Oat ( Avena Sativa ) is a species of cereal grain grown for its seed. While oats are suitable for human consumption a oatmeal and rolled oats , one of the most common uses is a livestock feed. Oat contains a great amount of starch and fatty acids. Compared to other cereal crops oat has amino acids similar to eggs. Oat fat varies between 3 to 9 percent which is higher compared to other Cereals. Oat cultivation in Iran is limited due to lack of information about its cultural practices. Oat has the highest quality protein levels among other cereal crops. This research was conducted to evaluate oats processing with various machines for the purpose of steam rolling. Experiments were conducted in three parts, i.e. dehulling of oats by a rice huller machine, dehulling by a rice milling (whitening) machine, and determination of processing index and particle weight percentages after steam rolling. Before conducting experiments some physical properties of oats such as coefficient of friction, density, and terminal velocity were determined. Feeding rate, grain moisture content, and blanching were factors considered in using the rice milling and huller machines. Experiments were conducted with moisture content at three levels (6, 10, and 15 %), feeding rate at two levels and blanching at two levels with four replications. The rollers gap in the huller machine was set at 0.4 millimeter. Experimental factors for evaluating steam rolling oats were roller rotational speed (RPM), rollers gap, and steaming duration with three replications. Roller speeds were set at three levels (250,300, and 350 RPM), rollers gap at three levels (0.4, 0.5, and 0.6 millimeters) and steaming duration selected was at three levels (10, 15, 20 minutes). Results of the experiments showed that rice milling machine dehulling performance was not satisfactory and grain damage was extensive, therefore, from an economic stand point is not a feasible method to perform dehulling process. Also, results showed that the dehulling at a moisture content of 6% give better results in terms of highest percentage of dehulled grain and the least percentage of broken grain. In steam rolling, the best steaming duration was 20 minutes with a roller rotational speed of 350 RPM and roller spacing of 0.5 millimeter.
