Transportation of bioactive (+) catechin from its aqueous solution using flat sheet supported liquid membrane

Abstract

Transport of (+) catechin through a flat sheet Supported Liquid Membrane (SLM) has been investigated and reported in this paper. Liquid membrane (LM) was composed of carrier, tributyl phosphate (TBP) dissolved in aliphatic n-decane. Aqueous feed solution containing catechin was maintained at acidic (pH=4) condition using 0.1N HCl whereas ethanol was used as stripping agent. The SLM operation yielded 53% extraction and 49% recovery of the catechin at the optimum operating conditions viz. 100mgL−1 initial feed concentration, 1.2M TBP in the membrane phase, 0.4M ethanol as stripping agent, 200rpm stirring speed and 25°C temperature. The SLM method was found reasonably stable using polyvinylidene difluoride (PVDF) as a support material that allows repeatability of use of same support-LM combination. Further, the above transport method was tested for the recovery of catechin compounds present in hot water extract of green tea leaves which contains mainly (+) catechin (65.6%) and (-) epigallocatechin (EGC) (33.8%). Thirty six percent of catechin compounds initially present in the tea leaves extract (269.3mgL−1) was recovered at the optimum conditions which were slightly different from the optimum conditions achieved for synthesized catechin solution. Initial flux of transport for catechin compounds from tea leaves extract was found to be 19.17×10−9gcm−2s−1.