Objective: To optimize technology conditions of protein removal from total polysaccharides in Chaenomelis Fructus by papain enzyme-Sevag method. Method: Taking ratios of total polysaccharides retention and proteins removal as indexes

central composite design-response surface methodology was used to optimize technology conditions of enzymatic hydrolysis with enzyme concentration

hydrolysis time and temperature as independent variables

single factor experiments were adopted to optimize pH and number of Sevag.The content of proteins was determined by UV

detection wavelength was set at 280 nm. Result: Optimal technology conditions were hydrolysis pH 7

the mass fraction of enzyme substrates 1.70%

hydrolysis temperature at 54℃

hydrolysis time 89 min

treatment once of Sevag.Under these conditions

ratios of total polysaccharides retention and proteins removal were 70.04% and 63.42%

whose deviations were 1.42% and 0.17% by comparing with their predicted values

respectively. Conclusion: This optimized had highly predictive

it could effectively remove proteins

at the same time

avoid loss of total polysaccharides as much as possible

reduce use of organic solvents.