Abstract: Nanocrystalline cellulose was prepared from soybean dregs, rich in cellulose, using acid hydrolysis followed by high-pressure homogenization. The effects of HCl concentration, hydrolysis time, temperature and liquid-to-solid ratio on degree of hydrolysis of soybean dregs were studied using one-factor-at-a-time combined with orthogonal array design method. The optimal preparation process involved hydrolysis with 3 mol/L HCl at 100 ℃ and a liquid-to-solid ratio of 45:1 for 120 min and subsequent homogenization at 30 MPa. The results of laser particle size analysis and scanning electron microscopic (SEM) observation showed that the obtained nanocrystalline cellulose was microspheres with a particle size range of 50－100 nm. In conclusion, HCl hydrolysis followed by high-pressure homogenization allows the preparation of soybean-derived nanocrystalline cellulose

Key words: soybean dregs-derived cellulose, hydrochloric acid, hydrolysis, high pressure homogenization, nano-crystalline cellulose