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Starch plays an important role in textural quality of infant food which is mainly affected by retrogradation of starch during storage. The acetylated rice was prepared and its physicochemical properties were evaluated to improve the textural quality of infant food when added. When the rice powder was reacted with acetic acid with its increasing concentration from 0.1 M, 0.2 M to 0.3 M, the amount of acetyl group and degree of substitution were increased by 0.39%, 0.8% and 1.27%, and by 0.0014, 0.031 and 0.048, respectively. The initial gelatinization temperature of rice paste determined by amylograph was decreased from 79.5℃ of unmodified rice to 67.5℃ of acetylated rice whose DS is 0.048. The apparent and maxium viscosity of rice paste at 95℃ before and after modification were increased from 92 B.U. to 201 B.U. and from 100 B.U. to 236 B.U., respectively. The degree of retrogradation and rate of syneresis were decreased from 28.7 to 18.8 and from 0.47% to 0.25%, respectively with increased by DS from 0 to 0.048. The digestibility rate of rice powder decreased from 9.19 of natural rice powder to 7.54 of acetylated rice powder whose DS is 0.048. In United State, there is no serious problem in total digestibility because only 4% of modified rice powder is added in production of infant food.
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