Preparation method of natural plant pigment composition and application thereof in food

Abstract

The present invention belongs to the technical field of food additives, and specifically relates to a method for preparing a natural plant pigment composition and its use in food. The preparation method comprises the following steps: S1: dissolving a natural plant pigment in water to obtain a natural plant pigment solution, adjusting the pH of the natural plant pigment solution to 7-8, then adding cyclodextrin and stirring evenly, continuously stirring, and allowing the solution to stand after stirring to obtain solution I; S2: adding spirulina peptidoglycan and polyamino acid to the obtained solution I in sequence, mixing evenly, stirring, adding a halide salt after stirring, continuing stirring, allowing the solution to stand after stirring, and then centrifuging. The resulting solid product is mixed with edible supplements and freeze-dried to obtain the natural plant pigment composition. The raw materials used in the present invention are all food-grade, safe and harmless, and can be used in food dyeing and coloring, imparting saturated and uniform color to food and beverage products, and enhancing the vividness of food.

Description

Technical Field

[0001] The present invention belongs to the technical field of food additives, and in particular relates to a method for preparing a natural plant pigment composition and application of the composition in food. Background Art

[0002] Natural pigments primarily fall into three categories: natural plant pigments, natural animal pigments, and natural mineral pigments. Natural plant pigments are the most widely used, encompassing a wide range of industries, including food, textiles, cosmetics, pharmaceuticals, leather processing, and printing and dyeing. Natural plant pigments refer to pigment components found in the roots, stems, leaves, flowers, fruits, and bark of plants, such as turmeric, sappanwood, indigo, safflower, black beans, and green walnut skins. Their environmentally friendly nature has made them a key focus in the development of new pigments and dyes. Compared to synthetic pigments, natural plant pigments offer numerous advantages. Derived from plants, they are highly safe, have no toxic side effects, and offer natural hues. They also possess certain physiological functions and medicinal value, such as preventing neurological and cardiovascular diseases and protecting the liver from oxidative damage. They can serve as excellent health supplements and seasonings in daily life.

[0003] Food is the most basic material guarantee for human survival. The development of green food is a necessity as people's environmental awareness, health awareness, and living standards continue to improve. Colorants play an important role in improving the appearance and quality of food. Compared with synthetic pigments, green and healthy natural plant pigments have become a hot spot for market development and application in the health industry. By adding natural pigments to food, due to the certain physiological functions of the pigments themselves, not only can the nutritional value of the food be increased, but also the sensory properties such as color, aroma and flavor of the food can be improved. However, natural plant pigments have poor stability and are easily affected by light, temperature, oxygen, and heavy metals. In addition, natural plant pigments have poor tinting power, which can easily lead to uneven dyeing. Summary of the Invention

[0004] The primary purpose of the present invention is to provide a method for preparing a natural plant pigment composition and its application in food, so as to enable the wide application of natural plant pigments in food.

[0005] To this end, the present invention provides the following technical solutions.

[0006] One aspect of the present invention provides a method for preparing a natural plant pigment composition, the preparation method comprising the following steps:

[0007] S1: dissolving a natural plant pigment in water to obtain a natural plant pigment solution with a mass concentration of 1-5%, adjusting the pH of the natural plant pigment solution to 7-8 with a 40-80 wt% sodium bicarbonate solution, then adding cyclodextrin and stirring uniformly, then placing in a 30-40° C. water bath and stirring at a speed of 200-600 rpm for 1-4 hours, and then standing for 20-40 minutes after the stirring to obtain a solution I;

[0008] S2: Spirulina peptidoglycan and polyamino acid are added to the obtained solution I in sequence according to a volume-to-mass ratio of 100 mL: 0.1-0.5 mg: 1-5 g, and the mixture is evenly mixed. The mixture is then stirred at 40-60° C. for 1-2 hours. After the stirring is completed, a halide salt is added and the stirring is continued for 30-60 minutes. After the stirring is completed, the mixture is allowed to stand for 30-60 minutes, and then centrifuged at 5000-10000 rpm for 5-10 minutes. The obtained solid product is mixed with edible excipients in a mass ratio of 1:0.2-0.6, and the mixture is freeze-dried at -30--20° C. to obtain a natural plant pigment composition.

[0009] In a preferred embodiment of the present invention, the natural plant pigments include anthocyanidins, chlorophyll, betacyanin, betacyanin, lithospermum red, gardenia yellow, anthocyanins, capsanthin, safflower yellow, sodium copper chlorophyllin, and curcumin.

[0010] In a preferred embodiment of the present invention, the cyclodextrin is selected from any one of α-cyclodextrin, β-cyclodextrin or γ-cyclodextrin.

[0011] In a preferred embodiment of the present invention, the added amount of the cyclodextrin is 20-30% of the mass of the natural plant pigment.

[0012] In a preferred embodiment of the present invention, the polyamino acid is γ-polyglutamic acid and / or polyaspartic acid.

[0013] In a preferred embodiment of the present invention, the halide salt is selected from one or a mixture of two or more of ferrous chloride, ferric chloride, calcium chloride, magnesium chloride, sodium chloride, and potassium iodide.

[0014] In a preferred embodiment of the present invention, the amount of the halide salt added is 0.1-0.5% of the mass of the polyamino acid.

[0015] In a preferred embodiment of the present invention, the edible excipient is selected from any one of carboxymethyl cellulose, sodium carboxymethyl cellulose, sodium alginate, chitosan, calcium alginate, arabinoxylan, microcrystalline cellulose, whey protein, soy protein isolate, and modified starch, or a mixture of two or more thereof.

[0016] Another aspect of the present invention also provides a use of the natural plant pigment composition prepared according to the preparation method as described above in food.

[0017] In a preferred embodiment of the present invention, the amount of the natural plant pigment composition added to the food is 1 to 5 wt%.

[0018] By means of the above technical solution, the present invention has at least the following advantages:

[0019] 1. The present invention addresses the problems of low stability and poor tinting power of natural plant pigments. By combining natural plant pigments with a certain amount of protective agent, on the one hand, the natural plant pigment molecules can be protected, and on the other hand, the stability of the natural plant pigment can be improved, thereby making the natural plant pigment have higher stability and improving its tinting power. The raw materials used in the present invention are all food grade, safe and harmless, and can be used in the dyeing and coloring of food, giving saturated and uniform colors to food and beverage products, and improving the vividness of food.

[0020] 2, the present invention utilizes the peculiar structure of cyclodextrin to wrap up, protect natural plant pigment molecule by using cyclodextrin in alkaline environment, obtains the natural plant pigment of cyclodextrin parcel.Alkaline environment can guarantee the structural stability of cyclodextrin, promotes the coating of cyclodextrin to pigment molecule, guarantees the stability of the natural plant pigment of cyclodextrin parcel.Add spirulina peptidoglycan and polyamino acid subsequently, spirulina peptidoglycan can provide antioxidant property, avoid the influence of oxygen and heavy metal in the external environment on pigment molecule, add polyamino acid and can cause the natural plant pigment of polymerized dextrin parcel to be gathered on the polyamino acid molecular chain under the existence of halogenated salt, and be precipitated out gradually in the adding process of halogenated salt, finally throw out is combined with edible auxiliary material and promptly obtain the natural plant pigment composition.

[0021] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention. DETAILED DESCRIPTION

[0022] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0023] Unless otherwise specified, the percentage content involved in the present invention refers to mass percentage for solid-liquid mixing and solid-solid mixing, and refers to volume percentage for liquid-liquid mixing.

[0024] Unless otherwise specified, percentage concentrations referred to in the present invention refer to final concentrations, which refer to the percentage of an added component in the system after the addition of the component.

[0025] The temperature parameters in the present invention, unless otherwise specified, allow for either constant temperature treatment or treatment within a certain temperature range. The constant temperature treatment allows for temperature fluctuations within the precision range controlled by the instrument.

[0026] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0027] Unless otherwise specified, the materials and reagents used in the following examples are all food grade and commercially available, wherein γ-polyglutamic acid (purity>99%) was purchased from Zhejiang Yicun Biotechnology Co., Ltd.

[0028] Example 1:

[0029] S1: Anthocyanidin was dissolved in water to obtain an anthocyanidin solution with a mass concentration of 3%, and the pH of the anthocyanidin solution was adjusted to 8 with a 40-80 wt% sodium bicarbonate solution. β-cyclodextrin (the amount added was 25% of the mass of the anthocyanidin) was then added and stirred evenly. The mixture was then placed in a 35°C water bath and stirred at 400 rpm for 2.5 h. After the stirring was completed, the mixture was allowed to stand for 30 min to obtain Solution I.

[0030] S2: Spirulina peptidoglycan and γ-polyglutamic acid were added to the obtained solution I in a volume mass ratio of 100 mL: 0.3 mg: 3 g, and the mixture was stirred at 50 ° C for 1.5 hours. After stirring, a mixture of ferrous chloride and ferric chloride in a mass ratio of 1:2 was added (the amount added was 0.3% of the mass of γ-polyglutamic acid) and continued to stir for 45 minutes. After stirring, it was allowed to stand for 45 minutes, and then centrifuged at 10000 rpm for 5 minutes. The obtained solid product was mixed with carboxymethyl cellulose in a mass ratio of 1:0.4 and freeze-dried at -30 ° C to obtain an anthocyanin composition.

[0031] Example 2:

[0032] S1: Betalain was dissolved in water to obtain a betalain solution with a mass concentration of 5%, and the pH of the betalain solution was adjusted to 8 with an 80 wt % sodium bicarbonate solution. β-cyclodextrin (the amount added was 30% of the mass of betalain) was then added and stirred evenly. The mixture was then placed in a 30° C. water bath and stirred at 600 rpm for 1 h. After the stirring was completed, the mixture was allowed to stand for 40 min to obtain a solution I.

[0033] S2: Spirulina peptidoglycan and γ-polyglutamic acid were added to the obtained solution I in sequence according to a volume mass ratio of 100 mL: 0.1 mg: 1 g and mixed evenly. The mixture was then stirred at 40°C for 2 h. After stirring, a mixture of calcium chloride and ferric chloride in a mass ratio of 1:3 was added (the added amount was 0.1% of the mass of γ-polyglutamic acid) and stirring was continued for 60 min. After stirring, the mixture was allowed to stand for 30 min, and then centrifuged at 10,000 rpm for 5 min. The obtained solid product was mixed with chitosan in a mass ratio of 1:0.6 and freeze-dried at -30°C to obtain a betalain composition.

[0034] Example 3:

[0035] S1: Dissolve shikonin in water to obtain a shikonin solution with a mass concentration of 1%, adjust the pH of the shikonin solution to 8 with a 40wt% sodium bicarbonate solution, then add β-cyclodextrin (the amount added is 20% of the mass of shikonin) and stir evenly, then place in a 40°C water bath and stir at 200 rpm for 4 h, and let it stand for 20 min after stirring to obtain solution I.

[0036] S2: Spirulina peptidoglycan and γ-polyglutamic acid were added to the obtained solution I in a volume mass ratio of 100 mL: 0.5 mg: 5 g, and the mixture was evenly mixed. The mixture was then stirred at 60°C for 1 hour. After stirring, a mixture of ferrous chloride and calcium chloride in a mass ratio of 1:1 was added (the amount added was 0.5% of the mass of γ-polyglutamic acid) and continued to stir for 30 minutes. After stirring, the mixture was allowed to stand for 60 minutes, and then centrifuged at 10,000 rpm for 5 minutes. The obtained solid product was mixed with microcrystalline cellulose in a mass ratio of 1:0.2 and freeze-dried at -30°C to obtain a shikonin composition.

[0037] Example 4:

[0038] S1: Wheat starch was dispersed in a 5% citric acid solution at a mass volume ratio of 10 g:100 mL to obtain a starch suspension. Manganese chloride (3% of the mass of the starch) was added to the obtained starch suspension and heated and stirred until the starch suspension became a translucent viscous colloidal solution. Sodium trimetaphosphate (0.5% of the mass of the starch) was then added and stirring was continued for 2 h. After the stirring was completed, the mixture was allowed to stand for 30 min and then filtered. The obtained precipitate was dried and crushed to obtain modified starch.

[0039] S2: Anthocyanidins were dissolved in water to obtain an anthocyanidin solution with a mass concentration of 3%, and the pH of the anthocyanidin solution was adjusted to 8 using a 40-80 wt% sodium bicarbonate solution. β-cyclodextrin (the amount added was 25% of the mass of the anthocyanidins) was then added and stirred evenly. The mixture was then placed in a 35°C water bath and stirred at 400 rpm for 2.5 h. After the stirring was completed, the mixture was allowed to stand for 30 min to obtain Solution I.

[0040] S3: Spirulina peptidoglycan and γ-polyglutamic acid were added to the obtained solution I in sequence according to the volume mass ratio of 100 mL: 0.3 mg: 3 g and mixed evenly. The mixture was then stirred at 50°C for 1.5 h. After the stirring was completed, a mixture of ferrous chloride and ferric chloride in a mass ratio of 1:2 was added (the added amount was 0.3% of the mass of γ-polyglutamic acid) and continued to stir for 45 min. After the stirring was completed, the mixture was allowed to stand for 45 min, and then centrifuged at 10,000 rpm for 5 min. The obtained solid product was mixed with modified starch in a mass ratio of 1:0.4 and freeze-dried at -30°C to obtain an anthocyanin composition.

[0041] Comparative Example 1: No cyclodextrin was added to anthocyanidins in step 1

[0042] S1: dissolving anthocyanidins in water to obtain an anthocyanidin solution with a mass concentration of 3%, which is referred to as solution I.

[0043] S2: Spirulina peptidoglycan and γ-polyglutamic acid were added to the obtained solution I in a volume mass ratio of 100 mL: 0.3 mg: 3 g, and the mixture was stirred at 50 ° C for 1.5 hours. After stirring, a mixture of ferrous chloride and ferric chloride in a mass ratio of 1:2 was added (the amount added was 0.3% of the mass of γ-polyglutamic acid) and continued to stir for 45 minutes. After stirring, it was allowed to stand for 45 minutes, and then centrifuged at 10000 rpm for 5 minutes. The obtained solid product was mixed with carboxymethyl cellulose in a mass ratio of 1:0.4 and freeze-dried at -30 ° C to obtain an anthocyanin composition.

[0044] Comparative Example 2: No peptidoglycan was added in step 2

[0045] S1: Anthocyanidin was dissolved in water to obtain an anthocyanidin solution with a mass concentration of 3%, and the pH of the anthocyanidin solution was adjusted to 8 with a 40-80 wt% sodium bicarbonate solution. β-cyclodextrin (the amount added was 25% of the mass of the anthocyanidin) was then added and stirred evenly. The mixture was then placed in a 35°C water bath and stirred at 400 rpm for 2.5 h. After the stirring was completed, the mixture was allowed to stand for 30 min to obtain Solution I.

[0046] S2: The γ-polyglutamic acid in the obtained solution I was mixed in sequence according to a volume-to-mass ratio of 100 mL: 3 g, and then stirred at 50°C for 1.5 h. After stirring, a mixture of ferrous chloride and ferric chloride in a mass ratio of 1:2 was added (the added amount was 0.3% of the mass of γ-polyglutamic acid) and continued stirring for 45 min. After stirring, it was allowed to stand for 45 min, and then centrifuged at 10,000 rpm for 5 min. The obtained solid product was mixed with carboxymethyl cellulose in a mass ratio of 1:0.4 and freeze-dried at -30°C to obtain an anthocyanin composition.

[0047] Comparative Example 3: No amino acid was added in step 2

[0048] S1: Anthocyanidin was dissolved in water to obtain an anthocyanidin solution with a mass concentration of 3%, and the pH of the anthocyanidin solution was adjusted to 8 with a 40-80 wt% sodium bicarbonate solution. β-cyclodextrin (the amount added was 25% of the mass of the anthocyanidin) was then added and stirred evenly. The mixture was then placed in a 35°C water bath and stirred at 400 rpm for 2.5 h. After the stirring was completed, the mixture was allowed to stand for 30 min to obtain Solution I.

[0049] S2: Add spirulina peptidoglycan to the obtained solution I in a volume-to-mass ratio of 100 mL: 0.3 mg and mix evenly. Then stir at 50°C for 1.5 h. After stirring, add a mixture of ferrous chloride and ferric chloride in a mass ratio of 1:2 (the added amount is 0.3% of the mass of γ-polyglutamic acid) and continue stirring for 45 min. After stirring, let it stand for 45 min, then centrifuge at 10,000 rpm for 5 min. Mix the obtained solid product with carboxymethyl cellulose in a mass ratio of 1:0.4 and freeze-dry at -30°C to obtain an anthocyanin composition.

[0050] Comparative Example 4: No halide salt was added in step 2

[0051] S1: Anthocyanidin was dissolved in water to obtain an anthocyanidin solution with a mass concentration of 3%, and the pH of the anthocyanidin solution was adjusted to 8 with a 40-80 wt% sodium bicarbonate solution. β-cyclodextrin (the amount added was 25% of the mass of the anthocyanidin) was then added and stirred evenly. The mixture was then placed in a 35°C water bath and stirred at 400 rpm for 2.5 h. After the stirring was completed, the mixture was allowed to stand for 30 min to obtain Solution I.

[0052] S2: Spirulina peptidoglycan and γ-polyglutamic acid were added to the obtained solution I in sequence according to the volume mass ratio of 100 mL: 0.3 mg: 3 g and mixed evenly. The mixture was then stirred at 50°C for 1.5 hours. After stirring, the mixture was allowed to stand for 45 minutes, and then centrifuged at 10,000 rpm for 5 minutes. The obtained solid product was mixed with carboxymethyl cellulose in a mass ratio of 1:0.4 and freeze-dried at -30°C to obtain an anthocyanin composition.

[0053] Comparative Example 5: No three were added in step 2

[0054] S1: Anthocyanidin was dissolved in water to obtain an anthocyanidin solution with a mass concentration of 3%, and the pH of the anthocyanidin solution was adjusted to 8 with a 40-80 wt% sodium bicarbonate solution. β-cyclodextrin (the amount added was 25% of the mass of the anthocyanidin) was then added and stirred evenly. The mixture was then placed in a 35°C water bath and stirred at 400 rpm for 2.5 h. After the stirring was completed, the mixture was allowed to stand for 30 min to obtain Solution I.

[0055] S2: Carboxymethyl cellulose was added to the obtained solution I (the amount added was the same as in Example 1), mixed, and then freeze-dried at -30°C to obtain an anthocyanin composition.

[0056] Test example: Stability test of different pigment compositions

[0057] Test subjects: pigment compositions / pigments of Examples 1-4 and Comparative Examples 1-5;

[0058] Test method: A spectrophotometer was used to measure the absorbance A0 of the pigment composition (the detection wavelength for anthocyanin was 500 nm, the detection wavelength for betacyanin was 535 nm, and the detection wavelength for shikonin was 516 nm) and the absorbance A of the pigment composition after storage at dark / room temperature (25°C), 3000 l ux light / room temperature (25°C), and 3000 l ux light / 35°C for 0 days, 10 days, 20 days, 30 days, 60 days, 90 days, 120 days, 150 days, and 180 days, respectively. Pigment retention rate (%) = A / A0*100.

[0059] Experimental results: see Table 1.

[0060] Table 1 Pigment retention rate of each group

[0061]

[0062]

[0063]

[0064]

[0065] It can be seen from the results in Table 1 that, compared with the pigment compositions of Comparative Examples 1 to 5, the pigment compositions of Examples 1 to 4 of the present invention have better stability and exhibit more excellent stability under both light and high temperature.

[0066] Test 2: Application of different compositions in beverages

[0067] The pigment compositions of Example 1, Example 4, and Comparative Examples 1-5 of the present invention were added to commercially available Sprite beverages at a rate of 3 g per 100 mL of commercially available Sprite beverage. The beverages were placed at room temperature and the color changes of the beverages were observed daily until the color of the beverages began to fade visibly to the naked eye. The time from the start of the color fading to the color fading was recorded. The results are shown in Table 2.

[0068] Table 2 Fading time of each group of beverages

[0069] Group Fading time (days) Example 1 272 Example 4 295 Comparative Example 1 176 Comparative Example 2 259 Comparative Example 3 247 Comparative Example 4 261 Comparative Example 5 195

[0070] It can be seen from the results in Table 2 that, compared with Comparative Examples 1-5, the color change time of the pigment-containing beverages in Examples 1 and 4 of the present invention is significantly longer.

[0071] Experiment 3: Application of different compositions in food noodles

[0072] 5g of each of the pigment compositions of Example 1, Example 4, and Comparative Examples 1-5 were dissolved in an appropriate amount of water, then added to 500g of flour to neutralize the mixture and prepare noodles. The noodles were then boiled for 10 minutes and their color was observed. The noodles containing the pigment compositions of Examples 1 and 4 showed no significant color change after 10 minutes of boiling, while the noodles containing the compositions of Comparative Examples 1-5 all showed some degree of discoloration after 10 minutes of boiling. These results demonstrate that the pigment compositions of the present invention have the advantages of good stability and strong coloring ability.

[0073] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with this profession can make slight changes or modifications to equivalent embodiments of the methods and technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a natural plant pigment composition, characterized in that: The preparation method comprises the following steps: S1: dissolving a natural plant pigment in water to obtain a natural plant pigment solution with a mass concentration of 1-5%, adjusting the pH of the natural plant pigment solution to 7-8 with a 40-80 wt% sodium bicarbonate solution, then adding cyclodextrin and stirring uniformly, then placing in a 30-40° C. water bath and stirring at a speed of 200-600 rpm for 1-4 hours, and then standing for 20-40 minutes after the stirring to obtain a solution I; S2: adding spirulina peptidoglycan and polyamino acid to the obtained solution I in a volume-mass ratio of 100 mL: 0.1-0.5 mg: 1-5 g in sequence and mixing them evenly; then stirring at 40-60° C. for 1-2 h; adding halide salt and continuing stirring for 30-60 min; after stirring, standing for 30-60 min; then centrifuging at 5000-10000 rpm for 5-10 min; mixing the obtained solid product with edible excipients in a mass ratio of 1:0.2-0.6; and freeze-drying at -30--20° C. to obtain a natural plant pigment composition; The natural plant pigments include anthocyanin, betacyanin, and lithospermum red; The halide salt is selected from one or a mixture of two or more of ferrous chloride, ferric chloride, calcium chloride, magnesium chloride, sodium chloride, and potassium iodide; The cyclodextrin is selected from any one of α-cyclodextrin, β-cyclodextrin or γ-cyclodextrin.

2. The preparation method of the natural plant pigment composition according to claim 1, wherein The added amount of the cyclodextrin is 20-30% of the mass of the natural plant pigment.

3. The preparation method of the natural plant pigment composition according to claim 1, wherein The polyamino acid is γ-polyglutamic acid and / or polyaspartic acid.

4. The preparation method of the natural plant pigment composition according to claim 1, wherein The added amount of the halide salt is 0.1-0.5% of the mass of the polyamino acid.

5. The preparation method of the natural plant pigment composition according to claim 1, wherein The edible auxiliary material is selected from any one of carboxymethyl cellulose, sodium carboxymethyl cellulose, sodium alginate, chitosan, calcium alginate, arabinoxylan, microcrystalline cellulose, whey protein, soy protein isolate, and modified starch, or a mixture of two or more thereof.

6. Use of the natural plant pigment composition prepared by the preparation method according to any one of claims 1 to 5 in food.

7. The use according to claim 6, characterized in that The added amount of the natural plant pigment composition in the food is 1 to 5 wt%.

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