The Effect of Hulling and Whitening on Quality of Rice Cultivar Daillman Mazandarani (DM)

Abstract

The experiment has been conducted to study of some qualitative characteristics of husking and whitening machines for rice cultivar Daillman Mazandarani, in the laboratories of the Tehran University in 2015. This research uses two types of machines Satake rubber-rolls -THU 35A type and Yanmar rubber - rolls -, ST SO type under three levels of the grain moisture 10-12%, 12- 14% and 14-16% and three levels of clearance between cylinders are 0.4, 0.6 and 0.8 mm. The study is conducted on two axes a hulling which included palea and lemma percentage, broken rice and hardness degree, and whitening which included bran, bench, whiteness percentage and whiteness degree.The results showed that the Satake type machine is significantly better than the Yanmar type machine in all studies properties. As well as grain moisture 10-12% is superior significantly on the two levels 12-14%, 14-16% in all studied traits. In addition of the clearance 0.8 mm significant superior on two levels 0.4,0.6 mm in all studies properties except the hardness degree, whiteness degree and whiteness percentage the which gives the best result with the clearance level 0.4mm, for both two stages husking and whitening.