Optimization of Conditions for Preparation of Ginger Essential Oil Microcapsules by Acid-Modified Palygorskite-Stabilized Pickering Emulsion Templating Methodology

Using the acid-modified palygorskite-stabilized oil-in-water Pickering emulsion templating methodology, microencapsulation of ginger essential oil was prepared exploiting pectin and chitosan hydrochloride. To improve efficiency of microencapsulation, the process of preparation was optimized by response surface methodology and a three-level and three-variable Box-Behnken design. Results showed that optimal preparation of Pickering emulsion was observed at acid-modified palygorskite concentration of 1.0%, oil phase volume fraction of 10%, and an aqueous phase pH of 7.5. The optimal preparation process of ginger essential oil microcapsules was as follows: water-bath temperature 55 degrees C, water-bath time 3 h, ratio of core to wall 1:2, stirring speed 600 rpm, and inlet air temperature 180 degrees C. The encapsulation efficiencies of ginger essential oil microcapsules prepared under such conditions were 94.064% +/- 0.133%.