Influence of Amylose Content and Particle Size on Physicochemical Properties of Rice Flours

Seven rice varieties (Suweonjo, Suweon232, BG276-5, IR44, IR41999-139, Suweon230 and Yongjubyeo) were used to study the influence of amylose content and particle size on the physicochemical properties of rice flours. Suweonjo had the highest amylose content (27.1%) and particle size distribution of rice flour prepared in a pin mill revealed that Yongjubyeo (17.2% amylose content) had the finest flour particle as supported by scanning electron microscopy (SEM). Suweonjo had the highest value in hardness of rice grain but the lowest length/width ratio. There were no significant differences in color values among the rice flours. Data of Brabender visco/amylograph was not associated with amylose content. Yongjubyeo had the highest maximum viscosity and breakdown value while Suweonjo had the lowest maximum viscosity, setback value and breakdown value. Yongjubyeo had the lowest water solubility index (WSI). The Suweon232 rice variety absorbed more water than any other varieties but rice varieties and amylose contents affected water absorption a little.