Isolation Modification Characterization and Application of Starch from Different Indian Rice Varieties

Abstract

Rice (Oryza sativa) is one of the richest and widely available sources of starch. Starches therefore needed to be modified to overcome shortcomings and enhance the desirable physicochemical and functional properties. On the basis of apparent amylose content rice is classified as high amylose (gt25%), intermediate amylose (20-25%), low amylose (7-20%) and waxy or glutinous (1-2%). In first study three rice starches Mushkbudij (IM), SR1 (LS) and Aghoni bora (WA) with wide difference in apparent amylose content (22.7%, 9.8% and 0.3%) were subjected to single retrogradation and dual retrogradation-annealing hydrothermal treatments. The results suggested the dual modification technique can be suitably used for the synthesis of resistant starch. In the second study four rice starches Ranjit (HR), Mushkbudij (IM), SR1 (LS) and Aghoni bora (WA) with wide variation in apparent amylose content (27.2%, 22.7%, 9.8% and 0.3%) were subjected to single acetylation, hydroxypropylation and dual acetylation followed by hydroxypropylation treatments. In next study raw, retrograded and retrograde-annealed starches from three rice varieties were used to partially replace fat in fresh cream and prepare whipping cream with approximately 15% final fat concentration. Incorporated starch resulted in better water retention and structural stability to freezing and thawing. Thereby, starch incorporated whipping cream with about 75% lower fat content than commercial variants could be obtained. Also starch from four Indian rice varieties Ranjit (27.2%), Mushkbudij (22.7%), SR1 (9.8%), Aghoni bora (0.3%) differ in amylose content in native and modified forms as acetylated, hydroxypropylated and acetylated-hydroxypropylated was used for preparation of custard. The pasting and textural properties as well as color values and sensory rankings demonstrated that the modified rice starches could be better substituents to native corn starch in custard preparation.