Design of liquid emulsions to structure spray dried particles
Résumé
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 (R) 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 2 mu m containing 40% w/w of total dry matter (g/100 g emulsion) using maltodextrin as wall material and 3.5% Tween (R) 20 (3.5 g/100 g oil) or using Agave Inulin in emulsions with a total dry mater content of 50% w/w (50 g/100 g emulsion) with a minimal concentration of emulsifier (1.17 g/100 g oil). The spray drying of these emulsions produced fine powders (<22 mu m) with a monodispersed size distribution and good oil encapsulation efficiency (>88%).