KR100384368B1 - Method for Preparing Conjugated Linoleic Acid Composition - Google Patents

Abstract

The present invention relates to a process for preparing conjugated linoleic acid compositions from linoleic acid or linoleic acid containing fats and oils. The present invention is prepared by adding linoleic acid or linoleic acid-containing fats and oils to an alkali-glycerol mixture, followed by isomerization by heating under anaerobic conditions, and a method for preparing a conjugated linoleic acid composition, which is prepared by the electrical method. To a conjugated linoleic acid composition.

According to the production method of the present invention, there is no safety hazard by the process additives, and the color value of the preparation is kept low, so that an edible conjugated linoleic acid composition can be produced easily and economically through a simple process. The conjugated linoleic acid composition produced through the production method of will be usefully used as food additives and feed additives.

Description

Method for Preparing Conjugated Linoleic Acid Composition

The present invention relates to a process for preparing conjugated linoleic acid compositions from linoleic acid or linoleic acid containing fats and oils. More specifically, the present invention relates to a method for preparing a conjugated linoleic acid composition comprising adding linoleic acid or linoleic acid-containing fat or oil to an alkali-glycerol mixed solution, and then heating and isomerizing the reaction under anaerobic conditions. It is about.

Linoleic acid is a C18 fatty acid with double bonds in cis-9 and cis-12 arrays, and conjugated linoleic acid (CLA) is linol with conjugated double bonds in cis or trans configuration. Isomers of rainic acid are generic.

CLA is synthesized in small amounts from linoleic acid by Butyrivibrio fibrisolvens , an anaerobic bacterium that lives in the rumen of a mammal, and is used in foods such as milk, cheese, and beef produced from animals with electric rumen. It is contained. The physiological effects of CLA reported so far include anti-cancer effects (Clement I., Am. J. Clin. Nutr . 66 (Suppl.): 1523, 1997), anti-allergic effects (Cook et al, US patents). No. 5,585,400), immunopotentiating effect (see Cook et al, US Pat. No. 5,674,901, US Pat. No. 5,430,066), cholesterol reducing effect (Nicolosi et al, Circulation 88 (suppl.): 2458, 1993, Lee et al, Atherosclerosis 108: 19, 1994). In addition to these medical effects, nutritional effects include body fat reduction and body protein increase (Cook et al., US Pat. No. 5,554,646), growth promotion and feed conversion improvement (see : Cook et al, U.S. Patent No. 5,478,072) and the like have been reported, the application of food and feed additives in order to utilize these physiological activities are being actively conducted.

Meanwhile, the CLA preparation method reported so far is a method for producing conjugated linoleic acid from linoleic acid using linoleic acid isomerase derived from chemical synthesis and microorganisms (Paiza, et al., US patent) 5,208,356, U.S. Patent 5,856,149. The method for producing conjugated linoleic acid using an enzyme derived from microorganisms takes a long time in the manufacturing process and has disadvantages that are inadequate for mass production. The production of conjugated linoleic acid mainly by chemical synthesis is mainly used. .

Conventional chemical synthesis of conjugated linoleic acid is mainly carried out by heating ethylene glycol containing mainly alkali, and then adding linoleic acid or linoleic acid-containing fat or oil to isomerize at 180 ° C. for at least 2 hours, acid treatment, solvent extraction, Through a process such as vacuum drying (Cook et al., US Pat. No. 5,554,646). Since the above method uses ethylene glycol, which is highly toxic and cannot be used in food processing, it is necessary to completely remove the remaining organic solvents, which requires several washings and a long time distillation process. The CLA produced by the method has a turbid yellow or brown color, and thus must be subjected to an impurity removal process. This implies that the economy is poor due to the complicated manufacturing process and the resulting cost increase effect.

In order to overcome the above disadvantages, a food CLA manufacturing process using propylene glycol, which has little toxicity compared to ethylene glycol, has been reported (Iwata et al, US Pat. No. 5,986,116). Although the former method does not use toxic solvents and has a light color of the manufactured product, propylene glycol is also listed as a food additive orbit, but the use standard is limited to 2% or less, which is not suitable for the economical food CLA manufacturing process. . In addition, the boiling point of propylene glycol is relatively low, which implies that the reaction temperature cannot be higher than 180 ° C. at normal pressure.

Therefore, there is a need to develop a new method for preparing conjugated linoleic acid that can solve the above problems and can be safely used for food and feed additives even with a simple process.

Accordingly, the present inventors made intensive studies to develop a method for preparing conjugated linoleic acid that can be used safely for food, and added linoleic acid or linoleic acid-containing fat or oil to an alkali-glycerol mixture, and then under anaerobic conditions. The conjugated linoleic acid composition was prepared through a process of isomerizing by heating to obtain a conjugated linoleic acid composition suitable for use as a food product using a solvent having a light color of the final reaction product and which is not toxic to the reaction process. It was confirmed that a simple process can be easily and economically produced, the present invention was completed.

After all, the main object of the present invention is to add a linoleic acid or linoleic acid-containing fats and oils to the alkali-glycerol mixed solution, and then to heat the isomerized reaction under anaerobic conditions to prepare a conjugated linoleic acid composition. To provide.

Another object of the present invention is to provide a conjugated linoleic acid composition produced through the electrical method.

1 is a graph showing the conversion rate of the conjugated linoleic acid composition of the present invention according to the reaction temperature and the reaction solvent.

2 is a graph showing the conversion rate of the conjugated linoleic acid composition of the present invention according to linoleic acid-containing fats and oils.

The present invention provides a process for preparing a conjugated linoleic acid composition from linoleic acid or linoleic acid containing fats and oils.

The inventors of the present invention show that glycerol is not toxic as a reaction solvent, and as a food additive orbital item, there is no particular limitation on its use or residual acceptance criteria, and it has excellent alkali solubility and a high boiling point of 290 ° C. to control the reaction temperature. In addition to providing flexibility, glycerol is produced as a reaction by-product of the alkali isomerization reaction, and when glycerol is used as the solvent for the alkali isomerization reaction, separation and purification of the solvent after the reaction are simplified, and the separated glycerol is added to the reaction again. In view of the fact that the amount of use can be reduced, conjugated linoleic acid produced by the conventional manufacturing method was selected as a new solvent of the isomerization reaction to overcome the disadvantage that can not be used for food.

Hereinafter, the present invention will be described in more detail.

The present invention prepares a conjugated linoleic acid composition by adding linoleic acid or linoleic acid-containing fat or oil to an alkali-glycerol mixture, followed by isomerization by heating under anaerobic conditions: wherein the alkali is sodium hydroxide. , Potassium hydroxide, calcium hydroxide and cesium hydroxide, one or more selected from the group consisting of 1 to 40% (w / w) of the total alkali-glycerol mixed solution is preferably used, linoleic acid-containing fats and oils are safflower oil, One or more selected from the group consisting of sunflower oil, soybean oil, corn oil and cottonseed oil may be used as 20 to 70% (w / w) of the total reactants, and the isomerization reaction is performed at 170 to 250 ° C.

Hereinafter, the present invention will be described in more detail with reference to Examples. These examples are only to specifically describe the present invention, it will be apparent to those skilled in the art that the scope of the present invention is not limited by these examples.

Example 1: Preparation of conjugated linoleic acid composition (I)

31 g of potassium hydroxide was added to the 500 ml flask to which 125 g of glycerol was added in nitrogen atmosphere, and the reaction liquid was stirred vigorously, increasing temperature to 150 degreeC. Then, 100 g of refined soybean oil was slowly added thereto, and the temperature was raised again to 180 ° C. and the stirring was continued. After the reaction was completed, the reaction mixture was cooled to 100 ° C. or lower, 100 g of water was added thereto, and then 48 g of HCl aqueous solution was added thereto, followed by reaction for 1 hour to adjust the pH to 3. After the reaction was completed, the reaction solution was extracted twice with 50 mL of hexane, the organic solvent layer was washed three times with water, and then concentrated to dryness to obtain a CLA composition (I) in the form of free fatty acid.

Example 2: Preparation of conjugated linoleic acid composition (II)

A CLA composition (II) was obtained in the same manner as in Example 1, except that the reaction temperature was set at 200 ° C.

Example 3: Preparation of conjugated linoleic acid composition (III)

A CLA composition (III) was obtained in the same manner as in Example 1, except that the reaction temperature was 210 ° C.

Example 4: Preparation of conjugated linoleic acid composition (IV)

A CLA composition (IV) was obtained in the same manner as in Example 1, except that the reaction temperature was 230 ° C.

Comparative Example 1: Preparation of conjugated linoleic acid composition (V)

Conjugated linoleic acid composition (V) in the same manner as in Example 1, except that ethylene glycol was used as the isomerization reaction solvent in order to compare the preparation method of the present invention with the conventional method for preparing the conjugated linoleic acid composition. Was prepared.

Comparative Example 2: Preparation of conjugated linoleic acid composition (VI)

Conjugated linoleic acid composition (VI) in the same manner as in Example 1, except that propylene glycol was used as the isomerization reaction solvent in order to compare the preparation method of the present invention with the conventional method for preparing the conjugated linoleic acid composition. Was prepared.

Experimental Example 1: Conversion rate of conjugated linoleic acid composition

In order to confirm the conversion rate according to the isomerization reaction time of the conjugated linoleic acid prepared in Examples and Comparative Examples, 5 ml of the reaction solution was collected at an hourly interval from the end of soybean oil addition, and added to a 100 ml flask. Distilled water and 2 ml of 6N HCl aqueous solution were added, the mixture was stirred at a temperature of 60 to 70 ° C. for about 1 hour, and left to stand, 0.25 ml of the supernatant oil was added to a 15 ml cap tube, and 4 ml of 2% sulfuric acid-methanol solution was added thereto. . The electric cap tube was reacted with stirring in a constant temperature water bath at 60 ° C. After two hours, the cap tube was taken out, and 2 ml of distilled water was added thereto, and 4 ml of hexane was added thereto, followed by shaking. When the layers are separated, remove the water layer, add 2 ml of distilled water to the organic layer, shake the mixture, and then stand still and repeat the same process once more. Take an organic layer, shake it with a small amount of anhydrous magnesium sulfate, leave it to stand, add 1 ml to an Eppendorf tube, and take 1 μl of the supernatant obtained by centrifugation at 3000 rpm for 5 seconds to obtain GC (gas chromatography; SUPELCOWAXTM-10). A fused silica capillary column (60 m × 0.32 mm × 0.25 μm film thickness), HP5890, Hewlett Packard, USA) was injected. The detector is a flame ionization detector (FID) and the carrier gas is nitrogen. The oven temperature program is first maintained at 170 ° C. for 1 minute, then heated to 230 ° C. at 1.5 ° C. per minute and lasted for 3 minutes at this temperature. Hourly conversion was obtained from the reduction of the linoleic acid peak area ratio in the chromatogram. Table 1 and Figure 1 shows the conversion rate according to the reaction time of each of the conjugated linoleic acid prepared in Examples and Comparative Examples.

As shown in Table 1 and Figure 1, when the reaction temperature is adjusted to 200 ℃ or more by using glycerol as a reaction solvent, it shows a conversion rate equal to or higher than the conventional method difficult to increase the reaction temperature at more than 190 ℃ at normal pressure Could know. That is, the reaction solvent glycerol of the present invention shows a high conversion even in a short reaction time due to the temperature flexibility, it can be confirmed that the reaction solvent in the conventional conjugated linoleic acid production method is more efficient.

Experimental Example 2: content ratio and absorbance of conjugated linoleic acid composition

10 hour reaction sample of Example 1, 6 hour reaction sample of Example 2, 3 hour reaction sample of Example 3, 4 hour reaction sample of Comparative Example 1, 4 hour reaction of Example 1 Gas chromatography was performed on the samples in the same manner as in Experimental Example 1. In the resulting chromatogram, the content of the conjugated linoleic acid component and the isomer ratio in the total composition were calculated from the peak area ratio of the conjugated linoleic acid isomer. In addition, absorbances were measured for the conjugated linoleic acid compositions prepared in the above Examples and Comparative Examples, respectively. The absorbance was measured at a wavelength of 420 nm using an ultraviolet-visible spectrophotometer (UV-1601 UV-VISIBLE Spectrophotometer, Shimadzu, Japan). Table 2 shows the total content of the two major isomers c9, t11-CLA and t10, c12-CLA, the ratio between the two isomers and the absorbance of the electrical composition among the CLA compositions prepared in each of Examples and Comparative Examples.

As shown in Table 2, the CLA composition obtained through the production method of the present invention using glycerol as the reaction solvent is similar to the CLA content obtained through the conventional production method, while the ratio between the isomers is t10, The c12 isomer showed a relatively increased result compared to the c9, t11 isomer, it was confirmed that the selectivity for the t10, c12 isomer is high. In addition, the content of other isomers other than the two main isomers was less than 2% in all preparation methods.

Since CLA must be low in color for food use, the absorbance of each CLA composition was measured at 420 nm in order to confirm the chromaticity of the CLA composition prepared from the previous and comparative examples (Table 2). As shown in Table 2, the CLA composition prepared by the preparation method of the present invention exhibited low absorbance compared to the process using ethylene glycol as the reaction solvent, and showed similar absorbance to the process using propylene glycol as the reaction solvent. . From the above results, it was confirmed that the CLA composition obtained through the production method of the present invention is suitable for use as a food.

Example 5: Preparation of conjugated linoleic acid composition

Corn oil was used as linoleic acid-containing fats and oils, and the reaction was carried out in the same manner as in Example 1, except that the reaction temperature was set at 200 ° C. to obtain a CLA composition.

Example 6: Preparation of conjugated linoleic acid composition

Sunflower oil was used as linoleic acid-containing fats and oils, and the reaction was carried out in the same manner as in Example 1 except that the reaction temperature was set at 200 ° C. to obtain a CLA composition (iii).

Example 7: Preparation of conjugated linoleic acid composition

A CLA composition was obtained in the same manner as in Example 1, except that safflower oil was used as a linoleic acid-containing fat and oil, and the reaction temperature was set at 200 ° C.

Example 8: Preparation of conjugated linoleic acid composition

A CLA composition was obtained in the same manner as in Example 1, except that safflower oil was used as linoleic acid-containing fat and oil, 38 g of potassium hydroxide as an alkali, and the reaction temperature was set at 200 ° C.

Experimental Example 3: Conversion Rate of Conjugated Linoleic Acid Composition

The conversion rate of the CLA composition prepared in Examples 5 to 8 was measured in the same manner as in Experimental Example 1 (FIG. 2). As shown in Figure 2, it was confirmed that the production method of the present invention using glycerol as a reaction solvent can be applied to any of the linoleic acid-containing fats and oils. In addition, the total isomer content and composition ratio of the CLA compositions prepared in Examples 5 to 8 were measured in the same manner as in Experimental Example 2, and are shown in Table 3.

As shown in Table 3, in the preparation method of the present invention, any effect of linoleic acid-containing fats and oils may be used to determine the effects of the same on the total content and composition ratio of the t10, c12 and c9, t11-CLA isomers. there was.

Therefore, when using the preparation method of the present invention using glycerol as the isomerization reaction solvent, the conversion rate and the total content of t10, c12 and c9, t11-CLA isomers are similar or increased, compared to the conventional CLA preparation method. The composition ratio was confirmed to have improved selectivity for the isomers, and because there was no risk because the reaction solvent used as food, it would be useful as a food additive and a feed additive.

As described and demonstrated in detail above, the present invention provides a process for adding a linoleic acid or linoleic acid-containing fat or oil to an alkali-glycerol mixture, followed by isomerization by heating under anaerobic conditions. It provides a manufacturing method. According to the preparation method of the present invention, due to the temperature flexibility of the reaction solvent exhibits a high conversion rate even in a short reaction time, there is no safety hazard by the process additives, the color value of the preparation is kept edible, edible conjugated linoleic acid composition Since it can be easily and economically prepared through a simple process, the conjugated linoleic acid composition produced through the production method of the present invention will be usefully used as food additives and feed additives.

Claims (7)

In the method for preparing a conjugated linoleic acid composition in which linoleic acid or linoleic acid-containing fat or oil is added to an alkali-solvent mixture and then heated under anaerobic conditions to induce an isomerization reaction, the solvent in the alkali-solvent mixture is A method for producing a conjugated linoleic acid composition, characterized in that the glycerol is 80% or more. The method of claim 1, The alkali is at least one selected from the group consisting of sodium hydroxide, potassium hydroxide, calcium hydroxide and cesium hydroxide, characterized in that it is used by adding 1 to 40% (w / w) of the alkali-solvent mixture. Process for the preparation of conjugated linoleic acid composition. The method of claim 1, Linoleic acid-containing fat or oil is one or more fats and oils selected from the group consisting of safflower oil, sunflower oil, corn oil, soybean oil and cottonseed oil, characterized in that used in addition to 20 to 70% (w / w) of the total reactants Process for the preparation of conjugated linoleic acid composition. The method of claim 1, Isomerization reaction is characterized in that carried out at 170 to 250 ℃ Process for the preparation of conjugated linoleic acid composition. A conjugated linoleic acid composition prepared by the method of claim 1. Food containing the conjugated linoleic acid composition of claim 5. A feed additive containing the conjugated linoleic acid composition of claim 5.