BLUE PIGMENT AND METHOD FOR PRODUCING SAME

Abstract

The purpose of the present invention is to provide: a gardenia blue pigment which contains a product of a reaction between genipin and a compound having a primary amino group, and which offers a bright, fresh blue color tone having reduced redness; and a method for producing same. This gardenia blue pigment, which offers a bright, fresh blue color tone having reduced redness, is obtained by carrying out a first step in which genipin and at least one peptide selected from the group consisting of soybean peptides, sesame peptides, and rice peptides are reacted in a solvent without supplying an oxygen-containing gas, and a second step in which a reaction liquid obtained in the first step is processed under an oxygen-containing gas supply.

Claims

1. A blue pigment comprising a reaction product of a primary amino group-containing compound and genipin, wherein when the blue pigment is diluted with water to obtain a solution having a color value E.sup.10%.sub.1 cm of 0.1, an L* value is 66 or more, an a* value is −24 or less, and a b* value is −25 or more in an Lab color space.

2. The blue pigment according to claim 1, wherein when operations (1) to (3) below are performed, a color difference ΔE*.sub.ab between a solution A heat-treated at 90° C. for 15 minutes and a solution B not heat-treated is 3.5 or less, and the solution A heat-treated at 90° C. for 15 minutes has an L* value of 64 or more, an a* value of −14 or less, and a b* value of −31 or more; operation conditions are: (1) a preparation, wherein the blue pigment is diluted with a 0.1 M citrate buffer solution having a pH of 2.5 to prepare a solution A having a color value E.sup.10%.sub.1 cm of 0.1, and the blue pigment is diluted with a 0.1 M citrate buffer solution having a pH of 6.0 to prepare a solution B having a color value E.sup.10%.sub.1 cm of 0.1; (2) a heat treatment of the solutions, wherein the solution A is heat-treated at 90° C. for 15 minutes, and the solution B is not heat-treated; and (3) measurement of color tone, wherein the L* value, the a* value, and the b* value in the Lab color space are measured for the solution A heat-treated at 90° C. for 15 minutes and the solution B not heat-treated.

3. The blue pigment according to claim 1, wherein a maximum absorption wavelength is present in a region of 604 nm or more.

4. The blue pigment according to claim 1, wherein the genipin is derived from gardenia of the family Rubiaceae, genipa americana, or a genetically modified microorganism.

5. A food or beverage product colored with the blue pigment according to claim 1.

6. A method for producing a blue pigment, the producing method comprising a first step and a second step below: first step: at least one peptide selected from the group consisting of a soybean peptide, a sesame peptide, and a rice peptide, and genipin are reacted in a solvent under a non-supply of an oxygen-containing gas; and second step: a reaction solution obtained in the first step is treated under a supply of an oxygen-containing gas.

7. The producing method according to claim 6, wherein the genipin is derived from gardenia of the family Rubiaceae, genipa americana, or a genetically modified microorganism.

8. The producing method according to claim 6, wherein the peptide has a ratio of a peptide having a molecular weight of 2000 or less of 45% or more and a free amino acid content of less than 20 mass %.

9. The producing method according to claim 6, wherein in the first step, a polyphenol is further caused to coexist in the solvent.

10. The producing method according to claim 6, wherein air is used as the oxygen-containing gas.

Description

EXAMPLES

[0139] Hereinafter, the present invention will be specifically described on the basis of Examples and the like; however, the present invention is not limited thereto.

Test Example 1

1. Production of Gardenia Blue Pigment (Using Jar Fermenter) (Examples 1-1 to 1-3 and Comparative Examples 1-1 to 1-15)

(1) Preparation of Genipin

[0140] First, a geniposide solution (color value E.sup.10%.sub.1 cm: 1335.48, measurement wavelength: 238 nm; geniposide content: about 45 mass %) extracted and purified from the fruit of gardenia of the family Rubiaceae was prepared. In 110 g of purified water, 11.0 g of β-glucosidase activity containing cellulase (Sumizyme C, 1500 U/g, SHINNIHON CHEMICALS Corporation) was dissolved, and 110 g of the geniposide solution (color value E.sup.10%.sub.1 cm at the start of reaction: 245, measurement wavelength: 238 nm; geniposide concentration at the start of reaction: about 0.2 mol/L) was added. Next, the pH of the solution was adjusted to 4.5, and then an enzymatic reaction was performed at 50° C. for 18 hours to obtain a genipin-containing solution (solution after the reaction).

(2) Reaction Under Oxygen Gas Non-Supply Condition

[0141] To 283 g of water, 5.5 g of monosodium hydrogen phosphate dihydrate, 4.27 g of trisodium phosphate (anhydrous), and 76.1 g of a peptide or amino acid shown in Table 1 were added and dissolved. The obtained solution was mixed with the genipin-containing solution (total amount) obtained above, and the pH was further adjusted to 7.5. The obtained solution was transferred to a jar fermenter (BMJ-01NC: ABLE Corporation) with a 1 L capacity, and reacted in an air-impermeable state at 35° C. for 15 hours under a gentle stirring condition in which air was not taken in.

(3) Reaction under Oxygen Gas Supply Condition

[0142] The reaction liquid after the reaction under the oxygen gas non-supply condition was adjusted to pH 7.0, and then the reaction was performed under stirring conditions of 35° C. and 420 rpm while supplying air into the reaction liquid at a supply amount of 0.25 vvm until an increase in the color value leveled off. The reaction time was 24 to 48 hours although the reaction time was different depending on the type of the peptide or amino acid used. Thus, a gardenia blue pigment-containing solution (solution after the reaction) was obtained.

2. Measurement of Color Tone of Gardenia Blue Pigment

[0143] The obtained gardenia blue pigment-containing solution was filtered, the pigment solution from which the insoluble matter had been removed was diluted with ion-exchanged water to prepare a solution having a color value E.sup.10%.sub.1 cm of 0.1. The color tone of this solution was measured using a spectrophotometric colorimeter (CM-5 Konica Minolta, Inc.). As measurement conditions, a light source was set to D65, a visual field was set to 10° C., a measurement diameter was set to φ20 mm, and an irradiation diameter was set to φ26 mm in the total transmission measurement. For reference, Food Blue No. 1 was diluted with ion-exchanged water to prepare a solution having a color value E.sup.10%.sub.1 cm of 0.1, and the color tone of this solution was measured in the same manner.

[0144] The obtained results are shown in Table 1. As a result, it was confirmed that the gardenia blue pigment obtained by reacting the soybean peptide, the sesame peptide, or the rice peptide with genipin under a non-supply of air and then reacting them under a supply of air had an L* value of 66 or more, an a* value of −24 or less, and a b* value of −25 or more when the gardenia blue pigment was diluted to obtain a solution having a color value E.sup.10%.sub.1 cm of 0.1, exhibited a bright and fresh blue color tone having reduced redness, and had a color tone closer to Food Blue No. 1 than the conventional gardenia blue pigment (Examples 1-1 to 1-3). On the other hand, even when a blue pigment was produced under the same conditions using peptides other than the soybean peptide, the sesame peptide, and the rice peptide or amino acids, reddish blue (a high value of the a* value) was exhibited, and the color tone close to Food Blue No. 1 could not be obtained (Comparative Examples 1-1 to 1-15).

TABLE-US-00001 TABLE 1 Maximum absorption Measurement result wavelength L* a* b* c* h* ΔE*.sub.ab Peptide or amino acid added (nm) value value value value value value.sup.#3 Example 1-1 Soybean peptide (Hinute AM, FUJI 605.5 67.74 −26.45 −22.35 34.63 220.20 24.41 OIL CO., LTD.).sup.#1 Example 1-2 Sesame peptide (Sesame Peptide 609.5 65.75 −30.81 −20.98 37.27 214.25 25.25 KM-20, MARUZEN PHARMACEUTICALS CO., LTD.).sup.#2 Example 1-3 Rice peptide (rice peptide powder, 604.5 70.19 −27.66 −24.53 36.97 221.57 22.20 Wuhan Tallyho Biological Product Co., Ltd.) Comparative Fish collagen peptide (tripeptide 600.0 67.11 −22.75 −29.08 36.92 231.96 28.05 Example 1-1 derived from air bladder, Wuhan Tallyho Biological Product Co., Ltd.) Comparative Walnut peptide (walnut peptide 602.0 66.67 −22.4 −29.15 36.76 232.46 28.58 Example 1-2 powder, Wuhan Tallyho Biological Product Co., Ltd.) Comparative Pea peptide (pea peptide powder, 602.0 67.28 −22.23 −30.03 37.36 233.49 28.48 Example 1-3 Wuhan Tallyho Biological Product Co., Ltd.) Comparative Sea cucumber peptide (sea cucumber 598.5 66.07 −21.11 −28.06 35.11 233.05 29.26 Example 1-4 oligomer peptide, Dalian Deep Blue Peptide Technology Research and Development Co., Ltd.) Comparative Bitter gourd peptide (bitter gourd 600.0 65.5 −19.66 −31.04 36.74 237.65 31.43 Example 1-5 peptide powder, Wuhan Tallyho Biological Product Co., Ltd.) Comparative Gelatin peptide (SCP-3100, Nitta 598.0 62.37 −17.04 −26.64 31.62 237.40 33.89 Example 1-6 Gelatin Inc.) Comparative Casein peptide (KYOKUTO 597.5 62.49 −15.67 −31 34.74 243.18 35.73 Example 1-7 PEPTONE, KYOKUTO PHARMACEUTICAL INDUSTRIAL CO., LTD) Comparative Corn peptide (AMIFLEX AL-1, MC 592.5 62.69 −13.57 −30.71 33.57 216.16 36.60 Example 1-8 Food Specialties Inc.) Comparative Wheat peptide (PROEXTRACT 593.0 62.45 −13.49 −30.71 33.54 246.29 36.83 Example 1-9 HVP-G, Bansyu Chomiryo Co. Ltd.) Comparative Potato peptide (Amino Acid Gold, 592.0 62.52 −12.08 −30.29 32.61 248.26 37.44 Example 1-10 Cosmo Foods Corporation) Comparative Silk powder peptide (Tango silk 589.0 61.46 −6.03 −31.31 31.89 259.10 42.28 Example 1-11 powder 100%, TANGO YU SILK Y Co., Ltd.) Comparative Histidine 595.5 67.09 −17.74 −29.61 34.52 239.07 30.58 Example 1-12 Comparative Glutamic acid 593.0 66.22 −13.51 −31.37 34.16 246.70 34.24 Example 1-13 Comparative Arginine 598.5 67.82 −19.91 −28.75 34.97 235.30 28.60 Example 1-14 Comparative Asparaginic acid 593.0 67.25 −16.64 −30.94 35.13 241.73 31.54 Example 1-15 Reference Example (Food Blue 630.0 90.72 −33.86 −18.79 38.72 209.03 Standard No. 1, KYORITSU FOODS CO, INC.) .sup.#1“Soybean peptide (Hinute AM, FUJI OIL CO., LTD.)” has a free amino acid content of 2 mass %, and has a peak area of the peptide having a molecular weight of 2000 or less of 78.1% of the total peak area in the analysis result according to a gel filtration chromatographic method using HPLC. .sup.#2“Sesame peptide (Sesame Peptide KM-20, MARUZEN PHARMACEUTICALS CO., LTD.)” has a peak area of the peptide having a molecular weight of 2000 or less of 90% or more of the total peak area in the analysis result according to a gel filtration chromatographic method using HPLC. .sup.#3The ΔE*.sub.ab value refers to a color difference value based on Food Blue No. 1 (Reference Example).

[0145] The gardenia blue pigment-containing solution each obtained in Examples 1-1 to 1-3 was filtered, the pigment solution from which the insoluble matter had been removed was diluted with ion-exchanged water to prepare a solution having a color value E.sup.10%.sub.1 cm of 0.05. The color tone of this solution was measured using an ultraviolet-visible spectrophotometer (V750 manufactured by JASCO Corporation) equipped with an integrating sphere. The obtained results are shown in Table 2. Also from this result, it was confirmed that the gardenia blue pigment each obtained in Examples 1-1 to 1-3 exhibited a bright and fresh blue color tone having reduced redness.

TABLE-US-00002 TABLE 2 Measurement result Peptide added L* value a* value b* value Example 1-1 Soybean peptide 76.07 −17.36 −16.42 Example 1-2 Sesame peptide 77.09 −18.82 −15.03 Example 1-3 Rice peptide 74.93 −15.84 −17.41

Test Example 2

1. Production of Gardenia Blue Pigment (Using Jar Fermenter) (Examples 2-1 to 2-5)

[0146] Gardenia blue pigments were produced in the same manner as in Test Example 1 above, except that soybean peptides shown in Table 3 were used in the reaction under an oxygen gas non-supply condition.

2. Measurement of Color Tone of Gardenia Blue Pigment

[0147] The color tone of the obtained gardenia blue pigment was measured under the same conditions as in Test Example 1. The obtained results are shown in Table 3. From this result, it was confirmed that when a predetermined peptide and genipin were reacted under a non-supply of air and then reacted under a supply of air, the lower the free amino acid content of the peptide to be used, the better the color tone of the gardenia blue pigment with suppressed redness was obtained.

TABLE-US-00003 TABLE 3 Peptide used Ratio (%) of Free amino peptide having Measurement result acid content molecular weight L* a* b* c* h* Trade name (mass %) of 2000 or less.sup.# value value value value value Example 2-1 Soybean peptide (soybean Unmeasured 80.0 66.8 −28.2 −23.53 36.73 219.84 peptide powder, Wuhan Tallyho Biological Product Co., Ltd.) Example 2-2 Soybean peptide (Hinute AM, 2 78.1 67.74 −26.45 −22.35 34.63 220.20 FUJI OIL CO., LTD.) Example 2-3 Soybean peptide (Hinute DA, 5 76.8 69.18 −27.81 −24.28 36.92 221.12 FUJI OIL CO., LTD.) Example 2-4 Soybean peptide (Hinute DC6, 2 61.1 66.61 −26.3 −23.86 35.51 222.22 FUJI OIL CO., LTD.) Example 2-5 Soybean peptide (Hinute D1, 1 45.8 65.98 −26.6 −23.92 35.77 221.96 FUJI OIL CO., LTD.) .sup.#The “Ratio (%) of peptide having molecular weight of 2000 or less” refers to a value obtained by determining the ratio of the peak area of the peptide having a molecular weight of 2000 or less to the total peak area of the peptide from the analysis measurement according to a gel filtration chromatographic method using HPLC.

Test Example 3

1. Production of Gardenia Blue Pigment (Using Jar Fermenter) (Examples 3-1 to 3-3 and Comparative Example 3-1)

[0148] Gardenia blue pigments were produced in the same manner as in Test Example 1 above, except that a soybean peptide (Hinute AM, FUJI OIL CO., LTD.) was used as a peptide to be used, and the reaction time under an oxygen gas non-supply condition was changed to 0 hours (Comparative Example 3), 4 hours (Example 3-1), 5 hours (Example 3-2), and 22 hours (Example 3-3).

2. Production of Gardenia Blue Pigment (Using Jar Fermenter) (Comparative Example 3-2)

(1) Preparation of Genipin

[0149] A genipin-containing solution was prepared under the conditions shown in Test Example 1 above.

(2) Reaction under Oxygen Gas Supply Condition

[0150] To 283 g of water, 5.5 g of monosodium hydrogen phosphate dihydrate, 4.27 g of trisodium phosphate (anhydrous), and 76.1 g of a peptide or amino acid shown in Table 4 were added and dissolved. The obtained solution was mixed with the genipin-containing solution (total amount) obtained above, and the pH was further adjusted to 7.5. The obtained solution was transferred to a jar fermenter with a 1 L capacity, and the reaction was performed under stirring conditions of 35° C. and 420 rpm while supplying air into the solution at a supply amount of 0.25 vvm until an increase in the color value leveled off. The reaction time was 33 hours.

(3) Reaction under Oxygen Gas Non-Supply Condition

[0151] The reaction liquid after the reaction under an oxygen gas supply condition was adjusted to pH 7.0, and then reacted in an air-impermeable state at 35° C. for 18 hours under a gentle stirring condition in which air was not taken in. Thus, a gardenia blue pigment-containing solution (solution after the reaction) was obtained.

3. Measurement of Color Tone of Gardenia Blue Pigment

[0152] The color tone of the obtained gardenia blue pigment was measured under the same conditions as in Test Example 1. The obtained results are shown in Table 4. In Table 4, Food Blue No. 1 was diluted with ion-exchanged water to prepare a solution having a color value E.sup.10%.sub.1 cm of 0.1, and the color tone of this solution was measured in the same manner. Also from this result, it was confirmed that when a predetermined peptide and genipin were reacted under a non-supply of air and then reacted under a supply of air, a gardenia blue pigment exhibiting a bright and fresh blue color tone having reduced redness was obtained.

[0153] Evan when a predetermined peptide and genipin were reacted under a supply of air and then reacted under a non-supply of air, a gardenia blue pigment exhibiting a bright and fresh blue color tone having reduced redness is not obtained.

TABLE-US-00004 TABLE 4 Reaction time (hrs) Measurement result under oxygen gas non- L* a* b* c* h* ΔE*.sub.ab supply condition value value value value value value.sup.# Comparative 0 65.87 −19.56 −30.99 36.65 237.74 31.16 Example 3-1 Example 3-1 4 67.60 −25.71 −28.45 38.35 227.90 26.35 Example 3-2 5 67.89 −26.44 −26.80 37.65 225.39 25.31 Example 3-3 22 67.97 −25.93 −28.14 38.27 227.34 25.84 Comparative Example 3-2 (performing 66.33 −22.09 −28.59 36.13 232.31 28.80 reaction under supply of air and then reaction under non-supply of air) Reference Example (Food Blue 90.72 −33.86 −18.79 38.72 209.03 — No. 1, KYORITSU FOODS CO, INC.) .sup.#The ΔE*.sub.ab value refers to a color difference value based on Food Blue No. 1 (Reference Example).

Test Example 4

1. Production of Gardenia Blue Pigment (Using Jar Fermenter) (Example 4-1)

[0154] A gardenia blue pigment was produced in the same manner as in Test Example 1 above, except that a soybean peptide (Hinute AM, FUJI OIL CO., LTD.) was used as a peptide to be used, and 1.2 g of transglycosylated hesperidin (α-triglucosyl hesperidin content: 85 mass %, αG HESPERIDIN PA-T, Ezaki Glico Co., Ltd.) was added to a solution to be subjected to a reaction under an oxygen gas non-supply condition.

2. Production of Gardenia Blue Pigment (Using Flask) (Example 4-2)

(1) Preparation of Genipin

[0155] First, a geniposide solution (color value E.sup.10%.sub.1 cm: 1240, measurement wavelength: 238 nm; geniposide content: about 45 mass %) extracted and purified from the fruit of gardenia of the family Rubiaceae was prepared. In 39.11 g of purified water, 3.56 g of β-glucosidase activity containing cellulase (Sumizyme C, 1500 U/g, SHINNIHON CHEMICALS Corporation) was dissolved, and 35.5 g of the geniposide solution (color value E.sup.10%.sub.1 cm at the start of reaction: 245, measurement wavelength: 238 nm; geniposide concentration: about 0.2 mol/L) was added. Next, the pH of the solution was adjusted to 4.5, and then an enzymatic reaction was performed at 50° C. for 18 hours to obtain a genipin-containing solution (solution after the reaction).

(2) Reaction under Oxygen Gas Non-Supply Condition

[0156] To 75 g of water, 1.65 g of monosodium hydrogen phosphate dihydrate, 1.28 g of trisodium phosphate (anhydrous), 22.83 g of a soybean peptide (Hinute AM, FUJI OIL CO., LTD.), and 0.18 g of transglycosylated hesperidin (α-triglucosyl hesperidin content: 85 mass %, αG HESPERIDIN PA-T, Ezaki Glico Co., Ltd.) were added and dissolved. The obtained solution was mixed with the genipin-containing solution (total amount) obtained above, and the pH was further adjusted to 7.5. The obtained solution was transferred to a beaker with a 300 mL capacity, the beaker was hermetically sealed, and the solution was reacted in an air-impermeable state at 35° C. under a stirring condition (magnetic stirrer) of 100 rpm for 18 hours.

(3) Reaction under Oxygen Gas Supply Condition

[0157] The reaction liquid after the reaction under an oxygen gas non-supply condition was adjusted to pH 7.0 and then transferred to a flask with a 500 mL capacity, and the reaction was performed at 35° C. for 30 hours under a stirring condition of 150 rpm in a state where the mouth of the flask opened to the air atmosphere until an increase in the color value leveled off. Thus, a gardenia blue pigment-containing solution (solution after the reaction) was obtained.

3. Measurement of Color Tone of Gardenia Blue Pigment

[0158] The color tone was measured in the same manner as in Test Example 1 above using the obtained gardenia blue pigment-containing solution. The obtained results are shown in Table 5. In Table 5, the results obtained by measuring the color tone of a solution having a color value E.sup.10%.sub.1 cm of 0.1 prepared by diluting Food Blue No. 1 with ion-exchanged water are also shown. As a result, it was confirmed that even when transglycosylated hesperidin was added at the time of reacting the soybean peptide with the genipin under an oxygen gas non-supply condition, by performing the reaction by supplying air after the reaction under a non-supply of air, a gardenia blue pigment exhibiting a bright and fresh blue color tone having reduced redness was obtained.

[0159] The maximum absorption wavelength of the gardenia blue pigment of Example 4-1 was 605.5 nm, and the maximum absorption wavelength of the gardenia blue pigment of Example 4-2 was 608.0 nm.

TABLE-US-00005 TABLE 5 Production condition Addition of Measurement result Device used transglycosylated L* a* b* c* h* ΔE*.sub.ab for reaction hesperidin value value value value value value.sup.# Example 4-1 Jar fermenter Present 70.75 −28.74 −25.61 38.49 221.70 21.71 Example 1-2 Flask Present 70.91 −28.54 −23.97 37.27 220.03 21.13 Reference Example (Food Blue 90.72 −33.86 −18.79 38.72 209.03 — No. 1, KYORITSU FOODS CO, INC.) .sup.#The ΔE*.sub.ab value refers to a color difference value based on Food Blue No. 1 (Reference Example).

Test Example 5

1. Production of Blue Pigment Using Purified Genipin (Using Flask) (Examples 5-1 to 5-4)

(1) Reaction Under Oxygen Gas Non-Supply Condition

[0160] 1.65 g of monosodium hydrogen phosphate dihydrate, 1.28 g of trisodium phosphate (anhydrous), 8.31 g of purified genipin (genipin content: 98 mass %, trade name: Genipin, manufactured by GLICO NUTRITION CO., LTD.), a predetermined amount of peptide shown in Table 6, 0 g or 0.38 g of transglycosylated hesperidin (α-triglucosyl hesperidin content: 85 mass %, αG HESPERIDIN PA-T, Ezaki Glico Co., Ltd.), and a balance of water were added to be a total amount of 180 g and dissolved. The pH of the obtained solution was adjusted to 7.5 and then transferred to a beaker with a 300 mL capacity, the beaker was hermetically sealed, and the solution was reacted in an air-impermeable state at 35° C. under a stirring condition (magnetic stirrer) of 100 rpm for 18 hours.

(2) Reaction Under Oxygen Gas Supply Condition

[0161] The reaction liquid after the reaction under an oxygen gas non-supply condition was adjusted to pH 7.0 and then transferred to a flask with a 500 mL capacity, and the reaction was performed at 35° C. for 48 hours under a stirring condition of 150 rpm in a state where the mouth of the flask opened to the air atmosphere until an increase in the color value leveled off. Thus, a blue pigment-containing solution (solution after the reaction) was obtained.

2. Measurement of Color Tone of Blue Pigment

[0162] The color tone was measured in the same manner as in Test Example 1 above using the obtained blue pigment-containing solution. The obtained results are shown in Table 6. In Table 6, the results obtained by measuring the color tone of a solution having a color value E.sup.10%.sub.1 cm of 0.1 prepared by diluting Food Blue No. 1 with ion-exchanged water are also shown. As a result, it was confirmed that even when the purified genipin was used as a raw material, the blue pigment obtained by reacting the soybean peptide, the sesame peptide, or the rice peptide with the purified genipin under a non-supply of air and then reacting them under a supply of air had an L* value of 66 or more, an a* value of −24 or less, and a b* value of −25 or more when the blue pigment was diluted to obtain a solution having a color value E.sup.10%.sub.1 cm of 0.1, and exhibited a bright and fresh blue color tone having reduced redness (Examples 5-1 to 5-4).

[0163] That is, from the present results, it was found that even when not only genipin prepared from geniposide extracted and purified from gardenia of the family Rubiaceae was used, but also genipin extracted and purified from huito, genipin prepared from geniposide extracted and purified from huito, genipin obtained by a genetic engineering technique, genipin prepared from geniposide obtained by a genetic engineering technique, or the like was used, a blue pigment exhibiting a bright and fresh blue color tone having reduced redness was obtained by reacting the genipin with the soybean peptide, the sesame peptide, or the rice peptide under a non-supply of air and then reacting them under a supply of air.

TABLE-US-00006 TABLE 6 Presence/ Maximum Peptide added absence of absorption Measurement result Addition transglycosylated wavelength L* a* b* c* h* ΔE*.sub.ab Type amount hesperidin (nm) value value value value value value.sup.#1 Example 5-1 Soybean peptide 22.83 g Absent 607.5 67.77 −28.89 −23.87 37.48 219.56 24.03 (Hinute AM, FUJI OIL CO., LTD.) Example 5-2 Soybean peptide 22.83 g Present 606.5 67.52 −28.90 −24.17 37.68 219.91 24.33 (Hinute AM, FUJI OIL CO., LTD.) Example 5-3 Rice peptide 22.83 g Absent 608.0 68.02 −29.10 −24.18 37.83 219.72 23.81 (rice peptide powder, Wuhan Tallyho Biological Product Co., Ltd.) Example 5-4 Sesame peptide 30.43 g Absent 610.5 68.33 −31.92 −22.02 38.78 214.59 22.70 (Sesame Peptide KM-20, MARUZEN PHARMACEUTICALS CO., LTD.) Reference Example — 630.0 90.72 −33.86 −18.79 38.72 209.03 Standard (Food Blue No. 1, KYORITSU FOODS CO, INC.) .sup.#1The ΔE*.sub.ab value refers to a color difference value based on Food Blue No. 1 (Reference Example).

Test Example 6

1. Production of Gardenia Blue Pigment (Using Flask) (Reference Example 1)

[0164] A gardenia blue pigment was produced according to the method of Example 2 described in Patent Document 3 (WO 2017/156744 A). Specifically, 0.6 g of genipin (purity: 98%, GLICO NUTRITION CO., LTD.), 9 mL of 99.5% ethanol, and 2.05 g of sodium glutamate monohydrate were dissolved in water. The obtained solution was placed in a flask and placed in a water bath at 75° C. to perform a reaction for 6 hours under the condition of 150 strokes/min. The ethanol in the reaction liquid after the reaction was removed by an evaporator and then freeze-dried to obtain a powdery gardenia blue pigment.

2. Measurement of Color Tone of Gardenia Blue Pigment

[0165] The obtained gardenia blue pigment was diluted with ion-exchanged water to prepare a solution having a color value E.sup.10%.sub.1 cm of 0.0337, and the color tone was measured using a spectrophotometric colorimeter (CM-5 Konica Minolta, Inc.). As measurement conditions, a light source was set to D65, a visual field was set to 10° C., a measurement diameter was set to φ20 mm, and an irradiation diameter was set to φ26 mm in the total transmission measurement. For reference, the gardenia blue pigment-containing solution obtained in Example 1-1 was diluted with ion-exchanged water to prepare a solution having an adjusted color value E.sup.10%.sub.1 cm of 0.0337, and the color tone was measured in the same manner also for these solutions.

[0166] The results are shown in Table 7. As a result, it was confirmed that the gardenia blue pigment obtained by the method of Patent Document 3 had a high a* value and exhibited a reddish color tone.

TABLE-US-00007 TABLE 7 Measurement result L* a* b* c* h* value value value value value Reference Solution having a color 86.43 −8.26 −13.52 15.85 238.57 Example 1 value E.sup.10%.sub.1 cm of 0.0337 Example 1-1 Solution having a color 85.37 −14.51 −13.15 19.58 222.19 value E.sup.10%.sub.1 cm of 0.0337

Test Example 7

1. Production of Gardenia Blue Pigment (Comparative Examples 7-1 to 7-3)

(1) Enzyme Treatment in Presence of Peptide and Reaction Under Oxygen Gas Non-Supply Condition

[0167] First, a geniposide solution (color value E.sup.10%.sub.1 cm: 1240, measurement wavelength: 238 nm; geniposide content: about 45 mass %) extracted and purified from the fruit of gardenia of the family Rubiaceae was prepared. In 39.11 g of purified water, 3.56 g of β-glucosidase activity containing cellulase (Sumizyme C, 1500 U/g, SHINNIHON CHEMICALS Corporation) was dissolved, and 35.5 g of the geniposide solution (color value E.sup.10%.sub.1 cm at the start of reaction: 245, measurement wavelength: 238 nm; geniposide concentration: about 0.2 mol/L) was added. Next, 1.65 g of monosodium hydrogen phosphate dihydrate, 1.28 g of trisodium phosphate (anhydrous), a predetermined amount of peptide shown in Table 8, and a balance of water were added to be a total amount of 180 g and dissolved. The obtained solution was transferred to a beaker with a 300 mL capacity, the pH of the solution was adjusted to 4.5 to 4.8, the beaker was hermetically sealed, and the solution was simultaneously subjected to an enzymatic reaction in the presence of a peptide and a reaction under an oxygen gas non-supply condition in an air-impermeable state at 50° C. under a stirring condition (magnetic stirrer) of 100 rpm for 18 hours.

(2) Reaction Under Oxygen Gas Supply Condition

[0168] The reaction liquid after the reaction under an oxygen gas non-supply condition was adjusted to pH 7.0 and then transferred to a flask with a 500 mL capacity, and the reaction was performed at 35° C. for 48 hours under a stirring condition of 150 rpm in a state where the mouth of the flask opened to the air atmosphere until an increase in the color value leveled off. Thus, a gardenia blue pigment-containing solution (solution after the reaction) was obtained.

2. Measurement of Color Tone of Blue Pigment

[0169] The color tone was measured in the same manner as in Test Example 1 above using the obtained gardenia blue pigment-containing solution. The obtained results are shown in Table 8. In Table 8, the results obtained by measuring the color tone of a solution having a color value E.sup.10%.sub.1 cm of 0.1 prepared by diluting Food Blue No. 1 with ion-exchanged water are also shown. As a result, when the soybean peptide, the sesame peptide, or the rice peptide was reacted under a non-supply of air simultaneously with the enzymatic reaction from geniposide to genipin, and then reacted under a supply of air, the maximum absorption wavelength was decreased, and when Food Blue No. 1 was diluted to obtain a solution having a color value E.sup.10%.sub.1 cm of 0.1, all of the L* value of 66 or more, the a* value of −4 or less, and the b* value of −5 or more were not satisfied, and a fresh blue color tone having reduced redness was not observed.

TABLE-US-00008 TABLE 8 Maximum Addition absorption Measurement result amount wavelength L* a* b* c* h* ΔE*.sub.ab Peptide added (g) (nm) value value value value value value.sup.# Comparative Soybean peptide (Hinute AM, FUJI 22.83 601.5 64.98 −22.34 −25.26 33.72 228.52 28.93 Example 7-1 OIL CO., LTD.) Comparative Rice peptide (rice peptide powder, 22.83 601.5 64.77 −22.74 −24.80 33.65 227.49 28.86 Example 7-2 Wuhan Tallyho Biological Product Co., Ltd.) Comparative Sesame peptide (Sesame Peptide 30.43 606.0 64.67 −24.96 −22.94 33.90 222.59 27.84 Example 7-3 KM-20, MARUZEN PHARMACEUTICALS CO., LTD.) .sup.#The ΔE*.sub.ab value refers to a color difference value based on Food Blue No. 1 (Reference Example).

Test Example 8

1. Production of Gardenia Blue Pigment (Using Flask) (Example 8-1)

(1) Preparation of Genipin

[0170] First, a geniposide solution (color value E.sup.10%.sub.1 cm: 1335.48, measurement wavelength: 238 nm; geniposide content: about 45 mass %) extracted and purified from the fruit of gardenia of the family Rubiaceae was prepared. In 41.67 g of purified water, 4.17 g of β-glucosidase activity containing cellulase (Sumizyme C, 1500 U/g, SHINNIHON CHEMICALS Corporation) was dissolved, and 41.67 g of the geniposide solution (color value E.sup.10%.sub.1 cm at the start of reaction: 245, measurement wavelength: 238 nm; geniposide concentration: about 0.2 mol/L) was added. Next, the pH of the solution was adjusted to 4.5, and then an enzymatic reaction was performed at 50° C. for 18 hours to obtain a genipin-containing solution (solution after the reaction).

(2) Reaction Under Oxygen Gas Non-Supply Condition

[0171] To 75 g of water, 1.65 g of monosodium hydrogen phosphate dihydrate, 1.28 g of trisodium phosphate (anhydrous), and 22.83 g of a rice peptide (rice peptide powder, Wuhan Tallyho Biological Product Co., Ltd.) were added and dissolved. The obtained solution was mixed with the genipin-containing solution (total amount) obtained above, and the pH was further adjusted to 7.5. The obtained solution was transferred to a beaker with a 300 mL capacity, the beaker was hermetically sealed, and the solution was reacted in an air-impermeable state at 35° C. under a stirring condition (magnetic stirrer) of 100 rpm for 18 hours.

(3) Reaction Under Oxygen Gas Supply Condition

[0172] The reaction liquid after the reaction under an oxygen gas non-supply condition was adjusted to pH 7.0 and then transferred to a flask with a 500 mL capacity, and the reaction was performed at 35° C. for 48 hours under a stirring condition of 150 rpm in a state where the mouth of the flask opened to the air atmosphere until an increase in the color value leveled off. Thus, a gardenia blue pigment-containing solution (solution after the reaction) was obtained.

2. Measurement of Acid Heating Resistance of Gardenia Blue Pigment

[0173] The obtained gardenia blue pigment-containing solution was diluted with a 0.1 M citrate buffer solution having a pH of 2.5 to prepare a solution A (color value E.sup.10%.sub.1 cm: 0.1). The obtained gardenia blue pigment-containing solution was diluted with a 0.1 M citrate buffer solution having a pH of 6.0 to prepare a solution B (color value E.sup.10%.sub.1 cm: 0.1). The solutions A and B were left to stand still at 5° C. for about 18 hours, and then the solution A was heat-treated at 90° C. for 15 minutes. The solution B was not heat-treated. The solutions A and B were centrifuged at 3,000 rpm for 10 minutes with a centrifuge, and the absorbance of the supernatant at a maximum absorption wavelength around 600 nm was measured. The ratio of the absorbance of the solution A to the absorbance of the solution B when the absorbance of the solution B was taken as 100% was determined, and this ratio was taken as the residual ratio when the heat treatment was performed at 90° C. for 15 minutes under the condition of a pH of 2.5.

[0174] The color tones of the solution A after the heat treatment and the solution B not heat-treated (after being left to stand still at 5° C. for about 18 hours) were used using a spectrophotometric colorimeter (CM-5 Konica Minolta, Inc.). As measurement conditions, a light source was set to D65, a visual field was set to 10° C., a measurement diameter was set to φ20 mm, and an irradiation diameter was set to φ26 mm in the total transmission measurement.

[0175] The results are shown in Table 9. From this result, the gardenia blue pigment obtained by reacting the rice peptide with genipin under an oxygen gas non-supply condition and then reacting them under a supply of an oxygen gas had an L* value of 64 or more, an a* value of −4 or less, and a b* value of −1 or more even when heated under the condition of a pH of 2.5 (color value E.sup.10%.sub.1 cm: 0.1), and further had a ΔE*.sub.ab of 3.5 or less even when compared with the condition of a pH of 6.0 (color value E.sup.10%.sub.1 cm: 0.1) in which heating was not performed, and thus had excellent acid heating resistance.

TABLE-US-00009 TABLE 9 Measurement result Residual L* a* b* c* ΔE*.sub.ab ratio (%) value value value value value.sup.# Example 8-1 Solution A after heat 97.63 66.75 −21.98 −24.01 32.55 2.89 treatment (pH 2.5) Solution B not heat- — 68.27 −24.43 −24.26 34.43 Standard treated (pH 6.0) .sup.#The ΔE*.sub.ab value refers to a color difference value based on the solution B not heat-treated.

Test Example 9

1. Production of Blue Pigment Using Purified Genipin (Using Flask) (Examples 5-1 to 5-4)

[0176] (1) Reaction under Oxygen Gas Non-Supply Condition

[0177] To 145.93 g of water, 1.65 g of monosodium hydrogen phosphate dihydrate, 1.28 g of trisodium phosphate (anhydrous), 8.31 g of purified genipin (genipin content: 98 mass %, trade name Genipin, manufactured by GLICO NUTRITION CO., LTD.), and 22.83 g of a rice peptide (rice peptide powder, Wuhan Tallyho Biological Product Co., Ltd.) were added and dissolved. The pH of the obtained solution was adjusted to 7.5 and then transferred to a beaker with a 300 mL capacity, the beaker was hermetically sealed, and the solution was reacted in an air-impermeable state at 35° C. under a stirring condition (magnetic stirrer) of 100 rpm for 18 hours.

(2) Reaction under Oxygen Gas Supply Condition

[0178] The reaction liquid after the reaction under an oxygen gas non-supply condition was adjusted to pH 6.0 and then transferred to a flask with a 500 mL capacity, and the reaction was performed at 35° C. for 46 hours under a stirring condition of 150 rpm in a state where the mouth of the flask opened to the air atmosphere until an increase in the color value leveled off. Thus, a blue pigment-containing solution (solution after the reaction) was obtained.

2. Measurement of Acid Heating Resistance of Blue Pigment

[0179] The acid heating resistance was measured under the same conditions as in Test Example 8. The results are shown in Table 10. From this result, the blue pigment obtained by reacting the purified genipin with the rice peptide under an oxygen gas non-supply condition and then reacting them under a supply of an oxygen gas had an L* value of 64 or more, an a* value of −4 or less, and a b* value of −1 or more even when heated under the condition of a pH of 2.5 (color value E.sup.10%.sub.1 cm: 0.1), and further had a ΔE*.sub.ab of 3.5 or less even when compared with the condition of a pH of 6.0 (color value E.sup.10%.sub.1 cm: 0.1) in which heating was not performed, and thus had excellent acid heating resistance.

[0180] That is, from the present results, it has become clear that even when genipin was not derived from gardenia of the family Rubiaceae, a blue pigment having excellent acid heating resistance was obtained by reacting the genipin with the rice peptide under a non-supply of air and then reacting them under a supply of air.

TABLE-US-00010 TABLE 10 Measurement result Residual L* a* b* c* ΔE*.sub.ab ratio (%) value value value value value.sup.# Example 9-1 Solution A after heat 102.0 65.22 −23.91 −27.63 36.54 3.41 treatment (pH 2.5) Solution B not heat- — 67.78 −26.12 −27.20 37.71 Standard treated (pH 6.0) .sup.#The ΔE*.sub.ab value refers to a color difference value based on the solution B not heat-treated.

Test Example 10

1. Production of Gardenia Blue Pigment (Using Flask) (Comparative Examples 7-1 to 7-5)

[0181] Gardenia blue pigments were produced under the same conditions as in Example 8-1, except that a peptide or amino acid shown in Table 10 was used instead of the rice peptide.

2. Measurement of Acid Heating Resistance of Gardenia Blue Pigment

[0182] The acid heating resistance was measured under the same conditions as in Test Example 8. The results are shown in Table 11. As a result, it was confirmed that the obtained gardenia blue pigment could not have acid heating resistance even when the peptide other than the rice peptide was reacted with genipin under a non-supply of air and then reacted under a supply of air.

TABLE-US-00011 TABLE 11 Measurement result L* a* b* c* ΔE*.sub.ab Peptide added value value value value value.sup.# Comparative Silk powder peptide (Tango silk Solution A after heat 64.38 −1.27 −25.04 25.07 5.72 Example 8-1 powder 100%, TANGO YU SILK Y |Co., Ltd.) treatment (pH 2.5) Solution B not heat- 63.26 −3.65 −30.11 30.33 — treated (pH 6.0) Comparative Pea peptide (pea peptide powder, Solution A after heat 65.45 −17.29 −29.50 34.19 6.17 Example 8-2 Wuhan Tallyho Biological Product treatment (pH 2.5) Co., Ltd.) Solution B not heat- 68.96 −17.31 −24.42 29.93 — treated (pH 6.0) Comparative Sea cucumber peptide (sea cucumber Solution A after heat 66.53 −15.33 −23.03 27.67 6.38 Example 8-3 oligomer peptide, Dalian Deep Blue treatment (pH 2.5) Peptide Technology Research and Development Co., Ltd.) Solution B not heat- 66.75 −19.75 −27.62 33.95 — treated (pH 6.0) Comparative Fish collagen peptide (tripeptide Solution A after heat 58.32 −14.24 −31.41 34.48 8.04 Example 8-4 derived from air bladder, Wuhan treatment (pH 2.5) Tallyho Biological Product Co., Ltd.) Solution B not heat- 62.10 −16.52 −30.00 34.25 — treated (pH 6.0) Comparative Histidine Solution A after heat 68.18 −13.24 −26.92 30.00 3.20 Example 8-5 treatment (pH 2.5) Solution B not heat- 69.67 −15.19 −27.23 31.18 — treated (pH 6.0) .sup.#The ΔE*.sub.ab value refers to a color difference value based on the solution B not heat-treated.

Production Example 1

[0183] The flesh of genipa americana is finely cut, and then subjected to a solvent extraction treatment using twice the amount of (60% aqueous ethanol solution) as an extraction solvent. After the solvent extraction treatment, the solid content is removed by filtration to recover the extraction liquid. An equal amount of ethyl acetate is added to the obtained extraction liquid and stirred to dissolve genipin in an ethyl acetate layer. Next, the ethyl acetate layer is separated, concentrated under reduced pressure, and crystallized, and then the genipin crystals are recovered and dried, so that genipin crystals (purity of 70 mass % or more) is obtained.

[0184] Next, to 145.93 g of water, 8.31 g of the genipin crystals obtained above, 1.65 g of monosodium hydrogen phosphate dihydrate, 1.28 g of trisodium phosphate (anhydrous), and 22.83 g of a soybean peptide, a sesame peptide, or a rice peptide are added and dissolved. The pH of the obtained solution is adjusted to 7.5 and then transferred to a beaker with a 300 mL capacity, the beaker is hermetically sealed, and the solution is reacted in an air-impermeable state at 35° C. under a stirring condition (magnetic stirrer) of 100 rpm for 18 hours. Next, the reaction liquid after the reaction under an oxygen gas non-supply condition is adjusted to pH 7.0 and then transferred to a flask with a 500 mL capacity, and the reaction is performed at 35° C. for 48 hours under a stirring condition of 150 rpm in a state where the mouth of the flask opens to the air atmosphere until an increase in the color value levels off. Thus, a blue pigment-containing solution exhibiting a bright and fresh blue color tone having reduced redness is obtained using genipin derived from genipa americana as a raw material.