Study On Extraction And Purification Of Astaxanthin And Preparation Of Nanostructured Lipid Carrier

Astaxanthin is the main natural active ingredient in Haematococcus pluvialis.It has the effects of anti-cancer,anti-blood pressure and enhancing immunity.However,the mature Haematococcus pluvialis has the thicker cell wall,which hinders the dissolution of astaxanthin,resulting in a generally low extraction rate of astaxanthin.In addition,the existence forms of astaxanthin in Haematococcus pluvialis are diverse,resulting in low purity of the product,which requires further separation and purification before the subsequent performance research and utilization.In this paper,firstly,ionic liquid and ultra-high pressure microjet technology were applied to the extraction of astaxanthin from Haematococcus pluvialis;Secondly,on the basis of crude purification of astaxanthin extract,high-purity astaxanthin was further prepared and collected by Pre-HPLC;Subsequently,the UV,FT-IR,~1H-NMR and¹³C-NMR were used for structural identification;Finally,AST-NLC was prepared by homogeneous emulsification-ultrasonic probe method,and the prepared AST-NLC was analyzed by FT-IR and XRD.The experiment contents are as follows:（1）Astaxanthin was extracted by ionic liquid and ultra-high pressure microjet technology.Using astaxanthin extraction rate as index,single factor experiment and Box-Behnken response surface optimization were used to optimize the extraction process of ionic liquid addition amount,extraction time,extraction pressure and the ratio of solid-liquid.The optimal process conditions were as follows:The amount of ionic liquid was 45 m L,The extraction time was 110 s,the extraction pressure was960 bar,and the ratio of solid-liquid was 1:650.Under these conditions,the extraction rate of astaxanthin was（81.66±1.21）%,which was（18.93±2.23）%higher than that of single and traditional ultra-high pressure microjet method.（2）Astaxanthin extract was used as raw material,saponification of astaxanthin extract was performed with Na OH-methanol solution,and then separation and purification were performed by Pre-HPLC.The chromatographic conditions were as follows:Hedera ODS column;Mobile phase:chromatographic methanol;Injection volume:5m L,Flow rate:10 m L/min.The structure of astaxanthin was characterized by UV,FT-IR,~1H-NMR and¹³C-NMR,and the purity of astaxanthin was more than94%by area normalization method.（3）AST-NLC was prepared by homogeneous emulsification-ultrasonic probe method.and the preparation process of AST-NLC was optimized by central composite design method with the encapsulation rate of AST-NLC as an index..The experimental results showed that the optimal preparation conditions of AST-NLC were as follows:the ratio of solid to liquid lipid was 1:11,the amount of emulsifier was 3.8%,and the ratio of oil to water was 1:34.The final prepared AST-NLC has a particle size of（80.3±1.21）nm,PDI value was（0.01±0.01）,encapsulation efficiency was（81.36±1.84）%,Zeta value was（-18.13±2.83）m V and the AST of drug loading was（1.68±.23）%.FT-IR and XRD structure analysis of AST-NLC showed that astaxanthin in the prepared AST-NLC existed in the form of molecules in the lipid carrier.