Effect of Milling Time on the Performance and Energy Consumption of some Short Grain Rice Varieties

Abstract

A study was carried out to test and evaluate the effect of different milling times ( 30, 45, 60, 75, 90 sec ) on total and head rice yield, whiteness degree of milled rice, power consumption of milling process and neutrino value of milled rice. The experimental work was proceeded for four different short grain rice varieties included Sakha 101, Sakha 102, Giza 178, and Sakha super -300 using a laboratory scale friction type milling machine. The results show that, for all studied varieties the total and head rice yields decreased with the increase of milling time. Meanwhile, increasing the milling time over 60 sec increased the whitening degree in a non distinguished matter by human eyes. However, it has showed a dramatically reduction in head rice yield and neutrino constitutes of milled rice and limited reduction in power consumption. In general, milling time of 60 sec is recommended for milling process using the friction type milling machines. This level of milling time showed higher milling yield and nutrion value without noticeable reduction in milling degree and reasonable power consumption.