determination of whitening energy, energy consumption index and whitening index in three varieties of rice

the rice conversion process is an agricultural transformative industry that consumes a great deal of fossil fuel and electricity. in this study, the effect of different factors on energy consumption, energy consumption index and whitening index were investigated. the experimental design was a split plot design with four whitening periods (15, 30, 45, 60s) (main plot), three rice varieties (khazar, beenam, alikazemi), three levels of final paddy moisture content (9.5-11%, 11-12.5%, 12.5-14% wb) and three replications for each test. the statistical analysis outcomes for energy consumption, energy consumption index and whitening index indicated that as whitening time increased, energy consumption increased and its index decreased. in the 15 and 60s whitening periods, decreasing the moisture content to 9.5-11%, significantly increased the energy consumption index. the energy consumption index of the khazar variety was significantly higher than the other two varieties at all levels of moisture content. increasing moisture content caused increased rice breakage, which resulted in decreasing quality and whitening indices. when the whitening period increased to 60­­­s, the whitening index increased significantly. the whitening index of the khazar variety was significantly greater than those of the other varieties. the results showed that the best state, considering the energy consumption index and whitening index, was obtained at 9.5-11% moisture contents and a 15s whitening period for all varieties.