Optimization of technology for almond oil microencapsulation

Almond oil has a high content of unsaturated fatty acids. In order to avoid the oxidation and enlarge the uses of almond oil, the microencapsulation of the almond oil extracted by the supercritical CO₂ technique was studied. The almond oil was microencapsulated by spray drying method with milk protein isolates and malt dextrin as wall materials, soy lecithin as emulsifier. The optimal microencapsulation formula was studied via response surface methodology (RSM) and the optimal technological parameters of spray drying technique were determined by orthogonal design. The results show that the optimal formula of the almond oil microcapsule is almond oil 25％, milk protein isolates 25％, soy lecithin 2％ and malt dextrin 48％, and the proper homogenizing pressure is 20 MPa; the optimal technological parameters of spray drying are inlet air temperature 180℃, outlet air temperature 80℃ and feed temperature 50℃. The high quality and embedding rate microencapsulation of almond oil is obtained, and the embedding rate can reach 94.7% under optimal conditions.