The annual output of RH of world is about 80 million tons. RH is rich in xylan and amorphous silica,which makes it possible to utilize RH effectively. The contents of xylan and amorphous silica in RH are each around 20%
(wt.%), varying with the variety, climate and geographic location of the growth of rice. The xylan in RH is one kind of good raw materials to produce D-xylose. D-Xylose is widely used in fields
related to the food and pharmaceutical industries for its low calorific value and acceptable organoleptic properties. According to the research of Toshiyuki et al. (1983), the xylan in RH is made up of substituted arabinoxylan. Xylan in RH can be easily converted into soluble product