Research On Purification Process Of High-purity Nervonic Acid Ethyl Ester From Acer Truncatum Bunge Seed Oil By Urea Inclusuon Combined With Molecular Distillation

Acer Truncatum Bunge is a woody plant of the maple family unique to China.It has a high fruit setting rate and a high oil content in the seed.The oil contains 5～7% nervonic acid,which is a high-quality source for the extraction of nervonic acid.Nervonic acid is a component of cerebroside.Nervous acid and its derivatives can delay aging,prevent and treat diseases such as senile dementia and Alzheimer’s disease,which is the most developed brain health special effect substance in the 21 st century.The derivative of nervonic acid,nervonic acid ethyl ester is convenient for storage and transportation,and is easy for human body to absorb.In this paper,the seed oil of Acer Truncatum Bunge was obtained by mechanical pressing,and fatty acid ethyl esters were prepared by transesterification,and purification of high-purity nervonic acid ethyl ester with fatty acid ethyl ester as raw material.In this thesis,a systematic study on the extraction of nervonic acid ethyl esters by urea inclusion method was carried out.The effect of solvent varieties on the urea inclusion process was explored,and it was found that ethanol had a good effect on the separation of fatty acid ethyl esters.It was determined that concentration of 95% ethanol was used as the solvent,which was conducive to the rapid dissolution of urea and greatly improved the urea inclusion rate effectiveness.The separation mechanism of urea inclusion was systematically investigated,and the inclusion order of urea and 11 fatty acid ethyl esters in seed oil of Acer Truncatum Bunge was obtained:lignoceric acid ethyl esters >behenic acid ethyl esters > arachidic acid ethyl esters > stearic acid ethyl esters > nervonic acid ethyl ester > palmitic acid ethyl esters > erucic acid ethyl esters > cis-11-eicosenoicacid ethyl esters > oleic acid ethyl esters >linoleic acid ethyl esters > linolenic acid ethyl esters,and a process of six-stage urea inclusion to purify nervonic acid ethyl esters was built based on this.The process is as follows: 1)First,the cis-11-eicosenoicacid ethyl esters,oleic acid ethyl esters,linoleic acid ethyl esters and linolenic acid ethyl esters,which are difficult to form inclusion complexes with urea,were separated from nervonic acid ethyl esters through two-stage urea inclusion.The color of the oil in the obtained inclusion compound became lighter,indicating that the sterol and other substances were basically removed.2)Using the oil product in the previous urea inclusion compound as the raw material,arachidic acid,begwnic acid ethyl esters and lignoceric acid ethyl esters,which are easy to form inclusion complexes with urea,were separated from nervonic acid ethyl esters through by the third-stage urea inclusion.3)Using the oil product in the previous uninclusion compound as the raw material,urea inclusion was carried out three times to separate erucic acid ethyl esters and nervonic acid ethyl ester,and the final purity of nervonic acid ethyl ester reached 52.4%,and the results of characterization analysis showed that the product was almost no urea residue,but the content of palmitic acid ethyl esters and stearic acid ethyl esters were 18.55% and 14.55%,respectively,and it is difficult to separate them from nervonic acid ethyl ester by urea inclusion.Then a seven-stage molecular distillation process was used to study the purification process of nervonic acid ethyl ester,and finally nervonic acid ethyl ester with a purity of77.25% was obtained.However,it was difficult to use molecular distillation to separate lignoceric acid ethyl esters or begwnic acid ethyl esters from nervonic acid ethyl ester.In order to obtain higher purity nervonic acid ethyl ester,a new process for the extraction of high-purity nervonic acid ethyl ester by urea inclusion and molecular distillation was constructed in this paper.Firstly,oleic acid ethyl esters,linoleic acid ethyl ester,sterol,etc were removed by one-stage urea inclusion.Then,using the oil in the inclusion compound as feed,according to the difference of the molecular mean free path between the components,the C16～C20 fatty acid ethyl ester and the nervonic acid ethyl ester were separated by two-stage molecular distillation.Then,using molecular distillation heavy oil products as raw materials,five-stage urea inclusion were used to remove arachidic acid,behenic acid ethyl esters and lignoceric acid ethyl esters and erucic acid ethyl esters,and finally obtain a high-purity nervonic acid ethyl ester with a purity of 91.8%.In this thesis,a new process for the purification of high-purity nervonic acid ethyl ester was constructed using the rich source kernels of Acer Truncatum Bunge as raw materials.The equipment has low cost and high efficiency,and can provide theoretical and technical support for its large-scale preparation.