Abstract:In this paper，cellulase was used to treat beer grains，which were aimed at hydrolyzing cellulose in brewers' spent grains. The content of reducing sugar in the enzymatic hydrolysate of brewers' spent grains was determined by method of direct titration. The effects of different feed-liquid ratio，enzymatic hydrolysis time，initial pH value，enzymatic hydrolysis temperature and cellulase addition on the content of reducing sugar in the enzymatic hydrolysate were studied preliminarily through single factor experiments.On this basis，three factors and three levels of orthogonal experiments were used to optimize the process conditions.The results showed that the optimum conditions for enzymatic hydrolysis of brewers'spent grains by cellulase were initial pH 6.0，2.5%enzyme addition and 4 h enzymatic hydrolysis time. At this time，the reducing sugar content in the enzymatic hydrolysate was 3.65 mg/mL.