Optimization of Preparation Technology and Properties of Amomum tsaoko Essential Oil Microcapsule

Amomum tsaoko essential oil (AEO) has the characteristics of volatility and instability, so it is difficult to be widely used in the food industry. Therefore, the essential oil was embedded in microcapsules to improve its undesirable properties. The AEO microcapsules were prepared by spray drying utilizing AEO and emulsifier as the core materials and octenyl succinic anhydride starch (OSA starch), maltodextrin, and hydrocolloids as the wall materials. The optimal preparation process was obtained via single factor and orthogonal experiment, and the physical properties, morphology structure, thermostability were also investigated. The results showed that the optimum conditions of AEO microcapsules was as follows: AEO 30% (w/w), glycerin monostearate 1% (w/w), OSA starch (N-CREAMER 46) 15% (w/w), gum arabic 0.2% (w/w). Under these conditions, the embedding rate of AEO microcapsules was 81.07%±3.20%, loading rate was 64.43%±5.32%, water content was 3.40%±0.08%, and an average particle size was (226.37±3.06) nm after rehydration. The AEO microcapsules were a dry powder and could be dissolved fast in the water. Additionally, the thermal stability of embedded AEO was obviously improved by synchronous thermogravimetric differential thermal analysis, and scanning electron microscopy demonstrated that the particles of AEO microcapsules were dispersed equally. This work could offer technological references for the industrial production of spray-dried AEO microcapsules.