Encapsulation of (-)-epigallocatechin gallate (EGCG) within phospholipid-based nanovesicles using W/O emulsion-transfer methods: Masking bitterness and delaying release of EGCG

A novel phospholipid-based nanovesicle (PBN) was developed to encapsulate (-)-epigallocatechin gallate (EGCG), a major polyphenol in green tea, to mask its bitter taste and expand its application in food products. The PBN was formed using W/O emulsion-transfer methods and showed a multilayer membrane nanovesicle structure (around 200 nm) observed with TEM. The PBN possessed a high encapsulation efficiency (92.1%) for EGCG. The bitterness of EGCG was significantly reduced to 1/12 after encapsulation. Fourier transform infrared spectroscopy (FTIR) indicated the EGCG mainly interacted with the upper chain/glycerol/head group region of the lipid bilayer in PBN. Quartz crystal microbalance with dissipation (QCM-D) showed the addition of gamma-cyclodextrin in PBN enhanced EGCG's adsorption with phospholipids and allowed for its good sustained release. Encapsulating EGCG in PBN inhibited its complexation with mucin, reducing bitterness and astringency. This provides a new method to improve EGCG's flavor, potentially expanding its application in the food industry.