Abstract
Changes of pectic substances in polished rice from insoluble into soluble by soaking, heating and cooling the rice were investigated. Carbazol method was applied to the study. The following results were obtained.
(1) The total pectic substances in rice was 0.44% and the insoluble pectic substances was 0.22%.
(2) Dissolution of the insoluble pectin by soaking rice required two hours which agreed with the time necessary for rice to reach the saturation with water. When the rice is drained on a basket after being washed with water, the dissolution of pectic substances was greater than that in the rice which had been soaked in water for the same time as draining.
(3) Dissolution of the pectic substances in rice continues during the course of cooking, and stops when the rice is removed from heat. No further change in pectic substances is observed with cooled rice.
