Preparation of zein-lecithin-EGCG complex nanoparticles stabilized peppermint oil emulsions: Physicochemical properties, stability and intelligent sensory analysis.

Peppermint oil emulsions were prepared by using zein-lecithin-EGCG (Z-L/E) complex nanoparticles as emulsifiers. The preparation conditions of emulsions were optimized via measuring the particle size, surface tension and stability of emulsions, and peppermint oil of 3% (particle size = 375 nm, polydispersity index (PDI) = 0.45), the zein:lecithin ratio of 4:1 (w/w) (particle size = 396 nm), and the zein:EGCG ratio of 10:1 (w/w) (surface tension = 47.32 N/m) was the optimal condition. The rapid stability analysis showed that the instability mechanism of emulsions was ascribed to creaming and stratification, and the stability mechanism of emulsions was explored, indicating that the complex nanoparticles adsorbed on the surface of oil droplets to give Pickering emulsions. Electronic tongue experiments showed that the Z-E/L4:1 stabilized emulsion was distinguished from the other three samples due to its good stability. The electronic nose experiment could distinguish the emulsions with different droplet sizes.