Continuous β-transelimination of citrus pectin was achieved using pectin lyase [PNL, poly(methoxygalacturonide)lyase, EC 4.2.2.10] purified fromPenicillium italicum and confined in a membrane reactor. Various operational parameters, such as enzyme and substrate concentrations, filtrate flowrate, and reaction volume were optimized. Kinetic studies indicated that β-transelimination of pectin in the continuous reactor occurred following a first-order reaction with respect to substrate concentration for up to 90 min at 1 mg/mL pectin. This time period could be extended up to 120 min when the reactor was fed with 3–4 mg/mL pectin. During the first 50 h of operation, the system was capable of maintaining a viscosity reduction of 55% below the initial value when it was continuously fed with 4 mg/mL pectin.