher set back ratio suggesting highest tendency to retrograde. The lowest To, Tp and Tc of 60.8, 67.1 and 74.1°C, respectively, were observed for starch from the cultivar ‘HHB-67’, whereas starch from cultivar ‘Varun 666’ showed the highest value for the same suggesting that the crystallite size and/or crystallite association within its granules are of higher order than starches from other cultivars. The retrogradation (%) was the highest for ‘Pioneer 86M86’ starch and it was the lowest for ‘HHB-67’ starch.