Food-grade Water in Oil Microemulsion as a Potential Approach for Tea Polyphenols Encapsulation

Abstract

Abstract Food-grade water in oil (W/O) microemulsions were developed and characterized in order to use them as potential tea polyphenols (TP) carriers. The physicochemical characteristics of microemulsions (TP-loaded and blank microemulsions) were investigated by rheological measurements, differential scanning calorimetry (DSC), dynamic light scattering (DLS) and 1H nuclear magnetic resonance (1H NMR). The thermal behavior of the microemulsion system implied that the water molecules were competitively bound. Chemical shift patterns for all samples were not sensitive to the addition of TP. The microscopic images showed that both the non-loaded and the TP-loaded microemulsions had a spherical shape, in particular the TP-loaded microemulsions had a specific core-shell morphology. TP solubilized in the microemulsions was much more stable than that dissolved in water solution. The release process of TP in water solution was faster than that of microemulsions.