Preparation Of Powdered Oil By Spray Drying And Numerical Analysis

Oil is an important nutrient for human body,but liquid oil is easily oxidized and difficult to store.Encapsulation of liquid oil into powdered oil can significantly improve their antioxidant properties,giving them better fluidity and dispersibility.Camellia oil is the main product of China's important economic forest oil tea.It has excellent health care performance and is a representative functional oil.In the presented study,powdered Camellia Oil were prepared by spray drying process.By evaluating the encapsulated efficiency of powdered oil,a series of single factor tests were performed to value the influence of process parameters in the production of powdered Camellia Oil by spray drying process.The process operating parameters were optimized by response surface method.The performance and characterization of the powdered oil were carried out.A three-dimensional numerical model of the centrifugal spray drying process was constructed to simulate the ail flow pattern and particle trajectory inside the drying chamber.The simulation results were in good agreement with the experimental results.In the process of preparation of powdered camellia oil by spray drying,the inlet air temperature,feed rate and emulsion solid content are the key factors affecting the spray drying process and the quality and encapsulated efficiency of powdered camellia oil.In this paper,soy protein isolate(SPI)and maltodextrin(MD)were used as compound wall materials,sucrose fatty acid ester(SE)and glyceryl monostearate(GM)were used as compound emulsifiers.The ratio of SPI to MD is 1:1,the ratio of core oil to compound wall material is 1:3,the amount of compound emulsifier added is 2% with SE to GM3:1.The emulsion has an emulsification temperature of 60 ° C,a shear emulsification speed of 19,000 rpm,and a shear emulsification time of 2 L/min.The produced emulsion shows good stability.After centrifugation at 2000 rpm for 10 minutes,it is left at room temperature for 12 hours without delamination.The emulsion stability reaches 97.8%,which is beneficial to the progress of the spray drying process.The effects of core-wall ratio,inlet air temperature,feed rate and solid content of feed liquid on the encapsulated efficiency of powdered camellia oil were investigated by single factor test.Combine with pre-experiment and single factor test results.Response surface analysis was carried out according to the Box-Behnken experimental design aimed on the encapsulated efficiency of powdered camellia oil as response value.The ANOVA analysis of the response surface regression equation showed that the overall p-value of the constructed response surface regression equation was less than 0.0001,which shows the constructed model has a significant effect to the response value.The model correction coefficient was 0.9781,indicating that the model can explain 97.81% of the response value.With the maximum product fat embedding rate as the index,the best process conditions for the preparation of powdered camellia oil were as follows: inlet air temperature 186 ° C,feed rate 16.8 rpm,solid content of feed liquid 14.3%.The embedding rate was 88.79% of powdered oil prepared under these conditions.The sensory evaluation,microscopic morphology and physical properties of the prepared camellia oil powder and fat were obtained.The prepared camellia oil powder had good fluidity and milky aroma,and the average moisture content was 2.90%.The microstructure of the sample was observed by scanning electron microscopy.Most of the products showed a smooth spherical surface without cracking,and a few particles showed collapse or atrophy of the capsule wall.A physical model and mathematical model of the centrifugal spray drying tower and spray drying process were constructed.Atomized droplets were simulated by the Discrete Phase Model.The three-dimensional numerical simulation of the centrifugal spray drying process was carried out.The simulation results were in good agreement with the experimental results.