Abstract
Convenient method for measuring the physical property of rice correlated to the eating quality of cooked rice was developed. Further, some problems about the rheological measurement of rice paste such as amylograph were illustratively discussed.
Multi-biting test of liquid samples prepared from rice by specified method were carried out for investigating the physical property correlated to the eating quality of cooked rice. Seven rice samples which different in rice qualities and the eating qualities were measured and analyzed by this method. Difference of the physical properties correlated to the eating qualities of these rices were estimated clearly by this method.
Difference of the physical property correlated to the eating quality between glutinous and nonglutinous rice was indicated normally by this method. Changes in the gelatinization character of waxy and non-waxy starch due to the heating conditions which produce an effect on the experiment conditions were illustrated by using corn starch and waxy corn starch.
Rice paste of relatively high concentration which usually used in the measurement of amylograph exhibits mostly non-Newtonian behaviours which have no relation directly to the real physical property of rice. These are rheologically complex and exhibit thixotropic properties which misleading the explanation of the rheological property of rice paste. Thixotropic structure of the rice paste was dissolved easily by diluting the paste with pure water. These suggest the importance of adopting optimum experiment conditions for preparing the rice paste.
Difference of physical property correlated to the eating quality between new rice and 1 year aged rice could be also estimated by our method by using optimum experiment conditions.
