Optimization of coating materials on microencapsulation of red galangal (Alpinia purpurata, K. Schum) rhizome essential oil with freeze dry method

The potential use of large red galangal (Alpinia purpurata, K. Schum) essential oil has a weakness that is prone to compound damage. Thus, it is necessary to make efforts to maintain the active compounds contained in the red galangal rhizome essential oil, one of which is by microencapsulation. The purpose of this study was to determine the appropriate formulation of the material coating used in the microencapsulation process using the freeze-drying method. The optimization of the microencapsulation process was carried out using the response surface method (RSM) with the central composite design (CCD). The optimization results of essential oil microcapsules showed that the yield response of 44.01%, water content of 5.75%, TPC of 34.227 mg GAE/g, antioxidant activity (IC50) of 136.01 ppm, and solubility of 87.70%. The GC-MS analysis has shown that there were five main compounds detected from the microcapsules, Diacetone alcohol of 31.36%, Chavicol of 15.26%, Methyl oleate of 6.87%, Alloaromadendrene of 5.82% and Methylhexadecanoate of 3. 44%. Overall, the choice of coating material can affect the characteristics and morphology of the microcapsules.