摘要
An attempt was made to determine the qualitative changes in basmati rice （Pusa Basmati 1121, PBl121） during soaking at 40 ℃ to 80 ℃. Soaking temperature had significant effect （a = 0.01） on chemical composition, glycemic index and starch characteristics of rice. Starch content, apparent amylose content, crude protein content and crude fat content in un-soaked rice were found to be 73.24%, 27.26%, 8.79% and 2.56%, respectively, but differences in these traits were observed after soaking. Amylose to amylopectin ratio （Am/Ap） decreased from 0.59 to 0.52 （soaked at 80 ℃）. Crude fibre and crude ash contents increased after soaking. The mineral composition （K, P, S, Ca, Mg, Mn, Fe, Cu and Zn） in soaked rice was found to be 16.46% higher than un-soaked rice at the same degree of polishing. Glycemic index of un-soaked rice was found to be 58.41, but decreased to 54.31 after soaking at 80 ℃. Pasting properties, scanning electron microscope images, and X-ray diffractograms suggested partial gelatinization of starch in the temperature range of 60 ℃ to 80 ℃. Based on qualitative changes in rice （apparent amylose content, Am/Ap ratio and crystallinity rate）, it was concluded that intermediate soakincl temperatures （60 ℃ to 70 ℃） would be useful for soaking of PB1121.
An attempt was made to determine the qualitative changes in basmati rice （Pusa Basmati 1121, PBl121） during soaking at 40 ℃ to 80 ℃. Soaking temperature had significant effect （a = 0.01） on chemical composition, glycemic index and starch characteristics of rice. Starch content, apparent amylose content, crude protein content and crude fat content in un-soaked rice were found to be 73.24%, 27.26%, 8.79% and 2.56%, respectively, but differences in these traits were observed after soaking. Amylose to amylopectin ratio （Am/Ap） decreased from 0.59 to 0.52 （soaked at 80 ℃）. Crude fibre and crude ash contents increased after soaking. The mineral composition （K, P, S, Ca, Mg, Mn, Fe, Cu and Zn） in soaked rice was found to be 16.46% higher than un-soaked rice at the same degree of polishing. Glycemic index of un-soaked rice was found to be 58.41, but decreased to 54.31 after soaking at 80 ℃. Pasting properties, scanning electron microscope images, and X-ray diffractograms suggested partial gelatinization of starch in the temperature range of 60 ℃ to 80 ℃. Based on qualitative changes in rice （apparent amylose content, Am/Ap ratio and crystallinity rate）, it was concluded that intermediate soakincl temperatures （60 ℃ to 70 ℃） would be useful for soaking of PB1121.
基金
Post Graduate School, Indian Agriculture Research Institute, New Delhi, India
the Council of Scientific and Industrial Research, New Delhi, India
