Abstract
Fine grinding technology is expected to permit various application of rice flour, however, it will decrease flowability of rice flour, resulting in formation of bridge and cohesion of powder inside the food processing machine. To determine necessary equipments and technologies for the processing of fine rice flour, this study investigated Carr’s flowability and floodability indices, moisture content, and roughness coefficient of the flours made from nonglutinous rice (white/brown) and glutinous rice (white), having the mean diameters of 3～30μm and 30～100μm milled by a jet mill and a hammer mill respectively. Although the moisture content and the roughness coefficient decreased as the mean diameter of the rice flour decreased, its flowability decreased as the mean diameter decreased down to 15μm. In the flours at 3μm mean diameter, the flowability of white rice flour was almost same with that of 15μm flour, while it increased in the brown rice flour. The rice flours with the mean diameter less than 30μm were less flowable than traditional rice flour joshinko, however as flowable as ordinary wheat flour.
