JPH10245499A - Red dye and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a red dye usable for foods, drinks, pharmaceuticals, cosmetics, etc., by immersing a colored part of taro (Colocasia esculenta, a plant of the family Araceae) in an acidic aqueous liquid, thereby eluting mainly a red dye (flavonoid-type anthocyanine) into the liquid. SOLUTION: The part of taro of the family Araceae colored in red or reddish purple color is cut, put into an acidic aqueous liquid of pH 1.5-4.0 and extracted at a temp. of 15-80 deg.C. The obtained extract is concentrated under normal or reduced pressure and purified to obtain the objective red dye. Preferably, the taro is selected from among Tonoimo, Akame, Ishikawa-wase, Yatsugashira and Kurojiku (all are cultivation varieties of taro), the acidic aqueous liquid is water, alcohol or their mixture containing an acid or its salt, e.g. an aqueous solution of citric acid and the extraction is carried out by circulating and/or stirring the above acidic aqueous liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a taro, a red taro, which is obtained by immersing a red-purple-colored portion in an acidic aqueous liquid (partially containing an organic solvent such as alcohol), heating if necessary, and then extracting. Elutes mainly red pigments (flavonoid anthocyanins) contained in potato stalks,
Concentrate, purify and process this to produce stable dye solutions, powders, granules, emulsions, etc., dyeing foods, beverages, pharmaceuticals, cosmetics, paper, fibers, resins and processed products It is used for.

[0002]

2. Description of the Related Art Pigments contained in plants are diverse and the number is very large. Therefore, pigments collected from the plants have been used as dyes for dyeing foods, clothing, paper, and the like. In particular, there are many kinds of coloring pigments for foods, but the main ones are flavonoid pigments, which are used in all fields of food such as staple rice, alcoholic beverages, side foods, beverages, and cosmetics . Therefore, many of these pigments are extracted and used as pigment preparations. (See, for example, JP-A-50-60524, JP-A-54-49364, JP-A-54-1478, and JP-A-2-248465).

[0003] As for the taros of the family Araceae, red taro (Colocasia antiquorum var. Esculenta), red turtle (C. antiquorum var. Esculenta), and Ishikawase (C.
antiquorum var. globulifara), hoopoe (C. ant)
iquorum var. esculenta), blackfish (C. antiquorum)
var. globulifara) and sweet potato (C. antiquorum va)
r. lypica). Among them, for example, potato stalks such as Tono-imo, Akame, Ishikawase, Yasugashira and Kurozik varieties have been used as foods for a long time since they have been called "zuiki". For example, a potato stalk of taro is cut to 10-20 cm except for the epidermis 200-
About 500-1000 ml of water was added to 300 g, 10-20 g of sodium bicarbonate was added, and the mixture was boiled, washed with about 1000 ml of water 2-3 times, drained, cut, seasoned, and used for food. However, during processing, the potato stalks were treated with a large amount of hot water or alkaline water in order to remove the “red” contained in the stalks, so the pigment contained therein was decomposed and turned brown. . Therefore, although these stems contain a large amount of pigments (flavonoid anthocyanins), there is no literature that effectively utilizes the pigments as pigment preparations.

[0004]

SUMMARY OF THE INVENTION The inventor of the present invention has proposed a red-reddish purple colored part of a taro family Araceae, which has a pH of 1.5.
The dye is eluted together with "Aku" and other impurities by immersing and thoroughly penetrating into an acidic aqueous solution of ~ 4.0, and furthermore, the extract is concentrated in an acidic state to obtain a deep dye containing impurities. Heading, furthermore, in order to color foods, beverages, and the above-mentioned objects to be colored at this level of quality, the quality is impure, so by refining, and for coloring purposes, solutions, powders, granules, The present invention has been completed by formulating an emulsion or the like.

[0005]

That is, according to the present invention, a red or reddish purple colored part of the taro family Araceae is cut, and added to an acid aqueous solution having a pH of 1.5 to 4.0 to add 15 to 8 parts.
The present invention relates to a method for producing a red pigment, comprising extracting at 0 ° C. and concentrating and purifying the obtained extract under normal pressure or reduced pressure, and a red pigment obtained by the production method. In the above-mentioned production method, when the taro family Araceae is selected from the group consisting of Tono yam, red turtle, Ishikawase, hoopoe and black croak, when the acid aqueous solution is water containing an acid or a salt thereof, alcohol or a mixture thereof, It is preferred if the extraction is carried out by circulating and / or stirring the aqueous acid solution.

Further, the present invention relates to a method for purifying a red dye obtained by the above-described method for producing a red dye, dissolving the red dye in an organic solvent, and adding an acid to the obtained solution to obtain an acidic solution having a pH of 1.7 to 4.0. The present invention relates to a method for producing a dye solution comprising a liquid, and a dye solution obtained by the method.

Next, the present invention provides a method for concentrating a dye solution obtained by the above-mentioned method for producing a dye solution under normal pressure or reduced pressure, and adding propylene glycol or ethanol to the obtained concentrated solution.
And / or a method for preparing a dye solution comprising adding monopotassium citrate or phosphates, and a dye solution obtained by the method.

[0008] Further, the present invention provides a method for preparing a dye solution comprising adding at least one component selected from the group consisting of citrates, phosphates, carbohydrates and an adsorbent to the dye solution obtained by the above-mentioned method. And a method for producing a pigment powder by performing heat drying, spray drying or freeze drying under normal pressure or reduced pressure, and a pigment powder obtained by the production method.

In addition, the present invention relates to a method for producing pigment granules comprising granulating the pigment powder, and to the pigment granules obtained by the production method.

[0010] In addition, the present invention relates to the above-mentioned red pigment, pigment solution, pigment solution, pigment powder or pigment granules, wherein edible oils and fats; propylene glycol; sucrose fatty acid ester; gum arabic; glycerin fatty acid ester; A monoester of citric acid and / or
Also, the present invention relates to a method for producing an emulsified preparation of an oil-dispersed aqueous pigment liquid, which comprises emulsifying by adding phosphates and water, and an emulsion preparation of an oil-dispersed aqueous pigment liquid obtained by the production method.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION "Araceae taro" used in the method for producing a red pigment of the present invention utilizes pigments present in a plant body thereof, and is preferably tonu, akame, ishikawawase, hoopoe and kurojiku, More preferably, they are red turtles, hoopoe, spruce and black croak, and require high pigment concentration, and thus are particularly preferably turtles and hoopoe. . However, the present invention can also be applied to the following plant-derived materials exhibiting red to magenta in addition to the taro family. Specifically, the production method of the present invention can also be applied to the stems of Acophoraceae Ohohange, the potatoes of Araceae Dutch calla and Konjac.

[0012] The "red to reddish purple colored portion" in the present invention includes potato stalks, leaves, potatoes and their outer hulls, and the appearance and the inside are colored. And, since it is widely used and has a high pigment concentration, a potato stalk is more preferable.

Araceae Araceae can be harvested from the end of June to December, so that colored portions such as potato stalks can be used for a long period of time.
Contains CAV dye. CAV has absorbance in the visible portion the maximum absorption wavelength lambda _max of the dye 0.3 to 0.6
The sample dye solution is diluted with an aqueous citric acid solution having a pH of 2.2 so as to be in the range of pH 2.2.
Using the aqueous citric acid solution as a control solution, the thickness of the light absorbing layer was 1 cm
= L The value a of the absorbance at 1 _cm is measured, and is obtained from the following equation.

CAV = a.times.dilution factor / sampled amount (g) The "red dye" in the present invention is pH 2.0 to 4.0.
0 to give a red to purple-red color in a 77% (w / w) aqueous solution,
A dye having a visible maximum absorption wavelength of 515 to 520 nm means "acid aqueous liquid", and citric acid, acetic acid, tartaric acid,
Water and alcohol containing at least one acid selected from the group consisting of organic acids such as lactic acid, malic acid, succinic acid and fumaric acid, inorganic acids such as hydrochloric acid, sulfuric acid and phosphoric acid and salts thereof, or salts thereof. Means at least one aqueous medium selected from the group consisting of: Preferred acids or salts thereof are citric acid, tartaric acid, succinic acid, malic acid, acetic acid, fumaric acid, lactic acid, hydrochloric acid, sulfuric acid, phosphoric acid and salts thereof, and more preferred acids or salts thereof are as food additives. As used, citric acid, monopotassium citrate is a particularly preferred acid is citric acid. Preferred aqueous media are water and ethanol, since the material to be dyed contains a large amount of water, and more preferred aqueous medium is water. Any mixing ratio of water to alcohol (by volume) of 100: 0 to 0: 100 can be used in the present invention, but a preferable mixing ratio is water: alcohol = 50: 50 to 80:20. A more preferred mixing ratio is water: alcohol: citric acid = 78: 20: 2 to 77: 20: 3 because citric acid is added.

The “acid aqueous solution” is preferably an aqueous citric acid solution, an aqueous tartaric acid solution, an aqueous malic acid solution, an aqueous lactic acid solution, or an aqueous succinic acid solution, and more preferably an aqueous citric acid solution, an aqueous tartaric acid solution, or an aqueous malic acid solution. Particularly preferred is an aqueous citric acid solution.

The preferred pH of the "acid aqueous solution" is as follows:
It is 5 to 4.0, and more preferable pH is 1.8 to 2.0.
0.

The amount (weight) of the acid aqueous solution used to obtain the red dye of the present invention is 1.0 to 5.0 times, preferably 1.times., The amount (weight) of the colored portion used for extraction. 0 to
2.5 times.

If the extraction temperature is less than 15 ° C., the extraction rate is low, and if it exceeds 80 ° C., the target pigment is decomposed, and the extraction temperature is 15 to 80 ° C. A more preferred extraction temperature is 15 to 50 ° C., since the pigment is less decomposed, and a more preferred extraction temperature is 15 to 50 ° C., because the pigment is not decomposed.
-40 ° C, particularly preferred extraction temperature is 20-30 ° C.

The extraction operation can be carried out by any means usually used in the art, but it is preferable to carry out the aqueous acid solution while circulating and / or stirring it from the viewpoint of improving the extraction efficiency of the dye. For example, when extraction is performed from a colored portion such as a potato stalk using the apparatus shown in FIG. 1, the potato stalk and the like float on the acid aqueous solution at the initial stage of the extraction. The acidic aqueous liquid is circulated by spraying the liquid from a dispersion liquid pipe 5 installed in the upper part of the SUS tank 1 through a feed pump 4 in a shower manner. When the extraction proceeds and the extracted liquid penetrates into the potato stalks and the like, the potato stalks and the like float in the liquid.

The extract obtained here is a liquid in which plant parts such as taro stalks, extracted pigments and substances other than pigments, and insolubles such as fibers are mixed.
Therefore, it is necessary to separate insolubles by means such as a filter plate, a wire mesh, a filter cloth, and centrifugal separation. For example, a first-stage coarsely filtered solution using a wire mesh is subjected to a second-stage filtration using a centrifugal separator, so that a relatively clear extract can be obtained.

The present invention can obtain a high-concentration extract by concentrating the relatively clear extract obtained above under normal pressure or reduced pressure. It may be filtered before and after concentration with a filter plate or filter paper of φ = 3 to 6 μm.

Concentration of the "obtained extract" is carried out under normal pressure or reduced pressure.
C, 5-6 hours; 20-200 mmHg, 10-50
C. for 3-5 hours, more preferably 20-100
Performed at 10 to 50 ° C. for 2 to 5 hours at mHg, more preferably at 10 to 40 ° C.
Perform for 4 hours.

The above-mentioned "purification" is carried out for the purpose of removing impurities such as muddy substances and fibrous substances with turbidity, which are not pigments, and so-called "aku". However, a preferred method is a filtration method using a filter plate, filter paper, a wire mesh, or the like, a sedimentation method in which the extract is allowed to stand in a cool and dark place to precipitate impurities causing turbidity, and a supernatant is separated. Separation methods, and combinations thereof, and more preferred methods are wire mesh filtration methods, filter paper filtration methods, centrifugal separation methods, combinations of sedimentation methods and filter paper filtration methods, combinations of wire mesh filtration methods and filter paper filtration methods, and particularly preferred. The method includes a centrifugal separation method, a filter paper filtration method, a method of re-filtering a settled liquid that has been left still with a filter paper, and a method of re-filtration of a filtrate filtered through a wire mesh with a filter paper.

Further, the present invention provides a method of purifying a red dye obtained by the above-mentioned process, dissolving the dye in an organic solvent, and adding an acid to the obtained solution to obtain an acidic solution having a pH of 1.7 to 4.0. And a dye solution obtained by the method. “Purification” in this production method can be performed by any method usually used in the art, but preferred methods are a centrifugal separation method, a filtration method using a filter plate, a filter paper, an adsorption method using ion exchange with an adsorbent or physical adsorption. More preferred methods are a centrifugal separation method, a filter paper filtration method, and an adsorption method using an adsorbent, and particularly preferred methods are a filter paper filtration method and an adsorption method using an adsorbent.

Specifically, in order to remove dissolved organic and inorganic impurities, an adsorbent (eg, Amberlite XAD-4, XAD-7 (manufactured by Organo Corporation)
Manufactured), Diaion HP-20, HP-2MG, SP-
207 (manufactured by Mitsubishi Chemical Corporation), S-102, S-102
A (Kurita Technical Service Co., Ltd.), but are not limited to these. ) To adsorb the dye through the red dye and remove the impurities with water or a weakly acidic solution, for example,
0.2-0.5% (w / v) citric acid aqueous solution (pH
2.0 to 6.0), and then separated. The adsorbed dye was then desorbed and dissolved in an organic solvent containing a commonly used buffer solution, and an acid was added to the obtained solution to adjust the pH to 1.7 to 2.0.
By using an acidic solution of 4.0, a purified red dye can be obtained.

Examples of the "acid" include organic acids such as citric acid, acetic acid, tartaric acid, lactic acid, malic acid, succinic acid, and fumaric acid, which are preferable because they have good stability to products and good solubility in water. Is citric acid, tartaric acid,
Particularly preferred is citric acid because of its good buffering power.

The acidic solution has a pH of 1.7 to 4.0, preferably has a pH of 1.7 to 2.5, more preferably has a pH of 1.7 to 2.2, and particularly preferably has a pH of 1.7 to 2.2. 1.7 to 2.0.

The "organic solvent" means alcohols such as ethanol, methanol and propanol, preferably ethanol and methanol, and more preferably ethanol.

The organic solvent may contain a "buffer". The term "buffer" includes any buffer usually used in the art, but a preferred buffer is
A buffer containing an organic acid such as citric acid, tartaric acid, succinic acid, malic acid and / or salts thereof, and a buffer containing inorganic acids such as phosphoric acid, polyphosphoric acid, hydrochloric acid and sulfuric acid and / or salts thereof. More preferred buffers include organic acids such as citric acid, tartaric acid and succinic acid and / or sodium or potassium salts thereof, inorganic acids such as phosphoric acid, pyrophosphoric acid and metaphosphoric acid and / or sodium or potassium salts thereof. An aqueous solution or an alcohol solution, particularly preferably a buffer solution is an aqueous solution or an ethanol solution containing citric acid or hexametaphosphoric acid.

The above “acid” is mixed with the above “obtained solution” 100
10 to 0.1 parts by weight, and
An acidic solution having a pH of 1.7 to 4.0 is obtained,
0.2 parts by weight, more preferably 3 to 0.3 parts by weight.

Next, the present invention provides a method for concentrating a dye solution obtained by the above-mentioned method for producing a dye solution under normal pressure or reduced pressure, and adding propylene glycol or ethanol to the obtained concentrated solution.
And / or a method for preparing a dye solution comprising adding monopotassium citrate or phosphate, and a dye solution obtained by the method.

The concentration of the obtained dye solution is carried out under normal pressure or reduced pressure. Preferably, the dye is partially decomposed at 70 ° C. or higher.
Time: 20 to 200 mmHg, 10 to 50 ° C., 3 to 5 hours, More preferably, the dye is decomposed at a high temperature, so it is 20 to 100 mmHg, 10 to 50 ° C., 2 to 5 hours, more preferably high temperature In this case, the dye is decomposed, so that the reaction is performed at 20 to 40 mmHg at 10 to 40 ° C. for 1 to 4 hours.

"Propylene glycol or ethanol and / or monopotassium citrate or phosphates" to be added to the obtained concentrate is preferably propylene glycol; propylene glycol and phosphates; ethanol; and ethanol and phosphoric acid. Salts, more preferably propylene glycol and phosphates; ethanol; and ethanol and phosphates.

The above-mentioned phosphates include sodium or potassium salts of phosphoric acid, pyrophosphoric acid and metaphosphoric acid, and are preferably potassium salts of metaphosphoric acid.

With respect to 100 parts by volume of the concentrated solution, 10 to 30 parts by volume of the above-mentioned "propylene glycol or ethanol and / or monopotassium citrate or phosphates" is added, preferably 15 to 28 parts by volume. Especially preferably, it is 18 to 25 parts by volume.

The present invention also relates to a dye solution obtained by the above-mentioned process for producing a dye solution, wherein the dye solution comprises at least one component selected from the group consisting of citrates, phosphates, carbohydrates and an adsorbent, and citric acid. And drying, heating, spray-drying or freeze-drying under normal pressure or reduced pressure, and a pigment powder obtained by the production method.

The citrates are monopotassium citrate,
It includes monosodium citrate and the like, and preferably monopotassium citrate.

The phosphates include polyphosphates such as monophosphates and pyrophosphates, and metaphosphates.
Preferred are sodium or potassium salts of monophosphoric acid, pyrophosphoric acid and hexametaphosphoric acid, and more preferred are sodium or potassium salts of hexametaphosphoric acid.

The saccharides are preferably dextrin, lactose, glucose and fructose, and more preferred saccharides are dextrin, lactose and glucose, and a particularly preferred saccharide is dextrin.

The adsorbent is a material which adsorbs a dye and makes it insoluble in water, and may be in the form of a dispersible dye (lake). Preferably, zeolite containing crystalline cellulose or aluminum hydroxide is used. However, a more preferable adsorbent is crystalline cellulose (for example, Avicel (manufactured by Asahi Chemical Industry Co., Ltd.), but is not limited thereto). In the method for producing this pigment powder,
Preferably added to the dye solution are citric acid and monopotassium citrate; citric acid and monosodium phosphate; citric acid, monopotassium citrate and dextrin; citric acid, monosodium phosphate and dextrin; citric acid, citric acid Monopotassium acid and lactose; citric acid, monosodium phosphate and lactose; citric acid, dextrin and lactose; citric acid, monopotassium citrate and crystalline cellulose; and citric acid, monosodium phosphate and crystalline cellulose, more preferably Are citric acid, dextrin and lactose; citric acid, monopotassium citrate and dextrin; and citric acid, monosodium phosphate and dextrin.

As the compounding ratio of the above components, preferably, the colorant: all the selected components: citric acid is 100: 50.
To 200: 2 to 10 (weight ratio), for example, 100 parts by weight of a dye solution (CAV = 40): 100 parts by weight of dextrin: 4 parts by weight of citric acid, but is not limited thereto.

The drying temperature in the heat drying is 50 to 80 ° C. at normal pressure and 30 ° C. under reduced pressure (20 to 100 mmHg).
５０50 ° C. The drying temperature for spray drying is 80 at the inlet.
１２０120 ° C. and the outlet temperature is 40-70 ° C. The drying temperature for freeze-drying is -20 to -40C. Preferably, heat drying at 30 to 100 mmHg, 35 to 45 ° C
Or spray drying at an inlet temperature of 100 to 120 ° C. and an outlet temperature of 40 to 70 ° C. for 1 to 5 minutes.

In addition, the present invention relates to a method for producing pigment granules comprising granulating the above-mentioned pigment powder, and to the pigment granules obtained by the production method. Granulation means in this manufacturing method,
Usually, any means used in the art can be used, but the preferred means is a granulator.

The procedure and conditions for granulation may be those commonly used by those skilled in the art. For example, an excipient may be added and mixed and passed through a granulator at 20 to 30 ° C. for 10 to 20 seconds.
20-30kg / from 1.2mm mesh screen
Extrusion at a pressure of ² cm ³ and a hot air of 40-50 ° C. for 20-3
Flow dry for 0 minutes.

The excipients include dextrin, lactose,
Glucose and the like are preferred, and dextrin and lactose are preferred.

In addition, the present invention relates to the above-mentioned red pigment, pigment solution, pigment solution, pigment powder or pigment granules, wherein edible oil / fat; propylene glycol; sucrose fatty acid ester; gum arabic; glycerin fatty acid ester; A monoester of citric acid and / or
Also, the present invention relates to a method for producing an emulsified preparation of an oil-dispersed aqueous dye liquid comprising emulsifying by adding phosphates and water, and an emulsion preparation of an oil-dispersed aqueous dye liquid obtained by the method.

The "edible oils and fats" may be those used in the art and include edible oil, soybean oil, rapeseed oil, margarine and the like, and are preferably edible oil and soybean oil.

The "sucrose fatty acid ester" includes esters of sucrose and stearic acid, esters of sucrose and palmitic acid, esters of sucrose and oleic acid, esters of sucrose and acetic acid, and esters of sucrose and isobutyric acid. And the like, preferably an ester of sucrose and stearic acid,
Esters of sucrose and palmitic acid and esters of sucrose and isobutyric acid, more preferably esters of sucrose and palmitic acid, and esters of sucrose and stearic acid, particularly preferably sucrose and palmitic acid It is an ester.

The "glycerin fatty acid ester" includes glycerin lactic acid fatty acid ester, glycerin citrate fatty acid ester, glycerin succinic acid fatty acid ester, glycerin diacetyltartaric acid fatty acid ester, glycerin acetate fatty acid ester, glycerin fatty acid ester and the like. Preferably, it is a glycerin citrate fatty acid ester having an HLB of 3 to 20, glycerin succinate fatty acid ester, glycerin diacetyl tartaric acid fatty acid ester and glycerin fatty acid ester (provided that
The fatty acid in said ester means oleic acid, palmitic acid or stearic acid), more preferably H
Glycerin citrate oleate, glycerin citrate palmitate, glycerin succinate oleate, glycerin succinate palmitate, glycerin oleate and glycerin palmitate having an LB of 3 to 20.

The “monoesterified product of propylene glycol” includes monoesters of propylene glycol and stearic acid, monoesters of propylene glycol and palmitic acid, monoesters of propylene glycol and oleic acid, and monoesters of propylene glycol and linoleic acid. And preferably monoesters of propylene glycol and stearic acid and monoesters of propylene glycol and palmitic acid, more preferably monoesters of stearic acid and monoesters of palmitic acid.

The phosphates include polyphosphates such as monophosphates and pyrophosphates and metaphosphates,
Preferred are sodium and potassium salts of monophosphoric acid, pyrophosphoric acid and hexametaphosphoric acid, and more preferred are sodium and potassium salts of hexametaphosphoric acid.

The emulsion preparation of the oil-dispersed aqueous dye liquid of the present invention can be produced by using any of the compounding ratios usually used in the technical field. For example, it can be prepared by the following compounding ratios. .

Formulation Example 1 Pigment solution 10 parts Glycerin fatty acid ester 30 parts Citric acid 2 parts Edible oil and fat 20 parts Arabic gum 10 parts Water 15 parts Formulation example 2 Pigment powder 15 parts Glycerin fatty acid ester 25 parts Citric acid 2 parts Edible oil and fat 25 parts Water 15 parts Formulation Example 3 Dye solution 10 parts Sucrose fatty acid ester 40 parts Citric acid 2 parts Edible oil and fat 20 parts Arabic gum 10 parts Water 15 parts Formulation example 4 Pigment powder 15 parts Sucrose fatty acid ester 30 parts Citric acid 2 parts Edible oil and fat 20 parts water 15 parts Among the above-mentioned formulation examples, formulation examples 2 and 3 are preferred, and more preferred is formulation example 2.

Next, the red dye of taro and the method for producing the same according to the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

[0055]

【Example】

Example 1 10 × 3 potato stalks of hoopoe, a taro family taro
It is cut into a size of about 0 mm, and 10 kg thereof is cut by 5% (w /
v) To a tank containing 15 kg of an aqueous citric acid solution (pH 1.8 to 1.9), drain the liquid from the bottom of the tank,
The liquid was sprayed from the top in the form of a shower so as to cover the entire contents, the extract was circulated, and then slowly stirred.
This operation was performed at 25 ° C. for 8 hours. It was confirmed that the extraction of the pigment was sufficiently performed by re-extracting the extracted potato stalks, and the obtained extract was concentrated at 20 mmHg and 35 ° C. for 5 hours, and a wire mesh saucer (manufactured by Iida Seisakusho Co., Ltd.) JIS
Separated by a standard product (Testing sieve, wire diameter: 0.740 mm = 10 mesh). This solution was purified and filtered with Toyo Filter Paper 5A (manufactured by Toyo Filter Paper Co., Ltd.), and the filtrate was 18 kg (pH 2.3, maximum absorption wavelength λ _max = around 515-520 nm, dye concentration CAV =
1.3 (Calculated from the value of λ _{max in} the ultraviolet-visible absorption spectrum) (The ultraviolet-visible absorption spectrum is a spectrophotometer 220A, manufactured by Hitachi, Ltd. as a measuring device, and a tungsten lamp 10V4A NOMA and an ultraviolet absorption lamp are used as light bulbs. H4141SV HITACHI,
(Measured using a 0.5% (w / v) aqueous solution of citric acid as a target solvent), and the same in the following). The remaining cut product was washed with 2 kg of a 0.5% (w / v) aqueous citric acid solution.

20 kg of the extract was put into a rotary vacuum concentrator (Yamato Scientific Co., Ltd.) and concentrated under reduced pressure of 20 to 30 mmHg at 30 to 45 ° C. for 12 hours. Dye concentration CAV
= 40 and 0.7 kg was obtained. This solution is 5-10 ° C
For 24 hours, and the precipitated precipitate was purified by filtration with Toyo Filter Paper 5A, and 0.15 kg of 95% (w / v) ethanol and 0.02 kg of citric acid were added to the filtrate, and the pH was adjusted to 2.4. 0.87 kg of a dye solution having a concentration of 20% (w / w) and citric acid 3% (w / w) was obtained.

Example 2 22 kg of the red dye obtained by the method of Example 1 was used as a synthetic adsorbent Amberlite XAD-7 (manufactured by Organo Corporation).
The solution was passed through a 1 kg resin tower to adsorb the dye. Further, an aqueous solution containing 0.2% (w / v) citric acid (p
H2.3-2.6) 2 kg were passed twice to wash impurities.

The dye is desorbed and dissolved in an ethanol solution by passing 5 kg of 80% (w / v) ethanol containing 0.2% (w / v) citric acid into the resin tower, and dissolving the dye.
Then, a solution having a pigment concentration CAV of 5.5 (pH 2.
4) I got 4kg.

The solution was added at 20 to 30 mmHg for 25 to 3
0.58 kg of a dye solution obtained by adding 0.05 kg of 95% (w / v) ethanol to a dye having a dye concentration of CAV = 40 obtained by concentrating at 0 ° C. for 4 hours to give an alcohol concentration of 20%.
I got

The concentration of the dye solution was 0.5% (w /
v) Solution adjusted to an absorbance of 0.6 with citric acid aqueous solution (p
H = 2.2), an ultraviolet-visible absorption spectrum and a liquid chromatogram were measured. The measurement conditions of the liquid chromatogram are shown below. FIG. 2 shows the obtained absorption spectrum.

Liquid chromatography Measurement device: Shimadzu Corporation, liquid chromatogram LC-10 Detector: SPD-10A Column oven: CTO-10A Column: 1) Shimadzu Corporation, STR ODSII guard column 2) ( Shimadzu Corporation, STR ODSII column 4.6φ × 250mm Mobile phase: 0.01M NaClO ₄ (phosphate buffer) Column temperature: 40 ° C. Flow rate: 0.8 ml / min Detection: ultraviolet absorption 210 nm FIG. 515-5 pigments obtained from potato stalks
It shows that it has the maximum absorption wavelength around 18 nm.

In the obtained liquid chromatogram, a peak appeared at a retention time of 3.823 minutes. The retention time was the same as the peak observed in the measurement of grape juice pigment, which is an anthocyanin pigment.

Therefore, it is recognized that the pigment obtained from the sweet potato stalk according to the present invention is an anthocyanin pigment.

The pH of the dye solution was adjusted to 2.0, 3.0, and 4.0 with citric acid and sodium hydroxide, respectively.
Solutions adjusted to 0, 5.0, 6.0 and 7.0 were prepared. The UV-visible absorption spectrum of each solution having a different pH was measured in the same manner as described above. The results are shown in FIG.

FIG. 3 shows that the pigment obtained from the sweet potato stalk according to the present invention changes the absorbance curve under the influence of pH. 515-5 at pH 2.0-4.0
A peak of the maximum absorption wavelength is observed around 18 nm.
As H increased, the peak of the maximum absorption wavelength disappeared.

Example 3 2 g of citric acid and 5 g of lactose were added to 25 g of the dye solution obtained in Example 2.
And 10 g of dextrin are added and dissolved, and 30 to 5
The solution was concentrated by heating at 35 ° C. under a reduced pressure of 0 mmHg.
A powder 2 having a pigment concentration of CAV = 30 was dried by heating by concentrating to dryness at 40 to 50 ° C. for 3 hours and then pulverized.
5 g were obtained.

Example 4 The dye solution before concentration prepared in Example 3 was dried with a spray drier (inlet temperature: 120 ° C., outlet temperature: 70 ° C.) for 2 to 5 minutes, and 25 g of powder having a dye concentration CAV = 30 was obtained. I got

Example 5 Dextrin 1 was added to 100 g of the pigment powder obtained in Example 4.
Then, using a granulator (Fuji Paudal Co., Ltd.) and mixing at 20-30 ° C. for 10-20 seconds.
20-30kg / cm from 2mm mesh screen
Extrusion at a pressure of ² , fluidized dryer (Okawara Seisakusho Co., Ltd.)
, And flow-dried with hot air at 40 to 50 ° C for 20 to 30 minutes to obtain pigment granules 2 having a size of 1 mmφ x 3 mm.
00 g (dye concentration CAV = 15) was obtained.

Example 6 10 g of the pigment powder obtained in Example 3 or 4 was added to 20 g of edible oil (Nisshin Oil), sucrose palmitate 5
g, 50 g (w / v) gum arabic aqueous solution 20 g, propylene glycol 10 g, glycerin oleate 5 g, propylene glycol monostearate 5 g, and emulsify with an emulsifier (manufactured by Tokushu Kika Kogyo Co., Ltd.). 70 g of an emulsion preparation of an oil-dispersed aqueous dye liquid was obtained.

Comparative Example 1 Using the same raw materials as in Example 1, a test was conducted under the conditions shown in the following table.

[0071]

[Table 1]

30 to 40 in the preparation of (a) and (b)
Extraction at 8 ° C. for 8 hours (while heating at 75 ° C. for 90 minutes as a means of “punching” according to the cooking method at home) was performed. Then, the concentration was performed in the same manner as in Example 1.
Separation and purification were carried out to obtain 530 ml of a purified liquid, and about 10 g of citric acid was added in (a) and about 15 g in (b) to adjust the liquid volume to 600 ml and pH 2.3. The absorption spectra of the obtained solutions (b) and (a) are shown in FIGS. 4 and 5, respectively. When these absorption spectra are compared with the extract of Example 1, λ at 515 to 520 nm
_{No max} was observed and the absorbance at 515 nm was CAV
(A) was 0.16 and (b) was 0.14.
These values are very low as compared with 1.3 in Example 1, and are no longer valuable as dyes.

Comparative Example 2 300 ml of each of the extracts (a) and (b) obtained in Comparative Example 1
Was passed through a synthetic adsorbent Amberlite XAD-7 (75 ml) in a resin tower to adsorb colored substances. 0.2% more
(W / v) citric acid aqueous solution (pH 2.3 to 2.6) 2
Washed twice with 5 ml. Next, 80 ml of 80% (w / v) ethanol containing 0.2% (w / v) citric acid, water 2
The adsorbate was desorbed through 0 ml. 0.5 g of citric acid was added to these liquids in (a) and 1.0 g in (b) to adjust the pH to 2.2. 6 and 7 show the absorption spectra of (b) and (a), respectively. In these absorption spectra, the absorbance increased about 2.5 times as compared with the extract of Comparative Example 1, but the same change in the absorption spectrum was shown. So this result is
In the extraction under the conditions of Comparative Example 1, the taro pigment was decomposed, indicating that the target pigment could not be separated even by purification with an adsorbent.

Test Example 1 0.2% prepared from the red dye solution obtained in Example 2
(W / v) The light resistance and heat resistance in an aqueous citric acid solution are superior to those of anthocyanin pigments obtained from other plants. Tables 2 and 3 show the results of the light resistance test and the heat resistance test, respectively. The purple corn pigment solution and grape juice pigment solution used for comparison in the light resistance test and the heat resistance test were those obtained as follows.

[0075] Purple corn (Maize Morad)
100 g of the seed of o), 500 g of water and 50 g of citric acid were mixed and stirred at 45 to 50 ° C day and night. Filter the extract,
The colored filtrate was purified and concentrated in the same manner as in Example 2 to obtain 20 ml of a CVA = 5 solution.

Grape fruit (Bitis-Labruska)
V. labrusca L .; ) 1000 g of fruit was squeezed with a pressing machine (filter bag made of cloth) to obtain 800 ml of liquid. 50 g of citric acid was added thereto, and the mixture was allowed to stand at a temperature of 4 to 5 ° C. for 20 days. After confirming that the viscosity of the obtained solution was lowered and the dye was dissolved, purification and concentration were carried out according to Example 2 to obtain 20 ml of a CVA = 3 solution.

[0077]

[Table 2]

[0078]

[Table 3]

Table 2 shows the light fastness of the taro pigment and grape juice pigment of the present invention using the residual ratio of the pigment as an index.

Each dye solution 30 having a dye concentration CAV = 0.5
ml in a transparent glass container (φ = 2 cm × 18 cm test tube, height 10 cm), placed on the north window side of the room, 5 days,
The residual dye rate after 10 days and 14 days was shown as a percentage when the CAV on the day when the dye solution was prepared was defined as 100%. CAV was measured the absorbance lambda _max of 520nm vicinity similarly by a spectrophotometer as in Example 1.

From Table 2, it was confirmed that the red taro dye of the present invention has excellent light fastness as compared with other known dyes.

Table 3 shows the heat resistance of the red taro pigment, purple corn pigment and grape juice pigment of the present invention, using the residual ratio of the pigment as an index. Dye concentration CAV during preparation
= 0.5 in a warm water bath for 85-9
The solution was heated at 0 ° C. for 1 hour, and the CAV at the time of preparing the dye solution was 1
The residual ratio of the dye after heating when it was set to 00% was shown as a percentage. CAV was measured by a spectrophotometer in the same manner as in Example 1.
The absorbance λ _max near 20 nm was measured.

From Table 3, it was confirmed that the red taro dye of the present invention has excellent heat resistance as compared with other known dyes.

The dye solution of the present invention is made acidic, concentrated and
A rich product can be obtained. A solid product such as a powder can be obtained by adding an excipient or the like to the solution of the present invention and drying. An oil-dispersed product can be obtained by emulsifying with a fat, an emulsifier, a solubilizer, a stabilizer and the like.

[0085]

According to the present invention, there is provided a colorant which is safe even when contained in food, has good color, is excellent in light resistance and heat resistance, and has high utility value, and a method for producing the same.

[Brief description of the drawings]

FIG. 1 is an apparatus for extracting a pigment in a colored portion such as a sweet potato stalk that can be used in the present invention.

FIG. 2 is an ultraviolet-visible absorption spectrum of the red dye of the present invention obtained in Example 2.

FIG. 3 is an ultraviolet-visible absorption spectrum of the red dye of the present invention at a pH of 2.0 to 7.0.

FIG. 4 is an absorption spectrum of an extract of a sweet potato stalk obtained in Comparative Example 1 (b) with an aqueous solution of sodium hydrogen carbonate.

FIG. 5 is an absorption spectrum of an extract of a sweet potato stalk in water obtained in Comparative Example 1 (a).

FIG. 6 is an absorption spectrum of a liquid obtained by purifying an extract of a sweet potato stalk obtained in Comparative Example 2 (b) with an aqueous sodium hydrogen carbonate solution using an adsorbent.

FIG. 7 is an absorption spectrum of a liquid obtained by purifying an extract of a sweet potato stalk in water obtained in Comparative Example 2 (a) with an adsorbent.

[Explanation of symbols]

 Reference Signs List 1 SUS tank 2 Stirrer 3 Valve 4 Liquid feed pump 5 Dispersion liquid tube

Claims (15)

[Claims] 1. A red or reddish purple colored part of the taro family Araceae is cut, added to an acidic aqueous solution having a pH of 1.5 to 4.0, extracted at 15 to 80 ° C., and the obtained extract is constantly extracted. A method for producing a red dye comprising concentrating and purifying under pressure or reduced pressure. 2. The process according to claim 1, wherein the taro family Araceae is selected from the group consisting of Tonoimo, Akame, Ishikawase, Hoopoe and Black sorghum. 3. The method according to claim 1, wherein the acidic aqueous liquid is water, an alcohol or a mixture thereof containing an acid or a salt thereof. 4. The method according to claim 1, wherein the extraction is carried out by circulating and / or stirring the aqueous acid solution.
Or the manufacturing method of 3. 5. A red pigment obtained by the method according to claim 1, 2, 3, or 4. 6. The red dye obtained by the method according to claim 1 is purified, dissolved in an organic solvent, and an acid is added to the obtained solution to obtain an acidic solution having a pH of 1.7 to 4.0. A method for producing a dye solution comprising: 7. A dye solution obtained by the method according to claim 6. 8. A dye solution obtained by the method according to claim 6, which is concentrated under normal pressure or reduced pressure, and propylene glycol or ethanol, and / or monopotassium citrate or phosphates are added to the obtained concentrate. A method for producing a dye solution comprising adding. 9. A dye solution obtained by the method according to claim 8. 10. Addition of at least one component selected from the group consisting of citrates, phosphates, carbohydrates and adsorbents and citric acid to the dye solution obtained by the process according to claim 8. And a method for producing a pigment powder, which comprises performing heat drying, spray drying or freeze drying under normal pressure or reduced pressure. 11. A pigment powder obtained by the method according to claim 10. 12. A method for producing pigment granules, comprising granulating the pigment powder according to claim 11. 13. Pigment granules obtained by the process according to claim 12. 14. The reddish pigment, the pigment solution, the pigment solution, the pigment powder or the pigment granules according to claim 5, 7, 9, 11, or 13, wherein edible oil and fat; propylene glycol; sucrose fatty acid ester; A method for producing an emulsified preparation of an oil-dispersed aqueous pigment liquid, comprising adding a fatty acid ester; a monoesterified product of propylene glycol; citric acid and / or phosphates; and water to perform emulsification. 15. An emulsified preparation of the oil-dispersed aqueous pigment liquid obtained by the production method according to claim 14.