Effect of alcohol-acid modification on physicochemical, rheological and morphological properties of glutinous rice starch

In the present study chemical modification of glutinous rice starch was carried out using 1-Buatnol-hydrochloric acid with varying time and temperature. The changes in physico-chemical, dynamic rheological and morphological properties of starch during hydrolysis was investigated. There was a significant increase in water solubility of starch due to modification; however, swelling and sedimentation value decrease after modification. The peak, hold and final viscosity of modified starches were decreased significantly as compared to native starch. Thermal properties and dynamic rheological properties of rice starch were changed with the change in time and temperature during modification. The storage (G') modulus, loss (G″) modulus, dynamic viscosity (η') and complex viscosity (η*) of modified starches were varied significantly. Analysis of microstructure revealed that the hydrolysis altered morphology of starch granules. The hydrolysis was affected the surface properties and granule size of rice starch. These results suggested that 1-butanol-HCl hydrolysis of glutinous rice starch can be a preferred way of modification.