JP2515839B2 - Phospholipid purification method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a method for purifying lecithin using an acetic ester, and more specifically, from lecithin containing a large amount of neutral lipids such as soybean lecithin and rapeseed lecithin. The present invention relates to a method for removing high-purity lecithin having a high phospholipid content such as phosphatidylcholine and phosphatidylethanolamine by removing neutral lipids.

In the present specification, the term "lecithin" is used as a mixture containing phospholipid as a main component.

The term "extraction" also includes the meaning of "fractionation" and is to be understood in the broadest sense.

<Prior Art> Lecithin has been applied to a wide range of fields such as foods, pharmaceuticals, cosmetics, feeds, and industrial products as emulsifiers, dispersants, stabilizers, and antioxidants.

Such lecithin is used in animal tissues such as egg yolk and beef brain.
It exists in plant tissues such as soybean, rapeseed, and alfalfa seeds, and many raw materials have been mentioned as raw materials for producing lecithin.

Of these, crude lecithin, which is particularly called soybean lecithin or rapeseed lecithin, is hydrated by adding hot water or steam to extracted crude oil obtained by extracting raw materials such as soybean and rapeseed with a solvent such as n-hexane. , Lecithin is coagulated and precipitated, and this is separated by a centrifuge or dried. The lecithin thus obtained varies depending on its raw material, but phosphatidylcholine (hereinafter abbreviated as PC), phosphatidylethanolamine (hereinafter abbreviated as PE), phosphatidylinositol (hereinafter abbreviated as PI),
In addition to phosphatidic acid (hereinafter abbreviated as PA) and other phospholipids, triacylglycerol (= triglyceride, neutral lipid), free fatty acid, etc. (hereinafter collectively referred to as “neutral lipid”) are 30-40 %, And also contains wax substances such as sterols and carbohydrates. The composition of a typical soybean crude lecithin is shown in Table 1.

Table 1 Composition of soybean crude lecithin (% by weight) Phosphatidylcholine (PC) 20 Phosphatidylethanolamine (PE) 15 Phosphatidylinositol (PI) 20 Phosphatidylate (PA), other phospholipids 5 Carbohydrates, wax substances 5 Neutral lipids ( NL) 35 In the above composition, PC is the main component of lecithin, and the one with higher PC content is usually called high-purity lecithin. In recent years, especially, neutral lipids have been removed from crude lecithin to increase PC content. The demand for high-purity lecithin has started to increase.

As an example of using such high-purity lecithin, there is modification of the emulsification function by an enzymatic method. For example, JP-A-61-199749
In the publication, modified soybean lecithin containing phosphatidylglycerol (hereinafter abbreviated as PG) obtained by causing a phosphatidyl group transfer reaction between soybean lecithin and glycerol with phospholipase D is described as calcium ion, sodium ion, etc. It is described that it is effective as a food-grade emulsifier whose emulsifying power is not hindered by metal ions and pH. The present inventors have found that a modified soybean lecithin having an excellent emulsification function preferably has a PG content of about 50% or more. In the currently known enzymatic reaction with phospholipase D, PC and PE in lecithin can be mainly used as substrates for the phosphatidyl group transfer reaction, so it is recommended to use high-purity lecithin with a PC + PE content of at least 50% as a raw material. Good.

As a method for purifying lecithin to produce high-purity lecithin, various fractionation or fractionation methods have been proposed so far, but as a method that has been put to practical use in terms of quality and price,
A solvent fractionation method using acetone or ethanol can be mentioned.

The present inventors have found that the removal rate of neutral lipids is superior to that of the acetone fractionation method or ethanol fractionation and that the recovery rate of PC is good, and that a small amount of solvent is used and a safer solvent than acetone can be used. , A method for fractionation of acetic ester, which has a better recovery rate of components such as PE and PI, which are more useful for emulsifiers, etc. than the fractionation method for ethanol, has been applied for a patent.

This acetic acid ester fractionation method is a method in which neutral lipid-containing lecithin is dissolved with acetic acid ester and then cooled to separate into a soluble component containing a neutral lipid as a main component and an insoluble component containing a phospholipid as a main component. . When the neutral lipid-containing lecithin is dissolved in acetic ester and then cooled, precipitation of phospholipids begins. The precipitation of phospholipid increases as the cooling progresses, and becomes almost constant at a predetermined cooling temperature. The neutral lipid remains in the solution with little fractional precipitation even when the solution is cooled. In this way, most of the neutral lipids are removed and most of the phospholipids are recovered, so that highly pure lecithin having a high phospholipid content can be obtained.

<Problems to be Solved by the Invention> However, in the above-mentioned acetic acid ester fractionation method, the fractionation temperature at which it is cooled and fractionated into soluble and insoluble components is, for example, 5 to 0 ° C. for methyl acetate and −5 to 5 for ethyl acetate. -10 ℃, -20 to -30 ℃ for propyl acetate, and -50 to butyl acetate
A temperature of about -60 ° C is preferable, and it is necessary to keep the temperature quite low.
It goes without saying that the closer the separation temperature is to room temperature, the less energy consumption is desired.

Therefore, the object of the present invention is to eliminate the problems of the above-mentioned acetate separation method, and to separate the soluble and insoluble fractions,
That is, it is an object of the present invention to provide a method for purifying phospholipids with an acetic acid ester, which has a high temperature for extracting soluble components and can be performed at a temperature near room temperature or at a temperature suitable for the process.

<Means for Solving Problems> The inventors of the present invention have conducted further research to achieve the above-mentioned object, and as a result, extract (separate) neutral lipids from lecithin in a system in which water is added to acetate. Therefore, it was found that the extraction temperature can be increased without substantially impairing the recovery rate of phospholipids.

That is, the present invention is characterized in that a neutral lipid-containing lecithin is brought into contact with acetic acid ester and water to extract a soluble component containing a neutral lipid as a main component, thereby increasing the phospholipid content of the insoluble component. This is a purification method, and there are various aspects as described below.

A method in which a neutral lipid-containing lecithin is brought into contact with a mixed solution of acetic ester and water, a soluble component containing a neutral lipid as a main component is extracted, and an insoluble component containing a phospholipid as a main component is separated.

A method of increasing the phospholipid content of insolubles by cooling neutral lipid-containing lecithin in contact with a mixed solution of acetic acid ester and water to extract soluble components containing neutral lipids as a main component.

Mixing lecithin containing neutral lipid with acetate (dissolving)
After that, water is added, and the soluble component containing the neutral lipid as the main component is extracted to separate the insoluble component containing the phospholipid as the main component.

Mixing (dissolving) neutral lipid-containing lecithin and acetate
After that, water is added and the mixture is cooled to extract a soluble component containing a neutral lipid as a main component and to separate an insoluble component containing a phospholipid as a main component.

A method in which a neutral lipid-containing lecithin is mixed with water and then acetic acid ester is added to extract a soluble component containing a neutral lipid as a main component to separate an insoluble component containing a phospholipid as a main component.

A method in which a neutral lipid-containing lecithin is mixed with water, and then an acetic acid ester is added and the mixture is cooled to extract a soluble component containing a neutral lipid as a main component to separate an insoluble component containing a phospholipid as a main component.

The neutral lipid-containing lecithin used as a raw material in the present invention is
Crude lecithin extracted from crude oil such as soybean and rapeseed, and crude lecithin obtained by further fractionating ethanol to remove ethanol insolubles (hereinafter referred to as "ethanol fractionated lecithin") can be preferably used. In principle, this ethanol fractionation utilizes the difference in the solubility of various phospholipids and neutral lipids in crude lecithin with respect to ethanol, and as an ethanol-soluble substance, a large amount of PC and a small amount of PE, PI and neutral substances are used. Lipids are extracted, and a large amount of PE, PI, and neutral lipids are separated from a small amount of PC as ethanol-insoluble matter.

The acetic acid ester is preferably an ester of acetic acid and an alcohol having 1 to 4 carbon atoms, and preferably methyl acetate or ethyl acetate can be used.

Generally, the total amount of acetic acid ester and water used is about 4 times or more than 4 times the volume (ml) / weight (g) of the weight of the neutral lipid-containing lecithin. Since the ratio of phospholipids to neutral lipids in lecithin containing neutral lipids varies, the composition, the composition of the target fractionated lecithin (purity of phospholipids), the recovery rate, etc., and the type of acetate ester used Adjust according to.

The larger the ratio of water to the total amount of acetic acid ester and water used, the higher the extraction temperature can be achieved without substantially impairing the recovery rate of phospholipids.

The attached drawing shows that 90% or more of phospholipids are extracted by extracting the total amount of acetic acid ester and water to 4 times (ml) with respect to lecithin (g) having a PC content of about 35 to 38% by weight. 6 is a graph showing the relationship between the ratio of water to the total amount of acetic acid ester and water used and the extraction temperature in each case, for each type of acetic acid ester. As can be seen from this graph, as the ratio of water to the total amount of acetic acid ester and water used increases, the extraction temperature (fractionation temperature) of any acetic acid ester becomes higher. This means that the extraction operation can be performed at a higher temperature.

When the amount of water is increased, the phospholipids existing as an emulsion become larger in size because the emulsion diameter becomes larger, but if the amount of water is too large, the removal rate of neutral lipids increases. It tends to get worse. In addition, the amount of water necessary for extraction at a predetermined temperature is determined by the ratio of phospholipid and neutral lipid of the raw material lecithin [= phospholipid / (phospholipid +
Neutral lipids)]. The raw material lecithin with a higher phospholipid content requires more water. In other words, the raw material lecithin with a higher content of neutral lipids requires a larger amount of acetic acid ester. Furthermore, the amount of water required for extraction at a given temperature is greatly affected by the type of acetate. As is clear from the above-mentioned accompanying drawings, the smaller the carbon number of the acetate ester, the smaller the amount of water.

Taking these factors into consideration, as described above, the respective amounts of the acetic acid ester and water are determined by the composition of the neutral lipid-containing lecithin, the type of the acetic acid ester used, the composition of the target fractionated lecithin (phospholipid purity), and the like. It may be determined experimentally according to the recovery rate, extraction temperature and the like. In the case of methyl acetate and ethyl acetate, generally, the ratio of water to the total amount of acetic acid ester and water used is preferably 10% by volume or less. Also,
The extraction temperature can be higher than room temperature, but is generally 30 ° C or lower, preferably 25 ° C or lower, and more preferably
It is better to keep it below 10 ℃.

When extracting at a temperature lower than room temperature, a method of contacting neutral lipid-containing lecithin with acetic acid ester and water from the beginning at a predetermined low temperature and a method of contacting neutral lipid-containing lecithin with acetic acid ester and water at room temperature at the beginning. There is a method of cooling after that, but any of these methods can be used.

By using acetic acid ester and water like this,
The extraction (fractionation) temperature can be increased. There are various modes for the method of bringing the acetate and water into contact with the neutral lipid-containing lecithin. That is, a mixed solution of acetic acid ester and water may be prepared in advance, and the mixed solution may be contacted with neutral lipid-containing lecithin, or water may be added after mixing the acetic acid ester and neutral lipid-containing lecithin. The contact with the above-mentioned acetic acid ester and water may be carried out, or further, after mixing the neutral lipid-containing lecithin and water, the acetic acid ester may be added. Therefore, there are various modes depending on the combination of the cooling time and the contact time of addition of acetic acid ester and water.

Hereinafter, one embodiment of the purification method of the present invention will be described for each step.

Mixing process For crude lecithin such as soybeans and rapeseed containing a large amount of neutral lipids of about 30 to 40% by weight, the total amount of acetic ester and water (ml) / crude lecithin (g) ratio Is 4 times or more, and the ratio of water to the total amount of acetic acid ester and water used is, for example, 5% by volume or less in the case of ethyl acetate, the acetic acid ester and water are added, and the mixture is stirred at room temperature. Mix with. The content of neutral lipids
When the ethanol fractionated lecithin reduced to about 20 to 25% is further purified by the method of the present invention, the ratio of total amount of acetic acid ester and water (ml) / crude lecithin (g) is the same as the above case. The ratio of water to the total amount of acetic acid ester and water used may be the same, but for example, ethyl acetate should be 10% by volume or less, and methyl acetate should be 5% by volume or less. Add. As described above, the amounts of acetic acid ester and water to be used are increased or decreased depending on the composition of the raw material neutral lipid-containing lecithin, and this increase or decrease may be confirmed by experiments.

Separation Step of Precipitation The mixture of neutral lipid-containing lecithin, acetic acid ester and water mixed at room temperature is cooled with stirring if necessary.

After sufficient mixing, or when it is necessary to cool the mixed solution, after the mixed solution reaches a predetermined temperature, stirring is stopped and the mixture is allowed to stand for about 5 minutes to precipitate the precipitate. The supernatant containing mainly acetic acid ester containing neutral lipids and water is removed, and the acetic acid ester is recovered by distillation or the like and reused.

When the soluble component containing the neutral lipid as the main component is extracted by contacting the neutralized lipid-containing lecithin with acetic acid ester to which predetermined water is added so that cooling is not required, for example, centrifugal countercurrent An extractor or the like can be used, and continuous treatment can be performed.

The precipitate or the treated product taken out from the extractor is
After performing centrifugal concentration if necessary, high-purity lecithin is recovered by recovering the acetic acid ester using a thin film concentrator, a spray dryer and the like and drying.

The high-purity lecithin thus obtained has been removed to below the detection limit (1 ppm or less) at which no acetic ester was detected, and a product with no problem in terms of odor or toxicity can be obtained. Further, when the above method is adopted, the acetic acid ester can be removed in a short time, so that the lecithin is not colored or the taste is not changed by oxidation or the like.

When the high-purity lecithin obtained by the method of the present invention is subjected to an enzymatic method using phospholipase D to modify the emulsifying function, the enzymatic reaction may be carried out in a homogeneous system of acetic ester, water and glycerin. Therefore, the precipitate or treated product obtained by the method of the present invention may be directly supplied to the enzyme reaction tank.

By subjecting the soybean crude lecithin having a standard composition to the extraction with the acetate ester and water according to the method of the present invention described above as a raw material, highly pure lecithin having a PC content of about 25 to 35% can be obtained. In order to produce highly pure lecithin having a PC concentration higher than this, it may be necessary to use the method of the present invention in combination with another fractionation method or fractionation method. That is, using the fractionated (fractionated) lecithin obtained by another fractionation method or fractionation method as the raw material for the method of the present invention,
Alternatively, the lecithin obtained by the method of the present invention may be used as a raw material for another fractionation method or fractionation method. In this case, a combination of the ethanol fractionation method and the acetate extraction method of the present invention is preferable.

As the ethanol fractionation method, ethanol or an aqueous ethanol solution having a concentration of about 95% by volume is used, and the volume (ml) / weight (g) ratio of this is about 4 times or more, preferably 10 times the volume of the lecithin raw material. In addition, it is preferable to employ a method in which after stirring and mixing (dissolving) at room temperature, the ethanol-soluble content and the ethanol-insoluble content are separated, and ethanol-separated lecithin is obtained as a residue obtained by removing ethanol by evaporation from the supernatant ethanol-soluble content.

When soybean crude lecithin having a standard composition is treated by a combination of the ethanol fractionation method and the acetate extraction method of the present invention, highly pure lecithin having a PC content of about 65% can be obtained. Therefore, if the lecithin obtained by the acetate extraction method of the present invention and the lecithin obtained by the ethanol fractionation-acetate extraction combination method are mixed in various proportions, the desired PC content in the range of 25 to 60% is obtained. It is possible to provide various high-purity lecithin products having

<Examples> The method of the present invention will be further described below with reference to Examples and Comparative Examples, but the scope of the claims of the present invention is not limited by these Examples.

To confirm phospholipids and neutral lipids in the following Examples and Comparative Examples, a flying spot scanner analyzer (manufactured by Shimadzu Corporation, model CS-9000) was used after development and separation by thin layer chromatography. That is, after spotting 20 to 30 μg of the total amount of the sample on the silica gel plate,
The mixture was developed and separated with a developing solution of chloroform: methanol: acetic acid (13: 5: 2), air-dried, developed with 50% sulfuric acid, and quantified with a flying spot scanner (wavelength 460 nm).

Example 1 Selection of Extraction Temperature and Water Ratio in Ethyl Acetate-Water Mixed Extraction As a raw material lecithin containing a large amount of neutral lipids, “Borec”
FS (BOLEC FS) "(trade name, manufactured by Unimills, West Germany) was used. Table 1 shows the composition of this raw material lecithin "Borec FS".

To 5.0 g of each of the raw material lecithin, 20 ml each of an ethyl acetate-water mixed solution containing 5% by volume of water and an ethyl acetate-water mixed solution containing 10% by volume of water were added, and stirred and mixed at 25 ° C. The former mixed solution (solution) thus obtained was added to each of 5,1
Cool to 0,15 ° C and add the latter mixture (solution) to 20,2
After cooling or heating to 5,30 ° C, each precipitate formed is treated with a centrifuge at 3000 rpm for 5 minutes and collected, and then a rotary evaporator is used to bath temperature 40 ° C, vacuum degree 30 torr, time 15
Pre-dried under the condition of minutes, and further vacuum degree 50to with a vacuum dryer
It was dried at rr, a temperature of 80 ° C. and a drying time of 1 hour.

Table 2 shows yields and yields of the dried and recovered lecithin according to extraction temperatures.

For comparison, 20 ml of water-free ethyl acetate and 5.0 g of the above-mentioned starting lecithin were mixed at 25 ° C., cooled to −5 ° C., and the resulting precipitate was treated in the same manner as above to recover recovered lecithin. The data are also shown in Table 2.

The yield at this time is (weight of dry recovered lecithin / weight of raw material lecithin) × 100.

Table 3 shows the composition of the dried and recovered lecithin according to the separation temperature and the water ratio.

Table 4 shows the recovery rates of neutral lipids (NL), PE, and PC in the dried and recovered lecithin with respect to the starting lecithin by extraction temperature and water ratio.

Here, the recovery rate is (weight of each component in dry recovered lecithin / weight of each component in raw lecithin) × 100.

As can be seen from the results in Table 2, the yield of dry recovered lecithin was as low as 33.4% at 15 ° C when the proportion of water was 5% by volume, but was as high as 57.0% at 10 ° C or less, and also 10% by volume. At that time, it was as low as 29.8% at 30 ℃, but it became 55% below 25 ℃, and the yield equivalent to the result obtained by extraction treatment with ethyl acetate at 25 ℃ without water was obtained.

In addition, from the results shown in Table 3, dried and recovered lecithin is
NL was well removed and highly pure lecithin with PC content of 62-66 wt% was obtained. From the result of the recovery rate in Table 4 calculated by multiplying the yield of dry recovered lecithin by the ratio of each component, the weight ratio of the PC amount in the recovered lecithin to the PC amount in the raw material is shown in Table 2. Is 90 to 95%,
It is equivalent to the result of extraction treatment with ethyl acetate at -5 ° C without addition of water.

Judging from these points, in the ethyl acetate-water mixed extraction with the raw material lecithin having a PC content of about 35 to 50%, when the proportion of water is 10% by volume, the extraction temperature is 25 ° C or lower, and when 5% by volume, It is judged that 10 ° C or lower is preferable.

Incidentally, without mixing the mixed solution of ethyl acetate and water to the raw material lecithin as described above, first the raw material lecithin and ethyl acetate are mixed, and then when a predetermined amount of water is added and mixed by stirring as well. , Similar results were obtained.

Example 2 Selection of Total Volume Ratio of Ethyl Acetate and Water in Ethyl Acetate-Water Mixed Extraction Using “Borec FS” as raw material soybean lecithin, 5
To 10 ml of an ethyl acetate-water mixture containing volume% water,
1.0g, 2.5g, 5.0g of this raw material lecithin was added, and the volume ratio (ml / g) of the total amount of ethyl acetate and water to the raw material lecithin at 25 ° C was 10 times, 4 times and 2 times, respectively. So that
Each was mixed with stirring. Cool these solutions to 10 ° C and
The resulting precipitate was collected and dried in the same manner as in Example 1.
The amount of ethyl acetate in the obtained dried and recovered lecithin was below the detection limit (1 ppm or less).

Table 5 shows the composition of the raw material lecithin "Borec FS" used in this example.

The yield and yield of dry recovered lecithin were calculated by the volume ratio of the total amount of ethyl acetate and water to the weight of raw material lecithin,
It is shown in Table 6.

The compositions of NL, PE and PC in the dried and recovered lecithin and the recoveries of the respective components are shown in Tables 7 and 8 according to the above volume ratios.

As can be seen from Table 6, a good yield was obtained when the volume ratio was 4 times or more, but no precipitation of lecithin was observed when the volume ratio was 2 times. Further, as shown in Table 7, when the volume ratio is 4 times or more, the NL content is about 3% and the PC content is 60% or more, and the quality is good.

Furthermore, as shown in Table 8, when the above capacity ratio is 4 times or more, the removal rate of NL is as high as 95% or more, and the recovery rate of PC is 96%.
%, PE recovery rate is good at 74%.

From the above results, the above volume ratio in the ethyl acetate-water mixed extraction containing 5% by volume of water at the extraction temperature of 10 ° C.
It is preferably at least 4 times or more.

In addition, in the ethyl acetate-water mixed extraction containing 10% by volume of water, the experiment was conducted at the extraction temperature of 25 ° C., but the same tendency was observed.

Example 3 Selection of Extraction Temperature in Methyl Acetate-Water Mixed Extraction “Borec FS” was used as a raw material lecithin, and 5.0 ml of this raw material lecithin was added with 20 ml of a methyl acetate-water mixed solution containing 5% by volume of water to obtain 25. Stir-mix at 0 ° C. Each of these solutions
After cooling or heating to 20, 25, 30 ° C., the formed precipitate was collected and dried in the same manner as in Example 1.

The composition of the raw material lecithin used in this example is shown in Table 9.

Table 10 shows yields and yields of the obtained dried and recovered lecithin according to extraction temperatures.

For comparison, 20 ml of water-free methyl acetate and 5.0 g of the above-mentioned starting lecithin were mixed at 25 ° C., and the precipitate produced by cooling to 5 ° C. was treated in the same manner as above to obtain a recovered lecithin. Data is also shown.

Tables 11 and 12 show the composition of the dried and recovered lecithin and the recovery rate of each component at each extraction temperature.

As shown in Table 10, when the extraction temperature was 25 ° C or lower, the yield was almost the same as the result of extraction treatment with methyl acetate without water at 5 ° C, but was poor at 30 ° C. . Also, as shown in Table 11 and Table 12, the extraction temperature
Below 25 ℃, the quality of NL is around 5% and the content of PC is over 60%, the quality is good, and the removal rate of NL is 92-95%, and P
The recoveries of C and PE were 90% and 70%, respectively, which were almost the same as the results of extraction treatment with methyl acetate without water at 5 ° C.

From the above results, in the methyl acetate-water mixed extraction, the extraction temperature is preferably 25 ° C. or lower when the proportion of water is 5% by volume.

Example 4 Selection of Total Volume Volume Ratio of Methyl Acetate and Water in Methyl Acetate-Water Mixed Extraction Using “Borec FS” as a raw material lecithin, 10 ml of a methyl acetate-water mixed solution containing 5% by volume of water, Add 1.0 g, 2.5 g, and 5.0 g of this raw material lecithin, respectively, and use the volume ratio (ml / g) of the total amount of methyl acetate and water to the raw material lecithin.
Of 10 times, 4 times, and 2 times, respectively, and each was stirred and mixed at 25 ° C. Keep these mixed liquids at 25 ℃,
The resulting precipitate was collected and dried in the same manner as in Example 1.
The amount of methyl acetate in the obtained dried and recovered lecithin was below the detection limit (1 ppm or less).

Table 13 shows the composition of the raw material lecithin "Borec FS" used in this example.

Table 14 shows yields and yields of the obtained dried and recovered lecithin according to the above volume ratios.

The compositions of NL, PC and PE in the dried and recovered lecithin and the recoveries of the respective components are shown in Tables 15 and 16 according to the above volume ratios.

As can be seen from Table 14, a good yield was obtained when the above capacity ratio was 4 times or more, but a poor yield was obtained when it was 2 times. Also,
As shown in Tables 15 and 16, when the volume ratio is 4 times or more, the NL content is 5 volume% or less, and the PC content is 60% or more, the quality is good, and the NL removal rate is 93-95%, and PC,
The PE recovery rates were good at 76% and 73% or higher, respectively.

From the above results, methyl acetate-
The above-mentioned volume ratio in the water-mixed extraction is preferably at least 4 times or more.

Example 5 Purification of crude lecithin containing low PC Using soybean crude lecithin having a relatively low PC content (manufactured by Ajinomoto Co., Inc.), 2.5 g of this raw material lecithin was used at 5% by volume.
10 ml of an ethyl acetate-water mixed solution containing water was stirred and mixed at 25 ° C. This solution was kept as it was at 25 ° C., and the precipitate for purification was recovered and dried in the same manner as in Example 1.

Table 17 shows the composition of soybean crude lecithin used as the raw material lecithin.

The amount of lecithin obtained by mixing and extracting the above-mentioned raw material lecithin with ethyl acetate-water was 1.53 g (yield 61.2%).
Table 18 shows the composition of the extracted ethyl acetate-water mixed lecithin and the recovery rate of each component.

As can be seen from Tables 17 and 18, in the ethyl acetate-water mixed extraction of the raw material lecithin with a PC content of 15 to 20%, the ratio of water to the total amount of ethyl acetate and water used was 5% by volume, and the extraction temperature was 25%. By setting the temperature to ℃, the contents of PC and PE could be increased from 17.0% and 15.2% in the raw lecithin to 27.2% and 23.3% in the recovered lecithin, respectively. The removal rate of NL was 96.7%, and the recovery rates of PC and PE were 97.9% and 93.7%, respectively.

Further, the amount of water required for extraction at 25 ° C. in Example 1 is preferably 10% by volume or less in the ratio of water to the total amount of ethyl acetate and water used. It can be seen that the less the raw material lecithin, the more the ratio of water to the total amount of ethyl acetate and water used can be treated at the same extraction temperature.

Example 6 Purification of Lecithin by Combination of Ethanol Fractionation and Ethyl Acetate-Water Mixed Extraction Soybean crude lecithin was used as a raw material lecithin,
After this was separated by ethanol, ethyl acetate-water mixed extraction was carried out by the method of the present invention. The conditions used for fractionation and extraction are as follows.

Ethanol fractionation: 95% ethanol concentration 95% solvent ratio 100% ethanol 100 ml / raw material lecithin 2.5 g (40 times) Fractionation temperature 15 to 20 ° C Fractionation time 30 minutes Insoluble fraction separation method Centrifugation, 3000 rpm x 5 minutes Soluble fraction drying method Rotary evaporator , Bath temperature 40 ℃, vacuum degree 30torr Ethyl acetate extraction: Solvent ratio Ethyl acetate 10ml (5% by volume of water mixed) / Ethanol fractionated lecithin 2.5g (4 times) Extraction temperature 15 to 20 ℃ After mixing to 10 ℃ Cooling Extraction time 10 minutes Insoluble matter separation method Centrifugation, 3000 rpm × 5 minutes Soluble matter drying method Rotary evaporator, bath temperature 40 ° C, vacuum degree 30 torr Table 19 shows the composition of soybean crude lecithin used as raw lecithin.

Table 20 shows the yield, yield and composition of lecithin obtained by fractionating the above-mentioned starting lecithin with ethanol.

From the results of Tables 19 and 20, the recovery rate of each component in the ethanol-fractionated lecithin is calculated as shown in Table 21.

Ethanol fractionated lecithin having the composition shown in Table 20 was further subjected to the ethyl acetate-water mixed extraction according to the present invention. Yield of the obtained ethyl acetate-water mixed extracted lecithin,
The yield and composition are shown in Table 22.

From the results shown in Tables 20 and 22, the recovery rate of each component in the ethyl acetate-water mixed extracted lecithin is calculated as shown in Table 23.

As can be seen in Table 22, by combining ethanol fractionation and ethyl acetate-water mixed extraction, PC and PE
The content of lecithin is 13.4% and 13.1% is 63.4%, respectively.
% And 10.8% and high quality high purity lecithin is obtained. The NL content also decreased from 35.3% to 2.5%.

Almost no coloring or odor generation of the product was observed through the ethanol fractionation and the ethyl acetate-water mixed extraction. In addition, the residue of ethyl acetate in the final product subjected to mixed extraction with ethyl acetate-water was measured by gas chromatography, but was not detected below the detection limit.

The yield of the product obtained was 33% for ethanol fractionation, 66.7% for ethyl acetate-water mixed extraction, and 2% for all treatments through fractionation and extraction, based on the raw material lecithin.
It was 2.0%.

As described above, a high-purity lecithin having a PC + PE content of 50% or more is preferable as a raw material for producing a modified lecithin having an excellent emulsifying function using phospholipase D. From this point of view, the PC + PE content of the ethanol fractionated lecithin obtained in this Example is 51.7%, and considering the enzyme reaction efficiency, there is a slight problem as the quality of the above-mentioned modified lecithin-producing raw material. However, the PC + PE content of the ethyl acetate-water mixed extracted lecithin of the final product obtained in this example was 74.2%, which is a sufficient quality as the raw material for producing the modified lecithin described above.

<Effects of the Invention> As can be seen from the above description, according to the method for purifying phospholipids of the present invention, the extraction temperature can be increased as compared with the conventional low temperature acetic acid ester method by simply adding water to the acetic acid ester. The means is very simple, and the energy for reducing the temperature can be reduced or eliminated altogether.

[Brief description of drawings]

The accompanying drawings are graphs showing the relationship between the ratio of water in the total amount of acetic acid ester and water used in the method of the present invention and the extraction temperature for each kind of acetic acid ester.

Claims (5)

(57) [Claims] 1. A neutral lipid-containing lecithin is brought into contact with acetic acid ester and water to extract a soluble component containing a neutral lipid as a main component, thereby increasing the phospholipid content of the insoluble component. Purification method. 2. The method for purifying a phospholipid according to claim 1, wherein the neutral lipid-containing lecithin is cooled in a state of being brought into contact with acetic acid ester and water. 3. The contact of the neutral lipid-containing lecithin with the acetic acid ester and water is carried out by contacting the neutral lipid-containing lecithin with a mixed solution of acetic acid ester and water. Or the method for purifying phospholipid according to 2. 4. The contact between the neutral lipid-containing lecithin and the acetic acid ester and water is performed by mixing the neutral lipid-containing lecithin with the acetic acid ester and then adding water. The method for purifying the phospholipid described. 5. The contact of the neutral lipid-containing lecithin with the acetic acid ester and water is performed by mixing the neutral lipid-containing lecithin with water and then adding the acetic acid ester. The method for purifying the phospholipid described.