| Abstract: | The colorimetric iodine method of amylose estimation in rice has been simplified. The flour is dispersed in alkali by heating in water bath or by overnight soaking at room temperature. The extract is neutralized before colour development by direct addition of phenolphthalein and decolourizing with dilute acid. No simplified method of defatting (including extraction by methanol at room temperature) was found satisfactory. But apparent amylose content as determined in undefatted milled rice flour was close to 86% of the true value in 46 milled rice samples tested; hence determination without defatting and multiplication of the results with 1.16 was satisfactory for routine and approximate work. The apparent amylose value was, however, dependent on the degree of polish of the rice. Particle size of the flour within reasonable limits had no appreciable effect on the results. The extract was quite stable even when stored in the room temperature. |
