Nano-encapsulation of grape and apple pomace phenolic extract in chitosan and soy protein via nanoemulsification

Abstract Enhancement of lipid solubility and antioxidant activity besides maintenance of the stability for phenolics extract of grape and apple pomace could be achieved by their encapsulation. This work aims mainly to optimize nanocapsules (NCs) of total polyphenols extracted from golden apple (APP) and red grape (GPP) pomace in chitosan (polysaccharide) and soy protein. Nanoemulsification method was adopted with high encapsulation efficiency in case of soy protein, about 95%, and slightly lower efficiency for chitosan, about 75%. The NCs characteristics were confirmed by FTIR spectra, TEM, fluorescence spectra and spectrophotometric analysis. Good lipid NCs of oil/water emulsion type with diameter range of about 5˗300 nm were obtained in presence of Tween20 surfactant according to TEM images. FTIR spectra indicated that the most extracted polyphenolic compounds were encapsulated successfully. The NCs have enhanced the antioxidant activity of phenolic extract, apple juice and pineapple juice indicating their potential as food edible materials.