Inclusion complexes of clove essential oil with sodium caseinate and gum arabic prepared by high-pressure homogenization: Characterization and non-contact antimicrobial activity

This study aimed to prepare clove essential oil (CEO) nanoemulsion through high-pressure homogenization (HPH) by using natural food-grade material sodium caseinate and gum arabic. The fabrication condition, structural characterization, and non-contact antimicrobial activity were investigated. The results showed that CEO nanoemulsion was obtained at pH 4 through electrostatic interaction. The size of emulsion oil droplets decreased with increasing homogenization pressure and the HPH-treated emulsions still had good stability after 60 days of storage. ATR-FTIR spectroscopy analysis demonstrated the interactions between the wall material and CEO. The surface morphology of freeze-dried powder was spherical with few cracks on the surface. In addition, the CEO nanoemulsion and powder displayed antimicrobial activity on spoilage microorganisms, especially suitable for non-contact antimicrobial packaging. This has been realized in the bread storage experiment. In conclusion, the CEO nanocapsule prepared by HPH displayed desirable physicochemical properties to perform non-contact antimicrobial effect, which showed great potential in extending the shelf life of bread.