The tradition of fruit dehydration in Serbia has been long and anviable. It seems that Serbian machine-building in the area of fruit processing technology has given its greatest contribution in this field. It has been one 100 years since the smoking house of Mr Stokovic, PhD was announced to be the best and the most promising plum dehydrator at the open competition organized in Topčider by the Ministry of Agriculture. It was the first real almost continual fruit dehydrator where plums were moved at certain intervals closer and closer to the source of heat.

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.