Preparation of a novel emulsifier by self-assembling of proanthocyanidins from Chinese bayberry (Myrica rubra Sieb. et Zucc.) leaves with gelatin

A physicochemically stable emulsion was developed by using a novel emulsifier, which was self-assembled colloidal complex of gelatin (GLT) and proanthocyanidins from Chinese bayberry (Myrica rubra Sieb et Zucc.) leaves (BLPs), with epigallocatechin-3-O-gallate (EGCG) as structure units. The GLT-BLP colloidal complexes were spherically shaped by transmission electron microscope (TEM). The data of Fourier transform infrared spectrum (FTIR), circular dichroism (CD), isothermal titration calorimetry (ITC) revealed that the main binding force between GLT and BLPs of the colloidal complexes was hydrogen bond. The incorporation of BLPs to GLT provided GLT with stronger affinity at oil-water interface and thus enhanced the physical stability of GLT-stabilizing emulsion. In addition, the emulsions stabilized by the colloidal complexes showed higher oxidation stability than that stabilized by free GLT only. The novel emulsifier developed in this study have potential applications as functional emulsifiers in food-grade emulsions with high anti-oxidation activity.