Proposing Novel Encapsulating Matrices for Spray-Dried Ginger Essential Oil from the Whey Protein Isolate-Inulin/Maltodextrin Blends

Abstract

The aim of this study was to evaluate the effects of the blending of whey protein isolate (WPI) with maltodextrin (MD) and inulin (IN) biopolymers as encapsulating matrices for spray-dried ginger essential oil. Encapsulation was performed by ultrasound-assisted emulsification and using spray drying, and the stability parameters of the emulsion (with or without ultrasound-assisted) were evaluated. The influence of these different wall material systems was investigated based on various functional properties of microparticles such as stability of the emulsion, encapsulation efficiency, reconstitution properties, chemical profile, microparticle stability, morphology, particle size distribution, and crystallinity. Higher viscosity values were obtained for the emulsions prepared with WPI and IN which had the apparent viscosity increased by the ultrasound-assisted emulsification process. Creaming index values indicated that ultrasound-assisted emulsions had higher stability. The composition of the wall materials did not affect the solubility and the moisture content of the particles. The wettability property of the powders was improved by the addition of IN. The lowest level of water adsorption under conditions of high relative humidity was also observed in microparticles containing IN. The partial replacement of WPI by MD significantly affected the efficiency of encapsulation. Moreover, MD led to high thermal microparticle stability. Larger particles were observed in the powders prepared with WPI. The powders obtained from WPI, WPI:IN, and WPI:MD treatments exhibited amorphous structures and did not have any cracks on the surface. The findings of this study indicate that IN and MD together with WPI proved to be good alternative secondary wall materials for spray-dried ginger oil.