SHOMER, I., Dept. of Food Technology, Agricultural Research Organization, Volcani Center, P.O. Box 6, Bet Dagan, 50250, Israel
MERIN, U., Dept. of Food Technology, Agricultural Research Organization, Volcani Center, P.O. Box 6, Bet Dagan, 50250, Israel

Microfiltration of reconsituted aqueous peel extract resulted in linear flux decline with time. Feed stream of reconstituted peel extract does not foul the membrane and flux decline is due solely to increased retentate viscosity. Cloud was concentrated up to 6.3% of washed dry matter, compared with 1.5% achieved by vacuum heat concentration. Permeate was at constant low viscosity during filtration experiment, free of insolubles, and crystal clear. Soluble sugars do not contribute to fouling gel layer; their permeation flux is constant, and is only a function of viscosity. Soluble high‐molecular‐weight polymers, such as pectins, cause membrane fouling and flux depression. Fluxes for soluble constituents, sucrose and pectin, were higher than those of reconstituted peel extract with similar viscosity. Copyright © 1984, Wiley Blackwell. All rights reserved