Multienzymatic conversion of sucrose into fructose and gluconic acid was studied through fed-batch and continuous (in a membrane reactor) processes. The law of substrate addition (sucrose or glucose) for the fed-batch process which led to a yield superior to 80% was the decreasing linear type, whose feeding rate (I center dot; L/h) was calculated through the equation: I center dot = I center dot(o) - k.t, where I center dot(o) (initial feeding rate, L/h), k (linear addition constant, L/h (2)), and t (reaction time, h). In the continuous process, the yield of conversion of sucrose (Y) was superior to 70% under the following conditions: dilution rate = 0.33 h(-1), total duration of 15 h, pH 5.0, 37 A degrees C and initial sucrose concentration of 64 g/L (Y = 92%), 100 g/L (Y = 83%), or 150 g/L (Y = 76%).