JP2001131197A - Method for producing plant sterol - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a plant sterol having a high purity from a crude fatty acid ester derived from a vegetable oil and fat by a simple treatment. SOLUTION: This method for producing the plant sterol from the crude fatty acid ester derived from the vegetable oil and fat containing the plant sterol comprises a step for holding a mixture of the crude fatty acid ester and a lower alcohol at 1-40 deg.C to precipitate a crystal containing the fatty acid ester, and separating the crystal from the lower alcohol solution containing the plant sterol and/or the fatty acid ester thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing plant sterols from crude fatty acid esters derived from vegetable oils and fats.

[0002]

BACKGROUND OF THE INVENTION Plant sterols are used not only for clinical administration, etc., which are expected to reduce blood cholesterol, but also as raw materials for pharmaceuticals as cholesterol substitutes, or as emulsifiers and emulsion stabilizers. Commonly used in cosmetics and food.

[0003] As a method for producing plant sterols, soybean oil,
A method of extracting and purifying sterols contained in vegetable oils such as rapeseed oil, rice bran oil, palm oil, palm kernel oil, and coconut oil from deodorized concentrates has been put to practical use. As an extraction method, a lower alcohol is added to the deodorized distillate of fats and oils, esterification is performed with an acid catalyst, and then the catalyst is removed by washing with water.
A method is known in which a lower alcohol and an alkali catalyst are newly added to carry out a transesterification reaction, the reaction-terminated liquid is allowed to stand overnight, the precipitated crystals are separated by filtration, washed with a small amount of hexane, and then recrystallized. (Japanese Patent Publication No. 52-830)
No. 9).

In this method, it is necessary to repeat recrystallization in order to obtain a sterol having a high purity, and it has been difficult to obtain a plant sterol having a high purity more easily.

An object of the present invention is to provide a method for producing high-purity plant sterols from crude fatty acid esters derived from vegetable oils and fats by a simple treatment.

[0006]

SUMMARY OF THE INVENTION The present invention provides a method for producing a plant sterol from a crude fatty acid ester derived from vegetable fats and oils containing a plant sterol, wherein a mixture of the crude fatty acid ester and a lower alcohol is heated to 1 to 40 ° C. A method for producing a plant sterol, comprising a step of holding and precipitating a crystal containing a fatty acid ester to separate the crystal from a plant sterol and / or a lower alcohol solution containing the fatty acid ester.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, plant sterols refer to sterols contained in vegetable oils and fats, such as sitosterol, stigmasterol, campesterol, brassicasterol, etc., which are collectively called phytosterols. Is what it is.

[0008] The vegetable oils and fats used herein include one or a mixture of two or more of soybean oil, rapeseed oil, rice bran oil, palm oil, palm kernel oil, coconut oil and the like. Oil and palm oil are preferred.

The crude fatty acid ester derived from vegetable oils in the present invention is mainly a mixture of various compounds including an ester of a higher fatty acid and a lower alcohol, particularly an ester of a fatty acid having 6 to 28 carbon atoms and a lower alcohol. It is preferably used. The composition varies depending on the difference between the vegetable oils and fats as raw materials and cannot be specified. However, the composition may contain monoglyceride, diglyceride, triglyceride, glycerin and the like. That is, it is not particularly limited as long as it contains a fatty acid ester and a plant sterol. For example, a crude fatty acid ester obtained by esterifying the above-mentioned deodorized distillate of vegetable oils and fats and then performing a transesterification reaction with a lower alcohol, if necessary, or a fatty acid ester thereof is disclosed in JP-A-8-500988. Distillation according to the technique described in
A raw material in which a part of the fatty acid ester formed by the transesterification reaction is distilled off to increase the plant sterol concentration can be used.

[0010] Alternatively, it is possible to increase the concentration of plant sterols by esterifying the above vegetable oils and fats, followed by a transesterification reaction with a lower alcohol, and distilling the obtained fatty acid ester to remove a low fraction. It is possible, and raw materials thus concentrated may also be used. This concentrate contains unreacted monoglycerides, diglycerides, and triglycerides that have not reacted in the previous transesterification reaction, in addition to the plant sterols and fatty acid esters, but crude fatty acid esters obtained by further transesterification of these may also be used. is there.

Generally, these raw materials contain 6 to 28 carbon atoms.
In many cases, an ester of a fatty acid and a lower alcohol is contained in an amount of 20% by weight or more. In the present invention, it is preferable to use a fatty acid ester having such a concentration.

In the present invention, any one of a straight-chain or branched-chain, saturated or unsaturated, or a mixture of two or more fatty acids can be used as the fatty acid. Examples of the lower alcohol include alcohols having 1 to 4 carbon atoms, specifically, methanol, ethanol, isopropanol, n-propanol, linear or branched butanol, and a mixture of one or more of these. Can be used.
Of these, methanol, ethanol or a mixture thereof is preferred, and those containing methanol are particularly preferred.

The content of the plant sterol in the crude fatty acid ester used in the present invention is not particularly limited.
It is preferably at least 1% by weight (based on the mixture excluding the lower alcohol), and more preferably 3 to 40% by weight in order to achieve the effects of the present invention.

The mixture of the crude fatty acid ester and the lower alcohol is adjusted so that the lower alcohol content is preferably 2% by weight or more, more preferably 20 to 300% by weight, based on the thus obtained crude fatty acid ester. In that case,
Lower alcohol may be newly added, or
If the lower alcohol remaining in the esterification step or transesterification step in the previous step is already left in the reaction system in a desired amount with respect to the crude fatty acid ester, it is not necessary to further add the lower alcohol. In short, the existence of a lower alcohol is required, and any means can be used.

In the present invention, the mixture containing the crude fatty acid ester and the lower alcohol prepared as described above
Hold at 4040 ° C. to precipitate crystals. The crystals precipitated here are mainly composed of an ester of a fatty acid having 6 to 28 carbon atoms and a lower alcohol, and this crystal contains almost no plant sterol. That is, plant sterol exists as a liquid component.

In the present invention, the retained crystallization temperature is very important. Esters of fatty acids having 6 to 28 carbon atoms and lower alcohols start crystal precipitation at 50 ° C or lower, but when the crystal precipitation temperature is high, the amount of precipitation is not sufficient, and the contribution of improving the purity of plant sterols is reduced, and , The purity of the plant sterol after the subsequent crystallization is reduced. On the other hand, if the cooling temperature is too low, plant sterols are mixed into the precipitated crystals, and the recovery of plant sterols decreases. Therefore, the crystallization temperature is controlled at 1 to 40 ° C, preferably 3 to 20 ° C. The time for maintaining the temperature at 1 to 40 ° C is preferably 0.1 to 2 hours.

In the present invention, the precipitated crystals are further filtered,
By separating from the system by a known method such as centrifugation or decantation, the purity of the plant sterol after the crystallization treatment performed on the remaining liquid can be significantly improved. That is, a known solvent purification method, that is, a crystallization method, is applied to the liquid after separating the precipitated crystals. The solvent at this time is not particularly limited. For example, methanol,
Methyl ethyl ketone, ethanol and the like can be used, but methanol is particularly preferred.

[0018]

EXAMPLES The percentages in the examples are percentages by weight unless otherwise specified.

Example 1 5,000 g of a fatty acid methyl ester derived from palm kernel oil was distilled to obtain 4,900 g of a distillate and 100 g of a residue. In this residue,
100 g of methanol and 1.0 g of potassium hydroxide were added, and transesterification was performed for 2 hours under reflux of methanol. The obtained crude fatty acid methyl ester contained 68% of a methyl ester of a fatty acid having 6 to 28 carbon atoms and 5.7% of plant sterol (all in proportion to the oil content excluding methanol). Unreacted methanol remained 90% of the crude fatty acid methyl ester as an oil component.

The reaction solution containing methanol is heated at 10 ° C. for 0.5
Hold for a time to precipitate crystals, and filter the crystals (filtration temperature 10
° C). The amount of crystals removed at this time was 3.0 g after drying at 110 ° C. for 12 hours, containing 95% of a methyl ester of a fatty acid having 6 to 28 carbon atoms, and almost containing plant sterols. I didn't.

An aqueous hydrochloric acid solution is added to the filtrate obtained by filtration.
H was added so that it might be set to 5-7, and neutralization was performed. afterwards,
The solution was kept at 5 ° C. to precipitate crystals again. 100 g of methanol was added to the crystals, recrystallization was performed at 5 ° C., and the crystals were dried in air at 110 ° C. for 12 hours. The obtained dried product was 1.84 g, and the purity of the plant sterol by gas chromatography (column: ULTRA1 manufactured by Hewlett-Packard Co.) was 82% (27% recovery of the plant sterol based on the raw material).

Comparative Example 1 The crude fatty acid methyl ester containing methanol after transesterification in Example 1 was not subjected to crystallization and filtration at 10 ° C. as in Example 1, but the pH was directly adjusted to 5 using an aqueous hydrochloric acid solution. Neutralization was performed so as to be ~ 7. Thereafter, the liquid was kept at 5 ° C. to precipitate crystals. 100 g of methanol was added to the crystal and recrystallized at 5 ° C.
Dried in air for hours. The obtained dried product was 3.48 g, and the purity of the plant sterol by gas chromatography was 43% (the recovery of the plant sterol relative to the raw material was 27%).

Comparative Example 2 The reaction solution containing methanol after transesterification of Example 1 was used.
The crystals were kept at 45 ° C. for 0.5 hour to precipitate crystals, and the crystals were separated and removed by filtration (filtration temperature: 45 ° C.). The amount of crystals removed at this time is 0.1 g after drying at 110 ° C. for 12 hours, which contains 99% of methyl esters of fatty acids having 6 to 28 carbon atoms and contains almost no plant sterols. Did not.

An aqueous hydrochloric acid solution is added to the filtrate obtained by filtration.
H was added so that it might be set to 5-7, and neutralization was performed. afterwards,
The solution was kept at 5 ° C. to precipitate crystals again. 100 g of methanol was added to the crystal and recrystallized at 5 ° C.
The crystals were dried in air at 110 ° C. for 12 hours. The obtained dried product was 3.47 g, and the purity of the plant sterol by gas chromatography was 44% (the recovery of the plant sterol relative to the raw material was 27%).

As can be seen from the examples and comparative examples, high purity phytosterols can be obtained by using the production method of the present invention without changing the recovery rate.

[0026]

According to the method of the present invention, crystals of fatty acid esters are precipitated from crude fatty acid esters with high selectivity,
The plant sterol can be separated and removed from the plant sterol-containing liquid, and a plant sterol with significantly improved purity can be obtained without adversely affecting the yield after crystallization.

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Masamitsu Horio 1334 Minato, Wakayama, Wakayama Pref.

Claims (5)

[Claims] 1. A method for producing a plant sterol from a crude fatty acid ester derived from vegetable fats and oils containing a plant sterol, comprising maintaining a mixture of the crude fatty acid ester and a lower alcohol at 1 to 40 ° C. and containing the fatty acid ester. A method for producing a plant sterol, comprising a step of precipitating a crystal and separating the crystal from a lower alcohol solution containing a plant sterol and / or a fatty acid ester thereof. 2. The method according to claim 1, wherein the content of the plant sterol in the crude fatty acid ester is 1% by weight or more. 3. The method according to claim 1, wherein the crude fatty acid ester contains at least 20% by weight of an ester of a fatty acid having 6 to 28 carbon atoms and a lower alcohol. 4. The method according to claim 1, wherein the content of the lower alcohol is 2% by weight or more based on the crude fatty acid ester. 5. The method according to claim 1, wherein the vegetable oil is palm kernel oil, coconut oil or palm oil.