The batch adsorption of the epigallocatechin gallate onto apple pomace

The ability of apple pomace for carrying a polyphenol (epigallocatechin-3-gallate, EGCG) was examined. The adsorption characteristics of epigallocatechin gallate onto apple pomace from aqueous solution were determined over a range of concentrations (25-600 mg/L) and temperatures (25, 40 and 55 °C). The adsorption of EGCG decreased with increasing temperature. Both the Langmuir and Freundlich models adequately describe the isothermal adsorption of EGCG onto apple pomace. The Gibbs free energy change (ΔG°) for the adsorption of EGCG onto apple pomace ranged from -15.90 to -22.98 kJ/mol over the temperature range 25-55 °C, indicating the adsorption of EGCG onto apple pomace is a spontaneous process, and further that the adsorption process is likely to be dominated by a physisorption mechanism. Our results show that apple pomace has good adsorption characteristics, suggesting that apple pomace may be a useful EGCG carrier for functional food applications.