A method for preparing high-purity soybean phospholipids

Abstract

The invention belongs to the field of soybean by-product processing, and discloses a method for preparing high-purity soybean phospholipid, which comprises the following steps: completely dissolving soybean concentrated phospholipid with an extractant, continuously adding the extractant, stopping adding the extractant after 30-50 wt% of precipitates are separated out, separating to obtain the precipitates and a mixed solution, standing the mixed solution, collecting the clarified mixed solution and the bottom precipitates, combining the precipitates to obtain soybean phospholipid mixture A; recovering the extractant in the clarified mixed solution to obtain soybean phospholipid mixture B, adding an ethanol aqueous solution, stirring until it becomes paste-like, adding an alkane solvent, stopping stirring after mixture B is completely dissolved, recovering the alkane solvent, soybean phospholipid mixture B is divided into two layers, removing the upper layer to obtain soybean phospholipid mixture C, removing water, and mixing it with soybean phospholipid mixture A. The acetone-insoluble matter content in soybean phospholipid mixture A is >95%, and the acetone-insoluble matter content in soybean phospholipid mixture C is >90%.

Description

Technical Field

[0001] The present invention belongs to the field of soybean by - product processing, especially the deep processing technology of phospholipids, and specifically relates to a method for preparing high - purity soybean phospholipids. Background Art

[0002] Phospholipids are by - products in the process of oil refining. Through a series of refining processes, phospholipid products with different functions can be prepared, which can be used in industries such as food, cosmetics, and biomedicine to exert their effects. For example, soybean phospholipids, as good natural amphoteric surfactants, can be used in the food industry as emulsifiers, dispersants, etc., and high - purity soybean phospholipids can be used as excipients for various pharmaceutical preparations in the pharmaceutical industry.

[0003] With social progress, the demand for soybean phospholipids has increased, and high - purity soybean phospholipids have received more and more attention, and the demand has also gradually increased.

[0004] Currently, the existing methods for preparing high - purity soybean phospholipids include chromatography, supercritical CO2 extraction, semi - permeable membrane method, acetylation method, solvent method, high - performance chromatography, etc. Currently, in industrial large - scale production, acetone is used as a solvent. Utilizing the property that phospholipid substances are insoluble in acetone, the neutral oil in soybean concentrated phospholipids is removed to prepare high - purity soybean phospholipids. Patent CN108066768 A discloses a preparation process of high - purity pharmaceutical soybean phospholipids, in which one of ether, acetone, and methyl ethyl ketone is used as the first extractant for removing neutral oil in soybean concentrated phospholipids; Patent CN 101613369A discloses a production process of oil - free powdered egg yolk lecithin. First, acetone is used to remove the neutral oil in egg yolk powder to prepare oil - free egg yolk powder, and then oil - free egg yolk powder is used to prepare egg yolk lecithin; CN 103864839 A discloses a method for extracting crude phospholipids from cottonseed oil soapstock and a method for extracting lecithin from crude phospholipids, which also uses acetone to remove oil first to extract crude phospholipids and then extract lecithin.

[0005] Problems such as acetone being toxic and volatile, high production control costs, and acetone residues exist. Other methods such as supercritical CO2 extraction method have problems such as high equipment requirements and small processing capacity. Therefore, safe, effective, and large - processing - capacity high - purity soybean phospholipid production processes and products have received more and more attention. Summary of the Invention

[0006] The purpose of the present invention is to overcome the disadvantages and deficiencies of the prior art and provide a method for preparing high - purity soybean phospholipids. This method is a safe, effective, and large - processing - capacity high - purity soybean phospholipid production process with simple operation.

[0007] The purpose of the present invention is achieved by the following technical solutions:

[0008] A method for preparing high - purity soybean phospholipids, comprising the following steps:

[0009] (1) First, completely dissolve the soy lecithin concentrate with an extractant, then continue to add the extractant and stir. After 30 - 50 wt% of the precipitate separates out from the soy lecithin concentrate, stop adding the extractant, separate, and obtain precipitate 1 and a mixed solution;

[0010] Let the mixed solution stand, separately collect the clarified mixed solution and the precipitate 2 at the bottom, combine precipitate 1 and precipitate 2 at the bottom to obtain precipitate 3. After recovering the extractant from precipitate 3, obtain soy lecithin mixture A and extractant a1;

[0011] (2) After recovering the extractant from the clarified mixed solution in step (1), obtain soy lecithin mixture B and extractant a2. Add an ethanol aqueous solution to soy lecithin mixture B, stir until it becomes paste-like, add an alkane solvent, continue to stir. After soy lecithin mixture B is completely dissolved, stop stirring, recover the alkane solvent. After the alkane solvent is completely recovered, soy lecithin mixture B separates into two layers. Remove the upper layer of neutral oil and collect the lower layer of hydrated lecithin;

[0012] (3) After dehydrating the hydrated lecithin, obtain soy lecithin mixture C, and mix it with soy lecithin mixture A in step (1) to obtain high-purity soy lecithin;

[0013] The extractant is obtained by mixing a non-polar solvent and a monohydric alcohol in a certain proportion.

[0014] Preferably, the method further includes step (4):

[0015] (4) Mix extractant a1 and extractant a2, and add them as the extractant to step (1) for reuse.

[0016] Preferably, in the extractant in step (1), the volume ratio of the non-polar solvent to the monohydric alcohol is 1:2 - 1:10.

[0017] Preferably, the non-polar solvent is one or more of butane, propane, n-pentane, n-hexane, n-heptane, and more preferably n-hexane; the monohydric alcohol is one or more of methanol, ethanol, propanol, and more preferably ethanol.

[0018] Preferably, the alkane solvent in step (2) is one or more of propane, n-butane, isobutane, tetrafluoroethane, and sulfur hexafluoride, and / or one or more of halogenated alkanes with the same function.

[0019] Preferably, the concentration of the ethanol aqueous solution in step (2) is 10% - 30% V / V, and the addition amount is 10% - 25% of the weight of soy lecithin mixture B.

[0020] Preferably, the conditions for recovering the alkane solvent in step (2) are as follows: the recovery temperature is 20-50°C, the vacuum degree is -0.05 MPa to -0.08 MPa, the valve at the inlet of the compressor is opened to 1 / 3-1 / 2, and the solvent recovery rate is 0.3-0.6 L / min.

[0021] Preferably, the precipitate 1 and the bottom precipitate 2 in step (1) are phospholipid substances insoluble in the extractant in soy lecithin concentrate.

[0022] Preferably, the stirring to a paste in step (2) is carried out by stirring to a paste under normal temperature and vacuum in a closed pressure vessel.

[0023] Preferably, the water removal in step (3) is carried out by vacuum drying, and the conditions are: -0.1 MPa to -0.08 MPa, 40-50°C.

[0024] Preferably, the acetone-insoluble matter content in the soy lecithin mixture A is >95%, the acetone-insoluble matter content in the soy lecithin mixture B is 10%-35%, and the acetone-insoluble matter content in the soy lecithin mixture C is >90%.

[0025] In this discovery, first, through a n-hexane-ethanol system, most of the phospholipids insoluble in the n-hexane-ethanol system are separated first, the supernatant solvent is recovered, and a low-phospholipid mixture containing neutral oil is obtained. An ethanol aqueous solution is added to this mixture and dissolved with a low-carbon chain alkane solvent. By controlling the recovery rate of the alkane solvent, the separation of phospholipids and neutral oil due to the difference in solubility can be achieved, thus achieving the purpose of preparing high-purity soy lecithin.

[0026] The present invention has the following advantages and effects compared with the prior art:

[0027] 1) In the present invention, by using a non-polar solvent and a monohydric alcohol to form a mixed solvent, the phospholipids insoluble in the mixed solvent system formed by the non-polar solvent and the alcohol are separated first to obtain a low-phospholipid mixture containing neutral oil. An ethanol aqueous solution is added to this mixture and dissolved with a low-carbon chain alkane solvent. By controlling the recovery rate of the alkane solvent, the separation of phospholipids and neutral oil due to the difference in solubility can be achieved. This method avoids the use of acetone, is simple to operate, and the solvent can be recycled.

[0028] 2) In the present invention, the phospholipid mixture insoluble in the mixed solvent system formed by the non-polar solvent and the alcohol is mainly phosphatidylinositol and phosphatidylserine, containing a small amount of phosphatidylcholine and phosphatidylethanolamine.

[0029] 3) In the present invention, the phospholipid mixture obtained by removing neutral oil from the low-phospholipid mixture containing neutral oil is mainly phosphatidylcholine and phosphatidylethanolamine, containing a small amount of phosphatidylinositol and no phosphatidylserine.

[0030] 4) The present invention can initially achieve the rough fractionation of soybean phospholipids. The two high-purity phospholipid mixtures obtained successively can be used as products respectively. The acetone-insoluble matter content in the soybean phospholipid mixture A is > 95%, and the acetone-insoluble matter content in the soybean phospholipid mixture C is > 90%. It provides high-purity raw materials for the fine fractionation of soybean phospholipids, or the two can be mixed to obtain high-purity soybean phospholipids. Specific embodiments

[0031] The present invention will be further described in detail below in conjunction with embodiments, but the embodiments of the present invention are not limited thereto.

[0032] Embodiment 1

[0033] Take 100 g of soybean concentrated phospholipids, add a mixed solvent of n-hexane and ethanol (volume ratio of n-hexane:ethanol is 1:8) while stirring until the soybean concentrated phospholipids are completely dissolved. Then slowly add the mixed solvent and fish out the precipitates while stirring. When the precipitation amount of the insoluble phospholipid substances (i.e., precipitates) in the soybean concentrated phospholipids reaches 45 g, stop adding the mixed solvent and let it stand. After the mixed solution becomes clear after fishing out the precipitates, collect the clear mixed solution and a small amount of precipitates at the bottom respectively, combine the precipitates, recover the solvent to obtain a high-purity soybean phospholipid mixture A. Recover the mixed solvent in the clear mixed solution to obtain a low-phospholipid mixture B containing neutral oil. Combine the recovered solvent with the solvent recovered from the precipitates for use in the next batch of production and reuse. Place the low-phospholipid mixture B containing neutral oil in a closed pressure vessel, add 11 g of an ethanol aqueous solution (volume concentration of 20%), stir while evacuating to a paste state, then add butane until completely dissolved and stop stirring. Heat up to 40 °C, control the vacuum degree at -0.07 MPa, open the compressor inlet valve to 1 / 2, and recover butane. At this time, the butane recovery speed can be controlled at 0.4 L / min. After the butane is completely recovered, the low-phospholipid mixture B containing neutral oil in the container is divided into two layers. The upper layer is neutral oil and the lower layer is hydrated soybean phospholipids. Carefully collect the neutral oil, take out the hydrated phospholipids in the lower layer, and dry them under vacuum to remove water to obtain a high-purity soybean phospholipid mixture C. Among them, the acetone-insoluble matter of the high-purity soybean phospholipid mixture A is 97.1%, and the acetone-insoluble matter of the high-purity soybean phospholipid mixture C is 91.8%.

[0034] Embodiment 2

[0035] Take 100 g of soy lecithin, add a mixed solvent of n - hexane and ethanol (volume ratio of n - hexane to ethanol is 1:10) while stirring until the soy lecithin is completely dissolved. Then slowly add the mixed solvent and fish out the precipitate while stirring. When the precipitation amount of the insoluble phospholipid substances (i.e., the precipitate) in the soy lecithin reaches 43 g, stop adding the mixed solvent and let it stand. After the mixed solution becomes clear after fishing out the precipitate, collect the clear mixed solution and a small amount of precipitate at the bottom respectively. Combine the precipitates, recover the solvent to obtain a high - purity soy lecithin mixture A. Recover the mixed solvent in the clear mixed solution to obtain a low - phospholipid mixture B containing neutral oil. Combine the recovered solvent with the solvent recovered from the precipitate for use in the next batch of production and reuse. Place the low - phospholipid mixture B containing neutral oil in a closed pressure vessel, add 10 g of an ethanol aqueous solution (volume concentration is 25%), stir while evacuating to a paste, then add propane until it is completely dissolved, stop stirring, heat up to 40 °C, control the vacuum degree at - 0.06 MPa, open the compressor intake valve to 1 / 3, and recover propane. At this time, the propane recovery rate can be controlled at 0.3 L / min. After the propane is completely recovered, the low - phospholipid mixture B containing neutral oil in the container is divided into two layers. The upper layer is neutral oil and the lower layer is hydrated soy lecithin. Carefully collect the neutral oil, take out the hydrated phospholipid in the lower layer, and dry it under vacuum to remove water to obtain a high - purity soy lecithin mixture C. Among them, the acetone - insoluble matter of the high - purity soy lecithin mixture A is 98.3%, and the acetone - insoluble matter of the high - purity soy lecithin mixture C is 90.5%.

[0036] Example 3

[0037] Take 500 g of soy lecithin concentrate, and while stirring, add a mixed solvent of n-hexane and ethanol (volume ratio of n-hexane to ethanol is 1:9) until the soy lecithin concentrate is completely dissolved. Then slowly add the mixed solvent while stirring and fish out the precipitate. When the precipitation amount of the phospholipid substances insoluble in the soy lecithin concentrate (i.e., the precipitate) reaches 220 g, stop adding the mixed solvent and let it stand. After the mixed solution becomes clear after fishing out the precipitate, separately collect the clear mixed solution and a small amount of precipitate at the bottom, combine the precipitate, recover the solvent to obtain a high-purity soy lecithin mixture A. Recover the mixed solvent in the clear mixed solution to obtain a low-phospholipid mixture B containing neutral oil. Combine the recovered solvent with the solvent recovered from the precipitate for use in the next batch of production and reuse. Place the low-phospholipid mixture B containing neutral oil in a closed pressure vessel, add 55 g of an aqueous ethanol solution (volume concentration is 20%), stir while evacuating to a paste, then add butane until completely dissolved, stop stirring, heat up to 45 °C, control the vacuum degree at -0.08 MPa, open the compressor intake valve to 1 / 2, and recover butane. At this time, the butane recovery rate can be controlled at 0.3 L / min. After the butane is completely recovered, the low-phospholipid mixture B containing neutral oil in the container is divided into two layers. The upper layer is neutral oil, and the lower layer is hydrated soy lecithin. Carefully collect the neutral oil, take out the hydrated phospholipid in the lower layer, and dry it under vacuum to remove water to obtain a high-purity soy lecithin mixture C. Among them, the acetone-insoluble matter of the high-purity soy lecithin mixture A is 96.6%, and the acetone-insoluble matter of the high-purity soy lecithin mixture C is 92.2%.

[0038] Example 4

[0039] Take 2000 g of soy lecithin, add a mixed solvent of n-hexane and ethanol (volume ratio of n-hexane to ethanol is 1:8) while stirring until the soy lecithin is completely dissolved. Then slowly add the mixed solvent and scoop out the precipitate while stirring. When the precipitation amount of the insoluble phospholipid substances (i.e., the precipitate) in the soy lecithin reaches 700 g, stop adding the mixed solvent and let it stand. After the mixed solution becomes clear after scooping out the precipitate, collect the clear mixed solution and a small amount of precipitate at the bottom respectively, combine the precipitate, recover the solvent to obtain high-purity soy lecithin mixture A, recover the mixed solvent in the clear mixed solution to obtain a low-phospholipid mixture B containing neutral oil. Combine the recovered solvent with the solvent recovered from the precipitate for use in the next batch of production and reuse. Place the low-phospholipid mixture B containing neutral oil in a closed pressure vessel, add 250 g of an aqueous ethanol solution (volume concentration is 15%), stir while evacuating to a paste, then add butane until completely dissolved, stop stirring, heat up to 35 °C, control the vacuum degree at -0.08 MPa, open the compressor inlet valve to 1 / 2, and recover butane. At this time, the butane recovery rate can be controlled at 0.4 L / min. After the butane is completely recovered, the low-phospholipid mixture B containing neutral oil in the container is divided into two layers. The upper layer is neutral oil and the lower layer is hydrated soy lecithin. Carefully collect the neutral oil and take out the hydrated phospholipid in the lower layer, and dry it under vacuum to remove water to obtain high-purity soy lecithin mixture C. Among them, the acetone-insoluble matter of high-purity soy lecithin mixture A is 97.7%, and the acetone-insoluble matter of high-purity soy lecithin mixture C is 91.9%.

[0040] Comparative Example 1

[0041] Take 100 g of soy lecithin, and while stirring, add a mixed solvent of n - hexane and ethanol (n - hexane:ethanol = 1:8) until the soy lecithin is completely dissolved. Then slowly add the mixed solvent and while stirring, fish out the precipitate. When the precipitation amount of the insoluble phospholipid substances (i.e., the precipitate) in the soy lecithin reaches 45 g, stop adding the mixed solvent and let it stand. After the mixed solution becomes clear after fishing out the precipitate, separately collect the clear mixed solution and a small amount of the precipitate at the bottom. Combine the precipitate, recover the solvent to obtain a high - purity soy lecithin mixture A. Recover the mixed solvent in the clear mixed solution to obtain a phospholipid mixture B containing neutral oil. Combine the recovered solvent with the solvent recovered from the precipitate and use it for the next batch of production for repeated use. Place the phospholipid mixture B containing neutral oil in a closed pressure vessel, add 11 g of an aqueous ethanol solution (volume concentration is 20%), stir while evacuating to a paste state, then add butane until it is completely dissolved and stop stirring. Heat up to 40 °C, control the vacuum degree at - 0.09 MPa, open the compressor intake valve to 1 / 2, and recover butane. At this time, the butane recovery rate can be controlled at 0.8 L / min. After the butane is completely recovered, the phospholipid mixture B containing neutral oil in the container is divided into two layers. The upper layer is neutral oil and the lower layer is hydrated soy lecithin. Carefully collect the neutral oil, take out the hydrated phospholipid in the lower layer, and dry it under vacuum to remove water to obtain a soy lecithin mixture C. Among them, the acetone - insoluble matter of the high - purity soy lecithin mixture A is 98.8%, and the acetone - insoluble matter of the soy lecithin mixture C is 73.2%.

[0042] Comparative Example 2

[0043] Take 100 g of soy lecithin concentrate, add a mixed solvent of n - hexane and ethanol (n - hexane:ethanol = 1:8) while stirring until the soy lecithin concentrate is completely dissolved. Then slowly add the mixed solvent and fish out the precipitate while stirring. When the precipitation amount of the insoluble phospholipid substances (i.e., the precipitate) in the soy lecithin concentrate reaches 45 g, stop adding the mixed solvent and let it stand. After the mixed solution becomes clear after fishing out the precipitate, collect the clear mixed solution and a small amount of precipitate at the bottom respectively, combine the precipitate, recover the solvent to obtain a high - purity soy phospholipid mixture A. Recover the mixed solvent in the clear mixed solution to obtain a low - phospholipid mixture B containing neutral oil. Combine the recovered solvent with the solvent recovered from the precipitate for use in the next batch of production and reuse. Place the low - phospholipid mixture B containing neutral oil in a closed pressure vessel, add 11 g of an aqueous ethanol solution (volume concentration is 20%), stir while evacuating to a paste state, then add butane until it is completely dissolved and stop stirring. Heat up to 45 °C, control the vacuum degree at - 0.1 MPa, fully open the compressor intake valve, and recover butane. At this time, the butane recovery rate can be controlled at 0.9 L / min. After the butane is completely recovered, the phospholipid mixture B containing neutral oil in the container is divided into two layers. The upper layer is neutral oil and the lower layer is hydrated soy phospholipid. Carefully collect the neutral oil and take out the hydrated phospholipid in the lower layer, and dry it under vacuum to remove water to obtain a high - purity soy phospholipid mixture C. Among them, the acetone - insoluble matter of the high - purity soy phospholipid mixture A is 97.1%, and the acetone - insoluble matter of the high - purity soy phospholipid mixture C is 69.4%.

[0044] The above - mentioned embodiments are the preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the above - mentioned embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A method for preparing high-purity soybean phospholipids, characterized in that, It includes the following steps: (1) First, completely dissolve the soy lecithin concentrate with an extractant, continue to add the extractant, stir, and stop adding the extractant after 30 - 50 wt% of the precipitate separates out from the soy lecithin concentrate. Then separate to obtain precipitate 1 and a mixed solution; Let the mixed solution stand, separately collect the clarified mixed solution and the bottom precipitate 2, combine precipitate 1 and the bottom precipitate 2 to obtain precipitate 3. After recovering the extractant from precipitate 3, obtain soy lecithin mixture A and extractant a1; (2) After recovering the extractant from the clarified mixed solution in step (1), obtain soy lecithin mixture B and extractant a2. Add an ethanol aqueous solution to soy lecithin mixture B, stir until it becomes a paste, add an alkane solvent, continue to stir, stop stirring after soy lecithin mixture B is completely dissolved, recover the alkane solvent. After the alkane solvent is completely recovered, soy lecithin mixture B separates into two layers, and collect the lower layer of hydrated lecithin; (3) After dehydrating the hydrated lecithin, obtain soy lecithin mixture C, and mix it with soy lecithin mixture A in step (1) to obtain high - purity soy lecithin; The extractant is obtained by mixing a non - polar solvent and a monohydric alcohol in a certain proportion; The non - polar solvent is n - hexane, and the monohydric alcohol is ethanol; The volume ratio of the non - polar solvent to the monohydric alcohol in the extractant is 1:8 - 1:10; The alkane solvent is butane or propane; The solvent recovery rate in step (2) is 0.3 - 0.4 L / min.

2. The method for preparing high-purity soybean phospholipid according to claim 1, characterized in that, The method further includes step (4): (4) Mix extractant a1 and extractant a2, and add them as the extractant to step (1) for reuse.

3. The method for preparing high-purity soybean phospholipid according to claim 1, characterized in that, The concentration of the ethanol aqueous solution in step (2) is 10% - 30% V / V, and the addition amount is 10% - 25% of the weight of soy lecithin mixture B.

4. The method for preparing high-purity soybean phospholipid according to claim 1, characterized in that, The conditions for recovering the alkane solvent in step (2) are: the recovery temperature is 20 - 50°C, the vacuum degree is - 0.05 MPa to - 0.08 MPa, and the compressor inlet valve is opened to 1 / 3 - 1 / 2.

5. The method for preparing high-purity soybean phospholipid according to claim 1, characterized in that, The precipitate 1 and the bottom precipitate 2 in step (1) are phospholipid substances in the soy lecithin concentrate that are insoluble in the extractant.

6. The method for preparing high-purity soybean phospholipid according to claim 1, wherein The stirring to a paste in step (2) is stirring to a paste under normal temperature and vacuum.

7. The method for preparing high-purity soybean phospholipid according to claim 1, characterized in that, The dehydrating in step (3) is dehydrating by vacuum drying.

8. The method for preparing high-purity soybean phospholipid according to claim 1, wherein The acetone - insoluble matter content in the soy lecithin mixture A is > 95%, the acetone - insoluble matter content in the soy lecithin mixture B is 10% - 35%, and the acetone - insoluble matter content in the soy lecithin mixture C is > 90%.