JPS6157310B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a method for producing high-purity tocopherol, and more particularly to a method for producing high-purity tocopherol using supercritical carbon dioxide gas.

Prior Art Tocopherol is a substance that exists in many vegetable oils and has the physiological activity and antioxidant ability of vitamin E, and is composed of homologues such as α, β, γ, δ, and ξ.
Conventionally, natural products such as soybean scum oil and wheat germ oil are extracted using solvents, molecular distillation, ion exchange resin treatment,
It was separated and purified through operations such as crystallization. However, although it is relatively easy to separate fatty acids and glycerides in raw materials using such conventional methods, the separation coefficient of tocopherols/sterols in raw materials is small, and it is difficult to increase the purity of separated tocopherols, which are the target substances. It was difficult. When molecular distillation is repeated to increase the purity of purified tocopherols, there is a problem in that the residence time in the high-temperature zone increases, resulting in thermal deterioration of the product. Therefore, with conventional methods, the purity of purified tocopherol products is up to approximately 60~
It was only about 80%.

OBJECT OF THE INVENTION Accordingly, an object of the present invention is to eliminate the drawbacks of the prior art described above and to provide a method for producing tocopherols of high purity (for example, purity of 80% or more).

Structure of the Invention The method for producing high-purity tocopherol according to the present invention comprises contacting a tocopherol-containing raw material or a crude product thereof with supercritical carbon dioxide gas to extract tocopherol.

Specific Description of Structure and Effects of the Invention The method for producing high purity tocopherol according to the present invention will be described in more detail below.

In order to solve the problems of the above-mentioned tocopherol purification method, the present inventors have carried out intensive studies on separation and purification using liquid chromatography, extraction and purification using various media, and separation and purification using adsorbents. We have discovered that highly purified tocopherols can be extracted from tocopherol-containing substances by using carbon dioxide gas in a supercritical state.

That is, according to the present invention, the critical pressure (Pc=
72.8ata) and supercritical carbon dioxide gas exceeding the critical temperature (Tc=31℃), preferably at a pressure of more than 72.8ata~
Tocopherol-rich components are efficiently removed by contacting supercritical carbon dioxide gas at a pressure of 500 ata and a temperature of more than 31 to 90 degrees Celsius, more preferably a pressure of 100 to 300 ata and a temperature of 35 to 75 degrees Celsius, with a tocopherol-containing raw material or its crude product. It can be easily extracted into supercritical carbon dioxide gas, and sterols and glycerides can be left in the stock solution to effectively concentrate tocopherols. In addition, in the case of extraction using normal liquefied carbon dioxide that does not reach a supercritical state, the amount of tocopherol extracted per unit weight of carbon dioxide is more than an order of magnitude smaller than in the case of a supercritical state, and it is difficult to achieve this industrially. .

Extraction of tocopherols from tocopherol-containing raw materials or their crude products using supercritical carbon dioxide gas is as follows:
It can be carried out using any conventionally used extraction equipment, such as various countercurrent or cocurrent contact equipment such as a mixer-settler, plate tower, or packed tower, and uses carbon dioxide gas in a supercritical state. Other than that, there is no difference from the conventional extraction operation. Further, either continuous processing or batch processing can be employed.

The tocopherol-rich components extracted into the supercritical carbon dioxide phase as described above are first reduced in solubility in carbon dioxide by reducing the pressure or changing the temperature of the supercritical carbon dioxide extracted from the extraction device. , the extracted tocopherol-rich liquid phase and carbon dioxide gas are separated using a suitable gas-liquid separator to recover high-purity (generally 70-90%) tocopherols, and the carbon dioxide gas is re-added using, for example, a compressor. It can be pressed and recycled again as a tocopherol extraction medium.

In this way, according to the method of the present invention, it is possible to produce high-purity tocopherols at a high yield without thermal deterioration of the product, and since the extraction medium used is carbon dioxide, There is no need to use organic solvents that are harmful to the human body and pollute the environment, as in the above, and there is no problem with the toxicity of residual solvents in the obtained products.

In the method of the present invention, tocopherols can be extracted with high purity by directly using natural products such as soybean scum oil and wheat germ oil, which have been commonly used in the production of tocopherols, or by using conventional methods. Therefore, the tocopherol crude product can be concentrated to a purity of about 60 to 70%, extracted with supercritical carbon dioxide gas by the method of the present invention, and further purified to obtain highly pure tocopherol. Further, the high purity tocopherol produced by the method of the present invention can be further purified by a molecular distillation method or the like to increase its purity. The extraction residue obtained by extracting tocopherol according to the method of the present invention can be mixed with the raw material tocopherol and used again, or mixed in a pretreatment or tocopherol rough purification step and recycled as an extraction stock solution.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but it goes without saying that the technical scope of the present invention is not limited to these Examples. In the following examples, "%" means "% by weight" unless otherwise specified.

Example 1 Crude tocopherol with a purity of 55.3% obtained from deodorized soybean scum by known solvent extraction and molecular distillation (composition: tocopherol 55.3%, sterol 40.2
%, squalene 2.5%, glyceride 1.4%, fatty acids and their esters 0.6%) were fed at a feeding rate of 10 kg/hr from the top of a packed column (packing material: 6 mm DIXON packing) with a column diameter of 100 mm and a packing height of 1000 mm. Supercritical carbon dioxide gas at a pressure of 250 atm and a temperature of 60° C. was supplied from the bottom at a supply rate of 80 kg/hr to bring the crude tocopherol and supercritical carbon dioxide into countercurrent contact in the packed column. During this period, hot water was circulated in the packed tower through a jacket provided around the main body of the tower to maintain the temperature inside the tower at 60°C.

As a result, tocopherol with a purity of 80.8% was extracted at a rate of 1.2 kg/hr into the carbon dioxide gas flowing out from the top of the tower.

Comparative Example 1 In Example 1, a crude tocopherol purification experiment was carried out using liquefied carbon dioxide at a pressure of 59 Kg/cm ² G and a temperature of 22°C instead of supercritical carbon dioxide, but tocopherol with a purity of 76.0% was obtained at 80 g/hr All I could get was that.

Example 2 Soybean scum oil containing 15% tocopherols (15% tocopherols, 22% fatty acids and their esters, 18% sterols, 6% squalene, 39% glycerides)
%) using the same equipment as Example 1 at 220Kg/cm ² G and 58℃.
When treated, the tocopherol content was 16%,
Crude tocopherol with a sterol content of 6% and almost no glyceride was obtained at a rate of 1.1 Kg/hr. However, at this time, the feed rates of raw materials and CO ₂ were the same as in Example 1. By subjecting the obtained crude tocopherol to molecular distillation, purified tocopherol with a purity of 68% could be obtained.

Claims (1)

[Claims] 1. A method for producing high-purity tocopherols, which comprises bringing a tocopherol-containing raw material or a crude product thereof into contact with supercritical carbon dioxide gas to extract tocopherols.