Journal of Membrane Science & Technology

Abstract

Fractionation of Biologically Active Compounds Extracted from Propolis by Nanofiltration

H. Tsibranska, G.A. Peev and B. Tylkowski

Fractionation of biologically active compounds (BAC) extracted from propolis was performed by nanofiltration. Direct nanofiltration with the feed solution was applied, as well as sequential filtration of each permeates; Duramem membranes with different molecular weight cut-off (MWCO), ranging from 300 to 900Da were used. During each filtration a constant flux was observed. When direct filtration of the raw extract was applied the measured flux was about 12% lower, but no fouling of the membrane was observed. The dependence of rejection on the MWCO of the membrane was obtained. The free radical scavenging activity of the feed, permeates and retentates as well as the kinetics of inhibition of free radicals were studied by DPPH test. Fractions of different composition were obtained, characterized by the relative content of flavonoids in the total phenols (0.08 to 0.21). They have shown very different antioxidant activity, ranging from 19 to 98% and proportional to the flavonoids content.