Application of ultrafiltration to apple juice clarification
Faculty of Agriculture, Belgrade-Zemun (1,2,3,4)
Raw depectinized apple juice was clarified in a laboratory scale ultrafiltration (UF) system using ceramic tubular membranes (Tech-Sep Carbosep) with a molecular weight cut-off of 300,000, 50,000, and 30,000 daltons. The experiments have been carried out over a wide range of transmembrane pressures (100-400 kPa), temperatures (293-328 K), and feed flow rates (100-900 mL/min). Permeate flux significantly decreased with time until a steady state was established. The steady-state permeate flux reached a maximum at a transmembrane pressure of about 200 kPa. Higher permeate flux was obtained at higher temperatures due to lower permeate viscosity. A linear relationship between steady-state permeate flux and feed flow rate in logarithmic coordinates was obtained and the slope of these lines ranged from 0.22 to 0.31.