Physical and chemical properties of encapsulated eugenol using whey protein-maltodextrin mixed solution and chitosan as emulsifier and wall materials

Abstract

Complexes of proteins and polysaccharides have excellent emulsifying properties and they could be used as encapsulating agents. In this study, eugenol was used as a model for essential oil encapsulation using a mixed solution of whey protein-maltodextrin as an emulsifier that also served as the first layer, with chitosan solution (0.2, 0.6, 1.0%-w/w) added as the second layer to stabilize the emulsion. Eugenol encapsulation was successfully carried out and produced emulsions with droplet sizes ranging from 194-266 nm. The addition of chitosan solution (1%-w/w) produced the most stable emulsion that having the highest zeta potential of 21.95 mV. The spray-dried powder of the best emulsion had the highest loading capacity (13.4%) as well as encapsulation efficiency (37.9%). Chitosan improved the thermal stability, however the difference in chitosan concentration did not affect the chemical structure of eugenol spray-dried powder.