JPS5950263B2 - Method for producing yellow pigment that does not cause greening - Google Patents

Description

[Detailed Description of the Invention] The present invention provides a method for extracting and purifying crocin contained in the fruits of plants belonging to the family Rubiaceae, the genus Gardenia, and the fruit of Mizuhiko and Yamazushi (hereinafter referred to as gardenia), and adding it to food. This invention relates to a method for producing a yellow pigment that does not cause greening.

Traditionally, crocin has been extracted from gardenia fruit with water or an aqueous alcohol solution, filtered and concentrated, and then formulated into liquid or powder and used as gardenia yellow pigment in various foods.

When commercially available gardenia pigment formulated in this way is used as a coloring agent in foods made from wheat flour, such as noodles, breads, pickles, egg tofu, etc., the color sometimes changes to blue or green, significantly reducing the commercial value. known to cause damage.
The mechanism by which the yellow pigment extracted and formulated from gardenia fruits causes greening is still unresolved, but crocin itself, which is the main body of the yellow pigment, is not involved in greening. It is a well-known fact that iridoid glycosides containing geniposide as a main component are the causative agent of green discoloration (Patent Application Publication No. 13971/1983).

Geniposide is a substance that is contained in approximately 6-7% of the dried fruit of gardenia (1972 Health and Welfare Science Research Report 37).
7-395 (1975)), it has an absorption maximum (solvent, water) at 238 mμ, and its content is determined by measuring the absorbance at 238 mμ.

On the other hand, the yellow pigment component crocin is 440 mμ (solvent,
It has an absorption maximum in water). (Pharmaceutical Journal 100 (9)
920-924 (1980)) In order to obtain a yellow pigment that does not cause green discoloration when added to food, the present inventors have developed a method that uses crocin, which is the main component of the yellow pigment, and geniposide, which is the causative agent of green discoloration, as the main components. The present invention was completed through extensive research into methods for separating iridoid glycosides.

Conventionally, as a method for separating geniposide, which is a substance causing green discoloration, a method has been proposed in which a gardenia extract is precipitated in 95% ethyl alcohol, and purified crocin recovered as the precipitate is used as a coloring agent.

(Publication of Patent Publication No. 54-64652) However, in this method, 18 volumes of 95% ethyl alcohol aqueous solution is added to 1 volume of extract obtained by extracting gardenia fruit with 3 times the amount of 50% ethyl alcohol aqueous solution and concentrating it to 1/10 volume. In addition, a large amount of ethyl alcohol is required to precipitate crocin, and purification and recovery of this ethyl alcohol is also a difficult task and must be prepared for uneconomical costs. On the other hand, when treated with activated carbon for the purpose of adsorbing and removing crocin or geniposide in gardenia extract, both crocin and geniposide products are adsorbed, and once adsorbed crocin,
Geniposide is difficult to desorb. In other words, activated carbon does not show particular selectivity for crocin and geniposide and is adsorbed simultaneously, making clear separation impossible.
In addition, cellulose and diatomaceous earth, which are adsorbents with relatively low adsorption power, selectively adsorb crocin and do not adsorb geniposide, so it is possible to separate crocin and geniposide, but the adsorption amount of crocin in these two products is is extremely small and is effective as an analytical tool, but not as an industrial tool. The present inventors conducted an intensive search for a synthetic adsorption resin that adsorbs only either crocin or geniposide and can be easily attached and detached by changing conditions, and completed the present invention.

Porous synthetic adsorption resins with intermediate polarity that meet the purpose of the present invention include a methacrylic acid ester polymer (Diaion 8HP-2MG1, manufactured by Mitsubishi Chemical Corporation) and an acrylic acid ester polymer (Amberlite 8XAD-7, XAD-
8, Rohm and Haas).

The characteristic of Diaion 8HP-2MG is the specific surface area of 550d.
/9, pore volume 1.12 d/9, water content 62.6%, true specific gravity 1.099/d, and its chemical structure is as follows. Also, Amberlight 8XAD-7, XAD-8
Its properties are shown in Table 1, and its chemical structure is as follows.

According to the present invention, gardenia fruits are extracted with water (including hot water) or an aqueous alcohol solution of an appropriate concentration, the insoluble portion is removed, and a clear liquid is obtained. The alcohol concentration of the extract is adjusted to a concentration suitable for adsorption by the above-mentioned porous resin by evaporation or dilution, and after adsorbing crocin to the resin, geniposide, which is a non-adsorbed substance, is mixed with water or the adsorbed liquid. Highly pure crocin can be easily obtained at low cost by thoroughly washing and removing the crocin with an aqueous alcohol solution of a different concentration, and then eluting the crocin using a water-containing organic solvent with a different concentration.

When cellulose or diatomaceous earth is used as an adsorbent, if alcohol remains in the adsorbed liquid, the adsorption effect of crocin will deteriorate significantly, so the extract must be distilled in advance to almost completely remove the alcohol. .

This operation is also not easy. However, in the case of the present invention, an aqueous solution may be used, but it is better that some alcohol remains, and the advantage of the present invention exists here as well. In the method of the present invention, the water extract or the liquid from which alcohol has been distilled off after extraction maintains acidity, but the pH of the liquid is not particularly limited through adsorption and desorption operations.

However, if the solution is kept alkaline, the gentibiose in crocin easily separates and becomes crocetin, which is not a desirable color for the yellow pigment. Therefore, it is preferable to keep the pH of the liquid between neutral and acidic. In the present invention, alcohols that can be used as extraction solvents in addition to water include methyl alcohol, ethyl alcohol, n-propyl alcohol, and isopropyl alcohol.

In the case of ethyl alcohol, n-propyl alcohol, and isopropyl alcohol, crocin, which is a yellow pigment component, hardly dissolves when used as is, so it is preferable to use a hydrous alcohol diluted with an appropriate amount of water. The water concentration of hydrous alcohol is determined by the amount of crocin extracted and the workability during filtration and purification. For methyl alcohol, the water concentration is 0 to 70% (V/V), preferably 30 to 50% (V/V).
/V), and the water concentration is 20 to 7 for ethyl alcohol, n-propyl alcohol, and isopropyl alcohol.
It is 5% (V/V), preferably 40 to 60% (V/V). In addition, the alcohol concentration of the adsorbed liquid in the present invention is o to 30% in the case of methyl alcohol and ethyl alcohol.
(V/V), preferably 0 to 20% (V/V).
If the concentration of methyl alcohol or ethyl alcohol used as a solvent for extracting crocin from gardenia fruits is outside the above range, the alcohol concentration may be adjusted by distilling the filtrate to remove the alcohol or by diluting it with water.

The temperature during adsorption is usually room temperature.

The amount of adsorption resin is extracted in Diaion 8HP-2MG,
Elcm (440 mμ) per 100 filtrated 1% liquid = 1
It is usually 250 go per 5, and for Amberlite [Co., Ltd.] Katsu AD-7, it is usually 250 m1 or more, preferably 300 ~
350m1) Usually 50 for Amberlight 8XAD-8
It is 0 ml or more, preferably 550 to 650 ml.

If the amount of adsorbent is too small, the adsorption of crocin will be insufficient and the yield will be reduced, and if the amount is too large, the adsorption effect will not be improved. The concentration of crocin in the crocin-containing liquid to be adsorbed is usually 5 to 36, preferably 10 to 20 in E1' (440 mμ).

The concentration may be adjusted to fall within this range. In the adsorption process, adsorption and desorption can be carried out using a method such as column chromatography, in which adsorption resin is usually packed in a column, but geniposide and crocin are separated by adding adsorption resin to the liquid to be adsorbed and then separating it. It is also possible to do so.

Next, a mixture of a hydrophilic organic solvent and water can be used as a solvent for eluting the adsorbed crocin.

Examples of the hydrophilic organic solvent include methyl alcohol, ethyl alcohol, isopyl alcohol, n-propyl alcohol, and acetone. Ethyl alcohol is the most preferred solvent considering safety and food sanitation laws. The water content ratio varies depending on each hydrophilic organic solvent, but
For example, in the case of ethyl alcohol, the alcohol concentration is 30~
It is 100%, preferably 40-60%. ´ The crocin eluent may be used as it is by adjusting the color value and the amount of ethyl alcohol to make a liquid preparation, but after distilling off the ethyl alcohol and concentrating if necessary, add excipients such as dextrin and drying with a spray dryer or vacuum. It can also be made into a powdered preparation using a suitable dryer such as a dryer or a freeze dryer. The present invention will be explained in detail below using Reference Examples, Examples, Comparative Examples, and Test Examples.

Synthetic adsorption resin Diaion 8HP-2MG200 fully soaked in water in a φ23mm x H620mwL column
ml (water-containing state) was filled.

Next, the ethyl alcohol concentration of the cutinan fruit water-containing ethyl alcohol extract was adjusted to 0, 5, 10, 15, 20, 25.
, 30% (V/V) and 15% E}ヱ(440mμ)
Adjusted to. After sufficiently passing through the column with aqueous alcohol of a predetermined concentration, 100 ml of the extract adjusted to the same ethyl alcohol concentration was adsorbed, and 1,000 ml of an aqueous alcohol solution of the same concentration was passed through the column to remove geniposide, which is a non-adsorbed substance, as the main component. Iridoid glycosides were removed, and adsorbed substances containing crocin as a main component were further eluted with 400 ml of a 50% ethyl alcohol aqueous solution.

Each sample was processed in the same manner to determine the recovery rate of yellow pigment and iridoid glycoside.

The content of yellow pigment was measured by absorbance at 440 mμ (solvent water),
The content of iridoid glycosides was determined by absorbance at 238 mμ (solvent water). The results are shown in Table 2. From this result, the ethyl alcohol concentration of the adsorbed liquid in the present invention is 0 to 2.
It turns out that 0% (V/V) is appropriate. That is, it can be seen that crocin is well adsorbed within this range of ethyl alcohol concentration, and furthermore, iridoid glycosides can be washed and removed with ethyl alcohol of the same concentration. Example 1. 200f of crushed gardenia fruit! 45% ethyl alcohol aqueous solution 10007n1! was added, and the mixture was stirred and extracted at room temperature for 2 hours.

Insoluble parts such as extraction residue were removed, and the residue was further washed with 200 ml of water, and the remaining liquids were combined to obtain 1050 ml. The ethyl alcohol in this bottom liquid was distilled off and concentrated to 250 TfL1. The E1% (440 mμ) of this liquid was 11.8 and 1 volume.

Synthetic adsorption resin DIAION 8HP is made by thoroughly impregnating water with a solution obtained by adding ethyl alcohol 257111 to this solution.
-2MG (Mitsubishi Kasei Corporation) 3807111 was filled and passed through a column which had been replaced with a 10% ethyl alcohol aqueous solution to adsorb crocin, and then 2000Tn1 of a 10% ethyl alcohol aqueous solution was poured to remove geniposide. Then 50% ethyl alcohol aqueous solution 800
ml was poured, and this portion of the fraction was concentrated under reduced pressure to obtain 200 ml of a liquid from which most of the ethyl alcohol had been removed. Dextrin (Pinedex+2 Matsutani Chemical Co., Ltd.) 1351%9 was added to this liquid, dried in a vacuum dryer, and then powdered.E)
A powdered yellow pigment 1659 with 1 crfL (440 mμ) = 15.3 was obtained.

Example 2. 65f) Methyl alcohol for crushed gardenia fruit 2009
A large liquid 10007111 was added thereto, and the mixture was stirred and extracted at room temperature for 2 hours.

After removing insoluble parts such as extraction residue, the residue was reduced to 65% of 200d.
Wash with methyl alcohol aqueous solution and combine the filtrate with 1080
m1 was obtained. This was the case.

Diaion 8HP- is a synthetic adsorption resin made by sufficiently soaking water with a solution obtained by adding 457n1 of methyl alcohol to this solution.
2MG (Mitsubishi Kasei Corporation) 380d packed in advance 1
A 5% aqueous methyl alcohol solution was passed through the replaced column to adsorb crocin, and then a 15% aqueous methyl alcohol solution 1800a was passed through the column to remove geniposide.

Next, 800 ml of 70% methyl alcohol was poured into the flask, and this fraction was concentrated under reduced pressure to obtain 230 ml of a liquid from which most of the methyl alcohol had been removed. Dextrin (Pinedex◆2 Matsutani Chemical Co., Ltd.) 140f in this liquid! was added, dried in a vacuum dryer, and then powdered to give E1% (to) 40
1 cm of powder of yellow pigment 1739 with mμ)=14.9 was obtained.

Example 3. 1000 ml of 40% isopropyl alcohol aqueous solution was added to the crushed gardenia fruit product 2009, and extracted at room temperature for 2 hours.

Insoluble parts such as the extraction residue were separated, and the residue was further washed with 400 ml of a 40 (fl) isopropyl alcohol aqueous solution, and the finished liquids were combined to obtain 1230Tf1i. The isopropyl alcohol of this finished liquid was distilled off and concentrated to 2501% ml.

Elcfn (440 mμ) of this liquid was 10.5. Synthetic adsorption resin Amberlite 8XA is made by adding 25ml of ethyl alcohol to this solution and thoroughly soaking it in water.
Filled with D-7 (Rohm and Haas) 450TI11, 10% ethyl alcohol aqueous solution was passed through the column which had been replaced in advance to adsorb crocin.
fl) Geniposide was removed by flowing 2000 ml of an aqueous ethyl alcohol solution.

Next, 800 ml of an aqueous solution of 5001) ethyl alcohol was poured, and this fraction was concentrated under reduced pressure to obtain 210 ml of a liquid from which most of the ethyl alcohol had been removed.

120 g of dextrin was added to this liquid, dried in a vacuum dryer, and then powdered to obtain 160 g of a powdered yellow pigment with an E1% of 1 cm (440 mμ) = 14.8.

Example 4. Tap water 21 was added to 200 g of crushed gardenia fruit and extracted by immersion overnight.

Insoluble parts such as extraction residue were filtered off, and the residue was washed with hot water at 80°C.
Then, the mixture was extracted with stirring for 1 hour, and the filtrates were combined to obtain 2800 ml. The E{Z (440 mμ) of this liquid was 1.02.

This solution was passed through 450 ml of synthetic adsorbent Amberlite 8XAD-7 (Rohm and Haas) sufficiently soaked in water to adsorb crocin, and then 900 ml of tap water was passed through to remove the remaining crocin inside the column. Geniposide was removed. Next, 800 wL1 of a 50% ethyl alcohol aqueous solution was poured, and this fraction was concentrated under reduced pressure to obtain a liquid 2207111 from which most of the ethyl alcohol had been removed. In this liquid, dextrose was added to ``;IA'. Changes in color tone over time were observed, but even after 48 hours there was no change in color tone and the color remained a beautiful yellow.

Comparative Example 45% ethyl alcohol aqueous solution 101 was added to 2 kg of crushed gardenia fruit, and the mixture was stirred and extracted at room temperature for 2 hours.

Insoluble parts such as the extraction residue were separated, and the residue was washed with 21 water, and the remaining liquids were combined to obtain 10.11. After distilling and concentrating the ethyl alcohol of this liquid to 2.8', dextrin (Pinedex◆2 Matsutani Chemical Co., Ltd.) 11709 and water 21 were added and powdered using a KC-10 type spray dryer manufactured by Kochiwa Seisakusho. 101) and E (440 mμ)=
15.1 powdered yellow color 101rL/dye 15909 was obtained Test example 25 kg of wheat flour (Nissin Seifun Co., Ltd. (special) wash 1), powdered yellow color 109 and salt 2509 dissolved in water 8.31, or Powdered yellow pigment 10g, salt 2509, powdered brine (Oriental Yeast Co., Ltd. Hiryu) 1509 and water 8.
A solution of No. 31 was added thereto, and Chinese raw noodles were prepared in the usual manner and stored in a thermostat at 30° C., and changes in color tone were observed.

This test was conducted on each of the powdered yellow pigments prepared by the methods of Examples 1, 2, and 3, and as a control, one without the addition of the powdered yellow pigment and one with the powdered yellow pigment prepared in Comparative Example were used. there was.

Claims (1)

[Claims] 1. A synthetic adsorption resin having a porous polymer structure with intermediate polarity is brought into contact with an aqueous or alcoholic extract of gardenia fruit to selectively adsorb crocin, which is a yellow pigment component of gardenia fruit. A method for producing a yellow pigment that does not cause greening, characterized by eluting crocin from the synthetic adsorption resin with a solvent to remove iridoid glycosides whose main component is geniposide, which is a substance that causes greening.