Alpha linolenic acid cryogenic separation and purification method

Abstract

The invention discloses an alpha linolenic acid cryogenic separation and purification method, comprising the steps of: uniformly mixing oil rich in alpha linolenic acid and acetone or a methanol solvent according to a volume ratio of 1:(3-6), placing a container containing the mixed solution in an environment at (-30)-(-60) DEG C for refrigeration, separating and removing crystals at low temperature when the temperature reaches (-30)-(-60) DEG C, and desolventizing the solution to remove the solvent accounting for 20-30% of the total volume; repeating the steps of refrigeration, crystal removal and desolventization for 3-5 times for separating and removing the crystals; and after circularly removing the crystals for 3-5 times, repeating the steps of refrigeration and crystal removal once again when the volume ratio of the alpha linolenic acid to the solvent reaches 1:(2-3), and desolventizing the finally obtained mixed solution to obtain the alpha linolenic acid. The method is a pure physical cryogenic separation technology and can improve product quality and yield stability, and the concentration of the obtained alpha linolenic acid is above 80%.

Description

technical field [0001] The invention relates to a separation and purification method of α-linolenic acid, in particular to a low-temperature freezing separation and purification method of α-linolenic acid. Background technique [0002] The main components in linseed oil are saturated fatty acids, unsaturated fatty acids (including alpha linolenic acid, linoleic acid, oleic acid, etc.) and some other trace components. Among unsaturated fatty acids, α-linolenic acid is a monotrienoic acid, also known as octadecatrienoic acid, linoleic acid is a monodienoic acid, and oleic acid is a monomonoenoic acid. Alpha-linolenic acid participates in the synthesis of phospholipids in the body, and is metabolized into EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) necessary for the human body. α-linolenic acid and its metabolites have the effects of improving intelligence, protecting eyesight, lowering blood fat, lowering blood pressure, inhibiting platelet aggregation, anti-th...

AI Technical Summary

Problems solved by technology

In Europe and the United States, it has been reported that sardine mixed fatty acids and solvents are mixed in a 5:95 volume ratio using a freezer, and EPA (pentaenoic acid) and DHA (hexaenoic acid) in the fatty acids can be increased from 17% and 10% to 30% and 30% respectively. 12%, the process takes 25h, and the solvent is acetone. Compared with the latter two processes, its advantages are simple process, no chemical residue, low production cost, and the disadvantage is that the purity of unsaturated fatty acids is not high, which can only reach below 40%. In fact, the content of EPA and DHA deep-sea fish oil currently imported into the Chinese market is less than 30%

Method 2, the most widely used urea inclusion method, can achieve a purity of α-linolenic acid above 80%, but this process obtains the product of ethyl α-linolenic acid. Although it does not affect its ability to be absorbed by the human body, it is not the original product after all. α-linolenic acid, and the amount of urea used in the production is large, the product loss is large, it is easy to cause pollution, and the production cost is high

In addition, the acid hydrolysis, complexation, and freeze-separation mixing method of method 3 is to process the α-linolenic acid raw material oil with a content greater than 45% through saponification acidolysis, polar solvent freeze-separation, complexation, solvent gradient freezing, and dehydration to obtain a content greater than 45%. 90% α-linolenic acid; the process is more complicated, the loss is large, the production cost is high, and it is rarely used in industrial applications

[0004]The above three methods all have low technical level and cannot produce high-purity oil α-linolenic acid; and the production cost is high, and the product is changed by chemical modification or directly into It is the product of α-linolenic acid ethyl esterification, resulting in the defect of unstable product performance