The Behaviour of Rice Grains during Polishing Process

Abstract

The sequential estimation of polishing progress of rice grains was investigated.
In saké brewing, the polishing ratio is defined as the weight percentage of white rice obtained from brown rice. Brown rice grains were polished in the mill until a 70% polishing ratio and the polishing time took 13 hours. Sampling was carried out at every one hour during polishing.
The weight distribution, the size distribution, and the weight of a thousand rice grains were measured. The mode of weight distribution and the mode of size distribution did not become smaller continuously but became smaller stepwise. The central weight (the average weight of rice grains which constitute the central part of weight distribution) was not always similar to the weight of a thousand rice grains. However, the weight of a thousand rice grains was presumed by weight distribution.
We considered that the multiple estimation about rice grains as the raw material in sake brewing in possible by weight distribution.