EFFECT OF EMULSION STABILITY AND SPRAY DRYING CONDITIONS ON PHYSICOCHEMICAL CHARACTERISTICS OF ENCAPSULATED POWDERS

In this investigation, four biopolymers were mixed with Maltodextrin (MDX) and used as emulsion stabilizers and wall materials to encapsulate lycopene natural pigment. These biopolymers were whey protein concentrate (WPC), soy protein concentrate (SPC), Gelatin (GEL) and Arabic Gum (AG). Some parameters such as droplet size, viscosity and creaming index of emulsions were investigated and then, to produce lycopene microcapsules, emulsions were transferred to spray dryer to be dried. Inlet air temperature (150 and 200 degrees C) and pressure of nozzle (1 and 2 bar) were considered as drying variables. Results showed that WPC emulsions had the smallest droplet size and lowest viscosity among other samples. The highest Encapsulation Efficiency (EE) belonged to WPC emulsions which were dried at 150 degrees C and 2 bar, also these samples had the highest bulk density. Results showed that samples which were atomized by using 2bar pressure at nozzle during spray drying, needed a significant longer time to be rehydrated (P<0.05).