Design of liquid emulsions to structure spray dried particles

Abstract

The formulation and structure of initial liquid emulsion have an impact on the efficiency of encapsulation (encapsulated oil quantity) in spray dried particles (dried emulsions) and must be adapted to spray drying. Two different protocols were tested varying the concentration of emulsifier (Tween® 20), conditions of homogenization and concentration of wall material (Maltodextrin and Agave Inulin). The concentration of emulsifier and wall material should allow avoiding micelle formation or coalescence. Results show that it was possible to produce stable emulsions with an oil droplet size around 2μm containing 40% w/w of total dry matter (g/100g emulsion) using maltodextrin as wall material and 3.5% Tween® 20 (3.5g/100g oil) or using Agave Inulin in emulsions with a total dry mater content of 50% w/w (50g/100g emulsion) with a minimal concentration of emulsifier (1.17g/100g oil). The spray drying of these emulsions produced fine powders (<22μm) with a monodispersed size distribution and good oil encapsulation efficiency (>88%).