2.2.1. Preparation of microcapsules
The microcapsules were formed according to the method described by Mendanha et al. (2009), with some modifications. The primary (W/O) emulsion was prepared using a 30% (w/w) solution of AA and corn oil at a ratio of 1:2 (w:w) plus 0.5% (w/w) of the lipophilic emulsifier PGPR 90 (Danisco, Denmark). The formulation for the primary emulsion was defined based on preliminary trials, which contained some varying factors, such as the AA:oil proportion and mixing speed. The stability of the primary emulsions was determined by visual evaluation of the phase separation and the occurrence of creaming. The primary W/O emulsions were emulsified with the gelatin solutions to obtain the double W/O/W emulsions. The emulsions (both the simple and the double emulsions) were prepared at 12,000 rpm for 4 min and 10,000 rpm for 3 min, respectively, in an Ultraturrax. The gum arabic solutions were added to the double emulsions at 40 °C with the aid of magnetic stirring.