JP5753373B2 - Method for producing red pigment and food and drink containing the red pigment - Google Patents

Description

  The present invention relates to a method for producing a red pigment, and particularly relates to a method for producing a red pigment using an iridoid compound and an amino acid or protein hydrolyzate. Moreover, this invention relates to the food / beverage products containing the red pigment | dye obtained by the said method.

  In order to expand the use of red pigments, there is a need for improving the color tone and acid resistance of red pigments. Examples of the red pigment include various pigments such as gardenia red pigment, safflower red pigment, food red No. 2, No. 3, No. 40, anthocyanin, red beet and cochineal pigment. For example, a red pigment is produced by allowing an aglycone of an iridoid compound obtained from a fruit extract of Gardenia and a primary amino group-containing substance to act under acidic conditions. The red pigment derived from this gardenia fruit extract is superior in acid resistance, heat resistance and light resistance compared to other red pigments.

  Patent document 1 describes the manufacturing method of a red pigment | dye. This production method is characterized in that an iridoid compound and a substance having a primary amino group are reacted under acidic conditions. Examples of substances having the primary amino group include amino acids, soybean protein, and peptone (Table 1, Example IV).

  In the method for producing a red pigment of Patent Document 2, the substance (A) having a carboxyl group at the 4-position of the iridoid skeleton in the iridoid compound is converted into citric acid, malic acid, and succinic acid in an amount of 2 molar equivalents or more with respect to the substance (A). , 0.7 mole equivalent or more of arginine, lysine, aspartic acid, glutamic acid or a salt thereof with respect to an organic acid and substance (A) selected from the group consisting of tartaric acid, adipic acid, fumaric acid, ascorbic acid and erythorbic acid The reaction is performed in a pH range of 3 to 6.

  In the method for producing a gardenia red pigment of Patent Document 3, a substance having a carboxyl group at the 4-position of an iridoid skeleton in an iridoid compound is reacted with a primary amino group-containing substance in the presence of a pentose under acidic conditions. It is characterized by.

  Patent Document 4 describes a method for producing a blue pigment under aerobic conditions by coexisting an aridone of an iridoid glycoside and a taurine-containing substance. The method is characterized in that the blue pigment is produced in the presence of a polyphenol compound or the polyphenol compound is added after the blue pigment is produced.

  Patent Document 5 describes a method for producing a red pigment by reacting an iridoid compound having a carboxyl group at the 4-position of an iridoid skeleton with a protein hydrolyzate. In the protein hydrolyzate, the amino acid content of the hydrolyzate is 35% by weight or more, and 50% by weight or more of the amino acid is glutamic acid when measured by the ninhydrin method. And the ratio of the weight of leucine to the total weight of glutamic acid and aspartic acid is 8% or less.

JP-A-54-86668 JP-A-3-277663 JP-A-5-59296 JP-A-7-111896 Japanese Patent No. 4526600

There is a demand for bright and vivid colors of red pigments. It is also required that the dye has sufficient acid resistance and light resistance. Since the use of the red pigment is spreading and it is applied to various foods, it is desirable that the red color is maintained even under various conditions. Particularly in recent years, processed foods have become extremely diversified. For example, red foods with excellent acid resistance are required for low pH foods with strong acidity, and light resistance is required for foods in transparent packages. There is a need for excellent red pigments. There is also a need to reduce the production cost of the dye.
An object of this invention is to provide the manufacturing method of the red pigment | dye which satisfy | fills these requirements.

The present invention includes a step of reacting a compound represented by the following formula (I) or (II) with an amino acid or protein hydrolyzate, and a compound that generates sulfite ion in the reaction product (hereinafter referred to as “sulfite ion-generating compound”). A method for producing a red pigment is provided.

  The red pigment produced by the method of the present invention has improved color tone due to the action of the sulfite ion-generating compound as compared to the red pigment produced by the method in which the compound is not added. That is, according to the present invention, it is possible to produce a red pigment having a bright and vivid color tone. Furthermore, even if various amino acid or protein hydrolysates are used as a raw material for producing a red pigment, a red pigment having a bright and vivid color tone can be produced according to the present invention.

  Moreover, the red pigment produced by the method of the present invention is excellent in acid resistance. That is, when the dye is subjected to acidic conditions, precipitation is unlikely to occur. Furthermore, the red pigment produced by the method of the present invention has excellent light resistance. That is, even when the dye is irradiated with light, the dye is less likely to fade. In addition, even when the dye is irradiated with light, the amount of dye precipitate formed is small. Furthermore, the red pigment produced by the method of the present invention is excellent in heat resistance. That is, even when the dye is exposed to heat, the dye is less likely to fade. In addition, even when the dye is exposed to heat, the amount of dye produced by precipitation is small. As a result, since the dye can be used under various conditions, the dye can be used for coloring a wide variety of foods.

  Conventionally, as described in the specification of Japanese Patent Application No. 2010-179678, acid resistance has been improved by a taurine-containing substance. However, the acid resistance of the red pigment produced by the method of the present invention is further improved than the red pigment produced using the taurine-containing substance. In addition, since taurine-containing substances are expensive, there is a problem of increasing the production cost of the red pigment. On the other hand, although the sulfite ion-generating compound used in the method of the present invention is cheaper than a taurine-containing substance, the acid resistance is improved. Thus, the present invention reduces the cost of producing red pigment.

The method for producing a red pigment according to the present invention includes:
(1) a step of reacting an iridoid compound having a carboxyl group at the 4-position of the iridoid skeleton with an amino acid or protein hydrolyzate, and (2) a step of adding a sulfite ion generating compound to the reaction product.
In step (1), a red pigment is produced, and in step (2), the color tone and / or acid resistance of the red pigment produced in step (1) is improved. The red pigment obtained after the step (2) is a red pigment obtained by the production method of the present invention (hereinafter also referred to as “red pigment of the present invention”).

  The “iridoid compound having a carboxyl group at the 4-position of the iridoid skeleton” used in the production method of the present invention is a glycoside represented by the following formula (I) and / or a compound represented by the following formula (II). is there. The glycoside represented by the formula (I) is, for example, geniposide acid. The compound represented by the formula (II) is, for example, an aglycone of geniposide acid.

Gardenia fruit extracts contain a large amount of iridoid compounds. Gardenia are, for example, Gardenia Augusta Merrill and Gardenia jasminoides Ellis. This fruit extract has a compound having a carboxyl group (—COOH group) at the 4-position of the iridoid skeleton like geniposide acid, and a methyl ester group (—COOCH ₃ group) at the 4-position of the iridoid skeleton like geniposide. Compounds can be included. The methyl ester group of the compound having a methyl ester group can be converted to the carboxyl group by ester hydrolysis. The ester hydrolysis can be performed by allowing an alkaline solution, an OH type ion exchange resin, an enzyme having esterase activity, or the like to act alone or in combination. The fruit extract can be obtained, for example, by extracting from dry fruit of gardenia with water-containing ethanol or water. Geniposide is crude or purified and has a high purity, and is commercially available.

  The amino acid used in the production method of the present invention includes compounds having a carboxyl group and an amino group in the molecule and salts thereof. In the production method of the present invention, one or more kinds of amino acids may be used. The amino acid in the present invention is preferably an acidic amino acid, a neutral amino acid or a salt thereof, and more preferably an amino acid constituting a living body among these amino acids. In the present invention, an acidic amino acid refers to an amino acid having an isoelectric point of less than 5. Examples of acidic amino acids include aspartic acid (isoelectric point 2.77) and glutamic acid (isoelectric point 3.22). The acidic amino acid used in the present invention may have an isoelectric point of less than 5, and amino acids other than those described above can also be used. In the present invention, a neutral amino acid refers to an amino acid having an isoelectric point of 5 to 7. As preferred neutral amino acids in the method of the present invention, asparagine (isoelectric point 5.41), glutamine (isoelectric point 5.65), alanine (isoelectric point 6.00), glycine (isoelectric point 5.97) , Valine (isoelectric point 5.96), serine (isoelectric point 5.68), and threonine (isoelectric point 6.16), in particular alanine and valine. In the present invention, the neutral amino acid preferably has a molecular weight of 120 or less. When neutral amino acids (excluding asparagine and glutamine) having a molecular weight of more than 120 are used and when basic amino acids (that is, amino acids having an isoelectric point of more than 7) are used, a large amount of precipitate is generated in the reaction of step (1). The amount of red pigment obtained in step (1) can be reduced.

  The protein hydrolyzate used in the production method of the present invention can be obtained by hydrolyzing an arbitrary protein. In the production method of the present invention, one or more kinds of protein hydrolysates may be used, or a mixture of protein hydrolysates and amino acids may be used. The hydrolysis can be performed with an acid, an enzyme, or the like. Examples of the acid include hydrochloric acid. Such enzymes include papain, bromelain, thermolysin, sputum or sputum degradation products, or other proteases.

  A gluten hydrolyzate is mentioned as an example of the protein hydrolyzate used in the manufacturing method of this invention. Examples of the gluten hydrolyzate include wheat gluten hydrolyzate, corn gluten hydrolyzate, or gluten hydrolyzate derived from cereals such as barley and rye, and mixtures thereof. A commercially available wheat gluten hydrolyzate can also be used as the protein hydrolyzate. Gluten is usually obtained as a by-product in the production of wheat starch from wheat flour. For example, when a kneaded product obtained by adding a small amount of water to a wheat flour and kneading it with water is washed with water, while the wheat starch is suspended in water, a residual solid mass not suspended in water is produced. The mass includes gluten and may further include about 60-70% by weight moisture. Water can be removed from the mass in order to enhance storage stability, but it can also be used as it is. The form of gluten can be pasty, powdery or granular.

Preferably, the lower limit of the amino acid content relative to the dry weight of the protein hydrolyzate is 35% by weight, preferably 36% by weight, preferably 37% by weight, preferably 38% by weight, preferably 39% by weight, more preferably 40%. % By weight, more preferably 41% by weight, even more preferably 42% by weight. With this amino acid content, the preferred red color is achieved in the red pigment obtained in step (1), the pigment is fastened, and sufficient color strength is achieved. The upper limit of the amino acid content relative to the dry weight of the protein hydrolyzate may be any value. For example, 99% by weight, 98% by weight, 97% by weight, 96% by weight, 95% by weight, 90% by weight, 85% %, 80%, 75% or 70% by weight. In the present invention, the upper limit and the lower limit of the amino acid content may be appropriately selected from the above values, but may be, for example, 35 to 99% by weight, particularly 36 to 98% by weight, and more particularly 37 to 97% by weight. . The “dry weight of the hydrolyzate” refers to the weight of the protein hydrolyzate excluding the weight of the excipient and moisture. The dry weight is measured by an atmospheric pressure drying method using an electronic moisture meter (Shimadzu Corporation, MOC-120H). In the method, heat drying is performed by heating to 120 ° C. with an infrared heater. The weight of moisture is based on the amount of decrease when a constant weight is reached in heat drying. The weight of the excipient can be measured by conventional techniques in the art. The weight of dextrin and starch can be measured, for example, by carrying out the Somogyi-Nelson method or enzymatic method after hydrolysis. The weight of lactose can be measured, for example, by the HPLC method. The “amino acid content” is obtained from the analysis result of amino acid composition by the ninhydrin method. In the ninhydrin method, the amino acid composition is analyzed by first separating the amino acids by HPLC (L-7000, Hitachi High-Technologies Corporation) and measuring the absorbance of the color developed by the ninhydrin reaction (for example, “Hygiene Test Method”). (See Note 2005, edited by the Japan Pharmaceutical Association, published February 2005, Kanehara Publishing).
The amino acid content refers to the weight percent occupied by free amino acids in the dry weight of the protein hydrolyzate, that is, aspartic acid, threonine, serine, glutamic acid, proline, glycine, alanine, cysteine, valine, methionine, isoleucine, It refers to the weight percentage occupied by the total amount of leucine, tyrosine, phenylalanine, lysine, histidine, arginine, glutamine, asparagine and tryptophan. In the present invention, free amino acids do not include amino acids present in proteins or peptides.
In the present invention, the weight of the free amino acid contained in the protein hydrolyzate is a value measured by the ninhydrin method. Glutamine is determined as glutamic acid when measured by the ninhydrin method. That is, the amount of glutamic acid determined by the ninhydrin method is the total amount of glutamine and glutamic acid in the free amino acid. Similarly, asparagine is determined as aspartic acid when measured by the ninhydrin method. That is, the amount of aspartic acid determined by the ninhydrin method is the total amount of asparagine and aspartic acid in the free amino acid.

  Of the total amino acid content of glutamic acid, aspartic acid, asparagine, glutamine, alanine, glycine, valine, serine and threonine (especially alanine, valine, glutamic acid and aspartic acid, more particularly glutamic acid and aspartic acid) The lower limit is 50 wt%, preferably 52 wt%, more preferably 54 wt%, even more preferably 56 wt%, even more preferably 58 wt%. With the total weight of these amino acids, the preferred red color is achieved, the dye is fastened, and sufficient color strength is achieved. The upper limit of the total weight may be any value, for example, 99% by weight, 98% by weight, 97% by weight or 96% by weight. In the present invention, the upper and lower limits are appropriately selected from the above values, and are, for example, 50 to 99% by weight, 52 to 98% by weight, or 54 to 97% by weight.

  Leucine relative to the total weight of glutamic acid, aspartic acid, asparagine, glutamine, alanine, glycine, valine, serine, and threonine (especially alanine, valine, glutamic acid and aspartic acid, and more particularly glutamic acid and aspartic acid) in the protein hydrolyzate The weight ratio is preferably 8% or less, more preferably 7% or less, and even more preferably 6% or less. In the method of the present invention, the ratio is preferably as low as possible, and the protein hydrolyzate may not contain leucine. By the said ratio, the red pigment | dye obtained at a process (1) has a bright and vivid color tone. Further, the above ratio ensures a sufficient yield of the red pigment obtained in the step (1). This ratio is obtained by analyzing the amino acid composition by the ninhydrin method.

  Proline relative to the total weight of glutamic acid, aspartic acid, asparagine, glutamine, alanine, glycine, valine, serine and threonine (especially alanine, valine, glutamic acid and aspartic acid, and more particularly glutamic acid and aspartic acid) in protein hydrolysates The ratio of the weight of is preferably 15% or less, more preferably 12% or less, and even more preferably 10% or less. In the method of the present invention, the ratio is preferably as low as possible, and proline may not be contained in the protein hydrolyzate. This ratio increases the amount of red pigment produced in step (1). This ratio is obtained by analyzing the amino acid composition by the ninhydrin method.

These ratios can be achieved by hydrolyzing, neutralizing and filtering the protein, optionally generating a precipitate by pH adjustment or cooling, and optionally dissolving the precipitate.
If the protein hydrolysis is carried out, for example with an acid, the said ratio can be achieved in the filtrate by neutralizing the protein hydrolyzate and then filtering. As the acid, hydrochloric acid or the like is used. The hydrolysis method is appropriately determined depending on the protein to be used and the hydrolyzate to be obtained, and is, for example, treatment with 3 to 6 M hydrochloric acid at 80 to 120 ° C. for 10 to 20 hours.
The neutralization can be performed by adding an alkali such as sodium hydroxide or potassium hydroxide. The neutralization conditions can be appropriately determined depending on the acid and protein used in the hydrolysis and the hydrolyzate to be obtained.
The filtration may be performed by natural filtration, vacuum filtration, pressure filtration, or centrifugal filtration, and preferably by pressure filtration. The pressure filtration can be performed by a filter press.
The pH adjustment is performed by adjusting the filtrate to pH 2-4. Next, the filtrate is cooled and stirred to form a precipitate, and the cake obtained by further filtering the precipitate-containing filtrate can be used as a protein hydrolyzate having the above ratio. The pH adjustment can be performed with an acid such as hydrochloric acid. Prior to the pH adjustment, the filtrate may be concentrated 1.2 to 2 times with an evaporator. In the cooling, the temperature of the filtrate is 40 ° C. or less, preferably 30 ° C. or less, more preferably 20 ° C. or less, and even more preferably 10 ° C. or less. The agitation may be performed so as to avoid a decrease in the amount of precipitate that is subjected to subsequent filtration due to sedimentation of the generated precipitate. The filtration may be performed by natural filtration, vacuum filtration, pressure filtration, or centrifugal filtration. The cake is again suspended in water and washed, and the cake obtained by filtering again is dried and used as a protein hydrolyzate having the above-mentioned ratio, but it can also be used as it is. The said ratio can also be reduced by repeating the said washing | cleaning and filtration.
The obtained cake is suspended in water, the pH is adjusted to 4-6 to dissolve the cake, and then filtered to obtain a filtrate. The filtrate can be used as the protein hydrolyzate. The pH adjustment can be performed with an alkali such as sodium hydroxide.
These filtrates can be spray dried with a spray dryer. The obtained dry powder can also be used as the protein hydrolyzate. Before spray drying, excipients such as dextrin can be added to the filtrate.

The protein hydrolyzate may be used in the form of a mixture containing excipients. Examples of the excipient include excipients commonly used in the art such as dextrin, lactose, and starch. The excipient may be added to the hydrolyzate, for example, before the following spray drying of the protein hydrolyzate or after drying as a bulking agent.
In the present invention, the protein hydrolyzate may contain substances other than amino acids, such as water, sodium chloride, peptides, proteins, and nitrogen-containing substances that do not affect the amino acid analyzer. These substances other than amino acids can be substances that are generated and / or added during the preparation of protein hydrolysates.

The “compound capable of producing sulfite ions” used in the production method of the present invention refers to a compound capable of producing sulfite ions in water. Examples of such compounds include sodium sulfite, potassium sulfite, sodium dithionite, potassium dithionite, sodium pyrosulfite, potassium pyrosulfite, sodium hydrogen sulfite, potassium hydrogen sulfite, and anhydrous sulfurous acid. It is commercially available.
In the present invention, in the step (2), the color tone of the red pigment obtained in the step (1) is improved by the action of the sulfite ion generating compound. To improve the color tone means that the brightness and / or redness of the red pigment increases compared to the reference red pigment, that is, the L value increases by 0.5 or more in the Hunter-Lab color system. This means that the a value increases by 0.5 or more, or that both the L value and the a value increase by 0.5 or more. Alternatively, the improvement in color tone means that the color difference is increased by 0.5 or more or the color difference is increased by 0.5 or more and the L value is increased in the Hunter-Lab color system as compared with the reference red pigment. It means that 0.5 or more increases, a value increases 0.5 or more, or both L value and a value increase 0.5 or more.
In the present invention, in the step (2), the acid resistance, heat resistance and / or light resistance of the red pigment obtained in the step (1) is improved by the action of the sulfite ion generating compound.

The addition amount of the sulfite ion-generating compound may be more than 0 mol with respect to the dye amount 1 ku (kilo unit) of the red dye in the reaction product obtained in the step (1). Preferably, the addition amount is more than 0 to 7 mmol, more preferably 0.01 to 5 mmol, even more preferably 0.1 to 4 mmol, and particularly preferably 0.5 to 3 mmol, with respect to 1 ku of the dye amount. With these addition amounts, particularly favorable color tone improvement and acid resistance improvement are achieved in step (2). Further, a sufficient amount of the dye can be obtained in the step (2) by adding these amounts.
Here, the pigment amount (u) is calculated by multiplying the color strength (u / g) by the pigment solution weight (g). The color strength is measured by the color strength measurement method, that is, the dye solution is diluted with water or a buffer as necessary, and the absorbance at the maximum absorption wavelength in the visible region is measured with an ultraviolet-visible spectrophotometer (UV-2450, Shimadzu Corporation). ) And multiply the measured value by the dilution rate. The unit of chromatic power is u / g, which indicates the amount of dye per gram of dye solution, that is, the dye concentration expressed by absorbance at the maximum absorption wavelength. Therefore, the amount of 1u dye is the amount of dye contained in a 1 g dye solution having an absorbance of 1 as measured at the maximum absorption wavelength. Here, since the solvent of the dye solution is generally water or a buffer solution, the amount of dye assumes that the density of the dye solution is 1 g / cm ³ , that is, the amount of dye of 1 u is the maximum absorption wavelength. It can be said that the amount of the dye contained in the 1 cm ³ dye solution having an absorbance of 1 is measured.

  In the production method of the present invention, the reaction product can be heated after the addition of the sulfite ion-generating compound in order to improve the color tone and / or acid resistance of the red pigment. Alternatively, the sulfite ion generating compound may be added to the heated reactant and the reaction may be further heated. The heating improves the color tone and / or acid resistance and shortens the time until these improvements. The heating temperature may be 40 to 100 ° C, preferably 50 to 97 ° C, more preferably 60 to 95 ° C. In the production method of the present invention, the heating time after the addition of the sulfite ion generating compound is 0.25 to 5 hours, preferably 0.5 to 4 hours, more preferably 0.75 to 3 hours. According to the heating temperature and the heating time, in step (2), the color tone and acid resistance are improved, and the time taken to achieve these improvements can be shortened. Further, a sufficient amount of the dye can be obtained in the step (2) by adding these amounts. The heating temperature and heating time can be appropriately combined by those skilled in the art according to the type and amount of the sulfite ion-generating compound, the apparatus used, and the production conditions.

  The sulfite ion generating compound is added to a reaction product of an iridoid compound having a carboxyl group at the 4-position of the iridoid skeleton and an amino acid or protein hydrolyzate. That is, the sulfite ion generating compound is preferably added after the step (d) or (e) described below, more preferably after the step (f). When added before the following step (d) or (e), the sulfite ion generating compound reacts with the amino acid or protein hydrolyzate, iridoid compound, organic acid or enzyme, and as a result, the amount of the compound is red. There is a problem that a desired red pigment cannot be obtained because the amount is less than the amount required for improving the color tone and acid resistance of the element. The addition of the sulfite ion-generating compound may be performed at any time after step (1). Therefore, it is also possible to perform only the production of the red pigment obtained in the step (1) by the above reaction first, and perform the step (2) when it is necessary to improve the color tone and / or the acid resistance.

In the present invention, the reaction product can be subjected to a separation treatment, particularly a filtration treatment, and more particularly an ultrafiltration treatment, before adding the sulfite ion-generating compound. For example, in the case of ultrafiltration treatment, a sulfite ion generating compound can be added to the concentrated liquid obtained by the treatment. By this treatment, unreacted substances such as organic acids, amino acids and iridoid compounds remaining in the reaction product are removed in the permeate, and the reaction product of the iridoid compound and amino acid or protein hydrolyzate is contained in the concentrated solution. Concentrated. And by adding a sulfite ion production | generation compound in a concentrate, reaction of the said unreacted substance and a sulfite ion production | generation compound reduces significantly. As a result, the acid resistance is efficiently improved by the sulfite ion generating compound. As these separation processes, other processes known to those skilled in the art may be employed.
In this invention, you may add a sulfite ion production | generation compound, without performing the said separation process. In this case, considering the reaction of unreacted substances such as organic acids, amino acids and iridoid compounds with the sulfite ion generating compound, a sufficient amount of the sulfite ion generating compound to react with the red pigment is added. The amount of sulfite ion generating compound can be adjusted. The amount added can be appropriately adjusted by those skilled in the art.

While the sulfite ion-generating compound provides an improvement in the color tone and acid resistance of the red pigment, it can also cause degradation of the red pigment. Therefore, when a large amount of the sulfite ion-generating compound remains in the reaction product, the red pigment may be decomposed by the sulfite ion-generating compound, and a sufficient amount of red pigment may not be recovered. Therefore, in the present invention, after the color tone and acid resistance are improved by adding a sulfite ion generating compound, the unreacted sulfite ion generating compound can be removed. The removal can be performed by, for example, an ultrafiltration process, but may be performed by other removal processes known to those skilled in the art.
In the present invention, by adjusting the amount of the sulfite ion generating compound, the amount of the sulfite ion generating compound remaining without reacting with the red pigment can also be minimized. As a result of the minimization, when the sulfite ion generating compound remaining in the reaction product can be ignored, the sulfite ion generating compound may not be removed.
Moreover, you may add a lot of sulfite ion production | generation compounds to the reaction material of an iridoid compound and an amino acid or a protein hydrolyzate, without performing the said separation process before addition of a sulfite ion production | generation compound. After acid resistance is improved by the reaction between the sulfite ion-generating compound and the red pigment, unreacted substances such as sulfite ion-generating compounds, organic acids, amino acids and iridoid compounds are collected by separation treatment, particularly ultrafiltration treatment. May be removed.

  Hereinafter, step (1) and step (2) of the method for producing a red pigment according to the present invention will be described.

Process (1)
The reaction between the iridoid compound having a carboxyl group at the 4-position of the iridoid skeleton and the amino acid or protein hydrolyzate can be performed under any conditions, but generally includes the following steps (a) to (f): .

(A) Mixing of iridoid compound and amino acid or protein hydrolyzate When amino acid is used, the amount of amino acid is 0.5 mol or more, preferably 0.5 to 5 mol, more preferably 0.6 to 1 mol of iridoid compound. The amino acid and the protein hydrolyzate are mixed so as to be ˜3 mol, and more preferably 0.7 to 2 mol. When a protein hydrolyzate is used, the amino acid in the protein hydrolyzate is 0.5 mol or more, preferably 0.5 to 5 mol, more preferably 0.6 to 3 mol, and even more per 1 mol of the iridoid compound. The iridoid compound and the protein hydrolyzate are mixed so that the amount is preferably 0.7 to 2 mol. When an iridoid compound having a methyl ester group at the 4-position of the iridoid skeleton is used, the methyl ester group is converted to a carboxyl group by ester hydrolysis before the mixing. The ester hydrolysis can be performed by allowing an alkaline solution, an OH type ion exchange resin, an enzyme having esterase activity, or the like to act alone or in combination. An example of the alkaline solution is a sodium hydroxide solution, but pellet-like or flaky solid sodium hydroxide can also be added to the iridoid compound aqueous solution. For example, a 10 to 40% by weight NaOH solution and a 40 to 60% by weight iridoid compound aqueous solution are mixed at a weight ratio of 40:60 to 60:40, and water is further added to the mixture in an amount of 10 to 30% by weight. Addition and ester hydrolysis are performed by heating at 30-70 ° C. for 1-3 hours.

(B) Addition of organic acid An organic acid may optionally be added to the mixture of the iridoid compound and the amino acid or protein hydrolyzate. Examples of the organic acid include citric acid, malic acid, tartaric acid, adipic acid, fumaric acid, ascorbic acid or succinic acid, or a mixture thereof. The organic acid may be added in an amount of 2 mol or more, preferably 3 to 6 mol, per 1 mol of the iridoid compound.

(C) Adjustment of pH with alkali An alkaline solution is added to the mixture obtained by the above (a) or (a) and (b) to adjust the pH to 3 to 6, more preferably 4 to 5. Examples of the alkaline solution include a 10 to 40% by weight sodium hydroxide solution, but it can also be prepared by adding the above solid sodium hydroxide.

(D) Reaction with enzyme having β-glucosidase activity An enzyme having β-glucosidase activity is added to the mixture after pH adjustment in (c) above to cause an enzyme reaction. As an enzyme having β-glucosidase activity, for example, cellulase AP5 (Amano Enzyme Co., Ltd.), cellulase Onozuka 3S (Yakult Pharmaceutical Co., Ltd.), Sumiteam AC (Shin Nippon Chemical Co., Ltd.), cellulase Y2-NC or cellulase Y- NC (Yakult Pharmaceutical Co., Ltd.) etc. are mentioned. The conditions for the enzyme reaction are appropriately selected according to the selected enzyme. Typically, the enzyme reaction is performed at 30 to 70 ° C. for 1 to 30 hours. The iridoid compound is hydrolyzed by the enzyme reaction to obtain an aglycone of the iridoid compound. (A) can also be abbreviate | omitted by performing the process of (a)-(f), using the said aglycone as a raw material.

(E) Heating of reaction product After the enzyme reaction of (d) above, the reaction product (particularly the reaction solution) is heated at 80 to 100 ° C for 0.5 to 12 hours, preferably 1 to 6 hours, more preferably 2 to 2 hours. Heat for 3 hours.

(F) Separation treatment After the heating in (e) above, the reactant is optionally subjected to a separation treatment. The separation process is particularly performed by a membrane filtration process. Any membrane that can permeate sulfite ions and concentrate the dye may be used. In the present invention, the preferred membrane filtration treatment is ultrafiltration membrane treatment or RO membrane treatment (particularly, loose RO membrane treatment). The fractional molecular weight of the membrane used in the ultrafiltration membrane treatment is preferably 1000 to 35000, more preferably 2000 to 30000. Examples of the material for the ultrafiltration membrane include polysulfone, polyethersulfone, polyacrylonitrile, polyimide, aromatic polyamide, and ceramic. Examples of the membrane type include a hollow fiber module type, a plate type module type, and a flat membrane type. The module type is preferable from the viewpoint of filtration speed. Examples of the ultrafiltration device include SIP-1013 and SIP-3013 (hollow fiber module, membrane material: polysulfone, molecular weight cut off: 6000) manufactured by Asahi Kasei Kogyo Co., Ltd., and UF-10PS (manufactured by Tosoh Corporation). And a molecular weight of 10,000). The exclusion limit of the RO membrane is preferably 1000 to 30000, more preferably 2000 to 25000. In the membrane filtration treatment, it is preferable to use a loose RO membrane. Here, the loose RO membrane is an RO membrane having a salt rejection rate (salt removal rate) of 98% or less and used at an operating pressure of 30 / G or less, particularly a membrane intended to remove divalent ions. It is. Examples of the material for the loose RO membrane include polysulfone, polyethersulfone, polyacrylonitrile, polyimide, aromatic polyamide, and ceramic. Examples of the membrane type include a hollow fiber module type, a plate type module type, and a flat membrane type. The module type is preferable from the viewpoint of filtration speed. As the loose RO membrane, for example, NTR-7410, NTR-7450, NTR-7250 and N-T-7250 manufactured by Nitto Denko Corporation, SU-610 and SU-620 manufactured by Toray Industries, Inc. can be exemplified. By this separation treatment, particularly by ultrafiltration treatment or RO membrane (particularly loose RO membrane) treatment, a reaction product of an iridoid compound and an amino acid or protein hydrolyzate, an iridoid compound, amino acid, protein hydrolyzate, organic Unreacted substances such as acids and enzymes can be separated. The separation may not be performed completely and only the amount of unreacted material relative to the amount of reactant may be reduced. These separation processes are known to those skilled in the art, but preferably an ultrafiltration process or an RO membrane process is used. Filtration treatment conditions can be appropriately determined by those skilled in the art.

Step (2)
The addition of the sulfite ion-generating compound is performed according to the following step (g), and then the step (h) can be performed.

(G) Addition of sulfite ion generating compound After the reaction of (d) above, after the heating of (e) above or after the separation treatment of (f) above, the sulfite ion generating compound is added to the reaction product. The addition amount of the sulfite ion-generating compound is more than 0 to 7 mmol with respect to 1 ku of the amount of dye present in the reaction product after the reaction of (d) above, after the heating of (e) above or after the separation treatment of (f) above. More preferably, it is 0.01-5 mmol, More preferably, it is 0.1-3 mmol. After the addition of sulfurous acid, the mixture of the reaction product of step (1) and the sulfite ion-generating compound may be heated to improve color tone and acid resistance. The heating temperature may be 40 to 100 ° C, preferably 50 to 97 ° C, more preferably 60 to 95 ° C. The heating time is 0.25 to 24 hours, preferably 0.5 to 5 hours, and more preferably 0.75 to 3 hours. The heating temperature and the heating time can be appropriately selected by those skilled in the art.

(H) Dye separation The means for separating the red pigment obtained in the step (g) can be appropriately selected by those skilled in the art. Examples of the separation means include centrifugation, filtration, particularly ultrafiltration, acidic precipitation, addition of a hydrophilic organic solvent, ion exchange, or a combination thereof.

In the present invention, the color tone is a color tone in the Hunter-Lab color system. The color system is a color system that forms a color solid composed of orthogonal coordinates including a and b axes indicating chromaticity and an L axis perpendicular thereto. If the a value increases on the positive side, it means reddish, and if it increases on the negative side, it means greenish. If the b value increases on the positive side, it means yellowish, and if it increases on the negative side, it means that the blueness is increasing. The L value corresponds to the brightness. The color when L = 100 is white, and the color when L = 0 is black. The color becomes lighter as the L value increases. The color tone of the red pigment of the present invention is preferably such that L is 70 or more, more preferably 71 or more, even more preferably 72 or more, and a is preferably 30 or more, more preferably 32 in the Lab color system. As described above, even more preferably 34 or more. The combination of the values of L and a can be appropriately selected from the above values, but L is preferably 70 or more and a is preferably 30 or more, L is 71 or more and a is 32 or more. It is more preferable that L is 72 or more and a is 34 or more. More preferably, the color tone of the red pigment produced by the method of the present invention is such that, in the Lab color system, L is preferably 70 or more, more preferably 71 or more, even more preferably 72 or more, and preferably a is 30 or more, more preferably 32 or more, even more preferably 34 or more, and b may be preferably −8.0 or less, more preferably −8.2 or less, and even more preferably −8.4 or less. . The combination of the values of L, a and b can be appropriately selected from the above values, but it is preferable that L is 70 or more, a is 30 or more and b is −8 or less, and L is 71 or more. More preferably, a is 32 or more and b is -8.2 or less, L is 72 or more, a is 34 or more, and b is -8.4 or less. More preferred. A moderately bright and bright red color can be achieved by the color tone having the values of L and a or the color tone having the values of L, a and b. That is, the color tone having the values of L and a or the color tone having the values of L, a, and b is a bright and vivid color tone. Furthermore, since the said color tone is reddish, in order to obtain the red color of the food / beverage products which should be added, the said pigment | dye alone can be used.
The measurement of the color tone can be performed using a measuring device known to those skilled in the art. Examples of the measuring device include a spectral color difference meter (for example, SD5000 (Nippon Denshoku Industries Co., Ltd.)), a colorimetric color difference meter (for example, ZE6000, SZ-Σ80 or SE-2000 (all Nippon Denshoku Industries Co., Ltd.)). It is done. The L value, a value, and b value of the color tone are values obtained by measuring, with a cell having an optical path length of 1 cm, a dye solution having a maximum absorption wavelength or an absorbance at a predetermined wavelength of 0.5 by dilution with water or a buffer solution. is there.

  The red pigment of the present invention is excellent in acid resistance. Due to the excellent acid resistance, precipitation and turbidity are hardly generated even when the dye solution is subjected to acidic conditions. In the present invention, acid resistance refers to the property of maintaining the color strength of an aqueous dye solution with little occurrence of turbidity and precipitation due to the dye in an aqueous dye solution under acidic conditions. In the present invention, excellent acid resistance means pH 3.8, particularly pH 3.5, more particularly pH 3.2 or lower, 10 hours, 12 hours, 14 hours, 16 hours, 18 hours. When the dye is applied for 1 day, 2 days, 3 days or longer, the dye residual ratio is 75% or more, preferably 80% or more, more preferably 85% or more, even more preferably 90% or more, most Preferably it means 95% or more. That is, the dye remaining rate of the red dye produced by the method of the present invention is 75% or more, preferably 80% or more, more preferably 85% or more, even more preferably 90% or more, and most preferably 95% or more. It is. In the present specification, the pigment remaining rate means how much pigment remains in the supernatant from which the turbidity and precipitation generated in the pigment solution have been removed. When turbidity or precipitation occurs, the pigment compound can also be present in the turbidity or precipitation. The dye residual ratio is evaluated by the method described in Example 8 below.

  The present invention also relates to a food or drink containing the red pigment of the present invention. That is, the red pigment of the present invention can be added to various foods and drinks. Examples of the food and drink to which the red pigment of the present invention is added include, but are not limited to, noodles, liqueurs, beverages, confectionery, milk beverages, salmon, fish meat, and meat sausages. The red pigment of the present invention may be used together with other pigments. The other pigments can be appropriately selected by those skilled in the art depending on the desired color, and examples thereof include blue pigments, yellow pigments, and red pigments other than the red pigment of the present invention.

  Especially the red pigment | dye of this invention can be added to the food-drinks which are in acidic conditions. The acidic food or drink may be acidic by itself or may show acidity as a result of adding various acids. The food or drink to which the red pigment of the present invention is added has little discoloration even if the food or drink is acidic. Because there is little discoloration, the quality of food and drink is not impaired. As food / beverage products in the said acidic condition, food / beverage products of pH 5 or less, food / beverage products of pH 4.5 or less, food / beverage products of pH 4 or less, or food / beverage products of pH 3.5 or less can be mentioned, for example. Examples of such foods and drinks include, but are not limited to, jelly, candy, beverages containing fruit juice or fruit flavored beverages, frozen desserts, ice confections and pickles.

  Especially the red pigment | dye of this invention can be added to the food-drinks irradiated with light. Such food and drink are, for example, food and drink sold in bags and containers that cannot be shielded from light such as plastic bags, plastic bottles, and glass bottles, but are not limited thereto. The food or drink to which the red pigment of the present invention is added has little discoloration even when the food or drink is irradiated with light. Because there is little discoloration, the quality of food and drink is not impaired.

  Although the addition amount to the food / beverage products of the red pigment | dye of this invention is suitably determined according to the color of the food / beverage products to be obtained, for example, 0.001-15 weight%, Preferably it is 0.01-10 weight%, More preferably Is 0.05 to 5% by weight.

The present invention will be described below with reference to examples, but the present invention is not limited to these examples.
In the following examples, the color strength and color tone of the dye solution were measured. These measurement methods are as follows. Further, the pigment amount and the color difference were calculated from the measured color strength and color tone, respectively.
The color strength (u / g) is determined by a color strength measurement method, that is, the dye solution is diluted with water or a buffer as necessary, and the absorbance at the maximum absorption wavelength in the visible region is measured with an ultraviolet-visible spectrophotometer (UV-2450). And obtained by multiplying the measured value by the dilution rate. The unit of chromatic power is u / g, which indicates the amount of dye per gram of dye solution, that is, the dye concentration expressed by absorbance at the maximum absorption wavelength.
The color tone is obtained by diluting the obtained dye solution with water or a buffer solution so that the absorbance at the maximum absorption wavelength or a predetermined wavelength is 0.5, and using the cell with an optical path length of 1 cm, the color difference meter (SZ-Σ80, Nippon Denshoku Industries Co., Ltd.).
The dye amount (u) is the product of the color strength and the weight (g) of the dye solution. That is, the amount of 1u dye is the amount of dye contained in a 1 g dye solution having an absorbance of 1 as measured at the maximum absorption wavelength. Here, the amount of the dye is based on the assumption that the density of the dye solution is 1 g / cm ³ because the solvent of the dye solution is water or a buffer solution, that is, the amount of dye of 1 u is the maximum absorption wavelength. It can be said that the amount of the dye contained in the 1 cm ³ dye solution having an absorbance of 1 is measured.
Color difference (Delta] E value), formula: was determined by ΔE = √ ((L-L' ) 2 + (a-a') 2 + (b-b') 2). In the above formula, L ′, a ′, and b ′ are the hues of the reference dye, and L, a, and b are the hues of the dyes to be compared with the reference dye. That is, the ΔE value indicates the degree to which the color tone of the pigment to be compared has changed with respect to the color tone of the reference pigment. When the ΔE value is 0.5 or more, particularly 1.0 or more, and more particularly 1.5 or more, it can be said that the color tone has been improved.

  Manufacture of red pigment

(1) Amino acid Sodium aspartate (Nacalai Tesque, Inc., sodium L-aspartate) was prepared.

(2) Preparation of iridoid compound Geniposide was prepared by adding 35 g of a 24 wt% aqueous sodium hydroxide solution to 60.8 g of geniposide solution containing 22.5 g of geniposide and heating at 60 ° C for 1.5 hours to saponify. An acid solution was prepared. In the obtained geniposide acid solution, 50 g of water and 35 g of DL-malic acid were dissolved to adjust the pH to 3.8.

(3) Production of red pigment The geniposide acid solution after pH adjustment was divided into two equal parts, and 1.2 molar equivalents of sodium aspartate (3.1 g) with respect to geniposide acid were added to one of them. The pH of the solution was adjusted to 4.6 with a 24 wt% aqueous sodium hydroxide solution. After pH adjustment, water was added to bring the liquid volume to 150 g, and 0.65 g of cellulase Y2NC (Yakult Pharmaceutical Co., Ltd.) was added to the solution. After replacing the container containing the solution with argon gas, the enzyme reaction was carried out by heating in a hot bath at 55 ° C. for 24 hours. After the enzyme reaction, the enzyme reaction solution was heated at 85 ° C. for 3 hours, and the heated reaction solution was cooled to room temperature and then centrifuged (10000 rpm × 10 minutes). The color strength of the supernatant obtained by centrifugation was 283.0 u / g. 10 g of this supernatant was weighed into 6 test tubes with lids, and 12.5, 25, 50, 100, 200, or 500 mg of sodium sulfite (Na ₂ SO ₃ ) was added per 1 ku of the dye amount calculated from the color strength. (That is, the amount of sodium sulfite added is 0.099, 0.198, 0.397, 0.793, 1.586, or 3.965 mmol / ku). After the addition, the test tube was vortexed and heated at 85 ° C. for 1 hour. After heating, the mixture was cooled to room temperature and centrifuged (3000 rpm × 10 minutes) to obtain a supernatant. The obtained supernatant is a solution of the red pigment of the present invention (hereinafter referred to as “red pigment of Example 1”).

(Comparative Example 1)
A red pigment (hereinafter referred to as “red pigment of Comparative Example 1”) was produced in the same manner as the red pigment of Example 1 except that sodium sulfite was not added.

  The color strength and color tone of the red pigment of Example 1 and the red pigment of Comparative Example 1 were measured. Further, the color difference was calculated from the measured color tone. Table 1 shows the measurement results of color strength and color tone, and the calculated color difference.

  From the results shown in Table 1, when the red pigment of Comparative Example 1 is used as a reference, the red pigment of Example 1 has an a value increased by 0.5 or more, and the amount of sodium sulfite added is 100 m to At 500 g / ku, the L value also increases by 0.5 or more. Further, when the red pigment of Comparative Example 1 is used as a reference, the red pigment of Example 1 has a color difference of 0.5 or more. That is, the red color of Example 1 was improved in color tone as compared with the red color of Comparative Example 1. In particular, the color tone was remarkably improved when the amount of sodium sulfite added was 100 mg / ku and 200 mg / ku. When the addition amount of sodium sulfite is 500 mg / ku, the color tone is improved as in the case of other addition amounts, but the color strength is lower than in the case of other addition amounts.

  Manufacture of red pigment

(1) Amino acids DL-alanine (Nacalai Tesque), valine (L-valine, Nacalai Tesque), asparagine (L-asparagine hydrate, Nacalai Tesque), glutamine (L-glutamine, Nacalai Tesque) Company) or sodium glutamate (hereinafter also referred to as “MSG”; sodium L-glutamate, Nacalai Tesque, Inc.).

(2) Preparation of iridoid compound Geniposide was prepared by adding 235 g of a 24 wt% aqueous sodium hydroxide solution to 304.1 g of geniposide solution containing 112.5 g of geniposide and heating to 60 ° C for 1.5 hours to saponify. An acid solution was prepared. In the obtained geniposide acid solution, 150 g of water and 167 g of DL-malic acid were dissolved to adjust the pH to 4.15.

(3) Manufacture of red pigment After pH adjustment, the geniposide acid solution is divided into 10 equal parts, and five of them are 1.1 molar equivalents of DL-alanine (2.84 g) and valine, respectively, with respect to geniposide acid. (3.74 g), asparagine (4.79 g), glutamine (4.69 g) or sodium glutamate (5.96 g) were added, respectively, and the pH was adjusted to 4.5 with 24 wt% aqueous sodium hydroxide. After pH adjustment, water was added to bring the liquid volume to 150 g, and 0.67 g of cellulase Y2NC (Yakult Pharmaceutical Co., Ltd.) was added to each solution. After replacing the inside of the container containing the solution with argon gas, the enzyme reaction was carried out by heating in a hot bath at 55 ° C. for 21 hours. After the enzyme reaction, the enzyme reaction solution was heated at 85 to 90 ° C. for 3 hours, and the heated reaction solution was cooled to room temperature. The color strength of this reaction solution was 271.5 u / g for those added with DL-alanine, 141.4 u / g for those added with valine, and 100.4 u / g for those added with asparagine. Yes, it was 243.5 u / g for those to which glutamine was added, and 410.5 u / g for those to which sodium glutamate was added. 10 g of these supernatants were weighed into a test tube with a lid, and 50 mg of sodium sulfite (Na ₂ SO ₃ ) was added per 1 ku of the dye amount calculated from the color strength (that is, the sodium sulfite addition amount was 0.397 mmol / ku). Is). After the addition, the test tube was vortexed and heated at 85 ° C. for 1 hour. After heating, the mixture was cooled to room temperature and centrifuged (3000 rpm × 10 minutes) to obtain a supernatant. The obtained supernatant is a solution of the red pigment of the present invention (hereinafter referred to as “red pigment of Example 2”).

(Comparative Example 2)
A red pigment (hereinafter referred to as “red pigment of Comparative Example 2”) was produced in the same manner as the red pigment of Example 2 except that sodium sulfite was not added.

The color strength and color tone of the red pigment of Example 2 and the red pigment of Comparative Example 2 were measured, respectively. Further, the color difference was calculated from the measured color tone. Table 2 shows the measurement results of color strength and color tone, and the calculated color difference.

  From the results shown in Table 2, when the red pigment of Comparative Example 2 is used as a reference, the red pigment of Example 2 has an a value increased by 0.5 or more, and L values for amino acids other than alanine Also increased by more than 0.5. Further, when the red pigment of Comparative Example 2 is used as a reference, the red pigment of Example 2 has a color difference of 1 or more, asparagine is 1.5 or more, and alanine, valine, and glutamine are 2 or more. is there. That is, in any case of using any amino acid, the red color of Example 2 is improved in color tone as compared with the red color of Comparative Example 2. Therefore, even when various amino acids were used, the color tone was improved by the addition of sodium sulfite.

Production of red pigments using various compounds that produce sulfite ions

(1) Amino acid MSG (sodium glutamate, Nacalai Tesque, Inc.) was prepared.

(2) Preparation of iridoid compound After adding 73 g of a 24 wt% aqueous sodium hydroxide solution to 94.6 g of geniposide solution containing 35 g of geniposide, water was added to make the solution volume 300 g, and then at 60 ° C. for 2 hours. A geniposide acid solution was prepared by saponification by heating.

(3) Production of red pigment To the obtained geniposide acid solution, 57 g of hydrous citric acid (Kyowa High Foods Co., Ltd.) and 20.2 g of MSG were added. After the addition, the pH was adjusted to 4.6 with a 24% by weight aqueous sodium hydroxide solution, then transferred to a 500 ml Erlenmeyer flask, and the liquid volume was adjusted to 500 g with water. To this solution, 2.5 g of cellulase Y2NC (Yakult Pharmaceutical Co., Ltd.) was added. After replacing the inside of the container of the solution with argon gas, the enzyme reaction was carried out by heating in a hot bath at 55 ° C. for 21 hours. After the enzyme reaction, the mixture was heated at 85 to 90 ° C. for 3 hours, and the reaction solution was cooled to room temperature. The color strength of the obtained reaction solution was measured. Based on the measured color strength (355.9 u / g), 10 ku (28.1 g) of a reaction solution corresponding to a dye amount of 10 ku is weighed into a plurality of 50 ml volumetric flasks, and the sulfite ion-producing compound is placed in the volumetric flask. As sodium sulfite, sodium dithionite (hydrosulfite), sodium pyrosulfite or sodium hydrogensulfite was added. The amount of sodium sulfite and sodium hydrogen sulfite added was about 0.4 mmol / ku. For sodium dithionite and sodium pyrosulfite, two kinds of addition amounts of about 0.4 mmol / ku and about 0.2 mmol / ku were used, respectively. After the addition of these compounds, the pH was adjusted to 5 with a 24 wt% aqueous sodium hydroxide solution, and water was added to bring the liquid volume to 50 g, followed by further mixing. After mixing, the flask was heated at 85 ° C. for 1 hour. After heating, the flask is cooled to room temperature, and the resulting dye solution is a solution of the red dye of the present invention (hereinafter referred to as “red dye of Example 3”).

(Comparative Example 3)
A red pigment (hereinafter referred to as “red pigment of Comparative Example 3”) was produced in the same manner as the red pigment of Example 3 except that the compound that generates sulfite ions was not added.

The color strength and color tone of the red pigment of Example 3 and the red pigment of Comparative Example 3 were measured. Further, the color difference was calculated from the measured color tone. Table 3 shows the measurement results of color strength and color tone, and the calculated color difference.

  From the results shown in Table 3, when the red pigment of Comparative Example 3 was used as a reference, the red pigment of Example 3 had an L value of 0.5 in any of sodium sulfite, sodium dithionite and sodium pyrosulfite. As a result, the a value increased by 0.5 or more in any of sodium sulfite, sodium pyrosulfite and sodium hydrogen sulfite. Furthermore, when the red pigment of Comparative Example 3 was used as a reference, the red pigment of Example 3 had a color difference of 1.5 or more. That is, the color tone of the red pigment of Example 3 was improved as compared with the red pigment of Comparative Example 3 in any case where any compound that generates sulfurous acid was used. When sodium dithionite was used, the color difference was the largest, but the decrease in color strength was also significant.

Production of red pigment using protein hydrolyzate A red pigment solution was produced by the method described in Example 1 of Japanese Patent No. 4526600. To 5 g (415.6 u / g) of this red dye solution, 100 mg of sodium sulfite was added and dissolved. And it heated at 85 degreeC for 30 minute (s). The red pigment solution obtained by heating is the red pigment of the present invention (hereinafter referred to as “red pigment of Example 4”).

(Comparative Example 4)
A red pigment (hereinafter referred to as “red pigment of Comparative Example 4”) was produced in the same manner as the red pigment of Example 4 except that sodium sulfite was not added.

The color strength and color tone of the red pigment of Example 4 and the red pigment of Comparative Example 4 were measured. Further, the color difference was calculated from the measured color tone. Table 4 shows the measurement results of color strength and color tone and the calculated color difference.

  In Table 4, the reference “before adding sodium sulfite” red pigment is a red pigment produced by the method described in Example 1 of Japanese Patent No. 4526600, that is, only by the above step (1). The manufactured red pigment is shown. In Table 4, “Ratio to stock solution” is the ratio of the color strength of the red pigment of Example 4 or Comparative Example 4 to the red pigment “before sodium sulfite addition”. From the results shown in Table 4, compared with the reference red pigment, the red pigment of Example 4 had an a value increased by 0.5 or more immediately after heating, and the color difference also increased by 2 or more. After two days, both the L value and the a value increased by 0.5 or more, and the color difference also increased by 3 or more. That is, the color tone of the red pigment of Example 4 was improved as compared with the reference red pigment. Further, from the results shown in Table 4, when the red pigment “before sodium sulfite addition” is used as a reference, the red pigment of Example 4 has a larger color difference than the red pigment of Comparative Example 4. That is, the color tone was improved more by adding sodium sulfite and heating than by heating without adding sodium sulfite. Further, in the result after standing at room temperature for 2 days, the color difference was further increased, that is, the color tone was further improved.

Production of red pigment using sodium bisulfite and protein hydrolyzate A red pigment was produced by the method described in Example 1 of Japanese Patent No. 4526600. UF membrane separation device (tubing pump: LP-3000, limited) equipped with the red dye, a membrane with a molecular weight cut off of 10,000 (membrane cassette: UF-2CS-10PS, filtration area is 200 cm ² per cassette) External filtration module: UF-LMSII, Tosoh Corporation). By this treatment, the purified and concentrated dye solution (1157 u / g) was weighed into 5 Erlenmeyer flasks each with a dye amount of 43.2 g (equivalent to 50 ku). To each of these five flasks was added 2.5 g of sodium bisulfite of the concentrate (100 mg of sodium bisulfite per 2 ku dye amount). After the addition, the pH of the concentrate was adjusted to 4, 5, 6, 7 or 8 using citric acid and sodium hydroxide, respectively. After adjusting the pH, water was added to each flask to bring the liquid volume to 100 g, and the concentrated liquid was heated at about 85 ° C. for 1 hour. After the heating, the concentrated solution was cooled to room temperature, and centrifuged (3000 rpm × 10 minutes) to obtain a supernatant. The obtained supernatant is a solution of the red pigment of the present invention (hereinafter referred to as “red pigment of Example 5”).

(Comparative Example 5)
A red dye (hereinafter referred to as “red dye of Comparative Example 5”) in the same manner as the red dye of Example 5 except that sodium bisulfite was not added and the pH was not adjusted with citric acid and sodium hydroxide. ) Was manufactured.

The red dye of Example 5 and the red dye of Comparative Example 5 were diluted with McIlvane buffer, and the color strength and color tone were measured. Further, the color difference was calculated from the measured color tone. Table 5 shows the measurement results of color strength and color tone, and the calculated color difference.

  From the results shown in Table 5, as compared with the red pigment of Comparative Example 5, all of the red pigments of Example 5 have an a value increased by 0.5 or more. Increased by 5 or more. Further, when the red pigment of Comparative Example 5 is used as a reference, the red pigment of Example 5 has a color difference of 1 or more. That is, even when sodium hydrogen sulfite was used, the color tone of the red pigment was improved. Moreover, even if the pH of the solution during the treatment with sodium hydrogen sulfite was any of 4 to 8, the color tone of the red pigment of Example 5 was improved as compared with Comparative Example 5.

  A red pigment (hereinafter referred to as “red pigment of Example 6”) was produced in the same manner as the red pigment of Example 5 except that the heating time at 85 ° C. was 2 hours.

(Comparative Example 6)
A red dye (hereinafter referred to as “red dye of Comparative Example 6”) was prepared in the same manner as the red dye of Example 5 except that the heating time at 85 ° C. was 2 hours and no sodium bisulfite was added. Manufactured.

  The color strength and color tone of the red pigment of Example 6 and the red pigment of Comparative Example 6 were measured. Further, the color difference was calculated from the measured color tone. Table 6 shows the measurement results of color strength and color tone and the calculated color difference.

  From the results shown in Table 6, when the red pigment of Comparative Example 6 was used as a reference, the red value of Example 6 increased the L value and the a value by 0.5 or more. Further, when the red pigment of Comparative Example 6 was used as a reference, the color difference of all the red pigments of Example 6 increased by 0.5 or more. That is, the color tone was improved even when the treatment time with sodium hydrogen sulfite was 2 hours.

Production of red pigment using sodium sulfite and protein hydrolyzate (1) Preparation of wheat gluten hydrolyzate Wheat gluten hydrolyzate (hereinafter referred to as “hydrolysis” by the method described in Example 1 of Japanese Patent No. 4526600 1)) was prepared. Table 7 shows the amino acid composition of hydrolyzate 1.

(2) Preparation of iridoid compound A geniposide acid solution was prepared by adding 150 g of water and 125 g of 24 wt% sodium hydroxide to 162 g of geniposide solution containing 60 g of geniposide and saponifying the mixture at 60 ° C for 2 hours. 150 g of crystalline citric acid (Wako Pure Chemical Industries, Ltd., special grade citric acid) was added to the obtained geniposide acid solution. The obtained liquid mixture was put into the Erlenmeyer flask.

(3) Production of red pigment 43 g of hydrolyzate 1 was added to an Erlenmeyer flask and mixed. The amount of hydrolyzate 1 added was adjusted so that geniposide acid and the amino acid were equimolar when the average molecular weight of the amino acid contained in hydrolyzate 1 was 139. The average molecular weight was calculated by performing a weighted average based on the amino acid composition of a commercially available gluten hydrolyzate (Nisshin Pharma Co., Ltd., WGH, http://www.wgh.jp/shiryoubako/000010.php). Next, 24 wt% sodium hydroxide solution was added to the mixture to bring the pH to 4.5. Water was further added to this mixture to make the liquid volume 900 g. Next, the inside of the Erlenmeyer flask was replaced with argon gas. After the replacement, 3.2 g of cellulase Y2NC (Yakult Pharmaceutical Co., Ltd.) was added, covered with aluminum foil, and allowed to react at 58 ° C. for 21 hours. After the reaction, the reaction product was heated at 85 ° C. for 3 hours with a heater (Yamato Scientific Co., Ltd., water bath incubator BT-25). Thereafter, the reaction solution was divided into three equal parts and transferred to three Erlenmeyer flasks. About two of them, the color strength of the reaction solution was measured, and based on the measured color strength, 2 g of sodium sulfite (about 20 mg per 1 ku of dye amount) and 5 g (about 50 mg for 1 ku of dye amount) were added, respectively. . After the addition, the reaction solution was heated at 85 ° C. for 1 hour by the heater. After heating, the reaction solution was cooled to about 50 ° C., centrifuged at 10,000 rpm for 10 minutes, and the resulting supernatant was subjected to ultrafiltration treatment. The filtration is performed by a UF membrane device (Tosoh Corporation, tubing pump: LP-3000, ultramembrane module: UF-LMSII) equipped with a membrane having a molecular weight cut off of 10,000 (Tosoh Corporation, UF-2CS-10PS). went. In the filtration method, 300 ml of deionized water was added to about 300 g of the reaction liquid and circulated and filtered, and when the permeate reached 300 ml, the concentrate was again supplemented with 300 ml of deionized water and circulated and filtered. The deionized water was replenished three times in total. The concentrated solution obtained by the filtration treatment is the red pigment of the present invention. (Hereinafter, 2 g of sodium sulfite added is referred to as “Red Dye 1 of Example 7”, and 5 g of sodium sulfite is added as “Red Dye 2 of Example 7”).

(Comparative Example 7)
A red pigment (hereinafter referred to as “red pigment of Comparative Example 7”) was produced in the same manner as the red pigment of Example 7 except that sodium sulfite was not added.

The color strength and color tone of the red pigment 2 of Example 7 and the red pigment of Comparative Example 7 were measured. Further, the color difference was calculated from the measured color tone. Table 8 shows the measurement results of color strength and color tone, and the calculated color difference.

  From the results shown in Table 8, when the red pigment of Comparative Example 7 was used as a reference, both the L value and the a value of the red pigment 2 of Example 7 increased by 0.5 or more. When the red pigment of Comparative Example 7 is used as a reference, the red pigment 2 of Example 7 has a color difference of 2 or more. That is, the red dye 2 of Example 7 has an improved color tone as compared with the red dye of Comparative Example 7.

The red dye 2 of Example 7 and the red dye of Comparative Example 7 were evaluated for heat resistance and light resistance. The heat resistance was evaluated according to the following procedure. A pH 4 or 6 McIlvine buffer (0.1 M aqueous citric acid solution and 0.2 M disodium hydrogen phosphate) was made. The red dye 2 dye liquid of Example 7 and the red dye dye liquid of Comparative Example 7 were mixed with the pH 4 and 6 buffer solutions, respectively, so that the color strength of the mixture liquid was about 1 u / g. . After the color strength adjustment, the test tube containing the mixture was immersed in boiling water for 30 minutes. Water-cooled after boiling treatment, the turbid test solution was filtered with No2 filter paper (Advantech Toyo Co., Ltd.), and the color tone of the filtrate itself and the absorbance of the filtrate were adjusted to 0.5 with a buffer solution of the same pH. The color of the thing was measured. In the light resistance evaluation, the above mixed solution was irradiated with 20000 lx light for 20 hours by a photo chamber (illuminated incubator, FLI-2000HT, Tokyo Rika Co., Ltd.). The test solution in which turbidity occurred after the irradiation treatment was filtered with No2 filter paper (Advantech Toyo Co., Ltd.), and the color tone of the filtrate whose absorbance was adjusted to 0.5 with a buffer solution having the same pH was measured. Table 9 shows the evaluation results of heat resistance and light resistance.

In Table 9, the red pigment treated in the pH 4 buffer was compared to the pre-treatment red pigment at pH 4. The red pigment treated in pH 6 buffer was compared with the pre-treatment red pigment at pH 6. From Table 9, the red pigment of Example 7 has a smaller color difference due to the heat treatment and the light irradiation treatment than the red pigment of Comparative Example 7. That is, the red pigment of Example 7 has less change in color tone than the red pigment of Comparative Example 7 even when subjected to heat treatment or light irradiation treatment. Therefore, the red pigment of Example 7 is superior to the red pigment of Comparative Example 7 in heat resistance and light resistance.

Production of red pigments using various amino acids and protein hydrolysates

(1) Amino acid MSG, L-sodium aspartate, and DL-alanine (all of which are Nacalai Tesque) and hydrolyzate 1 were prepared.

(2) Preparation of iridoid compound A geniposide acid solution was prepared by adding 90 g of a 24 wt% sodium hydroxide aqueous solution to 122 g of geniposide solution containing 45 g of geniposide and heating to 60 ° C for 1.5 hours to saponify. did. In the obtained geniposide acid solution, 100 g of water and 110 g of citric acid were dissolved to adjust the pH to 3.5.

(3) Manufacture of red pigment The geniposidic acid solution after pH adjustment was divided into 4 equal parts, and 1.1 molar equivalents of MSG (5.96 g), sodium aspartate (5.52 g), respectively, DL-alanine (2.84 g) and hydrolyzate 1 (8.51 g) were added, and the pH was adjusted to 4.5 by adding a 24 wt% aqueous sodium hydroxide solution. To 150 g. 0.6 g of cellulase Y2NC (Yakult Pharmaceutical Co., Ltd.) was added to each solution. After replacing the inside of the container of the solution with argon gas, the enzyme reaction was carried out by heating in a warm bath at 58 ° C. for 21 hours. After the enzyme reaction, the mixture was heated at 85 to 90 ° C. for 3 hours. After the heating, 10 g of each reaction solution was placed in a test tube with a lid, and 100 mg of sodium sulfite was added to the amount of dye 2 ku in the reaction solution. After the addition, vortexed and heated at 85 ° C. for 60 minutes. After the heating, the reaction solution was cooled and centrifuged (10000 rpm × 10 minutes). The obtained supernatant is a solution of the red pigment of the present invention (hereinafter referred to as “red pigment of Example 8”).

(Comparative Example 8)
A red pigment (hereinafter referred to as “red pigment of Comparative Example 8”) was produced in the same manner as the red pigment of Example 8 except that sodium sulfite was not added.

  The acid resistance of the red pigment of Example 8 and the red pigment of Comparative Example 8 was evaluated. The evaluation method is as follows. That is, a solution corresponding to 750 u in terms of the dye amount at the maximum absorption wavelength of each of the red dye solution produced in Example 8 and the red dye solution of Comparative Example 8 was weighed, and a pH 4 McIlvaine buffer was added to adjust the liquid volume. 150 g. Concentrated phosphoric acid (Wako Pure Chemical Industries, special grade phosphoric acid, 85%) was added dropwise to each solution with stirring to lower the pH, and when pH 3.2, 2.8 and 2.4 were reached, each was covered. About 10 ml of the solution was collected in a test tube. These pH solutions were allowed to stand in the refrigerator (about 4 ° C.) for 3 days. Three days later, 1 ml of the supernatant of the solution in the test tube was taken into another test tube, 4 ml of deionized water was added, and vortexed. After stirring, the absorbance was measured at a wavelength of 530 nm for the red pigment solution using DL-alanine as a raw material and at a wavelength of 535 nm for the red pigment solution using other amino acids and hydrolyzate 1 as a raw material. The dye residual ratio was determined from the obtained absorbance. The pigment remaining rate is the color strength of the red pigment solution excluding the precipitate after the pH treatment with respect to the color strength of the red pigment solution produced in Example 8. The unit is%, and the higher the residual ratio, the higher the acid resistance. Table 10 shows the dye residual ratio of each solution.

  From the results shown in Table 10, in any of the amino acids and the hydrolyzate 1, the dye residual ratio of the example is higher than that of the comparative example at any pH. Therefore, the acid resistance of the red pigment solution of Example 8 was improved by treatment with sodium sulfite. In addition, red pigments using alanine as a raw material had a higher pigment residual ratio at pH 2.8, particularly pH 2.4, compared with red pigments using other raw materials, and were excellent in acid resistance.

  Production of red pigment using sodium sulfite and protein hydrolyzate

(1) Protein hydrolyzate The hydrolyzate 1 used in Example 7 was prepared.

(2) Preparation of iridoid compound To 270 g of geniposide solution containing 100 g of geniposide, 250 g of water and 200 g of a 24 wt% sodium hydroxide aqueous solution were added, and heated at 60 ° C. for 2 hours to saponify the geniposide acid solution. Prepared.

(3) Production of red pigment To the geniposide acid solution obtained in (2), 250 g of crystalline citric acid (Wako Pure Chemical Industries, Ltd., special grade citric acid) was added and mixed. The obtained liquid mixture was put into the Erlenmeyer flask. To the Erlenmeyer flask, 64 g of the hydrolyzate 1 was added and mixed. After the addition, the pH was adjusted to 4.5 with a 24 wt% aqueous sodium hydroxide solution, and the liquid volume was adjusted to 1500 g with water. To this solution, 5.5 g of cellulase Y2NC (Yakult Pharmaceutical Co., Ltd.) was added, replaced with argon gas, covered with aluminum foil, and allowed to react at 55 ° C. for 21 hours. After the reaction, the reaction product is heated at 85 ° C. for 3 hours with a heater (Yamato Scientific Co., Ltd., water bath incubator BT-25), cooled to about 50 ° C., and centrifuged (10000 rpm × 10 minutes). went. The color strength of the supernatant after centrifugation was measured, and the supernatant corresponding to a dye amount of 200 ku was weighed, and 10 g of sodium sulfite was dissolved while stirring well. Then, the solution was gently stirred all day and night, and then the pH was adjusted to 5.3 with 4N hydrochloric acid. After pH adjustment, the solution was heated at 90 ° C. for 1 hour. After heating, the solution was cooled to room temperature. After cooling, a UF membrane separator (tubing pump: LP-3000, ultrafiltration) equipped with one membrane with a molecular weight cut off of 10,000 (membrane cassette: UF-2CS-10PS, filtration area is 200 cm ² per cassette) Module: UF-LMSII, Tosoh Corporation). Unreacted amino acids, citric acid, and sodium sulfite were removed by the filtration treatment. The concentrated solution obtained by the filtration treatment is a solution of the red pigment of the present invention (hereinafter referred to as “red pigment of Example 9”).

(Comparative Example 9-1)
Production of red pigment without adding sodium sulfite and taurine In Example 9, “(3) Production of red pigment”, in addition to hydrous citric acid and 48 g of hydrolyzate 1, taurine ( Nacalai Tesque, Inc.) Red dye (hereinafter referred to as “Comparative Example”) in the same manner as in Example 9, except that 8 g was added, sodium sulfite was not added, and heating was not performed at 90 ° C. for 1 hour. 9-1 red pigment ").

(Comparative Example 9-2)
Production of red pigment without addition of sodium sulfite Red pigment (hereinafter referred to as “Comparative Example”) was the same as that of Example 9 except that sodium sulfite was not added and heating was not performed at 90 ° C. for 1 hour. 9-2 red pigment ").

The acid resistance of the red pigment of Example 9, the red pigment of Comparative Example 9-1, and the red pigment of Comparative Example 9-2 was compared. The acid resistance was evaluated as follows. That is, each of the red pigment solution of Example 9, the red pigment solution of Comparative Example 9-1, and the red pigment solution of Comparative Example 9-2 was adjusted to pH 3.3, 3.2,. The solution was diluted with McIlvine buffer of 2.1 and 2.1 (with appropriate addition of phosphoric acid to adjust the pH) so that the color strength was 5 u / g, and left overnight in a refrigerator. After standing still overnight, the mixture was centrifuged at 3000 rpm for 10 minutes, and the color strength of the supernatant after centrifugation was measured. The ratio of the measured color power to the color power of the dye solution not subjected to pH treatment is the dye residual ratio. The higher the dye residual ratio of the dye, the better the acid resistance. Table 11 below shows the evaluation results of acid resistance.

  From the results in Table 11, the red pigment of Example 9 has a pigment residual ratio of more than 90% at pH 2.4. On the other hand, the red pigment of Comparative Example 9-2 decreased to a pigment residual ratio of about 43% at pH 3.2. Therefore, acid resistance improved by adding sodium sulfite. Further, in Comparative Example 9-1, the pigment residual ratio decreased to about 26% at pH 2.6. That is, the acid resistance of the red pigment is more improved in the method using sodium sulfite than in the method using taurine.

(Drinking fruit jelly)
A drinking fruit jelly containing the red pigment of the present invention was prepared with the following composition. First, 0.8 g of a gelling agent, 5 times the amount of sugar (4 g) of the gelling agent, and water were mixed. Next, the gelling agent and sugar were dissolved while the mixture was heated to 90 ° C. After dissolution, the mixture was cooled to 75 ° C. After cooling, the remaining raw materials were added, and citric acid was added so that the pH of the mixed solution was 3.8, and water was added so that the total weight of the mixed solution was 100 g. The resulting mixture was filled into beverage containers, sealed, and sterilized at 83 ° C. for 20 minutes. After sterilization, the mixed solution was cooled to obtain a drinking fruit jelly.
<Combination>
Sugar 18 parts by weight 1/5 concentrated fruit juice 6 parts by weight White liquor 2 parts by weight Gelling agent 0.8 parts by weight Red pigment of Example 3 0.05 parts by weight (using sodium sulfite. Color value E 10% to 100 Corresponding darkness pigment)
Amount of water to be 100 parts by weight Amount of citric acid pH = 3.8

    The color value E10% is a numerical value obtained by converting the absorbance at the maximum absorption wavelength of the colorant solution into the absorbance of a solution corresponding to 10% by weight / volume.

(Yotei)
An sheep containing the red pigment of the present invention was produced with the following composition. First, agar and water were mixed, and agar was dissolved while boiling the mixture for 15 minutes. After the solution was cooled to 70 ° C., the remaining ingredients were added and dissolved by stirring. Finally, the solution was boiled until the total amount of the solution became about 100 g, and then filled into a container. After filling, it was cooled to obtain a sheep.
<Combination>
Ginger 44 parts by weight Sugar 51 parts by weight Mizuame 5 parts by weight Agar 0.6 parts by weight Red pigment of Example 7 0.1 part by weight (Dye having a color value E of 10% corresponding to 100)
25 parts by weight of water

(Soft drink)
The soft drink containing the red pigment | dye of this invention was manufactured with the following mixing | blendings. The raw material was dissolved in hot water and then filled into a beverage container. The pH of the solution after dissolving with hot water was 3.8.
<Combination>
Sugar 30 parts by weight Liquid sugar 25 parts by weight Sodium citrate 1 part by weight Vitamin C 0.5 part by weight Red pigment of Example 7 0.05 part by weight (color pigment having a darkness corresponding to a color value E10% of 100)
Amount to make 100 parts by weight of boiling water Amount to make citric acid pH = 3.8 Perfume Appropriate amount

(jelly)
A jelly containing the red pigment of the present invention was produced with the following composition. 1.2 g of the gelling agent, 5 times the amount of the gelling agent sugar (6 g) and water were mixed. Next, the gelling agent and sugar were dissolved while the mixture was heated to 90 ° C. Next, the solution was cooled to 75 ° C. After cooling, the remaining raw materials were added and dissolved by stirring. The pH of this solution was 3.8. The solution was filled in a jelly container, sealed, and sterilized at 83 ° C. for 20 minutes. After sterilization, the solution was cooled to obtain a jelly.
<Combination>
Sugar 16 parts by weight Sodium citrate 1 part by weight Malic acid 1.35 parts by weight Gelling agent 1.2 parts by weight Red pigment of Example 4 0.05 parts by weight (Dye having a darkness corresponding to a color value E of 10% of 100) )
Amount of water 100 parts by weight Citric acid Amount of pH = 3.8 Perfume

(Gum)
A gum containing the red pigment of the present invention was produced with the following formulation. Gum was produced by kneading other ingredients into the gum base.
<Combination>
Gum base 99.5 parts by weight Ascorbic acid 0.1 parts by weight Red pigment of Example 7 0.05 parts by weight (color pigment having a color value E10% corresponding to 100)
50% by weight citric acid water 0.35 parts by weight

(Hard candy)
The hard candy containing the red pigment | dye of this invention was manufactured with the following mixing | blendings. Sugar and gardenia red pigment were added to the starch candy and mixed. The mixture was then heated to 120 ° C. The mixture was then cooled to 70 ° C. and then the remaining ingredients were mixed. Finally, the mixture was molded to prepare a hard candy.
Sugar 45 parts by weight Mizuame 55 parts by weight Citric acid 1.5 parts by weight Ascorbic acid 0.5 parts by weight Red pigment of Example 3 0.1 parts by weight (using sodium sulfite. Color value E 10% corresponds to 100 Dark pigment)
Perfume

(Beverages with a pH of 3.5 or less)
The drink containing the red pigment | dye of this invention was mix | blended with the mixing | blending of the following Table 12.

  The above raw materials were mixed and dissolved. 195 g each was filled into a can and sealed. The pH of the beverage was 3.5 or less.

Claims (5)

Compound represented by the following formula (I) or (II)

A method for producing a red pigment, comprising: a step of reacting a hydrolyzate with an amino acid or a protein hydrolyzate; and a step of adding a compound that generates sulfite ions to the reaction product.   The method according to claim 1, wherein the mixture of the reactant and the compound that generates the sulfite ion is heated at 40 to 100 ° C. for 0.25 to 5 hours. The method according to claim 1 or 2, wherein the compound is geniposide acid.   The compound that produces sulfite ions is selected from the group consisting of sodium sulfite, potassium sulfite, sodium dithionite, potassium dithionite, sodium pyrosulfite, potassium pyrosulfite, sodium bisulfite, potassium bisulfite and anhydrous sulfite, and mixtures thereof. 4. The method according to any one of claims 1 to 3, which is selected.   Food-drinks containing the red pigment | dye obtained by the method of any one of Claims 1-4.