Influence of maltodextrin and environmental stresses on stability of whey protein concentrate/κ-carrageenan stabilized sesame oil-in-water emulsions
The influence of maltodextrin with different concentrations (0–30%) and dextrose equivalent (dextrose equivalent 10 and dextrose equivalent 15) under different environmental stresses (pH 3–8, NaCl 0–500 mM, and sucrose 0–20%) on the stability of whey protein concentrate/κ-carrageenan stabilized sesame oil-in-water emulsions was investigated by mean particle diameter, particle size distribution, ζ-potential, microstructure, and viscosity. Sesame oil-in-water emulsions containing anionic droplets stabilized by interfacial membranes comprising whey protein concentrate/κ-carrageenan/maltodextrin (15% sesame oil, 0.5% whey protein concentrate, 0.2% κ-carrageenan, 0.02% sodium azide and 0–30% maltodextrin with dextrose equivalent of 10 and 15, 5 mM phosphate buffer, pH 7) were produced using a homogenizer. The primary emulsion (1°) containing whey protein concentrate-coated droplets was prepared by homogenizing. The secondary emulsion (2°) containing whey protein concentrate–κ-carrageenan in the absence or presence of maltodextrin was produced by mixing the 1° emulsion with an aqueous κ-carrageenan in the absence or presence of maltodextrin solution. There were no significant changes in mean droplet diameter and ζ-potential of droplets at any maltodextrin concentration (0–30%) or dextrose equivalent (10 and 15) after 24 h storage. The apparent viscosity of emulsions increased when the maltodextrin concentration increased. The 2° emulsion containing 15% maltodextrin with dextrose equivalent of 10 had the stability to aggregation at pH 6–8, NaCl ≤ 300 mM, and sucrose 0–20%. The addition of maltodextrin to emulsion can be used to form emulsions with different physicochemical properties for various applications in food processing (for example, encapsulation).