Preparation and Stability of Tea Tree Oil Microcapsules Encapsulated by Methyl Cellulose/chitosan/alginate

In the report, methylcellulose, chitosan, and alginate were used as the wall materials and the spray drying method was performed to prepare the tea tree oil microcapsules. The optimized spray drying conditions were as follows: air inlet temperature 210℃, needling frequency 2s, pump flow rate 55r/h. The orthogonal experiments were performed to obtain the best preparation conditions, which were as follows: methyl cellulose 0.6g in 100mL H₂O, 0.4mL tea tree oil, chitosan 0.6g in 50mL H₂O, alginate 3g in 50mL H₂O, and the highest oil content of microcapsules, 13.4%. The reproducibility of this technology was good. The microcapsules were spherical, and with smooth surface and relatively even diameters. Tea tree oil could be delayed released in the microcapsules. After being stored under room temperature in air for two weeks, small cracks appeared on the surface of the microcapsules and the diameter increased a little.