Characterization of rice starches extracted from Indian cultivars

Abstract

Physicochemical, morphological and pasting properties of starches isolated from four rice cultivars grown in India were studied. The amylose content ranged between 4.7 and 30.2% of starch, highest in K332 starch and lowest in SR1 starch. Swelling power, water solubility and water absorption capacity of starches increased with increase in temperature from 50 to 90 °C at 10 °C intervals. Highest swelling and water absorption was found in SR1 and lowest in K332 starches but reverse was observed in case of solubility that was highest for K332 and lowest for SR1 starch. The microstructure of starch granules from different rice cultivars showed the presence of mainly polyhedral granules having average size in the range of 4.0–5.2 µm. K332 showed the presence of smallest granules, whereas SR1 starch showed the presence of largest granules. X-ray diffraction pattern of rice starch from different cultivars showed typical A-type crystallinity. Pasting properties of starches differed significantly. Pasting temperature was highest for K332 and lowest for SR1, while peak viscosity was highest for aromatic rice and lowest for K448 starches. Higher setback was observed in K332 and lowest in SR1.