Production and characterization of multinuclear microcapsules encapsulating lavender oil by complex coacervation

The aim of this work was to encapsulate lavender oil by complex coacervation using gelatin and gum Arabic as encapsulants. The effects of various factors including pH value, the core/wall ratio, wall material concentration, stirring speed, cross-linkers and homogenization rate on the appearance, mean particle size, yield, loading capacity (LC) and encapsulation efficiency (EE) were investigated. The optimal conditions (pH 3.5, core/wall 3:2, wall material concentration 1%, stirring speed 450 rpm, homogenization rate 19 000 rpm and glutaraldehyde as cross-linker) for preparing spherical multinuclear microcapsules were obtained. At the optimal conditions, the highest yield is 65.8 +/- 1.0%; the maximum LC is 61.3 +/- 0.7%; the highest EE is 66.0 +/- 0.3%. The effect of three different cross-linkers on the hardening effectiveness of multinuclear microcapsules containing lavender oil was investigated. Glutaraldehyde and transglutaminase exhibit similar microcapsule hardening effectiveness. When tannic acid was used instead of glutaraldehyde and transglutaminase, the mean particle size and EE remained the same as that when hardening with glutaraldehyde or transglutaminase, but the morphology obviously changes, while the yield and LC significantly decrease. Copyright (c) 2013 John Wiley & Sons, Ltd.