JPH05306400A - Production of fat and oil having low cholesterol - Google Patents

Abstract

PURPOSE:To separate and remove cholesterol from fats and oils containing cholesterol. CONSTITUTION:In blending a soap formed in fats and oils containing cholesterol obtained by adding a free fatty acid and an aqueous solution of an alkali while stirring or an alkali metal salt of fatty acid, namely a soap added in fats and oils containing cholesterol with an oil layer, the soap is rapidly blended with the oil layer and uniformed while finely granulating and homogenizing oil drops formed in the soap to effectively remove cholesterol from the fats and oils containing cholesterol.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for separating and removing cholesterol from fats and oils containing cholesterol.

[0002]

2. Description of the Related Art It is well known that an increase in human blood cholesterol level is one of the causes of adult diseases such as arteriosclerosis and myocardial infarction.
So, in fact, in people with high blood cholesterol levels,
Many people have dietary restrictions to control their cholesterol intake.

On the other hand, cholesterol is abundantly contained in animal fats and oils and egg products, and it is an essential food from the viewpoint of its sensory appeal and nutrition, and the limitation of these foods is that It cannot be denied that this is a major negative factor in the actual diet.

For this reason, many studies have heretofore been made for the purpose of removing cholesterol in animal fat. For example, a method of adsorbing and removing cholesterol with an adsorbent such as activated carbon, diatomaceous earth, and clay (JP-A-61-161).
No. 136598), and a method of degrading cholesterol contained in fats and oils by a microorganism of the genus Rhodococcus (JP-A 1-229097). However, the method of using an adsorbent is inefficient in cholesterol removal compared to the amount used, and the method of using a microorganism is problematic in the safety of its decomposed products. However, it was difficult to implement it on a factory scale.

In view of these problems of the prior art, the inventors of the present invention have conducted earnest studies for the purpose of providing a low-cholesterol oil and fat safely and inexpensively, and as a result, the deoxidation step of the oil and fat refining step has been conducted. It was found that cholesterol can be effectively removed by adding a step of adding a fatty acid therein, and the present invention has already been filed as "method for producing low-cholesterol oil and fat" (Japanese Patent Application No. 2-338798).

Therefore, the object of the present invention is to easily, easily and efficiently in the above-mentioned method, by specifying the type of free fatty acid and the reaction conditions, without further lowering the oil yield, than in the above-mentioned method. It is an object of the present invention to provide a method for producing a low-cholesterol oil and fat, which is good in removing cholesterol from oil and fat and has an extremely high oil yield.

[0007]

[Means for Solving the Problems] In view of such circumstances,
As a result of further studies by the present inventors, (1) if free fatty acids were added to cholesterol-containing fats and oils in advance and uniformly dispersed in the oil layer, then an alkaline aqueous solution was gradually added while stirring, The resulting oil droplets in the soap layer are atomized and homogenized, and as a result, cholesterol can be effectively removed. (2) In this case, the free fatty acid added to the cholesterol-containing oil or fat is carbon chain 12
It is efficient that the melting point of the above long-chain fatty acids is 60 ° C. or lower, and (3) the fatty acid alkali metal salt, that is, soap, is added to the fats and oils containing cholesterol, and the resulting soap layer and Cholesterol can be effectively removed by mixing and stirring the cholesterol-containing oil and fat layer, and the soap may contain a certain amount of cholesterol. (4) In any of the above cases, soap The inventors have found that cholesterol can be more effectively removed by lowering the temperature when the layer and the cholesterol-containing oil and fat layer are mixed and stirred, and have completed the present invention.

That is, when free fatty acid and an alkaline aqueous solution are added to and stirred with cholesterol-containing fats and oils to mix the soap formed in the cholesterol-containing fats and oil with the oil layer, the oil droplets generated in the soap are atomized, By rapidly mixing and homogenizing the soap and the oil layer while homogenizing, cholesterol can be more effectively removed from the cholesterol-containing oil and fat.

Further, in this case, by using a long-chain fatty acid having a low melting point and lowering the stirring temperature during the process to a low temperature at the end of stirring, the oil yield, cholesterol removal rate, etc. can be further improved. Of.

Further, similarly, when an alkali metal salt of a fatty acid added to cholesterol-containing oil or fat, that is, a soap and an oil layer are mixed, oil droplets generated in the soap at that time are atomized and homogenized, By rapidly mixing and homogenizing the soap and the oil layer, cholesterol can be more effectively removed from the cholesterol-containing oil and fat.

The method for producing a low-cholesterol oil and fat according to the present invention will be described in detail below.

Basically, the method for producing a low-cholesterol oil according to the present invention is as follows: A method for producing a low-cholesterol oil or fat, which comprises the following steps: (a) cholesterol-containing oil or fat,
A first step of adding free fatty acid, further adding an aqueous alkali solution and stirring to emulsify the resulting alkali metal salt of fatty acid, that is, soap and oil layer; and (b) the first step
A method for producing a low-cholesterol oil or fat, comprising the step of separating the mixture obtained by the step into an oil layer and a soap layer, and separating the oil layer, wherein the first step comprises:
Free fatty acids are added to cholesterol-containing fats and oils in advance,
After sufficiently diffusing into the oil layer, an aqueous alkali solution is gradually added while stirring to form an alkali metal salt of fatty acid, so-called soap, and at the same time uniformly mixed and stirred with the oil layer,
A method for producing low-cholesterol oils and fats (hereinafter, referred to as "first invention").

The method for producing a low-cholesterol oil according to the present invention is A method for producing a low-cholesterol oil or fat, which comprises the following steps: (a) cholesterol-containing oil or fat,
An alkali metal salt of a fatty acid, that is, soap is added and stirred to emulsify the first step, and (b) the mixture obtained in the first step is separated into an oil layer and a soap layer, and the oil layer is separated. And a second step, which is a method for producing a low-cholesterol oil or fat (hereinafter referred to as "second invention").

A. About 1st invention: More specifically, in 1st invention of this invention, it is a manufacturing method of low-cholesterol oil and fat, Comprising: Basically, the alkali metal salt of a fatty acid, ie, soap, and cholesterol content. A low-cholesterol oil and fat is obtained by mixing and stirring the oil and fat, and then separating and separating the oil layer. At that time, the soap layer and the oil layer are quickly and sufficiently mixed, and in order to improve the cholesterol removal efficiency by separating the oil layer, the free fatty acid is added to the oil layer in advance and thoroughly mixed,
After diffusing, an aqueous alkali solution is gradually added with stirring to form soap, and is uniformly mixed with the oil layer.

By the way, the cholesterol contained in the cholesterol-containing oil or fat as the starting material of the present invention is more effective when it is in free form. If cholesterol fatty acid ester is present, it is converted into free form in advance by an enzyme such as cholesterol esterase. It is better to keep it.

In this case, the free fatty acid to be added is
The removal rate of cholesterol is not so high for free fatty acids having a carbon chain of 10 or less, and for fatty acids with high melting points such as palmitic acid and stearic acid, the alkali metal salts easily take up oil and require high temperature treatment. Therefore, it is often not preferable for efficient cholesterol reduction. Therefore, as the fatty acid added in the present invention, a fatty acid which is liquid at room temperature and has 12 or more carbon atoms, such as lauric acid, myristic acid, oleic acid, and linoleic acid, is desirable. Oleic acid is particularly preferable in terms of reduction efficiency and cost.

Further, the amount of fatty acid added to the oil and the concentration and amount of the aqueous alkali solution may be such that the added free fatty acid can be removed as an alkali metal salt within the range where the generated soap layer and the oil layer can be separated. Preferably, the fatty acid is 0.5 to 10% by weight of the oil layer, and the alkaline aqueous solution is 5%.
It is desirable to add an aqueous solution having a concentration of ˜40% by weight within an amount of 50% by weight of the oil layer.

In this reaction, when an alkali metal salt of a fatty acid serves as a surfactant and oils and fats are incorporated into micelles as an o / w type emulsion, cholesterol in the oils and fats is the same as the alkali metal salts of fatty acids. It acts as a surfactant, and is caused by the active migration of cholesterol into micelles, and it is therefore considered that low-cholesterol oils and fats can be obtained.

Further, in order to improve the yield of oil and efficiently reduce cholesterol, it is desirable to make the micelle small and homogenized in order to reduce the volume in the micelle and increase the surface area.

Further, the stirring condition is preferably as low as possible as far as the oil layer and the soap layer can be separated from the viewpoint of the reduction of cholesterol, but considering the oil yield, stirring at low temperature is not recommended. A short time is preferred.

The stirrer used for stirring is not particularly limited, and while producing soap,
It is better to quickly mix with the oil layer and to make the oil droplets to be taken in small, and to have the ability to homogenize, but from the viewpoint of cholesterol removal alone, soap can be generated while gently stirring with a propeller etc. Then, the soap may be mixed with the oil layer by stirring as it is, and then the oil layer may be separated.

Further, in the actual oil refining step, the step of removing the free fatty acid by adding the alkaline aqueous solution, that is, the deoxidizing step is carried out at 70 to 80 ° C. When taking it in, add free fatty acid into oil at high temperature, add alkaline aqueous solution with stirring to make soap, and gradually cool with stirring, and when the temperature becomes low to some extent, form oil layer and soap layer. It is desirable to separate immediately.

Further, in this case, although the cholesterol removal rate is somewhat lowered, the treatment may be carried out at a high temperature, and the oil yield is slightly lowered, but the treatment is preferably performed after the temperature is lowered in advance. It is also possible to do so.

Next, in this way, the mixture obtained by stirring and emulsifying the soap layer and the oil layer is separated and separated into an oil layer and a soap layer.

In this case, as a separation / separation method, a general filter, a centrifuge or the like can be used. Considering the actual oil and fat refining process, preferably the centrifuge is used as it is. good.

The oil layer thus separated and collected is low-cholesterol oil and fat, and if necessary, for example, activated clay that is used in the actual oil and fat refining process is used. It is possible to use it as an edible oil and fat without any problems through the decoloring step and the deodorizing step of steam distillation with oil and fat heated at high temperature under reduced pressure.

B. Regarding the second invention: Next, in the second invention of the present invention, in the first invention, a free fatty acid and an alkaline aqueous solution are added to and agitated with a cholesterol-containing fat and oil, a soap produced in the cholesterol-containing fat and oil, and an oil layer. By mixing and stirring, the cholesterol was removed from the cholesterol-containing fats and oils, while an alkali metal salt of a fatty acid was added to the cholesterol-containing fats and oils, that is, soap was added, and the soap layer and the cholesterol-containing fat layer were mixed, By stirring, cholesterol can be removed as in the first invention.

In this case, the alkali metal salt of the fatty acid to be added is not particularly limited, and for example, a hydrous oil slag such as a sodium salt of a fatty acid, which is usually a by-product when degreasing and refining fats and oils, may be used. Absent.

When the soap is directly added to the cholesterol-containing fats and oils as in the second aspect of the present invention, if the soap layer contains a sufficient amount of fats and oils, a low-cholesterol fats and oils can be obtained with almost no decrease in oil yield. Obtainable.

The stirring may be carried out by sufficiently mixing the fat and oil and the alkali metal salt of the fatty acid to be added, and the temperature during stirring may be such that the fat and oil are kept in a liquid state. It is preferable to lower the temperature within the range where separation is possible.

After the alkali metal salt of a fatty acid, so-called soap, is uniformly stirred and mixed with oil, the stirring is stopped immediately without excessive stirring and the oil layer is separated, whereby cholesterol is efficiently produced. It can be removed.
Also, taking into consideration the yield of oil, the removal rate of cholesterol, etc., gentle stirring at low temperature for a short time is effective.

Further, as the stirrer used for stirring, particularly in the case of the second invention of the present invention in which soap is added to cholesterol-containing fats and oils, the emulsified particles are made small and the ability to be rapidly mixed is provided. Better is better.

Further, it is effective to lower the temperature of the oil layer to reduce the solubility of cholesterol in the oil layer.

The amount of soap to be added may also be within the range where the water layer containing the soap layer and the oil layer can be separated after stirring and mixing.

If only the cholesterol content in the fats and oils is to be reduced, the cholesterol-containing fats and oils may be mixed with an alkali metal salt of a fatty acid which already contains water and fats, and shaken lightly.

Next, the mixture thus obtained by stirring and emulsifying the soap layer and the oil layer is separated and separated into the oil layer and the soap layer.
The sorting method may be basically the same as that of the above-described first invention.

On the other hand, the soap layer thus separated and collected can be used again in the present invention, and it is added to cholesterol-containing fats and oils to produce low cholesterol fats and oils by repeating the same operation. You can That is, in the soap used in the present invention, cholesterol may be contained in the fat and oil preliminarily contained in the soap layer as long as it does not migrate from the soap layer to the oil layer.

In addition, the soap layer repeatedly used as described above contains a large amount of cholesterol and can be sufficiently used as a cholesterol extraction source. For example, the soap layer used repeatedly, ethanol, acetone,
An organic solvent such as isopropanol is added to separate and separate soap-containing fats and oils.
Cholesterol can be separated and purified by a cholesterol extraction method by crystallization, adsorption, and complex formation from the unsaponifiable matter after the oil and fat are alkali-fed. At this time, the organic solvent used has low polarity and is insoluble in water, for example, hexane, ether, etc.,
The above-mentioned ethanol and acetone, which are also soluble in water, are desirable.

[0039]

EXAMPLES Hereinafter, the method for producing a low-cholesterol oil according to the present invention will be described in more detail with reference to Comparative Examples and Examples.

The cholesterol-containing oil used in the following comparative examples is corn oil or rapeseed oil, to which egg yolk was added, and the mixture was vigorously stirred at 15,000 rpm with a homogenizer and then at 5,000 rpm for 5 minutes. It is an oil containing cholesterol obtained by centrifugation to separate into an yolk layer and an oil layer.

Comparative Example 1 (Addition: fatty acid + aqueous alkali solution)
Liquid) (Effect of fatty acid type and stirring temperature) (Stirrer:
Propeller) Cholesterol-containing oil (cholesterol 4.09 mg /
g) To 200 g, add 8 g each of oleic acid, stearic acid, and caprylic acid, and further add oleic acid and stearic acid to 20% sodium hydroxide solution.
0 ml was added, to the caprylic acid-added product, 20 ml of 20% sodium hydroxide solution was added, and the mixture was stirred with a propeller at 500 rpm for 15 minutes. The stirring temperature was (1) maintained at 60 to 70 ° C. for 15 minutes,
(2) 70 ° C for the first 5 minutes, 10 ° C over 5 minutes, and maintained at 10 ° C or lower for the last 5 minutes, (3)
It was carried out with 3 kinds of one, that is, maintained at 10 ° C. or lower for 15 minutes. After the stirring was completed, the mixture was centrifuged at 5000 rpm for 5 minutes to measure the yield and cholesterol content of the oil layer. The results are shown in Table 1.

[0042]

[Table 1]

Since stearic acid is a solid at 10 ° C. and does not become an alkali metal salt of a fatty acid even if an aqueous alkali solution is added, no experiment was conducted.

As is clear from this table, the oil yield and cholesterol removal rate of oleic acid, stearic acid, and caprylic acid differed greatly, and it was found that there were differences depending on the temperature as the alkali metal salt of fatty acid. It is considered that the lipophilicity and affinity for cholesterol differ depending on the type of fatty acid and temperature.

Further, stearic acid and oleic acid having a long carbon chain were effective in removing cholesterol, and the effect was low when caprylic acid was used.

Further, the oil yield is preferably treated at 60 to 70 ° C., but the lower temperature is better from the viewpoint of cholesterol removal. Also, when using oleic acid, 6
When the stirring was started at 0 to 70 ° C. to form soap, and when the stirring was completed, the temperature was lowered to 10 ° C. or lower, the oil yield was increased, and the cholesterol was most effectively removed.

Comparative Example 2 (Addition: fatty acid + aqueous alkali solution)
Liquid) (Effect of fatty acid type and stirring temperature) (Stirrer:
Homomixer) 200 g of cholesterol-containing oil (cholesterol 4.
46 mg / g), 8 g each of propionic acid, caprylic acid, and oleic acid were added, and 40%, 20 ml, and 10 ml of 20% sodium hydroxide aqueous solution were added, and the mixture was mixed with a homomixer at (1) 60 to 70 ° C. 10,0
Stirred at 00 rpm for 2 minutes, (2) 20 to 30
Agitated at 10,000 rpm for 2 minutes,
(3) Three treatments of 10 ° C. or lower, 10,000 rpm, and stirring for 2 minutes were performed. After stirring, 5000r
After centrifugation for 5 minutes at pm, the yield and cholesterol content of the oil layer were measured. The results are shown in Table 2.

[0048]

[Table 2]

Further, based on the results of Comparative Example 1, for confirmation, propionic acid and caprylic acid were used as free fatty acids having a short carbon chain, and oleic acid was used as a long one, and the temperature was high (60 to 70). ℃), room temperature (20-30
C.) and low temperature (10.degree. C. or less). Further, the stirring time was shortened to 10,000 rpm for 2 minutes. The results are almost the same as in Comparative Example 2, and the treatment at room temperature and low temperature when oleic acid was used exhibited the most effective effect on the efficient removal of cholesterol.

Comparative Example 3 (Addition: fatty acid + aqueous alkali solution)
Liquid) (Effect of fatty acid type and stirring temperature) (Stirrer:
Propeller) 200 g of cholesterol-containing oil (cholesterol 4.
17 mg / g), 8 g each of lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, and erucic acid were added, and 20% aqueous sodium hydroxide solution was added to each of 14 ml, 12 ml, 11 ml, 10 ml, and 10 m.
1 and 8.3 ml, and with a propeller, (1) 60-7
Stirred at 0 ° C, 500 rpm for 15 minutes, (2)
The mixture was stirred at 500 rpm for 5 minutes at 70 ° C., cooled to 10 ° C. in 5 minutes, and stirred at 10 ° C. or less for 5 minutes, and then treated by two methods. After stirring, 5
After centrifugation at 000 rpm for 5 minutes, the yield and cholesterol content of the oil layer were measured. The results are shown in Table 3.

[0051]

[Table 3]

It is clear from the experiments so far that free fatty acids having 10 or less carbon atoms have little effect on the removal of cholesterol even if an alkali metal salt thereof is prepared.
I investigated what difference there are in free fatty acids having 12 or more carbon atoms. As you can see from the table, carbon number is 12
Above, it can be seen that all of them have a uniform cholesterol-removing action, but when palmitic acid and stearic acid, which have high melting points, are used, lowering the temperature decreases the oil yield,
The effect of removing cholesterol also tends to decrease. On the other hand, lauric acid, myristic acid, erucic acid, which have a low melting point,
It can be seen that oleic acid, which comes out as a liquid at room temperature, has a good yield and is excellent in removing cholesterol.

Comparative Example 4 (Addition: fatty acid + aqueous alkali solution)
Liquid) (Effect of stirring temperature) ( Stirrer : propeller ) 200 g of purified fish oil (cholesterol 2.65 mg / g)
To the above, 8 g of oleic acid or linoleic acid was added, and 10 ml of 20% sodium hydroxide aqueous solution was added.
(1) Stirred at 60 to 70 ° C., 500 rpm for 5 minutes, (2) Stirred at 500 rpm, 70 ° C. for 1 minute, and then rapidly cooled to 10 ° C. or less for a total of 5 minutes,
Four treatments were carried out: (3) stirred at 20 to 30 ° C., 500 rpm for 5 minutes, and (4) stirred at 10 ° C. or lower at 500 rpm for 5 minutes. After stirring, 5000r
It was centrifuged at pm for 5 minutes, and the yield of the oil layer and the cholesteroleol content were measured. The results are shown in Table 4.

[0054]

[Table 4]

The same experiment was conducted using linoleic acid, which has the same carbon number as oleic acid and is liquid at room temperature, and the effect was confirmed. As is apparent from Table 4, linoleic acid was confirmed to be as effective as oleic acid.

Comparative Example 5 (Addition: After adding an alkaline aqueous solution,
200 g of cholesterol-containing fats and oils ( when fatty acid is added) (cholesterol 4.
00mg / g), 20m sodium hydroxide solution 10m
l, and (1) with a homogenizer, 20 to 30 ° C.,
While stirring at 10,000 rpm, 8 g of oleic acid was added, and stirring was continued for 2 minutes. (2) With a propeller, 8 g of oleic acid was added while stirring at 500 rpm and 20 to 30 ° C., and further stirring was performed for 5 minutes. Two treatments were performed, one that continued for a minute. After completion of stirring, the mixture was centrifuged at 5000 rpm for 5 minutes to measure the yield and cholesterol content of the oil layer. The results are shown in Table 5.

[0057]

[Table 5]

As is clear from the results in this table, when an alkaline aqueous solution is added to the oil layer and then free fatty acid is added to form soap, in order to carry out sufficiently uniform and efficient stirring, It turns out that strong stirring has to be done. Further, it is understood that when the o / w type emulsification is caused, oil is easily taken in, the oil yield is deteriorated, and the cholesterol removal rate is lowered.

Comparative Example 6 (Addition: fatty acid + aqueous alkali solution)
(Liquid) (effect of stirring time) (stirrer: propeller) 200 g of cholesterol-containing oil / fat (cholesterol 4.
12 mg / g), 8 g of oleic acid was added, and further,
Add 10 ml of 20% sodium hydroxide aqueous solution and propeller at 10 ° C or less at 500 rpm, and
Stirred for 4 minutes, 6 minutes, 8 minutes, 10 minutes, 15 minutes.
After completion of stirring, the mixture was centrifuged at 5000 rpm for 5 minutes to measure the yield and cholesterol content of the oil layer. The results are shown in Table 6.

[0060]

[Table 6]

Comparative Example 7 (Addition: fatty acid + alkali water solution)
(Liquid) (effect of stirring time) (stirrer: propeller) 200 g of cholesterol-containing oil / fat (cholesterol 4.
(00 mg / g), 8 g of oleic acid was added, and
Add 10 ml of 20% aqueous sodium hydroxide solution, and propeller at 60 to 70 ° C. at 500 rpm for 2 times each.
Stirred for 4 minutes, 6 minutes, 8 minutes, 10 minutes, 15 minutes.
After completion of stirring, the mixture was centrifuged at 5000 rpm for 5 minutes to measure the yield and cholesterol content of the oil layer. The results are shown in Table 7.

[0062]

[Table 7]

From Comparative Examples 6 to 7, it can be seen that the cholesterol removing effect can be obtained in a short time if soap is produced in the cholesterol-containing fat or oil and stirred at high or low temperature. The higher the oil yield is, the lower the cholesterol removal rate is. Therefore, it can be said that the low-temperature treatment is superior to the high-temperature treatment in terms of removing cholesterol. However, in the low-temperature treatment, the longer the stirring time, the more the oil yield tends to decrease, and therefore the stirring time at the low temperature is preferably short.

Comparative Example 8 (Addition: fatty acid + aqueous alkali solution)
Liquid) purified fish oil (cholesterol content 2.29 mg / g) 20
Add 0 g of oleic acid to 0 g, and with a homomixer,
While stirring at 10,000 rpm, 10 ml of 20% sodium hydroxide solution was added. After stirring at 25 ° C for 1 minute, the obtained mixture was centrifuged at 5,000 rpm for 5 minutes to separate an oil layer and a soap layer. The yield and cholesterol content of the separated oil layer were measured.

Further, 50 g of the separated soap layer was again used for refined fish oil (cholesterol content 2.29 mg / g).
Add to 200g, and use a homomixer for 10,000r
After stirring at pm at 25 ° C. for 1 minute, the resulting mixture was centrifuged at 5,000 rpm for 5 minutes to separate an oil layer and a soap layer. The yield and cholesterol content of this separated oil layer were measured.

The results are shown in Table 8 below.

[0067]

[Table 8]

Comparative Example 9 (Addition: Soap) 8 g of oleic acid was added to 200 g of corn oil, 10 ml of 20% sodium hydroxide was added with stirring, and the mixture was stirred with a homomixer at 10,000 rpm for 1 minute. Then, centrifugation was performed at 5,000 rpm for 5 minutes to separate the soap layer. The water content and fat content of this soap layer were 19.2% and 30.3%, respectively. 50 g of this soap layer was added to the cholesterol-containing oil / fat 200
g (cholesterol 4.13 mg / g), and the mixture was stirred with a homomixer at 10,000 rpm for 1 minute.
After centrifugation, the yield and cholesterol content of the oil layer were measured. As a control, cholesterol-containing oil (cholesterol 4.13 mg / g) 200 g, oleic acid 8 g,
10 ml of 20% sodium hydroxide was added, the mixture was stirred with a homomixer at 10,000 rpm, 25 ° C. for 1 minute, and after centrifugation, the yield of the oil layer and the cholesterol content were measured and compared. The results are shown in Table 9 below.

[0069]

[Table 9]

Comparative Example 10 (Addition: with soap and with fat
(Comparison of fatty acid + alkali aqueous solution) 100 g of rapeseed oil is heated to 120 ° C., and 50 ml of 50% sodium hydroxide solution is added. 120-130 ℃
Then, after boiling for 10 minutes, it becomes a viscous, semi-transparent liquid. After allowing to cool for a while, salting out with saturated saline forms a soap layer on the upper layer and an aqueous layer on the lower layer. This soap had a solid content of 80%, an oil content of 4%, and a water content of 16%. 50 g of this soap was added to 200 g of cholesterol-containing oil (cholesterol 4.03 mg / g),
The mixture was stirred with a homomixer at 10,000 rpm at 25 ° C. for 1 minute, and after centrifugation, the yield of the oil layer and the cholesterol content were measured.

As a control, 8 g of oleic acid and 10 ml of 20% sodium hydroxide were added to 200 g of cholesterol-containing oil (cholesterol 4.03 mg / g), and the mixture was mixed with a homomixer at 10,000 rpm at 25 ° C.
After stirring for 1 minute and centrifugation, the yield of the oil layer and the cholesterol content were measured and compared. The results are shown in Table 10.

[0072]

[Table 10]

As is clear from the results of Comparative Examples 8 to 10, the soap is not only produced in the cholesterol-containing fat and oil and stirred, but also the soap is added in advance to the cholesterol-containing fat and oil, and the mixture is stirred and separated. By doing
It is possible to obtain low-cholesterol oil and fat. If the soap already contains oil, only cholesterol can be removed with almost no loss of oil yield, and even if cholesterol is contained in the oil layer included in the soap layer, the effect of that effect can be obtained. It is clear that there is.

From the results of the above comparative examples, in terms of oil yield, it is better that the melting point of the free fatty acid to be added is lower and the treatment temperature is higher. Considering the removal of cholesterol, the free fatty acid to be added preferably has 12 or more carbon atoms, and the treatment temperature is preferably low. Further, if the soap layer and the oil layer can be rapidly and uniformly stirred, a shorter treatment time is more efficient. Therefore, the most effective overall effect such as oil yield, cholesterol removal, etc. is short-time stirring at low temperature using free fatty acids having 12 or more carbon atoms and being liquid at room temperature.

Example 1 Butter was dissolved and the cholesterol content was 2.29 mg / g.
200 g of oil layer was obtained. Add to this oleic acid 8g, 20
% Aqueous sodium hydroxide solution (10 ml),
After stirring at 00 rpm and 500 rpm for 2 minutes,
After centrifugation at 5,000 rpm for 5 minutes, 143 g and 169 g of oil layers were obtained, respectively. The cholesterol contents of this oil layer are 1.17 mg / g and 0.76 mg / g, respectively.
Met.

Example 2 Chicken egg yolk was added to 1,000 g of corn oil, vigorously stirred with a homogenizer at 15,000 rpm for 20 minutes, and then centrifuged at 5,000 rpm for 5 minutes to separate an yolk layer and an oil layer. , 1,200 g of an oil layer having a cholesterol content of 4.23 mg / g was obtained.

To 200 g of this oil, 8 g of oleic acid was added, and 10 ml of 20% sodium hydroxide solution was added while stirring at 10,000 rpm with a homomixer.

Then, after stirring at 25 ° C. for 1 minute, the resulting mixture was centrifuged at 5,000 rpm for 5 minutes to obtain an oil layer 159 having a cholesterol content of 0.92 mg / g.
g was obtained.

The soap layer generated at this time was again used for the original cholesterol-containing oil (cholesterol 4.23 mg / g).
Add to 200g, 10,000 rp with homomixer
m, 25 ° C., and stirred for 1 minute.

The resulting mixture was mixed at 5,000 rpm and 5
Centrifuge for 1 minute, cholesterol content 1.66mg /
178 g of oil layer was obtained.

The soap layer formed at this time was again used for the original cholesterol-containing oil (cholesterol 4.23 mg /
g) 200 g, and the same operation was performed to obtain 192 g of an oil layer having a cholesterol content of 2.00 mg / g.

Further, the same operation is performed once more,
192 g of an oil layer having a cholesterol content of 2.25 mg / g was obtained.

Example 3 Butter was dissolved and the cholesterol content was 1.94 mg / g.
200 g of oil layer was obtained. To this, 40 g of soap (oil content 30.3% by weight, water content 19.2%) prepared by adding oleic acid and sodium hydroxide to corn oil in advance was added, and after stirring at 10,000 rpm for 1 minute, 5,0
Centrifugation was performed at 00 rpm for 5 minutes to obtain 195 g of an oil layer. The cholesterol content of this oil layer is 1.06 mg /
It was g.

Example 4 20 g of a soap layer having a water content of 22.0% by weight, an oil and fat content of 28.5% by weight, and a cholesterol content of 7.04 mg / g.
Was added to 100 g of cholesterol-containing fats and oils (cholesterol 3.98 mg / g), and the mixture was stirred at 500 rpm for 15 minutes. After the mixture was centrifuged, the yield of the oil layer and the cholesterol content were measured. As a result, the yield was 96 g, and the cholesterol content was 1.03 mg / g.

[0085]

In the first aspect of the present invention, the free fatty acid is added to the oil layer in advance and sufficiently mixed and diffused, and the alkaline aqueous solution is gradually added with stirring to form a soap and make it uniform with the oil layer. When mixing, the oil droplets generated in the soap are atomized and homogenized, the soap and oil layer are rapidly mixed and homogenized, and the oil layer and the soap layer are rapidly separated and separated, resulting in the oil It is a method for removing cholesterol from cholesterol-containing fats and oils that does not reduce the yield, is simple, easy and efficient, and has no problems in terms of cost and safety and can be carried out on a factory scale.

In this case, the free fatty acid to be added is a long-chain fatty acid having a carbon number of 12 or more and a melting point of 60 ° C. or less and is liquid at room temperature. By sometimes lowering the temperature and shortening the processing time during the process, the yield of oil and the removal rate of cholesterol can be further improved.

On the other hand, the second invention of the present invention is basically the same as the first invention, but in the first invention, the free fatty acid is added to the oil layer in advance and sufficiently mixed and diffused, followed by stirring. However, instead of gradually adding the alkaline aqueous solution and uniformly mixing it with the oil layer while producing soap, in the second invention, an alkali metal salt of fatty acid, that is, soap, is added to cholesterol-containing fats and oils in advance. After stirring, by separating the soap and the oil layer,
It is possible to provide a method capable of removing cholesterol from a cholesterol-containing fat or oil as excellent as the first invention.

Furthermore, in the present invention, the separated and recovered oil layer is a low-cholesterol oil and fat, which can be used as a general edible oil and fat, while the separated and recovered soap layer is , Which can be used repeatedly in the present invention, can be added to cholesterol-containing fats and oils, and by repeating the same operation, a low-cholesterol fat or oil can be produced, so that there is no problem in terms of cost and safety, and at a factory scale. Can also be implemented.

Further, as described above, the soap layer repeatedly used contains a large amount of cholesterol and can be sufficiently used as an extraction source of cholesterol, and cholesterol can be separated and purified by the conventionally known cholesterol extraction method. It will be possible.

Claims (5)

[Claims] 1. A method for producing a low-cholesterol oil or fat, which comprises the following steps, ie, (a) adding a free fatty acid to a cholesterol-containing oil or fat and further adding an aqueous alkali solution and stirring the mixture to produce an alkali metal fatty acid. A first step of emulsifying salt, i.e. soap and oil layer, and (b)
A method for producing a low-cholesterol oil or fat, comprising the step of separating the mixture obtained in the first step into an oil layer and a soap layer, and collecting the oil layer, wherein the cholesterol-containing To fats and oils, free fatty acid is added in advance and sufficiently dispersed in the oil layer, and then an aqueous alkali solution is gradually added to the oil layer with stirring to form an alkali metal salt of fatty acid, so-called soap, and at the same time uniformly mixed with the oil layer and stirred. A method for producing a low-cholesterol oil or fat, comprising: 2. A method for producing a low-cholesterol oil or fat, which comprises the following steps, ie, (a) adding a free fatty acid to a cholesterol-containing oil or fat and further adding an alkaline aqueous solution and stirring the mixture to produce an alkali metal fatty acid. A first step of emulsifying salt, i.e. soap and oil layer, and (b)
A method for producing a low-cholesterol oil or fat, comprising the step of separating the mixture obtained in the first step into an oil layer and a soap layer, and collecting the oil layer, wherein the cholesterol-containing The method for producing a low-cholesterol oil or fat, wherein the free fatty acid added to the oil or fat is a long-chain fatty acid having a carbon chain of 12 or more and the melting point thereof is 60 ° C or less. 3. A method for producing a low-cholesterol oil or fat, comprising the following steps, namely, (a) a first step of adding an alkali metal salt of a fatty acid, ie, soap, to a cholesterol-containing oil or fat and stirring the mixture to emulsify it. , (B) a second step of separating the mixture obtained in the first step into an oil layer and a soap layer, and separating the oil layer, the method for producing a low-cholesterol oil or fat. 4. The cholesterol-containing fat or oil is kept at a low temperature in the first step within a range in which the oil layer remains liquid and can be separated from the soap layer. Method for producing low-cholesterol oils and fats. 5. The method for producing a low-cholesterol oil or fat according to claim 3, wherein the alkali metal salt of fatty acid contains cholesterol.