JPH01197492A - Method for refining lecithin - Google Patents

Abstract

PURPOSE:To effectively remove neutral lipids with a safe solvent, simultaneously obtain high-refined lecithin and contrive reduction in the amount used of a solvent required for fractionation, by dissolving neutral lipid-containing lecithin in an acetic acid ester at ordinary temperature and cooling the resultant solu tion. CONSTITUTION:A neutral lipid-containing lecithin, such as soybean lecithin, is dissolved in an acetic acid ester (preferably methyl acetate or ethyl acetate) at ordinary temperature and the resultant solution is cooled to fractionate the lecithin into a soluble fraction consisting essentially of neutral lipids and insoluble fraction consisting essentially of phospholipids. Furthermore, the am ount of the acetic acid ester used is preferably so as to generally provide >=4 ratio of the acetic acid ester (ml)/neutral lipid-containing lecithin (g). The frac tionation temperature is preferably -5--10 deg.C when, e.g., ethyl acetate, is used.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a method for purifying lecithin using acetate, and more specifically, it relates to a method for purifying lecithin using acetic acid ester. The present invention relates to a method for removing neutral lipids and obtaining highly purified lecithin with a high content of phosphatidylcholine, phosphatidylethanolamine, and the like.

In this specification, the term "lecithin" refers to a mixture containing phospholipids as a main component.

<Prior Art> Lecithin is applied as an emulsifier, dispersant, stabilizer, antioxidant, etc. in a wide range of fields such as foods, medicines, cosmetics, feeds, and industrial products.

Such lecithin exists in animal tissues such as egg yolks and beef brains, and plant tissues such as soybeans, rapeseed, and alfalfa seeds, and there are many raw materials that can be used as raw materials for lecithin production.

Among these, crude lecithin, which is particularly called soybean lecithin or rapeseed lecithin, is produced by adding hot water or steam to extracted crude oil, which is obtained by extracting raw materials such as soybean or rapeseed with a solvent such as n-hexane, to hydrate it. It can be obtained by flocculating and precipitating lecithin and separating it with a centrifuge or drying it. The lecithin thus obtained may contain phosphatidylcholine (hereinafter abbreviated as PC), although it varies depending on the raw material.
), phosphatidylethanolamine (hereinafter abbreviated as PE) °, phosphatidylinositol (hereinafter abbreviated as PI)
In addition to , phosphatidic acid (hereinafter abbreviated as PA) and other phospholipids, triadylglycerol (= triglyceride, neutral fat), free fatty acids, etc. (hereinafter collectively referred to as neutral lipids) are usually 30 to 40%. degree included,
Zara also contains substances such as sterols and carbohydrates. The composition of typical soybean crude lecithin is
Shown in the table.

Table 1 Composition of soybean crude lecithin (wt%) Phosphatidylcholine (PC) 20 Phosphatidylethanolamine (PE) 15 Phosphatidylinositol (PI) 20 Phosphatidic acid (PA), other phospholipids 5 Carbohydrates, wax substances 5 Neutral lipids (NL>
35 PC in the above composition
is the main component of lecithin, and lecithin with a high PCC metal content is usually called high-purity lecithin.In recent years, the demand for high-purity lecithin with a high PCC metal content by removing neutral lipids from crude lecithin has begun to increase. There is.

An example of the use of such highly purified lecithin is the modification of emulsifying function by enzymatic methods. For example, JP-A-61-199
749, phosphatidylglycerol (hereinafter referred to as P) obtained by causing a phosphatidyl group transfer reaction between soybean lecithin and glycerol using phospholipase D.
It is described that modified soybean lecithin containing (abbreviated as G) is effective as a food emulsifier whose emulsifying power is not inhibited by metal ions such as calcium ions and sodium ions, and l)H. The present inventors have found that the composition of modified soybean lecithin with excellent emulsifying function has a PG content of approximately 5.
It has been found that 0% or more is preferable. In addition, in the currently known enzymatic reaction using phospholipase D, PC, PE, etc. in lecithin can mainly serve as substrates for the phosphatidyl group transfer reaction, so high-purity lecithin with a PC+/PE content of at least 50% is used as the raw material. It is better.

Various fractionation or fractionation methods have been proposed to purify lecithin to produce high-purity lecithin (
“Lecithin production and fractionation technology” by Muneo Sakai and Masato Nakazato
, Food Chemical, December 1985, pp. 68-73), a method that has been put to practical use in terms of quality and cost is a solvent fractionation method using acetone or ethanol.

The acetone fractionation method separates soybean crude lecithin into neutral lipids as acetone-soluble matter and PC, as acetone-insoluble matter.
This is a method of separating phospholipids such as PE and PI, and the basic principle is defatting. This method has been applied for a long time and is currently the most commonly used technology for producing high purity lecithin.

On the other hand, the ethanol fractionation method differs in principle from acetone fractionation in that it utilizes the difference in solubility of various phospholipids and neutral lipids in crude lecithin in ethanol. That is, in this method, a large amount of PC and a small amount of PE are extracted from crude lecithin as ethanol-soluble matter.
PI and neutral lipids are separated into large amounts of PE, PI and neutral lipids as ethanol insoluble materials, and small amounts of PC.

<Problems to be Solved by the Invention> However, in the above-mentioned acetone fractionation, i) the amount of acetone used must be 10 times or more as compared to the raw material crude lecithin, and it is also difficult to recover the acetone; iD acetone is classified as a class 4 hazardous material and a petroleum class 1, and its designated quantity is as small as 100β.
i) When modifying lecithin using an enzyme, there are problems such as an influence on the enzymatic reaction. Furthermore, iv) acetone is difficult to be sufficiently removed from lecithin even by drying. Residual acetone exceeding 50 D pm generates harmful mesityl oxide through aldol condensation and the like. Therefore, to suppress the formation of harmful acetone oxide, the amount of acetone should be 50 ppm or less, preferably 25 ppm.
At present, it is necessary to distill off the amount below, which is a process that requires considerable effort.

On the other hand, in ethanol fractionation, the obtained high-purity lecithin usually contains about 20 to 25% neutral lipids, and the removal rate of neutral lipids is not good, and it is difficult to improve the PC content in lecithin. There has to be a limit.

Therefore, the purpose of the present invention is to solve the above-mentioned problems in acetone fractionation and ethanol fractionation, and to use a solvent that requires less amount than acetone and is safer than acetone. An object of the present invention is to provide a method for purifying lecithin that can effectively remove lecithin to obtain highly pure lecithin.

<Means for Solving the Problems> In order to achieve the above object, according to the present invention, neutral lipid-containing lecithin is dissolved in acetate at room temperature and then cooled to make neutral lipids the main component. Separate into soluble content and unnecessary content whose main component is phospholipid.

The acetic acid ester is preferably an ester of acetic acid and an alcohol having 1 to 4 carbon atoms, preferably methyl acetate or ethyl acetate. The amount of acetate used is - 1 volume (mfl>
/ weight @ (g) around 4 times or more than 4 times is used, but since there are variations in the ratio of phospholipids and neutral lipids in the neutral lipid-containing phospholipids, it is important to consider the composition and purpose. Adjust the amount of acetate ester used depending on the composition of the fractionated lecithin to be used.

The neutral lipid-containing lecithin used as a raw material in the present invention is crude lecithin extracted from crude oil such as soybean or rapeseed,
This crude lecithin can be further fractionated with ethanol to remove ethanol-insoluble components (hereinafter referred to as "ethanol fractionated lecithin").

The lower the fractionation temperature is, the better; however, the temperature is determined depending on the composition of the neutral lipid-containing lecithin, the type of acetate ester, the composition of the intended fractionated lecithin, etc.

Each step of the purification method of the present invention will be explained below.

Dissolution process: For crude lecithin from soybeans, rapeseed, etc., which contain a large amount of neutral lipids (approximately 30-40%), acetate ester (
Add acetic acid ester so that the ratio of mu>,/crude lecithin (g) is 4 times or more, and dissolve at room temperature while stirring. Ethanol-fractionated lecithin with a neutral lipid content reduced to about 20 to 25% is further purified using the method of the present invention to produce high-purity lecithin with a PC concentration similar to that of crude lecithin purified using the method of the present invention. If desired, the amount of acetate used can be reduced to about three times.

As described above, the amount of acetate used can be increased or decreased depending on the composition of the neutral lipid-containing lecithin as a raw material, but this increase or decrease can be confirmed through experiments.

Cooling step When the solution obtained by dissolving at room temperature is cooled while stirring, phospholipid precipitation begins at around 5° C. in the case of ethyl acetate. The onset of precipitation is earliest in PC, followed by PI and PA, and slowest in PE. As cooling progresses, more phospholipids precipitate. The precipitation of PC becomes almost constant at around -10°C. The amount of neutral lipid remaining in the solution remains almost constant with little change depending on temperature.

The attached drawing shows the recovery rate of lecithin and the removal rate of neutral lipids at different fractionation temperatures when 4 times the amount of ethyl acetate is added to the ethanol-fractionated lecithin, stirred and dissolved at room temperature, and then the solution is cooled. This is a graph. As can be seen from this graph, as the separation temperature is lowered, the amount of precipitated yl of each phospholipid such as PC, PI, PA, and PE increases, and when cooled to -10°C, about 96% of PC,
Approximately 88% of PI, PA, and PE are precipitated separately. On the other hand, neutral lipids hardly undergo fractional precipitation even when the solution is cooled, and about 98% remains in the solution (removal rate of 98%). In this way, most of the neutral lipids are removed and most of the PC is recovered, thereby obtaining highly purified lecithin with a high PC content. Similarly, the content of PE is relatively increased by removing neutral lipids, and highly purified lecithin with a high PC+PE content can be obtained.

Even if the separation temperature is lower than -10'C, there is little improvement in the recovery rate of PC or PE. Considering the cost of energy consumption for cooling, in the case of ethyl acetate, it is considered appropriate that the fractionation temperature is preferably below 15°C, more preferably up to about 10'C.

On the other hand, in the case of methyl acetate, the fractionation temperature is preferably 5°C.
It is more preferably O'C or less, in the case of propyl acetate it is 120'C or less, preferably 130'C or less, and in the case of butyl acetate it is 150'C or less, preferably 160'C or less. The fractionation temperature needs to be lower as the number of carbon atoms in the acetate ester increases.

Precipitate Separation Step Cooling When the precipitation is completed, stirring is stopped and the mixture is allowed to stand for about 30 minutes to allow the precipitate to settle sufficiently. The supernatant liquid consisting mainly of acetate ester containing neutral lipids is removed, and the acetate ester is recovered by distillation or the like and reused.

On the other hand, the precipitate is taken out from the bottom of the container, centrifuged if necessary, and then placed in a vacuum stirring dryer, thin film concentrator, etc.
The acetate ester is recovered using a centrifugal thin film concentrator or the like and dried to recover high-purity lecithin. The high-purity lecithin thus obtained has acetic acid ester removed to the extent below the detection limit (11) 0m or less), and a product with no problems in terms of odor or toxicity can be obtained. Furthermore, by employing the above method, acetic ester can be removed at low temperatures, so lecithin will not be colored or its taste will change due to oxidation or the like.

In addition, when attempting to modify the emulsifying function by subjecting the high-purity lecithin obtained by the method of the present invention to an enzymatic method using phospholipase D, the enzymatic reaction should be performed in a homogeneous system of acetate ester, water, and glycerin. Therefore, the precipitate obtained in the cooling step in the method of the present invention can be directly fed to the enzyme reaction tank.

By applying the acetate ester fractionation according to the method of the present invention described above using soybean crude lecithin with a standard composition as a raw material, it is possible to obtain high purity lecithin with a PC content of 130 to 40%. In order to produce high-purity lecithin, it may be necessary to use the method of the present invention in combination with other fractionation methods or fractionation methods.

That is, either fractionated (fractionated) lecithin obtained by another fractionation method or fractionation method is used as a raw material for the method of the present invention, or lecithin obtained by the method of the present invention is 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 ester fractionation method of the present invention is preferred.

The ethanol fractionation method uses ethanol or an aqueous solution of ethanol at a temperature of approximately 95% by volume, and the ratio of volume H (m!
A preferred method is to add more than double the volume, stir and dissolve at room temperature, then separate the ethanol-soluble and ethanol-insoluble components, and obtain ethanol-fractionated lecithin as a residue by evaporating ethanol from the supernatant ethanol-soluble fraction. Can be adopted.

When soybean crude lecithin having a standard composition is treated by a combination of the ethanol fractionation method and the acetate ester fractionation method of the present invention, highly pure lecithin with a PC content of about 65% can be obtained.

Therefore, if the lecithin obtained by the acetic acid ester fractionation method of the present invention and the lecithin obtained by the ethanol fractionation-acetate ester fractionation combination method are blended in various proportions, 30 to 6
It becomes possible to provide various high-purity lecithin products having a desired PC content in the range of 0%.

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

The following analysis method was used to confirm phospholipids and neutral lipids in the following Examples and Comparative Examples.

As an analyzer, IatroScan (TLC/FID) Model H-10 thin layer chromatography analyzer was used.

Confirmation of phospholipid content was made by spotting a total of 10 to 20 μ9 of a sample onto a chromarod, developing and separating it with a developing solution of chloroform:methanol:ammonia (10:10:1), and performing combustion measurements after air drying.

To measure neutral lipids, develop the chromarod to the middle with the above-mentioned developing solution, then use hexane:ether:formic acid (40:40).
A double development method was used in which the sample was developed and separated again in step 1) and then combustion measurement was performed after air drying.

Example 1 Selection of fractionation temperature in ethyl acetate fractionation "Borek FS (B
OLECFS) J (West German Uni Mills (UNI) I
This raw material lecithin 1
50ml of ethyl acetate was added to the mixture and stirred to dissolve. Dissolution was easy at room temperature. This solution is each O'C, -5
The precipitate produced by cooling to -10'C was collected in a centrifuge at 3000 ml for 5 minutes, and then dried in a rotary evaporator at a vacuum level of 3 Q torr and a drying time of 1.
It was dried for 5 minutes.

Table 2 shows the yield and yield of the dried recovered lecithin obtained by fractionation temperature.

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

Table 3 (Unit duplex weight %) Table 4 shows the recovery rate of each component in the dry recovered lecithin relative to the raw lecithin, according to the separation temperature.

As can be seen from the results in Table 2, the yield of the product is 3 at 0°C.
Although it is low at 1.9%, at -5℃, it is 5o, 7%, -10
At ℃, a fairly good yield of 50.8% was obtained.

From the results shown in Table 3, neutral lipids (NL) were well removed in the ethyl acetate fractionated product, and highly pure lecithin with a PC content of 70% by weight was obtained.

In addition, from the results of the recovery rate in Table 4 calculated by multiplying the product yield by the ratio of each component, the weight ratio of the amount of PC in the product to the amount of PC in the raw material is 89.9% at -5℃, - 9 at 10℃
It was 7.0%. Judging from this point, the fractionation temperature in ethyl acetate fractionation should be at least 15°C or lower, preferably 11°C or lower.
It is determined that the temperature is below 0°C.

Example 2 Selection of solvent ratio in ethyl acetate fractionation Borek FSJ was used as raw lecithin containing a large amount of neutral lipids, and 0.5 (II, 1.0 g) of this raw lecithin was used for 10 mJ2 of ethyl acetate. .

In addition, 2.5 g and 4 g were added, and the volume ratio (ml!/g) of the solvent to the weight of raw lecithin was 20 times and 10 times, respectively.

The volumes were adjusted to 4 times and 2.5 times, and each was stirred and dissolved at room temperature. These solutions were cooled to -10°C and the resulting precipitate was collected in the same manner as in Example 1.

Dry. The amount of ethyl acetate in the dried recovered lecithin obtained was below the detection limit (itpm).

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

Table 5 (unit double %) Table 6 shows the yield of dried recovered lecithin and the yield relative to raw lecithin by solvent ratio.

As can be seen from Table 6, good yields were obtained when the solvent ratio was 4 times or more, but poor yields were obtained when the solvent ratio was 2.5 times.

The contents (composition) of NL, PC, and PE in the dry recovered lecithin and the recovery rate of each of these components relative to the raw lecithin are shown in Tables 7 and 8, respectively, by solvent ratio.

Table 7 (Unit: Weight %) Table 8 (Unit Duplex D%) As shown in Table 7, when the solvent ratio is 4 times or more, the content of neutral lipids (NL>) is almost 2%, The quality is good with a PC content of 60% or more, but when the solvent ratio is 2.5 times, the neutral lipid content suddenly increases and the PC content decreases relatively to 49.0%.Table 8 As shown in , when the solvent ratio is 4 times or more, the removal rate of neutral lipids is high at 97-98%, the recovery rate of PC is around 97%, and the recovery rate of PE is also good at around 88%. When the solvent ratio is 2.5 times, the removal rate of neutral lipids decreases significantly.

From the above results, the solvent ratio in -10'C ethyl acetate fractionation needs to be at least 4 times or more.

Incidentally, an experiment was also conducted in -5°C ethyl acetate fractionation, and the results were similar.

Example 3 Purification of crude lecithin with low PC content Soybean crude lecithin with a relatively low PC content was used as a raw material lecithin, and 10 g of ethyl acetate was added to 2.5 g of this raw material lecithin.
mβ was stirred and dissolved at room temperature. This solution was mixed at 0°C, -
The precipitate produced by cooling to 5°C and -10°C was collected and dried in the same manner as in Example 1.

Table 9 shows the composition of the raw material lecithin used in this example.

Table 9 (Unit duplication: 2%) Table 10 shows the yields and yields of the dried and recovered lecithin according to the fractionation temperature.

Table 10 Table 11 shows the composition of the dried and recovered lecithin according to the fractionation temperature.

Table 11 (Unit: Weight %) Table 12 shows the recovery rate of each component in the dry recovered lecithin relative to the raw material lecithin, according to the separation temperature.

Table 12 (Unit doublet) Crude lecithin used in this example has a PC content of 19.4
%, but as shown in Table 11, in ethyl acetate fractionation, PC content was 36.2% to 38.0% in the range of O to -10°C, which was a fairly high concentration of PC.
I was able to obtain the following products.

On the other hand, as shown in the results in Table 12, the yield is low at 32.5% at the fractionation temperature of 0°C, but the yield improves to 47.7% and 49.2% at -5°C and -10°C. I know what you're doing.

Example 4 Combination of ethanol fractionation and ethyl acetate fractionation Soybean crude lecithin was used as a raw material lecithin, and after ethanol fractionation, ethyl acetate fractionation was subsequently carried out by the method of the present invention.

The conditions used for each classification are as follows.

Ethanol fractionation: Ethanol concentration 95% Solvent ratio 95% ethanol 10 m, C/raw material lecithin 2.5 (] (44 times) Fractionation temperature Room temperature (15-20'C) Fractionation time 3
0 minute insoluble separation method Centrifugation, 3000 rpm x 5
Soluble fraction drying method Rotary evaporator.

Degree of vacuum 3 Q tOrr Ethyl acetate fractionation: Solvent ratio Ethyl acetate 10mN/ethanol fractionation resin 2.5g (4 times) Fractionation temperature Cooled to -10℃ after dissolving at room temperature Fractionation time 1
0 minute insoluble matter separation method Centrifugation, 3000 rpm x 5 minutes Soluble matter drying method Rotary evaporator.

Degree of vacuum: 30 torr Table 13 shows the composition of soybean crude lecithin used as raw material lecithin.

Table 13 (Unit: Weight %) Table 14 shows the yield, yield, and composition of lecithin obtained by fractionating the raw material lecithin with ethanol.

Table 14 Table 15 shows the recovery rate of each component in the ethanol-fractionated lecithin from the results in Tables 13 and 14.

Table 15 (Unit Duplex Weight %) Ethanol fractionated lecithin having the composition shown in Table 14 was roughly subjected to ethyl acetate fractionation according to the present invention. Table 16 shows the yield, yield and composition of the obtained ethyl acetate fractionated lecithin.

Table 16 Table 17 shows the recovery rate of each component in the ethyl acetate fractionated lecithin from the results in Tables 14 and 16.

Table 17 (Unit Duplex Weight %) As shown in Table 16, by combining ethanol fractionation and ethyl acetate fractionation, the contents of PC and PE are 19.4% and 8.8%, respectively, of the raw lecithin. is 7
High purity lecithin with high quality of 3.6% and 8.8% was obtained. The content of neutral lipids (NL) is also 34.6%.
It has decreased from 0.5% to 0.5%.

Almost no coloration or odor was observed in the product during ethanol fractionation and ethyl acetate fractionation. Furthermore, the residual ethyl acetate was measured by gas chromatography for the final product subjected to ethyl acetate fractionation, but it was below the detection limit and was not detected.

Note) The yield of the product q is based on the raw material lecithin.
33% for ethanol fractionation and 71% for ethyl acetate fractionation.
, the total processing through these two fractions was 23.4%.

Example 5 Combination of ethanol fractionation and ethyl acetate fractionation Soybean crude lecithin with low PC content was used as the raw material lecithin, and ethanol fractionation was carried out in the same manner as in Example 4, followed by ethyl acetate fractionation by the method of the present invention. .

Table 18 shows the composition of soybean crude lecithin used as raw material lecithin.

Table 18 (Unit: Weight %) The yield of lecithin obtained by fractionating the above raw material lecithin with ethanol was 0.825 (1 (yield 33.0%).The composition of this ethanol fractionated lecithin was Shown in the table.

Table 19 (Unit Duplex Amount %) Table 20 shows the recovery rate of each component in the ethanol fractionated lecithin from the results of Tables 18 and 19.

Table 20 (Unit: % by weight) g+I lecithin was roughly subjected to ethyl acetate fractionation according to the invention. The yield of the obtained ethyl acetate fractionated lecithin was 1.
575! ;1 (yield 63%). The composition of this ethyl acetate fractionated lecithin is shown in Table 21.

Table 21 (Unit Duplex Weight %) Table 22 shows the recovery rates of each component in the ethyl acetate fractionated lecithin from the results in Tables 19 and 21.

Table 22 (unit: double weight %) The PC content of the final product subjected to ethyl acetate fractionation was 73.6% when crude lecithin with a PC content of 119.4% was used as the raw material lecithin (Example 4). was obtained, whereas PC-containing ff114 was obtained as raw material lecithin.
．． In this example using 1% crude lecithin, it was 59.
Only 0% product was obtained. Therefore, it can be seen that the PC content of the obtained products varies considerably depending on the raw material lecithin.

In addition, neutral lipids (NL) of the final product subjected to ethyl acetate fractionation are
) The foot content was 0.5% when raw lecithin with a PC content of 19.4% was used (Example 4);
In this example using raw material lecithin with a CC content of 141%, the removal rate of neutral lipids was 6.7%, which was lower than in Example 4.

The yield of the obtained product was 33% for raw material lecithin by ethanol fractionation, 63% by ethyl acetate fractionation, and 63% for ethyl acetate fractionation.
The total treatment through these two fractions was 20.8%.

As mentioned above, P is a raw material for producing modified lecithin with excellent emulsifying function using phospholipase D.
Preferably, the lecithin is a highly purified lecithin with a C+'PE content of 50% or more. From this point of view, the PC+PE content of the ethanol fractionated lecithin obtained in this example is 4.
The PC+PE content of the ethyl acetate fractionated lecithin, the final product obtained in this example, was 69.6%, which is somewhat problematic as a quality of the raw material for producing the modified lecithin.
9%, which is of sufficient quality as a raw material for producing the above-mentioned modified lecithin.

Comparative example Acetone fractionation (conventional method) Porex FSJ was used as a raw material lecithin containing a large amount of neutral lipids, and 20 g of acetone was added to 5 g of this raw material lecithin.
Add 0 mN and sonicate for 5 minutes, then centrifuge at 5°C and 3000 ppm.

Processed for 5 minutes. Then discard the acetone layer and add another 10
0 mfJ of acetone was added. The solvent ratio at this time is acetone (200 m, 11 + 100 mN)/5 g of raw material lecithin = 60 times (ml/F). Then, after being sonicated again for 5 minutes, it was centrifuged at 5”C, 3000p.
pm, treated for 5 minutes. The acetone layer was discarded, the resulting precipitate was placed in a rotary evaporator, and acetone was distilled off at a bath temperature of 40°C and 30 torr while blowing a small amount of N2 gas, and then dried to obtain 3.291 l of acetone-fractionated lecithin. Obtained.

Table 23 shows the composition of the raw lecithin, the composition of the acetone-fractionated lecithin, and the recovery rate of each component.
Table 23 (unit: weight %) Acetone fractionated lecithin has a yield of 65.8% and a PC content of 4
The yield of PC was 9.2% and 81.2%. Solvent ratio (6
The PC content of the product obtained was not so good compared to the PC content of the product obtained by fractionation of ethyl acetate with a solvent ratio of 4 times according to the method of the present invention, even though the ratio was 0 times (ml 17 g). Also, the recovery rate of PC was not good.

<Effects of the Invention> As can be seen from the above explanation, the method of the present invention provides the following effects.

i) The amount of solvent required for fractionation can be reduced.

The acetic acid ester capacity required for fractionation can be approximately 4 times (mu/a) the weight of neutral lipid-containing lecithin as a raw material, compared to approximately 10 times the acetone capacity in conventional acetone fractionation. It costs less. Accordingly, solvent recovery costs can also be reduced.

ii) PC - The highest high degree lecithin is obtained.

There are differences depending on the composition of the neutral lipid-containing lecithin used as a raw material, but if standard lecithin is used as a raw material, P
High purity lecithin with a C content of about 30 to 40% and a PE content of about 10% at the most can be obtained.

Furthermore, if ethanol fractionation and acetate ester fractionation of the present invention are combined, highly pure lecithin with a PCC content of about 6 to 15% and an E content of about 15% can be obtained.

Therefore, acetate fractionated lecithin and ethanol fractionation -
By blending acetate ester fractionated lecithin in various proportions, high purity lecithin products with various PC contents can be prepared.

1ii) The acetic acid ester used in the present invention, for example, ethyl acetate, has a larger specified quantity for storage than acetone, and there are problems with storage and manufacturing equipment. It is advantageous. Also, the problem of unpleasant odors during handling of solvents is reduced. The disadvantages of residual solvent concentration and formation of harmful oxides, which are problematic in acetone fractionation, can also be greatly improved by the method according to the invention.

The precipitate obtained in the precipitate separation step in the method of the present invention can be supplied to the enzyme reaction column as it is without drying, which is advantageous compared to fractionation methods using other solvents such as acetone.

[Brief explanation of the drawing]

The attached figure (=J) is a graph showing the relationship between fractionation temperature, lecithin recovery rate, and neutral lipid removal rate in the method of the present invention. Patent applicant: Food Industry Bioreactor System Technology Research Association

Claims (1)

[Claims] 1. Neutral lipid-containing lecithin is dissolved in acetate ester at room temperature, then cooled and separated into a soluble component whose main component is neutral lipids and an insoluble component whose main component is phospholipids. A method for purifying lecithin, characterized by: 2. The method for purifying lecithin according to claim 1, wherein the acetate is ethyl acetate. 3. Purification of lecithin according to claim 1, wherein the amount of the acetate used is at least 4 times the weight of the neutral lipid-containing lecithin in terms of volume (ml)/weight (g) ratio. Method. 4. Claim 1, wherein the neutral lipid-containing lecithin is crude lecithin, or crude lecithin is fractionated with ethanol to remove ethanol-insoluble components.
Method for purifying lecithin as described. 5. The method for purifying lecithin according to claim 1, wherein the fractionation is carried out at -5°C or lower.