JPH0725888A - Purification of lecithin - Google Patents

Abstract

PURPOSE:To obtain lecithin free from disagreeable smell and taste such as grassy smell, hay smell, bitter taste and astringent taste and having excellent taste and flavor. CONSTITUTION:This process for the purification of lecithin is characterized by the washing of lecithin with an alkaline aqueous solution, separation of lecithin, washing with water and recovery of the purified lecithin or characterized by the treatment of lecithin with an alkaline aqueous solution containing lecithin-dissolving non-polar organic solvent and a water-soluble polar organic solvent, separation of the non-polar organic solvent phase containing lecithin from the aqueous solution phase, addition of an aqueous solution containing the water-soluble polar organic solvent to the obtained lecithin-containing non- polar organic solvent phase, washing of the mixture with water, separation of the non-polar organic solvent phase from the aqueous solution phase and the recovery of lecithin. The pH of the alkaline aqueous solution containing suspended lecithin is preferably 7.5-9.0.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for purifying lecithin in which lecithin (mixture of phospholipids) having a specific odor and bitterness is removed to obtain lecithin having an improved flavor.

[0002]

2. Description of the Related Art Lecithin has a high surface-active function, and is therefore widely used in general industrial fields such as foods, cosmetics, and paints. In addition, today, it has been confirmed that it has a physiologically active function.
It is also used in fields such as pharmaceuticals and health foods, and its fields of use are expanding. Lecithin is
Industrially, soybeans, which can be provided inexpensively, are used as the main raw material. Lecithin is manufactured by first filtering crude soybean crude oil to remove impurities, then adding water (degumming water) and organic acids such as oxalic acid to the lecithin while controlling the temperature of the filtered oil. Is precipitated as an oil-insoluble gum, which is then separated by a centrifugal separation method (degumming step), and then the obtained water-containing gum substance (wet gum) is dried with a vacuum dryer or the like and then solidified. It is generally performed by adding additives such as an inhibitor, aging, and finally performing heat treatment.

The lecithin thus obtained is called oil-containing lecithin and is in the form of a paste. It usually has a phospholipid content of 70 to 65%, and other 30 to 35% mainly glycerides (acetone-soluble content). Is included. In addition, there are some applications that are difficult to use with pasty lecithin, making it easier to handle,
In addition, in order to obtain high purity, powdery lecithin obtained by dissolving paste lecithin in acetone etc. and dissolving and removing glyceride (phospholipid content 90% or more)
Are also proposed.

By the way, pasty lecithin has a problem that it is difficult to use because it has an unpleasant odor such as a blue odor or hay odor which is considered to be transferred from raw crude oil and a taste such as bitterness or astringency. Although it is possible to improve the flavor unique to lecithin to some extent by using powdered lecithin, it still remains. Especially in the fields of medicine and health foods, taking lecithin as it is,
Since they tend to eat, further improvement is desired.

For the purpose of improving the flavor, after the degumming step,
An aqueous solution of calcium chloride, polybasic fatty acid (citric acid, succinic acid, etc.), ascorbic acid, or hydrochloric acid is added to the obtained hydrous gum substance to suspend the hydrous gum substance, and then the gum substance is added. Separated, then washed with water, dehydrated,
A method of drying has been proposed (JP-A-55-5759).
5, No. 55-62095, No. 55-76892,
And 55-92658). In addition, JP-A-55-
Japanese Patent No. 50859 also discloses a method in which propylene glycol is added to oil-containing lecithin to extract lecithin, and then an organic acid aqueous solution is added to the extract to separate coagulated lecithin and washing with water. . Furthermore, a method of obtaining lecithin having a good flavor and stability by using a specific soybean as a raw material has been proposed (JP-A-3-1433).
No. 56). However, using the above method,
The improvement in flavor is not entirely satisfactory. It is also economically disadvantageous.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for purifying lecithin capable of obtaining lecithin having a good flavor without any unpleasant odor such as blue odor and hay odor, and taste such as bitterness and astringency. Is to provide.

[0007]

Means for Solving the Problems The present invention comprises a method for purifying lecithin (first method), which comprises washing lecithin with an alkaline aqueous solution, separating lecithin, washing with water, and recovering lecithin. It is in.

In the present invention, after treating lecithin with an alkaline aqueous solution containing a non-polar organic solvent in which lecithin is soluble and a water-soluble polar organic solvent, the non-polar organic solvent phase containing lecithin is separated from the aqueous phase, Then, an aqueous solution containing a water-soluble polar organic solvent is further added to the obtained non-polar organic solvent phase containing lecithin to wash with water, and the non-polar organic solvent phase is separated from the aqueous phase, and then lecithin is recovered. In the method for purifying lecithin (second method). As a result of research by the present inventor, it was found that lecithin having good flavor as described above can be obtained by carrying out a method including a step of washing or treating lecithin with an alkaline aqueous solution, and then washing with water, The present invention has been completed. In carrying out the method of the present invention, the washing or treatment with an alkaline aqueous solution is performed such that the pH of the alkaline aqueous solution in which lecithin is suspended and mixed is in the range of 7.5 to 9.0 (more preferably, 8.0 to 8). 0.5 range). In addition, of the above methods, when the first method is carried out, in particular, when lecithin in a paste form is used, it is preferable that the lecithin is treated with a water-soluble polar organic solvent in advance.

The method for purifying lecithin of the present invention will be described below. The lecithin of the present invention can be purified by the following two methods. The first method is a method including a step of recovering lecithin by washing lecithin with an alkaline aqueous solution, separating lecithin, washing with water, and then drying. Also,
The second method is to treat the lecithin with an alkaline aqueous solution containing a non-polar organic solvent in which lecithin is soluble and a water-soluble polar organic solvent, then separate the non-polar organic solvent phase containing lecithin from the aqueous phase, and then obtain An aqueous solution containing a water-soluble polar organic solvent is further added to the non-polar organic solvent phase containing lecithin and washed with water, and then the non-polar organic solvent phase containing dissolved lecithin is separated from the aqueous phase, and the solvent is extracted from the non-polar organic solvent phase. It is a method including a step of recovering lecithin by drying after evaporation. Both methods are characterized by including a washing step after washing or treating lecithin with an alkaline aqueous solution. The lecithin used in the present invention may be either lecithin in paste form or lecithin in powder form as described above.

First, the first method for purifying lecithin will be described in detail. The lecithin is washed with an aqueous alkaline solution (step 1). Lecithin is directly put into an alkaline aqueous solution at room temperature and stirred to suspend lecithin in the aqueous phase and wash the lecithin. The amount of lecithin and the amount of the alkaline aqueous solution to be added may be such that the lecithin forms a good suspension state in the alkaline aqueous solution. For example, an amount of 5 to 30 parts by weight is preferable with respect to 1 part by weight of lecithin. It should be noted that an additive such as calcium chloride that promotes aggregation may be present in the alkaline aqueous solution in advance so that lecithin is aggregated and a better suspension state is obtained. The addition amount is about 0.5 to 5% by weight with respect to the alkaline aqueous solution. The washing with the alkaline aqueous solution is carried out when the pH of the alkaline aqueous solution in which lecithin is suspended and mixed is 7.5 to
It is preferably carried out in the range of 9.0 (preferably in the range of 8 to 8.5). The alkaline agent is not particularly limited, but sodium hydroxide is preferable. The stirring conditions can be carried out by using a stirring means such as an ordinary stirrer and a propeller mixer. Specifically, the stirring time is 50 to 100 rpm, and the stirring time is 2 hours or more, preferably 2.5 to 5 hours. , And more preferably 3 to 4 hours. After the stirring operation,
The pH of the system is weakly acidic (pH 5.5 to 5.5) by using hydrochloric acid or the like to prevent deterioration of lecithin and ensure storage stability.
It is preferable to set it as 6.5).

Next, lecithin in a suspended state washed with an aqueous alkaline solution is separated from the aqueous phase (step II). Separation of lecithin can be performed by allowing the lecithin content to precipitate by allowing it to stand, but it may also be performed by a separating operation such as centrifugation or filtration.

Next, the separated lecithin component is washed with water (step III). The obtained lecithin component is put into water at room temperature, and the lecithin is suspended in the aqueous phase by stirring and washed with water. The relationship between the amount of lecithin and the amount of water to be added is
Although not particularly limited, for example, with respect to 1 part by weight of lecithin,
Amounts of 3 to 10 parts by weight are preferred. The stirring can be performed by the same method as described above. The stirring condition is 5 to 10 rpm
The stirring time is 15 minutes or more, preferably 20 minutes to 1
Time is appropriate. In addition, in order to more efficiently perform the subsequent step of separating lecithin, it is preferable to add an appropriate amount of salt such as sodium chloride to water. The washing operation as described above is preferably performed twice or more, and more preferably,
It is preferable to carry out three or more times.

After the above washing with water, lecithin is separated from water according to the above-mentioned separating operation, and lecithin is recovered. Purified lecithin can be obtained by drying the obtained lecithin. Drying may be performed by a known method such as a reduced pressure drying method under an appropriate heating condition that does not cause deterioration. The first purification method described above is suitable for purifying powdered lecithin. That is, it is a preferable method for purifying lecithin containing almost no fat and oil component. In the case of carrying out the above-mentioned first method, when fractionating a phospholipid having a specific composition, for example, when obtaining a phospholipid composition having a reduced phosphatidylcholine composition, lecithin is previously water-soluble. Treatment with a polar organic solvent is preferred. Further, a method of previously washing lecithin with a water-soluble polar organic solvent is a preferable method when purifying lecithin by the first method using lecithin in a paste form. That is, by washing the lecithin with a water-soluble polar organic solvent, the oil content in the oil-containing lecithin is removed,
This is because it can be handled almost like lecithin in powder form.
Examples of the water-soluble polar organic solvent include lower alcohols (ethanol, propanol, butanol, etc.), acetone and cyclohexane. The relationship between the amount of lecithin to be charged and the water-soluble polar organic solvent is not particularly limited, but is, for example, 5 to 10 parts by weight relative to 1 part by weight of lecithin.
Amounts by weight are preferred.

Next, the second purification method will be described in detail. The second method includes the treatment of lecithin with an alkaline aqueous solution under basically the same conditions as in the first method, and the subsequent washing step with water. However, when the treatment is carried out using an alkaline aqueous solution, it differs in that the alkaline aqueous solution contains a non-polar organic solvent in which lecithin is soluble and a water-soluble polar organic solvent. That is, the treatment with the alkaline aqueous solution,
It is performed in an environment containing a non-polar organic solvent in which lecithin is soluble and a water-soluble polar organic solvent. In this environment, lecithin is dissolved in the non-polar organic solvent, and at the same time, the non-polar organic solvent containing lecithin is well dispersed in the aqueous phase in the presence of the water-soluble polar organic solvent. The non-polar polar organic solvent is not particularly limited as long as it can dissolve lecithin and fats and oils. For example, alkanes such as butane, pentane, hexane, peptane and octane can be used. Also,
Diethyl ether, dichloromethane, chloroform, etc. may be used. As the water-soluble polar organic solvent, those mentioned above can be used. The amount of the nonpolar organic solvent used is preferably 2 to 5 parts by weight with respect to 1 part by weight of lecithin, and the weight ratio of the amounts of the nonpolar organic solvent and the water-soluble polar organic solvent used is:
A range of 1: 1 to 1: 4 is suitable. Furthermore, the weight ratio of the amounts of the nonpolar organic solvent and the alkaline aqueous solution used is 1: 1 to
A range of 1: 4 is suitable.

After the alkali treatment under the above environment,
The non-polar organic solvent phase and the water-soluble phase are statically separated. next,
To the separated non-polar organic solvent phase containing lecithin, a water-soluble polar organic solvent and water are further added and washed with water. Washing with water can be performed under substantially the same conditions as in the first method. The amount of the water-soluble polar organic solvent added is preferably such that a good dispersion state is obtained, and 0.3 to 1 part by weight is suitable for 1 part by weight of the nonpolar organic solvent containing lecithin. The weight ratio of the non-polar organic solvent phase containing lecithin to the aqueous phase containing the water-soluble polar organic solvent is preferably in the range of 1: 1 to 1: 4.

After washing with water, the non-polar organic solvent phase containing lecithin and the water-soluble phase are allowed to stand and separate. Purified lecithin can be obtained by removing the solvent from the separated non-polar organic solvent phase containing lecithin and then drying by the same method as above to recover lecithin. Incidentally, also in the second method described above, in order to more efficiently carry out the alkali treatment, or the dispersion of lecithin at the time of washing with water to be performed later, the addition of a salt or the repetition of the washing operation for further enhancing the degree of purification,
Further, the pH adjustment for preventing the deterioration of lecithin and the like are appropriately performed as in the first method. The above-mentioned second method can be applied to any of paste-like lecithin and powder-like lecithin, and in that lecithin can be purified with almost no change in the component of phospholipid of lecithin as a raw material, it can be recovered. This is a preferable method because of its high rate.

[0017]

EXAMPLES The present invention will be described more concretely with reference to the following examples. [Example 1] 100 g of powdery lecithin (trade name; SLP-White, manufactured by Trulecithin Industry Co., Ltd.) was dissolved in 500 ml of ethanol, and this was stirred with a stirrer at 50 ° C for 20 minutes, and then heated to 10 ° C. Was lowered and kept in this state for 30 minutes. Then, suction filtration is performed, and the solvent is removed under reduced pressure, and then 65 g of lecithin (residue: insoluble fraction)
Got This operation was repeated twice. 55 g of the obtained lecithin was suspended in 1500 ml of a 2% by weight calcium chloride solution, 2N aqueous sodium hydroxide solution was added dropwise, and the pH of the alkaline aqueous solution at the time of suspension was maintained at room temperature with a stirrer (50 rpm). ) Was stirred for 3 hours, and alkali washing was performed. After the stirring operation was completed, 1N hydrochloric acid was added dropwise to adjust the pH of the solution to 6.0, and the mixture was centrifuged to separate lecithin. Next, 1% by weight of the obtained lecithin
400 ml of an aqueous sodium chloride solution was added, and the mixture was stirred at room temperature with a stirrer (50 rpm) for 30 minutes and washed with water. Then, after washing with water, it was centrifuged to separate lecithin. The above washing operation was repeated 3 times. The obtained lecithin was dried under reduced pressure to obtain 50 g of purified lecithin (yield 50%).

[Example 2] In Example 1, instead of the powdery lecithin, paste lecithin (trade name; SL
33 g of lecithin purified in the same manner as in Example 1 except that P-paste and Trulecithin Industry Co., Ltd. were used.
Was obtained (33% yield).

[Example 3] Pasty lecithin (trade name; SLP-paste, manufactured by Trulecithin Industry Co., Ltd.)
100 g was dissolved in 250 ml n-hexane. To this, 400 g ml of 2 wt% sodium chloride aqueous solution and 400 ml of ethanol (purity 90%) were added and mixed with stirring. A 2N sodium hydroxide aqueous solution was added dropwise to this, and the mixture was stirred at room temperature for 3 hours with a stirrer (50 rpm) while the pH of the alkaline aqueous solution was maintained at 8.0 to carry out alkali treatment. After alkali treatment, leave still, hexane phase (upper layer)
After separating the water-containing ethanol phase (lower layer) from the above, only the upper layer was taken out. To the obtained lecithin-containing hexane solution, 150 ml of a 1% by weight sodium chloride aqueous solution and 150 ml of ethanol (purity 90%) were further added, and the mixture was stirred at room temperature with a stirrer (50 rpm) for 30 minutes and washed with water. After washing with water and standing, the hexane phase (upper layer) and the hydrous ethanol phase (lower layer) were separated, and then only the upper layer was taken out. The above washing operation was repeated 3 times. After the washing operation was completed, 1N hydrochloric acid was added dropwise to the hexane solution to adjust the pH of the solution to 6.0. Next, hexane was distilled off under reduced pressure and further dried under reduced pressure to obtain 95 g of purified lecithin (yield 95%).

Example 4 In Example 3, powdery lecithin (trade name: SL) was used instead of the paste lecithin.
95 g of lecithin purified in the same manner as in Example 3 except that P-white, Trulecithin Industry Co., Ltd. was used.
Was obtained (yield 95%).

Table 1 shows the phospholipid composition of each purified lecithin obtained as described above. In addition, in Table 1,
“PC” means phosphatidylcholine, “PE” means phosphatidiethanolamine, “PA” means phosphatidic acid, and “PI” means phosphatidylinositol.

[0022]

[Table 1] Table 1 ──────────────────────────────────── First refining method Second Purification method Raw material lecithin Example 1 Example 2 Example 4 Example 3 ────────────────────────────────── ── Raw material Powder paste Powder paste Powder paste Lecithin Lecithin Lecithin Lecithin Lecithin Lecithin ──────────────────────────────────── ─ Yield −−−− 50% 33% 95% 95% ──────────────────────────────────── -Phospholipid composition PC 41.0 41.6 8.3 2.6 40.5 43.2 PE 29.2 32.3 36.8 30.0 30.3 30.1 PA 9.8 11.9 21 .4 3 0.5 9.5 10.1 PI 16.2 13.6 30.3 36.1 17.9 13.8 Other 3.8 0.4 3.8 0.8 0.8 1.8 2.8 ──────────────────────────────────

The purified lecithin obtained above was evaluated as follows. Sensory evaluation was performed by 20 specialized panels on taste and smell. Odor: 20 g of purified lecithin was put into a 100 ml glass bottle, heated at 30 ° C. for 10 minutes, and then smelled in the bottle (blue odor,
The odor of dead grass and the smell of burning were evaluated. Taste: Directly purified lecithin was licked and its taste (bitterness, astringency, astringent taste) was evaluated. The evaluation criteria are as follows. A: 18 out of 20 had almost no odor and no taste. B: 18 out of 20 people had a slight smell and taste. C: 18 out of 20 people smelled and felt the taste. D: 18 out of 20 people had a strong odor and taste. The results are shown in Table 2 below.

[0024]

[Table 2] Table 2 ──────────────────────────────────── First refining method Second Purification method Raw material lecithin Example 1 Example 2 Example 4 Example 3 ─────────────────────────────────── ── Odor D A A B B B Taste D A A A A ───────────────────────────────────── From the above results, it can be seen that the purified lecithin obtained by the method of the present invention has a good flavor with no odor or bitterness.

[0025]

EFFECTS OF THE INVENTION By carrying out the purification method of the present invention in which a step including washing or treatment with an alkaline aqueous solution and subsequent washing with water is carried out, lecithin having a good flavor can be obtained.

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[Procedure amendment]

[Submission date] March 22, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

The separated lecithin component is then washed with water (step III). The obtained lecithin component is put into water at room temperature, and the lecithin is suspended in the aqueous phase by stirring and washed with water. The relationship between the amount of lecithin and the amount of water to be added is
Although not particularly limited, for example, with respect to 1 part by weight of lecithin,
Amounts of 3 to 10 parts by weight are preferred. The stirring can be performed by the same method as described above. The stirring condition is 50 to 100 r
In pm, the stirring time is 15 minutes or longer, preferably 20 minutes to 1 hour. In addition, in order to more efficiently perform the subsequent step of separating lecithin, it is preferable to add an appropriate amount of salt such as sodium chloride to water. The above-mentioned washing operation is preferably performed twice or more, more preferably three times or more.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction content]

Next, the second purification method will be described in detail. The second method includes the treatment of lecithin with an alkaline aqueous solution under basically the same conditions as in the first method, and the subsequent washing step with water. However, when the treatment is carried out using an alkaline aqueous solution, it differs in that the alkaline aqueous solution contains a non-polar organic solvent in which lecithin is soluble and a water-soluble polar organic solvent. That is, the treatment with the alkaline aqueous solution,
It is performed in an environment containing a non-polar organic solvent in which lecithin is soluble and a water-soluble polar organic solvent. In this environment, lecithin is dissolved in the non-polar organic solvent, and at the same time, the non-polar organic solvent containing lecithin is well dispersed in the aqueous phase in the presence of the water-soluble polar organic solvent. The non-polar organic solvent is not particularly limited as long as it can dissolve lecithin and fats and oils. For example, alkanes such as butane, pentane, hexane, peptane and octane can be used. Further, diethyl ether, dichloromethane, chloroform or the like may be used. As the water-soluble polar organic solvent, those mentioned above can be used. The amount of the nonpolar organic solvent used is preferably 2 to 5 parts by weight with respect to 1 part by weight of lecithin, and the weight ratio of the amounts of the nonpolar organic solvent and the water-soluble polar organic solvent is 1:
A range of 1 to 1: 4 is suitable. Furthermore, the weight ratio of the amounts of the nonpolar organic solvent and the alkaline aqueous solution used is 1: 1 to 1:
A range of 4 is suitable.

Claims (4)

[Claims] 1. A method for purifying lecithin, which comprises recovering lecithin after washing lecithin with an alkaline aqueous solution, separating lecithin and washing with water. 2. The method for purifying lecithin according to claim 1, wherein lecithin is treated with a water-soluble polar organic solvent and then washed with the alkaline aqueous solution. 3. A lecithin-containing non-polar organic solvent and an aqueous alkaline solution containing a water-soluble polar organic solvent are used to treat lecithin, and then the non-polar organic solvent phase containing lecithin is separated from the aqueous solution phase. An aqueous solution containing a water-soluble polar organic solvent is further added to the non-polar organic solvent phase containing lecithin to wash with water, and the non-polar organic solvent phase is separated from the aqueous phase, and then lecithin is recovered. Purification method. 4. The method for purifying lecithin according to claim 1, 2 or 3, wherein the alkaline aqueous solution in which lecithin is suspended and mixed has a pH of 7.5 to 9.0.