Extraction Of Seed Oil From Prickly Pear Residue And Its Application In Preparation Of Vesicles

Guizhou thorn pear wine production will produce a large amount of thorn pear pomace,the seed oil extracted from the pomace seed is rich in unsaturated fatty acids such as linoleic acid and linolenic acid;unsaturated fatty acid vesicles in drug embedding and sustained release There are important applications.From the perspective of turning the prickly pear pomace into waste and saving resources,the research was carried out to extract the seed oil from the prickly pear wine production in Guizhou,and to extract the seed oil from the seed oil and purify the linoleic acid and linolenic acid in the seed oil by urea encapsulation.The purified fatty acid is used for the preparation of mixed fatty acid vesicles,and finally applied to the sustained release of the anticancer drug cytarabine.The research can provide new ideas for the recycling of prickly pear pomace.The research work is mainly divided into four parts:The first part is about the enrichment of seed oil and fatty acid in microwave extraction of thorn pomace.The seeds of thorn pear pomace were used as raw materials,and the seed oil of Prickly Pear was extracted by microwave method.The oil extraction rate was used as the evaluation index to optimize the extraction process.The urea in the seed oil was purified by urea encapsulation.Oleic acid and linolenic acid were determined by gas chromatography for linoleic acid and linolenic acid in seed oil.According to the regression analysis,the order of influence of each factor on the extraction process was as follows: ultrasonic > extraction time > liquid to material ratio;the optimal extraction parameters were: liquid to material ratio 1:11,microwave power 400 w,extraction time 40 min.The average oil yield of the verified experiment is 12.51%.The theoretical prediction value is close to the experimental result,indicating that the optimization process parameters have high credibility,and the optimization process parameters have high credibility and reference value.The gas phase results showed that the total content of linoleic acid and linolenic acid in the thorn pear seed oil was 26.52%(including linoleic acid content 17.93% and linolenic acid content 8.59%)before urea inclusion.After that,the content of linoleic acid and linolenic acid increased by more than three times,the total content of both was 97.7%(the content of linoleic acid was 65.38%,the content of linolenic acid was 32.32%),which achieved the purpose of purification,mixed before and after purification.The ratio of fatty acids(linoleic acid and linolenic acid)remained unchanged at approximately 2:1.The second part is about the self-assembly of vesicles from the mixed fatty acids(2:1 ratio of linoleic acid and linolenic acid)in the purified pear seed oil.The purified mixed fatty acid was used as the template fatty acid of fatty acid vesicles,and its self-assembly behavior under different pH conditions was studied by surface tension method.The pH range of vesicles formed by mixed fatty acid self-assembly was analyzed by acid-base equilibrium titration experiment.The particle size distribution was analyzed by dynamic light scattering(DLS)and its morphology was observed by transmission electron microscopy(TEM).The experimental results show that when the pH is between 13.0 and 9.0,the appearance of the system solution is clear and transparent,and the mixed fatty acids mainly exist in the ionic state.The electrostatic repulsion between the ions makes them self-assemble into micelles;when the pH is between 9.0 and 8.0,the system solution The appearance is characterized by strong opalescence,and the amount of mixed fatty acid molecules is equivalent to that of ions.The two are self-assembled into vesicles by hydrogen bonding force;when pH<8.0,the appearance of the system solution is turbid or even oil-water separation,mainly in solution.It is a mixture of fatty acid molecules that disintegrate the vesicle self-assembly.The results of transmission electron microscopy and dynamic light show that the spherical micelle structure of 9 nm is obtained at pH 10.0,the vesicle structure of about 22 nm is obtained at pH 9.0,and the vesicle structure of about 40 nm is obtained at pH 8.0,indicating that the mixed fatty acid can The pH response self-assembly forms a self-assembled structure of various morphologies and scales such as micelles or vesicles.The third part is about the study of migration and expansion of the pH window of mixed fatty acid vesicles.Mixed fatty acid vesicles are pH dependent,have a narrow pH window and deviate from the pH range accommodated by the life system,limiting their use in drug embedding/sustained release.In order to migrate and expand the pH window of the mixed fatty acid vesicles,the surfactant Tween 80 was selected as a template surfactant,added to the mixed fatty acid system,and the pH window was migrated to the range suitable for the life system.The experimental results show that Tween 80 is added to the mixed fatty acid system,and the vesicle window migrates from the original pH 8.0 ~ 9.0 to pH 5.5 ~ 7.5.The pH window of the vesicle falls within the pH range that the living system adapts.Because Tween 80 contains a polyoxyethylene(PEO)structure,it can generate hydrogen bonding interactions with fatty acid molecules in mixed fatty acids under acidic conditions,instead of hydrogen bonding between fatty acid molecules and ions in the alkaline range.At the same time,due to the solubilization effect of Tween 80,the solubility of the mixed fatty acid under acidic conditions is increased,so that the mixed fatty acid vesicles are formed and stabilized in a wider pH range and a lower pH environment.The particle size of the vesicles increases with decreasing pH.This is because the change in pH will cause changes in the self-assembled units that form vesicles in the system.The lower the pH,the less carboxylate ions in the mixed fatty acid system,the carboxylic acid.The electrostatic repulsion between acid ions is reduced,and the closer the vesicle structure is formed,the larger the vesicle size.The fourth part is about the study of mixed fatty acid vesicles in drug embedding/sustained release.The mixed fatty acid vesicles containing Tween 80 were coated with the anticancer drug cytarabine to study its encapsulation efficiency and its release in artificial intestinal fluid.The results showed that the encapsulation efficiency of mixed fatty acid/Tween 80 vesicles on cytarabine was 42.07%;in artificial intestinal juice,the time was 9h,the vesicle-encapsulated cytarabine release rate was 30%,free The release rate of cytarabine was 80%,indicating that the mixed fatty acid/Tween 80 vesicles had a significant sustained release effect on cytarabine.Comparing the mixed fatty acid/Tween 80 vesicles with linoleic acid/Tween 80 vesicles and linolenic acid/Tween 80 vesicles,it was found that the encapsulation efficiency and sustained release effect of the three vesicles were comparable.The separation process of linoleic acid and linolenic acid is complicated,costly and laborious.If the two are not separated,the direct application can simplify the process and improve the economic effect.The purification process of linoleic acid and linolenic acid in thorn pear seed oil is simple,and the purified seed oil is directly prepared into vesicles,which is applied to drug embedding/sustained release,and the operation is simple and feasible,and has good theoretical and practical application value.