A study about the influence of time on the hydrolisis of ”rice straw” to produce microcrystalline cellulose has been done. The hydrolytic process was conducted in 2.5 N hydrochloric acid solution at 100ºC for 1 hour, 1.5 hours, 2 hours, 2.5 hours respectively. The physical properties of microcrystalline cellulose yielded were compared to those of Vivacel®102. The results indicated that there was a decrease in the true density value with the increase in hydrolytic time of the microcrystalline cellulose yielded, where as its water adsorption capacity, tapped and untapped density values increased. Noticing the physical properties of microcrystalline cellulose, it seemed that the physical properties of microcrystalline obtained from hydrolysis of the “rice straw” in 2.5 N hydrochloric acid solution at 100ºC for 1.5 hours the were more similar to those of Vivacel®102. Keywords : microcrystalline cellulose, Oryza sativa, and hydrolysis
