Abstract: Grape pomace (GP) is a by-product of food industry production rich in polyphenols which is beneficial to the human body. Using the electrochemical (EC) method to remove the bitterness and astringency of tannins in grape extract. An optimized current 0.15A, 1.5 g/L NaCl concentration, electrolysis time 30 minutes and pH 5.0 were chosen to remove tannins. The TTC (total tannin content) decreased by 83% after the electrochemical treatment. The HPLC (High performance liquid chromatography) results also showed that EC was effective in removing tannins from grape pomace extracts, and analysis showed that phenolic acids, flavonoids and anthocyanin polyphenols were still contained in the extract after removal of tannins. Furthermore, a novel food grade O/W/O (oil in water in oil) double emulsion delivery system was designed using sunflower oil as internal (O1) and external (O2) oil phase with psyllium husk and water (W) using low-frequency ultrasound (20kHz). Ultrasound improved the emulsion stability and reduced the emulsion droplet size which confirmed by PLM (Polarized light microscopy). Under the optical microscope, the distribution of the single emulsion (O1/W) was more uniform, and the average diameter of the emulsion particles was reduced by 91.67%. The best formulation of double emulsion was 81% oil, 1% psyllium husk and 18% water. The feasibility of this novel double emulsion system was studied by applying it to GP phenolic extracts to investigate the delivery of polyphenols and other oil-soluble substances.In this study, Vitamin D and Omega-3 were encapsulated in the inner oil phase by double emulsion to explore whether the double emulsion could act as a delivery system. The double emulsion was stable up to 30 days in ORAC (Oxygen radical absorbance capacity) assay.
