Studies On Aqueous Enzymatic Extraction Of Seed Oil From Acer Truncatum Bunge And Separation And Purification Of Nervonic Acid With High Purity

The seed oil prepared from Acer truncatum bunge seed is rich in a variety of essential fatty acids for human beings,including 5-6% of nervonic acid and more than 90% of unsaturated fatty acids,which has high nutritional value.The nervonic acid is the dual-effect miraculous substance that can repair damaged nerve fibers and promote nerve cell regeneration.It can be used to prevent and treat Alzheimer’s disease,brain atrophy and other brain diseases,which has extremely high medicinal value.In this paper,systematic studys on the process of aqueous enzymatic extraction of seed oil from Acer truncatum bunge and the separation and purification of high-purity nervonic acid were carried out with the seed kernel of Acer truncatum bunge as raw material,providing theoretical basis for large-scale extraction of seed oil from Acer truncatum bunge and preparation of high-purity nervonic acid.The research content and results of this paper are as follows.(1)According to the cell wall compositions of cotyledon and parenchyma cell of Acer truncatum bunge kernel,a aqueous enzymatic extraction process of Acer truncatum bunge seed oil was constructed with cellulase-pentosanase complex enzyme as reactive enzyme.The results showed that the first addition of cellulase could effectively degrade the cellulose skeleton of the cotyledon cell wall,allowing the pentosanase added later to enter the interior of the cell and disintegrate the cell wall of parenchyma mainly composed of pentosan,which leads to releasing a large number of oil contained in parenchyma cells.By optimizing the parameters of aqueous enzymatic extraction,the highest extraction yield of Acer truncatum bunge oil was up to 82.32%.The results of oil quality testing showed that compared with the oil extracted by traditional methods,the seed oil obtained by aqueous enzymatic extraction could directly meet the national standard of Acer truncatum bunge oil without chemical refining,and the aqueous enzymatic residue was rich in protein and could be further recycled.(2)A new combined process of molecular distillation,urea inclusion and low temperature crystallization was constructed to prepare high-purity nervonic acid with the mixed fatty acids obtained after saponification and acidification of Acer truncatum bunge oil as raw materials.First,according to the difference in the the mean free path of fatty acids,molecular distillation was used to separate and remove C16-C20 fatty acids.The content of C16-C20 fatty acids decreased from 72.92% to 19.22% after two stage molecular distillation processes,in which both the contents of saturated fatty acids of palmitic and stearic acids decreased to about 0.5%.Then,according to the difference in carbon chain length and saturation of fatty acid,the contents of tetracosanoic and docosanoic acids decreased to 0.21% and 0.07% by urea inclusion.Finally,according to the difference in the solubility of fatty acids in solvents,the content of C18-C20 unsaturated fatty acids decreased to less than 5% with n-amyl alcohol as the solvent of first stage low temperature crystallization.The content of erucic acid decreased to 3.47% with anhydrous ethanol as the solvent of second to fifth stage low temperature crystallization.The combined process of molecular distillation,urea inclusion and low temperature crystallization constructed in this paper innovatively adopted an efficient,simple and easy-toindustrial low temperature crystallization method to separate erucic and nervonic acids,obtaining high-purity nervonic acid with purity of 96.53%,which solves the the problem of both increase of nervonic acid content and yield.This combined process had the characterizations of easy operation,low energy consumption,green and environmental protection.The preliminary economic accounting results showed that this technology had high economic benefit and the potential of large-scale production of high purity nervonic acid.In this paper,a complete process of aqueous enzymatic extraction of Acer truncatum bunge oil and extraction of high-purity nervonic acid from the oil was constructed with Acer truncatum bunge seed kernel as raw material,realizing the transformation from simple utilization to in-depth development of Acer truncatum bunge seed kernel,which is of great significance for the further comprehensive development and utilization of Acer truncatum bunge resources.