JPH0675472B2 - Method for producing high-purity egg yolk lecithin - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing lecithin from egg yolk powder, and provides a method capable of inexpensively producing high-purity egg yolk lecithin from egg yolk powder by a simple operation. .

<Prior art and its problems> Lecithin is used as a safe emulsifier in the food field, drugs,
It is widely used in the field of medicine such as ointments, and it is well known that egg yolk contains a large amount of this lecithin (for example, egg yolk powder contains approximately 18 ωt%).

In recent years, various egg yolk lecithins have been commercialized and sold in the market, but the purity is about 65 to 75%,
Some of them are highly purified (about 95%),
The purification operation is complicated.

Moreover, since egg yolk inherently contains a large amount of cholesterol that causes hypertension (for example, 2 to 4 ωt% in egg yolk powder), this cholesterol is inevitably contained in commercially available egg yolk lecithin as an impurity. It is mixed.

By the way, the fact is that even with egg yolk lecithin that boasts a high purity of 98.3%, of the remaining 1.7% impurities, most of it is cholesterol.

Therefore, in order to specifically clarify the above circumstances, first, a conventional method of obtaining lecithin from egg yolk using an organic solvent is described. As shown in JP-B-59-5263, ethanol is used as a solvent. Some extract lecithin from dried egg yolk at 35 ° C or lower.

With this method, even if the ethanol concentration is changed, the affinity between the egg yolk component and ethanol is limited, so only crude egg yolk lecithin exceeding about 60% can be obtained, the recovery rate is not so high, and cholesterol contamination is not high. Inevitable.

Further, as described above, since egg yolk contains a large amount of cholesterol, as a purpose for reducing the cholesterol content in the final product, for example, JP-A-47
There is an invention related to -19062.

The present invention is to extract cholesterol from egg yolk using acetone as an extractant and extract the residual components thereof as a low-cholesterol egg yolk product.

Cholesterol can be reduced by this method, but this is not a method of obtaining highly pure lecithin, and there is a high possibility that acetone will remain in egg yolk products.

Therefore, in the above-mentioned conventional technology, it is not possible to avoid contamination of the egg yolk lecithin as the final product with impurities, and in order to obtain highly pure lecithin, it is necessary to repeat the extraction operation with an organic solvent multiple times (solvent Therefore, it is also necessary to perform an operation of draining this below the allowable amount), which makes the operation complicated.

An object of the present invention is to be able to recover lecithin from egg yolk powder with high purity and high yield at low cost by a simple operation.

<Means for Solving Problems> The inventors of the present invention have examined the application of supercritical carbon dioxide as an extraction solvent having both high diffusivity and high dissolution ability, and contacted egg yolk powder with supercritical carbon dioxide, In relation to its affinity, triglycerides, neutral lipids such as cholesterol can be eluted and lecithin in egg yolk powder can be retained as a residual component to be separated from neutral lipids. Focusing on the fact that proteins and the like can be retained as insoluble components and separated from lecithin when a mixed solvent of either of them and ethanol is allowed to act, the present invention has been completed as an organic matter.

That is, the present invention, the supercritical carbon dioxide is contacted with the egg yolk powder contained in the extraction tank, the neutral lipid is extracted with the supercritical carbon dioxide, and the supercritical carbon dioxide in which the neutral lipid is dissolved is While taking it out of the extraction tank, the residual solvent in the extraction tank of the egg yolk powder is brought into contact with a mixed solvent of either supercritical carbon dioxide or liquefied carbon dioxide and ethanol, and lecithin is mixed with the residual solvent from the residual solvent. Is extracted.

The above supercritical carbon dioxide has a critical pressure of 75.2 kg / cm ² and a critical temperature.
It means carbon dioxide in a supercritical state exceeding 31.1 degrees, and liquefied carbon dioxide means carbon dioxide in a liquid state.

The egg yolk powder as a raw material is obtained by drying egg yolk separated from egg white by freeze drying, low temperature drying, spray drying, or the like.

<Extraction Step> The actual extraction step for producing egg yolk lecithin will be described in detail with reference to FIG.

(A) Raw material storage step Commercially available egg yolk powder is stored in the extraction tank 1.

(B) Extractant supply step Carbon dioxide is used as an extractant, and carbon dioxide is discharged from the carbon dioxide supply source 2 through the on-off valve 3 while being pressurized by a pressurizer (compressor etc.) 4 and heated by a heat exchange system. It is heated in a vessel 5 to produce supercritical carbon dioxide gas exceeding the above critical pressure and critical temperature, and this is supplied to the extraction tank 1.

(C) Neutral Lipid Extraction Step In the extraction tank 1, the egg yolk powder is contacted with supercritical carbon dioxide to elute the neutral lipid in the egg yolk into the supercritical carbon dioxide, and other components constituting the egg yolk, that is, Lecithin, various proteins, etc. are left as insoluble components in the extraction tank 1 to separate neutral lipids.

(D) Neutral lipid recovery step Supercritical carbon dioxide gas containing neutral lipids is decompressed by the pressure regulating valve 6 for setting the primary pressure and continuously transferred from the extraction tank 1 to the separation tank 7 to obtain a critical pressure of 75.2. Set to a pressure of less than kg / cm ² .

Carbon dioxide gas below this critical pressure rapidly loses its affinity for neutral lipids, so that neutral lipids can be easily separated, and neutral lipids composed of triglyceride, cholesterol, etc. can be rapidly collected in the separation tank 7.

The recovered neutral lipid is taken out of the separation tank by opening the open / close valve 8 and then used for utilization of nutrients, drugs and the like.

(E) Extractant supply process Open the on-off valves 3 and 11 simultaneously to supply carbon dioxide gas from the carbon dioxide gas supply source 2 and ethanol from the ethanol supply source 10, and pressurize and heat the pressurizer 4 and the heater 5. Then, a mixed solvent of supercritical carbon dioxide and ethanol is supplied to the extraction tank 1.

(F) Lecithin extraction step The above-mentioned mixed solvent is brought into contact with the components remaining in the extraction tank 1 to elute the lecithin in the residual components into the mixed solvent, thereby removing other components constituting the residual components, that is, various proteins and the like. It is left as an insoluble component and separated from lecithin.

(G) Lecithin Recovery Step Similar to the step (D) above, while reducing the pressure of the supercritical carbon dioxide containing lecithin by the pressure regulating valve 6, the extraction tank 1 to the separation tank 7 are separated.
Continuously transferred to a pressure state below the critical pressure.

The inside of the separation tank 7 is divided into a liquid phase of ethanol containing dissolved components and a carbon dioxide gas phase. After carbon dioxide gas is discharged from the separation tank 7, ethanol is evaporated to recover lecithin dissolved therein.

Moreover, since nutrients such as proteins that are insoluble in both supercritical carbon dioxide and a mixed solvent of supercritical carbon dioxide and ethanol remain as residual components in the extraction tank 1, they are recovered and used for various foods and the like. Provide for use.

In addition, in the extraction / recovery steps (e) to (g), a mixed solvent of liquefied carbon dioxide and ethanol can be used instead of the mixed solvent of supercritical carbon dioxide and ethanol as the extractant.

In this case, in the extraction agent supply step (e), it is only necessary to open the carbon dioxide gas supply source and supply the liquefied carbon dioxide gas as it is, so that it is not necessary to pressurize or heat it.

<Effects of the Invention> (1) In the step of allowing supercritical carbon dioxide to act on egg yolk powder (hereinafter referred to as “first stage extraction”), neutral lipids are eliminated and lecithin is concentrated in a residual component, so to speak, supercritical carbon dioxide. Since only lecithin is recovered from this residual component in the step of allowing a mixed solvent of either gas or liquefied carbon dioxide and ethanol to act (hereinafter referred to as "second stage extraction"), there is almost no loss of lecithin in the extraction process. Selective extraction,
Therefore, lecithin can be recovered from egg yolk with high purity and high yield.

(2) Since the residual components of the first-stage extraction are directly subjected to the second-stage extraction, continuous operation is possible, and since the carbon dioxide gas is also used for the first-stage and second-stage extraction operations, the entire extraction facility can be designed compactly. The operation within one extraction process can be simplified.

Further, according to the present invention, as described in (1), since lecithin can be efficiently recovered, it is not necessary to repeat the extraction operation a plurality of times as in the conventional case, and highly pure lecithin can be obtained by one extraction operation. , The extraction operation can be performed quickly.

(3) Since the present invention performs extraction using carbon dioxide and ethanol, it is unlikely that this gas will remain in the final lecithin because carbon dioxide is a gas at room temperature and atmospheric pressure. Even if a small amount remains in the final lecithin, there is no problem in safety, so in any case lecithin can be used in a safe and non-toxic state.

(4) Generally, in the extraction method using an organic solvent,
Organic solvents often remain in the extraction tank residue in a considerable proportion.

However, according to the method of the present invention, since the ethanol used as the mixed solvent can be easily recovered and reused from the extraction tank by flowing only carbon dioxide gas after the second stage extraction, it is economical compared to the conventional example. Extraction can be performed.

(5) Most of the extracted components obtained in the first-stage extraction are neutral lipids, and most of the insoluble components in the second-stage extraction are proteins, so these components may be added as they are or in addition. If it is manipulated, it can be expected to be used as a health food or a drug, and the added value of the production method of the present invention can be increased.

<Example> Regarding the following components A, B, and C obtained by carrying out the present invention, the yield and composition of each were confirmed by experiments through comparison with the extraction method with ethanol.

(A) Primary extraction component A obtained by first-stage extraction (b) Secondary extraction component B obtained by second-stage extraction (c) Final residual component C obtained by second-stage extraction (1) Extraction Experimental Example 1 500 g of commercially available egg yolk powder was placed in a 4 l extraction tank, and the temperature was 40 ° C.
Using supercritical carbon dioxide at a pressure of 400 kg / cm ² , an average flow rate of 10 k
While conducting extraction for 5 hours at g / hr, supercritical carbon dioxide was transferred to the separation tank under reduced pressure to separate and recover the primary extraction component A from carbon dioxide.

Next, in the extraction tank, temperature 40 ℃, pressure 400kg / cm ² , average flow rate 1
Liquid mixture of supercritical carbon dioxide and ethanol under the condition of 0 kg / hr (ratio of ethanol to the total amount of mixed solvent 10 ωt
%) For 5 hours to extract the components remaining in the extraction tank in the above-mentioned first-stage extraction, and the insoluble component remains in the extraction tank while the mixed liquid in which the extraction components are dissolved is transferred to the separation tank. It was transferred under reduced pressure.

At this time, since the inside of the separation tank is divided into two phases of gas and liquid, the ethanol liquid phase is separated from the carbon dioxide gas, and the component dissolved in the ethanol liquid phase is recovered as the secondary extraction component B, and The insoluble component in the extraction tank was recovered as the final residual component C.

The yield of each component A, B, C was as follows.

Primary Extraction Component A 214.9g Secondary Extraction Component B 74.0g Final Residual Component C 197.6g (2) Extraction Experimental Example 2 In Example 1, a mixed solvent of supercritical carbon dioxide and ethanol was used in the second stage. Although extraction was performed, in this example, extraction was performed using a mixed solvent of liquefied carbon dioxide gas and ethanol.

That is, 500 g of commercially available egg yolk powder was contacted with supercritical carbon dioxide to recover the first extraction component A, and the temperature was adjusted to 20
At a temperature of 70 ° C., a pressure of 70 kg / cm ² , and an average flow rate of 10 kg / hr, a liquid mixture of liquefied carbon dioxide and ethanol (the ratio of ethanol to the total amount of the mixed solvent is 10 ωt%) is flowed for 5 hours,
The components remaining in the extraction tank during the first extraction were extracted.

Then, by the same operation as in Example 1, the secondary extraction component B was recovered from the separation tank, and the final residual component C was recovered from the extraction tank.

The yield of each component A, B, C was as follows.

Primary Extraction Component A 211.6g Secondary Extraction Component B 48.0g Final Residual Component C 221.3g (3) Comparative Extraction Example 500g of egg yolk powder was placed in a 4l extraction tank, atmospheric pressure, temperature 30 ° C,
Ethanol was allowed to flow at an average flow rate of 2.5 kg / hr, extraction was carried out for 3 hours, and then the following extract component D was recovered from the ethanol liquid phase.

Extraction component D 126.8 g (4) Composition confirmation test example of primary extraction component A, secondary extraction component B, and final residual component C Each component A, B, C obtained from extraction example 1 or 2
First, a qualitative test by thin layer chromatography was performed to clarify the components, and then a quantitative test was performed to examine the composition ratio.

Silica gel 6 with hexane / ether (1: 1) solvent
When the primary extraction component A was spread on the thin layer plate of 0F254, the chromatogram of FIG. 2 was obtained.

According to the same chromatogram, it is found that the extraction component A is composed of triglyceride, diglyceride and monoglyceride glyceide and cholesterol.

In addition, each secondary extraction component B obtained from extraction experiment examples 1 and 2
And with respect to the extracted component D obtained from the comparative example, when these were spread on a thin layer plate of silica gel 60F254 using a solvent of chloroform / methanol / water (65: 25: 4),
The chromatogram of FIG. 3 was obtained.

According to the chromatogram, the extraction examples 1 and 2 show that
The spots of the lecithin group consisting of phosphatidylcholine, phosphatidylethanolamine, sphingomyelin and lysophosphatidylcholine were prominent, but the spots showing glyceride and cholesterol were only trace.

On the other hand, in the comparative example, in addition to the lecithin spot group, in addition to glyceride, particularly spots of cholesterol appeared clearly.

Therefore, the components A, B, and C obtained from Extraction Example 1 were quantified by the following ordinary method to clarify the composition ratio.

First, the secondary extraction component B was divided into three samples, and one of them was divided by the Allen method (Allen method, RJLAllen, J. Biochem., 34,85).
8 (1940)) was applied to obtain the lecithin content (note that
The final composition ratio is the lecithin content in this sample,
The ratio (%) of the lecithin content relative to the total amount of each of the components A, B, and C before analysis was reconverted and shown, hereinafter the same).

In addition, zeolite is allowed to act on other samples to remove lecithin, cholesterol, etc., and the glycerin contained in the obtained glyceride is subjected to saponification, oxidation and addition reaction to remove 3,5-diacetyl-1,4-dihydro. The content of glyceride in the sample was determined by changing to lutidine and measuring the absorbance.

Abel extraction method (Abell extraction method, LLAbell et al.
J. Biochem., 195, 357 (1952)) was applied to extract cholesterol in a free form, and this was colored in blue-green by the Liebermann reaction, and its absorbance was measured to measure the content of cholesterol in the sample. The amount was calculated.

Further, when the Horch method (so-called chloroform = methanol extraction method) was applied to each of the components A, B, and C, most of the component C remained as an insoluble component. After confirmation, vacuum drying was performed and the weight was measured, which was defined as the protein content.

FIG. 4 is a chart showing the results. According to the chart, the first extracted component A contained 93.6% of glycerides and 6.2% of cholesterol, and both of them accounted for about 100%.

This result is in agreement with the above-mentioned thin layer chromatogram for the component A (see FIG. 2).

The second extracted component B was mostly lecithin as shown by the numerical value of 98.6%, and cholesterol was mixed in only 0.2%.

This is in agreement with the thin layer chromatogram described above for component B (see Figure 3).

Also, 96.6% of the final residual component C was protein.

(5) Confirmation Test Example of Lecithin Content in Secondary Extraction Component B Each of the secondary extraction components B obtained from Extraction Examples 1 and 2 and the extraction component D obtained from Comparative Example are described above. Analysis was carried out by the method used in the test example of (4), and the proportion (%) of pure lecithin contained in each extracted component was examined.

FIG. 5 is a chart showing the results. According to the chart, the lecithin content in Extraction Example 1 is 98.6% and that in Extraction Example 2 is 98.7%, whereas the lecithin content in Comparative Example is The rate was 67.7%.

In addition, the cholesterol content in Extraction Examples 1 and 2 was 0.2%, which was a very small amount, but in Comparative Example, the cholesterol content was as high as 6.3%.

Therefore, the extract component B obtained from Extraction Examples 1 and 2, that is, the egg yolk lecithin, shows a high purity of 98% or more, and there is almost no cholesterol in the remaining impurities, and it can be used as a health food or drug. It is suitable for use.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of an apparatus for carrying out the present invention, FIG. 2 is a thin-layer chromatogram of the primary extraction component A of Extraction Example 1, and FIG. Next extraction component B
And a thin-layer chromatogram of the extraction component D of the comparative example, FIG. 4 is a table showing composition analysis results for each of the components A, B, and C of the extraction experimental example 1, and FIG. 5 is each of the extraction experimental examples 1 and 2. It is a chart which shows the composition analysis result about the secondary extraction component B and the extraction component D of a comparative example. 1 ... Extraction tank, 2 ... Carbon dioxide gas supply source, 4 ... Pressurizer, 5 ... Heater, 7 ... Separation tank, 10 ... Ethanol supply source.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Fumio Ibu 4-23-5-308 Esaka-cho, Suita City, Osaka Prefecture (72) Inventor Hiroshi Yamamoto 1-11-8 Shiroyamadai, Sakai City, Osaka Prefecture ( 72) Inventor Yuuji Komori 116 1300 Minamisakura, Yasu-cho, Yasu-gun, Shiga Prefecture (72) Inventor Hiroshi Wada 6-7 Tsumon Kureha-cho, Nishinomiya-shi, Hyogo Prefecture (72) Hironobu Iwashita Takagi-nishi-cho, Nishinomiya-shi, Hyogo Prefecture No. 19 No. 51 Osaka Water Industry Co., Ltd. Nishinomiya Dormitory (56) References JP-A-60-224695 (JP, A)

Claims (1)

[Claims] 1. Supercritical carbon dioxide is brought into contact with egg yolk powder contained in an extraction tank, neutral lipids are extracted with supercritical carbon dioxide, and supercritical carbon dioxide in which the neutral lipids are dissolved is extracted. While taking it out of the tank, the components remaining in the extraction tank of the egg yolk powder are brought into contact with a mixed solvent of either supercritical carbon dioxide or liquefied carbon dioxide and ethanol, and lecithin is mixed with the mixed solvent from the above residual components. Extraction method of high-purity egg yolk lecithin characterized by extraction