Microfiltration of apple juice using inorganic membranes: Process optimization and juice stability

Crossflow membrane microfiltration of low-pectine raw apple juice was studied using inorganic membranes (TECH SEP Carbosep(R), Lyon, France) having a nominal pore size of 0.2 mu m. Permeate nux was measured at different operation conditions (trans-membrane pressure between 100 and 500 kPa, feed velocities between 1 and 6 m/s, and temperatures of 293, 298 and 323 K). Some concentration experiments were made in order to study the rejection of pectins and polyphenols at different VCR (volume concentration ratio) values. Final stabilization tests were carried out to analyze the long-term clarified juice behaviour.