تعیین شاخص قابلیت شکست توده دانه برنج بوسیله یک دستگاه آسیاب آزمایشگاهی

Abstarctfor determining the rationale of reducing rice grain strength during harvesting and post-harvesting and measuring the quality of grains, it is necessary to use the proper method and device, especially in bulk samples. one of this quality indices is grain breakage susceptibility index (bsi). for determining this index it is possible to use a centrifugal impact tester and calculate the bsi in weight percent. accordingly, after modifying a laboratory milling device, the effect of type of blade, blade rotating speed, time of milling and grain moisture content were investigated on the rate of grain breakage in an experimental design and in the form of a factorial test by conducting 108 milling tests. the results of the tests showed that all of independent factors had a statistical significant effect on bsi. the minimum value of bsi equal to 3.5%, was related to minimum rate of rotational velocity, minimum rate of milling time and minimum value of moisture content using flat blade, while the maximum value of bsi was equal to 96.8%. based on the results of this research, it seems that by conducting more experiments in a wider range of milling time and rotational velocity in common varieties, it will be possible to achieve a reliable method for determining the rice quality in bulk samples according to its breakage susceptibility index.keywords: centrifugal impact test, rice, breakage susceptibility, grain quality