Technological Study On Preparation Of Anisaldehyde By Star Anise

Star anise is one of the most valuable economical wood species in China, whose peel,seeds and leaf even could distill Star anise oil. Chinese star anise exports is more than 80% of the world market. It has great economic value. The anisaldehyde of star anise is much more widely used. Anisaldehyde can be used as raw materials for synthetic drugs, also can be used as insecticides, brighteners, pesticides, additives, and biological growth inhibitors. So study on preparation of anisaldehyde by star anise start a bright future in developement and exploitation of rescours of star anise.Here star anise as a raw material, adopt Supercritical CO2 extraction to extract star anise oil. Using GC-MS technology to identify the effective composition of star anise oil. Then using GC technology to determine the content of trans-anethole by molecular distillation. At last, using microwave extraction equipment to prepare anisaldehyde. The main studies and results are as following:(1) Pass to orthogonal experiment, the best supercritical CO2 extraction technology to extract star anise oil is:extraction temperature 45℃, extraction pressure 30Mpa, extraction time 1.6, granularity 40-60. Extraction temperature affects much significantly on star anise oil's yield. Extraction pressure affects significantly on star anise oil's yield. Extraction time has no significant effect of the star anise oil's yield. Influence of the three factors adopt SFT to extract star anise in the relationship between primary and secondary is:T>P>t. The rate of extracting star anise in this best condition can reach 13.34%.(2) Adopt GC-MS to analyze the chemical composition of star anise oil by supercritical CO2 extraction. There are 42 kinds of chemical components identified. The relative percentage of their total content is 99.88%. Trans-anethole was the most important component in star anise oil aboat 81.02%. It contains 1-(3-Methyl-2-butenoxy)-4-(1-propenyl)benzene 2.42%, Estragole 2.34%, cis-Anisaldehyde 2.24%, p-Anisaldehyde 2.14%, p-Acetonylanisole 2.08%,α-Bergamotene 1.13 %, and so on.(3) Compare the content of star anise oil which are from SD, SDE, SE, SFT. Relative content of star anise in SFT was 80.72%. The relative content of star anise oil by SD was 70.71%. The relative content of star anise oil by SDE was 66.80%. The relative content of star anise oil by SE was 57.59%. The relative content of star anise oil by SFT was 81.02%. It's much higher than other methods, and the smell of trans-anethole was more dence.(4) Using molecular distillation technology to purify trans-anethole. And determine to determine the content of trans-anethole by GC technology. The results showed that the content of trans-anethole was improved to 80.02% from 68.15% after one step molecular distillation. The content of trans-anethole was improved to 89.58% from 80.02% after two step molecular distillation. The color of star anise oil was changed from Brown to Colorless.The smell of star anise was more dence.(5) Microwave power affects much significantly on anisaldehyde's yield. H2O2% affects significantly on anisaldehyde's yield. Reaction temperature and extraction time has no significant effect of anisaldehyde's yield. Influence of the four factors to extract star anise in the relationship between primary and secondary is:microwave power>H202%> reaction temperature>extraction time. In this condition the rate of extracting star anise is 87.81%. The best Micro-Wave technology to extract anisaldehyde is:microwave power 300W, H2O2% is 25%, reaction time is 25min, reaction temperature is 20℃, reduction time is 1.5h.