| Extraction of a single component from natural essential oils or petrochemical end products is rather tedious, laborious, energy intensive and expensive owing to their similar physical properties. Therefore, it is essential to carry out investigation for new promising separation ways with high capacity and ease of separation. A thin-film evaporation/distillation coupled technology has received many attentions for using in selective separation of different components.Firstly, the extraction conditions such as temperature, particle size and distillation time on the yield and content of the five components were investigated, which include benzaldehyde, benzene propanal, cinnamaldehyde, cinnamyl acetate and O-methoxy cinnamicaldehyde. Based on the results of single factor experiments, the optimal conditions were obtained with the three factors and three levels orthogonal experiments. Gas chromatography/mass spectrometry (GC/MS) was used to identify and quantify the cinnamon oil extracted at optimum conditions, and the results of GC/MS analysis were consistent with that in the literature, at the same time, the cinnamaldehyde content were higher than the date reported.Secondly, an molecular distillation and rectification coupled technology was used to purify cinnamon oil, and evaporator temperature, pressure and reflux ratio which effects the yield and purity of five components were studied in the coupling process. Based on the results of single factor experiments, two important process parameters including evaporator temperature and pressure were optimized by response surface methodology for maximizing cinnamaldehyde yield and purity. The optimal coupling conditions resulted in a cinnamaldehyde yield of84.5%and purity of99.2%. Results of variance analysis, general probability analysis and internal residual analysis carried out that the model was highly significant, which was fit with experimental results good, so it can be used to predict the actual value.Thirdly, the coupled technology is using to separate acetophenone and1-phenylethyl alcohol mixture system. Effects of evaporation temperature, pressure, and reflux ratio on purity and yield of each product is evaluated. Experiments based on the arrangement of the orthogonal array are conducted to obtain the optimum separation conditions with purity and yield of each product as a reference.Finally, arabic gum(GA)-sodium alginate(ALG)/cinnamaldehyde(CIN) microcapsules were prepared by spray-drying technique. Conditions that impacted the loading capacity and inclusion ratio, for example inlet air temperature, inter pump speed, concentration of GA and the mass ratio of GLA and CIN were studied. FTIR, TG-DSC, particle size analyser, SEM and optical microscopy were utilized to analyze the morphological structure of microcapsules. FTIR results indicated that there was exist interaction in cinnamicaldehyde and sodium alginate. Size distribution showed that the average particle size of microcapsules was about10μm. Controlled release performance of GA-ALG/CIN microcapsules was measured by controlling the temperature and humidity of the environment, and the outcome confirmed that composite wall materials had a very strong controlled release effect on cinnamaldehyde. Antibacterial properties and minimum inhibitory concentration (MIC) of cinnamaldehyde and its microcapsules were investigated on three kinds of bacteria (S. aurueus, T. escherich, aspergillus niger) using disk diffusion method. Alginic acid unit and cinnamicaldehyde affected through hydrogen bonding by DMol3method, and the binding energy between them was negative.In a word, investigation on separation of difficult separation systems and microencapsulation of cinnamaldehyde may be significant for solving the separation question and improving its value and achieving a reasonable application of natural and petrochemical end products. |
PDF Full Text Request