Simplified Determination of Water‐Insoluble Amylose Content of Rice

The traditional “starch‐iodine blue value” of rice gives the hot‐water‐soluble amylose content of rice, but previous defatting is essential for its correct determination as amylose by iodine colorimetry. Since defatting of flour is laborious and time‐consuming, the hot‐water extract of rice flour is defatted by shaking with petroleum ether. Colour is then developed with iodine and read at 630 nm against an amylose standard. Subtracting the above value from the total amylose content gives the insoluble amylose content.