JP2012240991A - Method for producing concentrated carotene - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing carotene capable of recovering carotene in high yield from ester containing carotene, which is obtained by alcoholysis of oil-and-fat containing carotene with a lower monoalcohol, and suppressing deterioration of the filler used in chromatography at minimum.SOLUTION: The concentrated carotene is obtained by mixing the carotene-containing ester with a mixed solvent having an adjusted composition ratio (in mass) of hydrophilic solvent:water of 80:20-60:40, and stationarily separating it in heated conditions, the water soluble contaminant contained in the ester containing carotene can be removed, the carotene can be recovered in a high yield, and the deterioration of the filler for the chromatographic column can be suppressed.

Description

  The present invention relates to a production method capable of realizing a high recovery rate of a carotene concentrate.

  Carotene, which is a fat-soluble pigment of yellow terpenoids, is contained in vegetable oils and the like, is widely used as a natural colorant, and also has a function as a vitamin A precursor. Various methods have been proposed for recovering carote from natural fats and oils.

Prior Document 1 discloses a production method in which a fat and oil containing carotene is alcoholicized with a lower monoalcohol to produce an ester containing carotene, and then the ester is removed to obtain a carotene concentrate.
However, water-soluble impurities such as unreacted substances and impurities are also concentrated, and there are problems such as a reduction in the recovery rate of carotene and promotion of deterioration of the filler when purifying and separating carotene in the column chromatography step.

Prior Document 2 discloses a method of subjecting the resulting ester to alcoholysis, subjecting the resulting ester to vacuum distillation, recrystallizing impurities in the residue with a hydrocarbon solvent, and further washing with methanol water. .
However, this method has a problem that carotene is dissolved together with water-soluble impurities in methanol in methanol water, resulting in a recovery loss of carotene.

JP-A-61-115062 JP 2004-131480 A

  The present invention can recover carotenes in high yield from esters containing carotenes obtained by alcoholysis of fats and oils containing carotenes with lower monoalcohols, and minimizes deterioration of packing materials used in column chromatography processes. It is intended to provide a production method that can be suppressed.

  As a result of intensive studies to solve the above problems, the present inventor has a ratio of a specific hydrophilic solvent and water of 80:20 to an ester containing carotene obtained by alcoholysis of a fat and oil containing carotene with a lower monoalcohol. The present inventors have found that water-soluble impurities can be removed from an ester containing carotene by mixing a mixed solvent in a range of ˜55: 45 and standing and separating in a heated state.

The present invention has been made based on the above findings, and provides a method for producing a carotene concentrate having the following constitution.
That is,
(1)
(A) Step of obtaining crude palm alkyl ester containing carotene after transesterification of crude palm oil containing carotene using lower alcohol and alkali catalyst (B) Methanol for the ester A step of mixing a hydrophilic solvent having a mass ratio of 80/20 to 60/40 in a water / water mixing ratio and heating to 50 to 80 ° C. to separate into an ester phase containing carotene and a methanol / water phase (C ) Purified by column chromatography from the ester phase containing carotene obtained in step B
Obtaining carotene (2)
In the step (B), the methanol / water mass ratio is 75/25 to 65/35, and the temperature after mixing is 65 to 75 ° C. The method for producing a carotene concentrate according to (1).

  According to this production method, loss of carotene recovery can be prevented. Moreover, deterioration of the separation column used in the column chromatography step can be prevented. Furthermore, the hydrophilic solvent / water mixture can be recovered and reused.

Hereinafter, the present invention will be described in more detail.
(A) Process
In the step (A), crude palm oil containing carotene is transesterified using a lower alcohol and an alkali catalyst to obtain a palm alkyl ester containing carotene, and a hydrophilic phase mainly containing glycerin and It is a process of separating and collecting. The crude palm oil containing carotene is converted into glycerin and a fatty acid alkyl ester by transesterification using a lower alcohol and an alkali catalyst.

  As an example of the crude palm oil used as a raw material in the production method of the present invention, it is obtained by squeezing the pulp of oil palm, and the main component is a fatty acid oil (fatty acid triglyceride) having 16 to 18 carbon atoms (hereinafter referred to as “the fatty acid triglyceride”). The main component refers to a component that occupies at least 50% by mass) and includes an unpurified mixture. In addition to triglycerides having 16 to 18 carbon atoms, the crude palm oil usually contains gum, carotene, protein, resinous substance, glycerin, free fatty acid (hereinafter referred to as free fatty acid) having phospholipid as a main component. In some cases, such as triglyceride having 20 carbon atoms. In addition, as crude palm oil, a commercially available thing can be used. In addition, the composition of the crude palm oil (ratio of each component, fatty acid composition in the fat and oil) can be confirmed by a conventionally known method such as “Standard fat and oil analysis test method 2.4.2.1-1996 fatty acid composition”.

  The alcohol is preferably a lower alcohol, and specifically, ethanol, methanol, propanol or the like can be used. Particularly preferred is methanol.

  The amount of the alcohol used can be appropriately determined depending on the type of oil and fat, the type of alcohol, and the like. It is the range of 2 to 0.5 mass times, More preferably, it is the range of 0.35 to 0.45 mass times.

  The transesterification is preferably performed in the presence of a catalyst, and as the catalyst, for example, an alkali catalyst such as sodium hydroxide, potassium hydroxide, sodium methylate or the like can be used. The use ratio of the catalyst is, for example, in the range of 0.001 to 0.01 times by mass, preferably in the range of 0.002 to 0.008 times by mass, more preferably 0.003. It is the range of -0.006 mass times.

  The transesterification reaction temperature is, for example, in the range of 30 to 120 ° C, preferably in the range of 50 to 100 ° C, and more preferably in the range of 60 to 80 ° C. The transesterification reaction time is, for example, in the range of 5 to 120 minutes, and preferably in the range of 60 to 90 minutes.

After the transesterification, the fatty acid ester (upper layer) is separated and recovered by separating into a glycerin phase (lower layer) and a fatty acid ester phase (upper layer) containing carotene. The separation and recovery method may be, for example, stationary separation or separation by centrifugation or the like.

Step (B) The step (B) is a step of removing water-soluble contaminants that cause deterioration of the filler used in the column chromatography step and contribute to loss of carotene recovery from the carotene-containing ester. .
(A) With respect to the carotene-containing crude palm alkyl ester produced in the step, the methanol / water mixing ratio is in the range of 80/20 to 60/40, preferably in the range of 75/25 to 65/35, by mass ratio. The hydrophilic solvent is preferably mixed in a mass ratio of 1 to 5 times, more preferably 2.5 to 3.5 times. At that time, the temperature is raised to 50 to 80 ° C., preferably 65 to 75 ° C., stirred for several minutes, and then allowed to stand. It is preferable to maintain the heating condition at the time of stirring and to keep the temperature at 65 to 75 ° C. even at the time of standing. When the temperature is lower than 50 ° C., the separation efficiency of the two layers is lowered, and even if the temperature is higher than 80 ° C., the extraction effect of impurities is not improved. The stirring time is preferably 5 minutes or longer, and the standing time is preferably 10 minutes or longer, more preferably 30 minutes or longer, and further preferably 1 hour or longer.

By this operation, the upper layer becomes a (methanol / water) phase containing impurities (for example, glycerin, monoglyceride, diglyceride, soap, etc.), and the lower layer becomes a carotene-containing ester phase, resulting in two-phase separation. The process B is performed until the lower-layer carotene-containing ester phase is recovered.
By selecting the methanol / water mixing ratio within the appropriate range, loss of carotene yield can be prevented. If the water content in the methanol / water mixture ratio is less than 20% by mass, the carotene in the crude palm ester is partially dissolved in the methanol / water mixture, resulting in a loss of carotene recovery. On the other hand, when the water content exceeds 45% by mass, the specific gravity of methanol / water changes and the upper layer and the lower layer are partially reversed, resulting in poor separation and difficulty in extracting the lower layer.

  The water-soluble contaminant-containing methanol / water of the upper layer separated into two layers is cooled and allowed to stand for a certain period of time to separate into a phase containing the water-soluble contaminant and a methanol aqueous phase. Water can be recycled.

  In addition, you may perform a (B) process, after removing the fatty-acid alkylester obtained at the (A) process by short process distillation.

Step (C) Step (C) is a chromatographic step in which carotene is purified and separated from the carotene-containing ester phase recovered in step (B) using a column packed with a solid phase component.
(B) A mixed liquid of a hydrocarbon solvent such as hexane and a small amount of polar solvent (for example, acetone) is mixed with the carotene-containing ester separated and recovered in the step so that the mass ratio becomes 1: 1, and the mixture is heated and stirred. Meanwhile, the mixed solution is added to a column filled with a solid phase component (for example, silica gel or alumina). The temperature is preferably 40 to 60 ° C., and stirring is preferably 10 minutes or more, more preferably 30 minutes or more.

Next, the hydrocarbon solvent is continuously passed as a developing solution for the column. Sorting is started and ended while managing the absorbance value with an ultraviolet detector (UV meter) near the column outlet. Next, the solvent is removed from the collected carotene fraction to obtain purified carotene.

  The shape of the absorbance peak in the UV meter obtained in the step (C) is affected by impurities accumulated in the filler. The smaller the amount of accumulated impurities, the sharper the peak. As shown by the images in FIGS. 1 and 2, if the peak is sharp, the fractionation time is shortened, so that the amount of solvent used can be reduced and the amount of energy required for solvent removal can be suppressed.

Examples and Comparative Examples will be described below, but the present invention is not limited to the following Examples and the like. In the following examples, “%” is “mass%” unless otherwise specified.
In the following examples and comparative examples, the recovery rate and column life were evaluated by the following methods.
(Calculation of recovery rate)
The mass in the crude palm alkyl ester used as a raw material, the carotene concentration%, the carotene-containing ester mass in the lower layer after Step B treatment, and the carotene concentration% were measured, and the recovery rate was calculated by the following equation.
Recovery rate (%) = ((1) / (2)) × 100
In the above formula, (1) mass × carotene concentration% of the carotene-containing ester separated in the B-process treatment
(2) Mass x carotene concentration% of carotene-containing crude palm alkyl ester obtained in step A
Here, the carotene concentration was determined by the following formula by measuring 100 mg of a sample diluted with cyclohexane to 500 to 1000 times, measuring the absorbance at 448 nm with a spectrophotometer.
Carotene concentration (%) = (dilution rate × absorbance) / (sample mass × 2500)
In the formula, 2500 is the extinction coefficient of all-trans β-carotene.

(Column life)
In the chromatographic process for purifying carotenes, the silica gel in the column before and after continuously passing the hydrocarbon solvent as the developing solution for the column is taken out, dried at 60 ° C. for 60 minutes, and then subjected to comparison by the BET method. The surface area was measured. The device is manufactured by Shibata Science Co., Ltd., type P-85
0 was used. The column life was evaluated based on the degree of decrease in the specific surface area, and the greater the degree of reduction, the worse the column life.
Specific surface area (m ² / g)
Before use: 470 m ² / g
After use: 469-420 m ² / g (pass) ○
419-370 m ² / g (failed) △
369 m ² / g or less (failed) ×

Example 1 will be described.
(A) Process The crude palm oil containing 600 ppm carotene is mixed with methanol and sodium hydroxide so that the mass ratio of the crude palm oil: methanol: sodium hydroxide = 73.7: 25.8: 0.3. The mixture was mixed to give an alcoholysis reaction. The produced carotene-containing ester phase was collected, washed with 1/5 volume of water added to the volume of the crude palm oil, and then dehydrated by a conventional method.

(B) Process Next, the methanol aqueous solution containing 25 mass% water was mixed 3.5 volume times with respect to the said ester phase. Then, it heated up to 70 degreeC, stirred for 5 minutes, and left still for 30 minutes. By standing, the ester phase (fraction A) containing carotene in the lower layer was phase-separated, and the phase was recovered. The carotene concentration in this ester phase was 610 ppm. By the B process, most of the water-soluble impurities were transferred to the upper methanol / water phase.

Step (C) A chromatographic column in which silica gel having a particle size of 40 to 70 μm was packed in a column was prepared, and a hexane developing solution containing 3500 ppm of acetone was poured to prepare a chromatographic column. Next, a diluted solution of the carotene-containing ester obtained in the step (B) was prepared at a temperature of 55 ° C. using a hexane / acetone mixed solvent (acetone 4000 ppm). The mixing ratio was ester: hexane / acetone mixed solvent = 1: 50.
After the carotene-containing diluent was added to this column, development was started by flowing the developing solvent. Concentration of outlet liquid was continuously measured with a UV meter, and only the fraction in which carotene was detected (sorting started at an absorbance value of 1.0 and then finished again when it dropped to 1.0 again) Separated. Sunflower oil was mixed with the fraction so as to have a mass ratio of 99.5 / 0.5, and then the solvent was removed under reduced pressure at 45 ° C. and 3 kPa in a solvent removal tank to distill off the developing solvent. .

In Example 2 and Comparative Examples 1 and 3, carotene was separated in the same manner as in Example 1 except that the amount of water in the aqueous methanol solution was changed to 35%, 13%, and 50%.
In Example 3, the ester in the carotene-containing ester produced after the alcoholysis in step (A) was partially distilled off by short-step distillation, and then step (B) was performed. In Comparative Example 2, the methanol / water solution was only water.

  The results are shown in Table 1. In Table 1, the fractionation time for column chromatography is the time from the start of fractionation at an absorbance value of 1.0 to the point when it subsequently falls to 1.0 again. In addition, for the comprehensive evaluation, the evaluation was evaluated as “good” when the recovery rate was 98.5% or more, the preparative time was within 45 minutes, and the column life evaluation was “good”, and the others were “good”.

(Table 1)

From Table 1, the recovery rate is high for the examples prepared in the range of 25 to 35% of the water content of the hydrophilic solvent and water mixture, the fractionation time of column chromatography is short, and the column life (specific surface area of silica gel) It was found that it was also good. On the other hand, in the comparative example 1 which prepared the water | moisture content in the range below 20%, the carotene recovery rate was low. Further, in Comparative Examples 2 and 3 in which the water content was higher than 40% or only water was used, although the recovery rate was high, the fractionation time in the column became longer and the column life was significantly reduced. This is because the specific surface area of the column filler has decreased.

FIG. 1 is an image of a sharp peak in the absorbance peak shape in the UV meter obtained in the step (C) according to the present invention. FIG. 2 is an image of a broad peak in the absorbance peak shape in the UV meter obtained in the step (C) according to the present invention.

Claims (2)

The manufacturing method of the carotene concentrate containing the following (A) process, (B) process, and (C) process.
(A) Step of obtaining crude palm alkyl ester containing carotene after transesterification of crude palm oil containing carotene using lower alcohol and alkali catalyst (B) Methanol for the ester A step of mixing a hydrophilic solvent having a mass ratio of 80/20 to 60/40 in a water / water mixing ratio and heating to 50 to 80 ° C. to separate into an ester phase containing carotene and a methanol / water phase (C ) Purified by column chromatography from the ester phase containing carotene obtained in step B
Obtaining carotene The method for producing a carotene concentrate according to claim 1, wherein the methanol / water mass ratio in step (B) is 75/25 to 65/35, and the temperature after mixing is 65 to 75 ° C.