effect of speed variations in abrasive rice whitening on milling properties of two varieties of rice in fars province

in this study, the effect of the speed of the mill-rotor during the whitening process was evaluated for the milling properties of two varieties of rice in fars province. a split plot design with five replications and the duncan test were used for statistical analysis. two varieties of paddy rice, amol-3 and kamfiruzi, and five mill-rotor speeds, 550, 600, 650, 700 and 750 rpm, were selected as main plot and sub-plot, respectively. the samples were milled at different speeds and the milling-output parameters of percentage of breakage and cracking, break strength and whiteness degree of rice kernels was measured. the results showed that the speeds of 600 and 600-650 rpm are the most proper mill-rotor speeds for the kamfiruzi and amol-3 varieties, respectively. furthermore, the percentage of breakage and degree whiteness of the amol-3 rice was 6.36% and 3.46%, respectively, more than for the kamfiruzi variety. the percentage of cracking and break strength were 13.31% and 17.22 kgf more in the kamfiruzi variety compared to the amol-3 variety.