(279b) Combined Osmotic and Membrane Distillation for Concentration of Anthocyaninfrom Muscadine Pomace

Bioactive anthocyanins from aqueous extract of muscadine grape pomace were concentrated using osmotic distillation (OD) and direct contact membrane distillation (DCMD) using gas filled membrane pores. The lowest fluxes were obtained for osmotic distillation. Given the temperature sensitive nature of anthocyanins, the maximum temperature difference during membrane distillation was limited to 30 °C and consequently, the flux during membrane distillation was also limited. A combination of OD and DCMD was found to perform better. High performance liquid chromatography (HPLC) and HPLC-electrospray mass spectrometry were used to identify and quantify anthocyanins;cyanidin-3,5-O-diglucoside; delphinidin-3,5-O-diglucoside; petunidin-3,5-O-diglucoside; peonidin-3,5-O-diglucoside and malvidin-3,5-O-diglucoside. Membranes were analyzed after operation using scanning electron microscopy (SEM) and Fourier transformed infrared spectroscopy (FTIR) in order to investigate fouling.