Extraction Of Seed Oil Of Acer Truncatum Bunge And The Separation And Purification Of Nervonic Acid

Seed oil of Acer truncatum Bunge is rich in fatty acids that are essential to human beings' body and fat-soluble vitamins, up to 92 % and 5.52 % of which is unsaturated fatty acids and nervonic acid respectively. It has a very beneficial effect on human health. Extraction of seed oil of Acer truncatum Bunge and separation and purification of nervonic acid was studied in this thesis in order to provide a theoretical basis for exploitation and utilization of seed oil of Acer truncatum Bunge and nervonic acid.The following research contents were studied in this thesis: (1) Moisture content, kernel content and oil content in seed kernel of Acer truncatum Bunge samara was dynamically analyzed; (2) Seed oil of Acer truncatum Bunge was extracted by employing the methods of soxhlet extraction, pressing and ultrasound-associated extraction and its physical-chemical indicators and fatty acid components were detected; (3) Separation and purification of nervonic acid in mixed fatty acids of Acer truncatum Bunge seed oil was studied by employing the methods of low-temperature crystallization and molecular distillation; (4) The functionality of memory improving of four-level distillation products of Acer truncatum Bunge seed oil mixed fatty acids was preliminarily studied through mice water labyrinth and jumping test.The results are as follows:(1) The formation and accumulation process of seed kernel and oil of Acer truncatum Bunge in Beijing Shunyi starts at the end of July, and the peak values of kernel content in samara and oil content in seed kernel both occur at the end of October, when the kernel content in samara is 34.75 % and the oil content in seed kernel is 46.69 %, which is equal to the 16.22 % oil content in samara. Therefore, the end of October is the suitable harvest time of Acer truncatum Bunge samara in Beijing Shunyi. At the same time the moisture content of samara is from 8 % to 9 %, which it is quite suitable for the extraction, exploitation and utilization of seed oil.(2) The extracting effect of ultrasound-associated extraction is better than the other two extracting methods, and the optimal extracting parameters are: the extracting solvent petroleum ether, the ultrasonic power 80 W, the ultrasonic time 50 min, the ratio of material to liquid 1:16 and extracting 3 times, the rate of extracting yield 37.02 %. The physical-chemical indicators and fatty acid components of seed oil by pressing are similar to literature values. Besides, the nervonic acid content of Acer truncatum Bunge seed oil in Beijing Shunyi (6.07 %) is 10% higher than that in Yunnan (5.52 %). Therefore, Acer truncatum Bunge seed oil is a favorable resource for extracting and exploiting nervonic acid.(3) The separating effect of molecular distillation is the better one between the two separating methods, and the appropriate separating condition obtained by using wiped-film molecular distillation is: system pressure 0.1 Pa, distillation temperature 112℃～115℃, feed temperature 60℃, feed rate 25 mL/h～40 mL/h, and the wiper rolling speed 300 r/min. The purity of nervonic acid can be increased from 6.07 % to 41.62 % through four steps molecular distillation. The content is seven times as much as the original one and yield is 36.5 %.The optimal condition of the third step which was optimized by using response surface analysis in order to obtain a higher purity and yield of nervonic acid and analyzed by SAS software is: using wiped-film molecular distillation, system pressure 0.1 Pa, distillation temperature 114.5℃, feed temperature 60℃, feed rate 12 mL/h, and the wiper rolling speed 295 r/min. The purity rate of nervonic acid can be increased from 6.07 % to 39.02 %. The content is nearly 6.5 times as much as the original one and yield is 66.6 %.(4) It is preliminarily shown that nervonic acid can improve the memory of mice in varying degrees through water labyrinth and jumping testing of four level distillation products of Acer truncatum Bunge seed oil mixed fatty acids. In water labyrinth test, each dosage group of distillation product in each level can significantly improve space and working memory and the ability to identify space. In the jumping test, the influence of 6 dosage groups on the process of mice's learning and memorizing is comparatively obvious, while that of the other groups is not obvious.