Preparation method of acidic anthocyanin blue pigment

Abstract

The invention relates to the technical field of pigment preparation, and discloses a preparation method of an acid anthocyanin blue pigment, which comprises the following steps: selecting dried butterfly bean flower or fresh purple cabbage, removing impurities, and properly crushing for later use; mixing the raw materials with a cellulase aqueous solution; performing sterilization treatment after fermentation is completed; combining the extracting solutions; and concentrating the clear liquid under reduced pressure, and freeze-drying to obtain the product. The preparation method of the acidic anthocyanidin blue pigment is simple and convenient to operate, safe and reliable, and the anthocyanidin pigment can be well obtained; the obtained butterfly bean flower (purple cabbage) blue pigment has a good blue color generation effect under the acidic condition that the pH value is low and is 2.5, and the application range of the anthocyanin blue pigment is expanded; the obtained butterfly bean flower blue pigment has a relatively good and stable blue color generation effect in a relatively wide range of PH 2.5-PH 11.5 (the PH of purple cabbage blue pigment is 2.3-PH 10.5).

Description

Technical Field

[0001] The invention relates to the technical field of pigment preparation, in particular to a method for preparing acidic anthocyanidin blue pigment. Background Art

[0002] Anthocyanidin, also known as flower pigment, is a kind of water-soluble natural pigment widely found in plants in nature. Most of the main coloring substances in fruits, vegetables and flowers are related to it. Under different pH conditions of plant cell vacuoles, anthocyanidins make the petals present colorful colors. Anthocyanidins are widely found in flowering plants (angiosperms). According to preliminary statistics, 27 families and 73 genera of plants contain anthocyanidins, such as purple sweet potatoes, grapes, blood oranges, red cabbage, blueberries, eggplants, cherries, cranberries, strawberries, mulberries, hawthorns, morning glory, butterfly peas and other plant tissues. Anthocyanidin pigments have broad applications in the food and pharmaceutical industries, but some characteristics of anthocyanidin pigments limit their application scope and application environment. Among them, the most prominent common characteristics of anthocyanidin pigments are: red or purple-red color under acidic conditions, and blue or blue-green color under alkaline conditions.

[0003] Butterfly pea flower and purple cabbage are both common edible plants with rich colors. They are rich in vitamins A, C and E, and are rich in anthocyanins. The pigments extracted from butterfly pea flower or purple cabbage have broad application prospects in the food industry. In the existing technology, complex extraction operations are required to achieve the extraction of anthocyanin blue pigments. In view of this, we propose a method for preparing acidic anthocyanin blue pigments. Summary of the invention

[0004] The object of the present invention is to provide a method for preparing an acidic anthocyanin blue pigment to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for preparing an acidic anthocyanidin blue pigment, the preparation method comprising the following steps: S1. Pick and remove the impurities of dried butterfly pea flowers or fresh purple cabbage, and crush them appropriately for later use; S2. Mix the raw materials with 0.1%-0.5% (m / m) cellulose aqueous solution at 40-45°C and stir for enzymolysis for 3h-5h; S3, add 0.5%-1.0% (m / m) aqueous solution of brewer's yeast to the enzymatic hydrolysate, ferment at 35°C for 4-5 days, seal and ferment for 12 hours, open for ventilation for 10-20 minutes every time, maintain intermittent aerobic fermentation, and sterilize after fermentation; S4, extract the pigment of the fermentation product with 3-5 times the amount of pure water at room temperature for 3 times, each time for 2-3 hours, centrifuge and filter, and combine the extracts; S5. Add 0.1%-0.5% (m / m) ferrous sulfate as the raw material to the extract, stir for 10 minutes, adjust the pH to 9.0 with calcium hydroxide water, let stand for 0.5h-1h, centrifuge and filter to obtain the liquid, adjust the pH of the clear liquid to 7.0-7.5 with dilute hydrochloric acid, let stand for 0.5h-1h, centrifuge and filter to obtain the liquid, concentrate the clear liquid under reduced pressure and freeze-dry to obtain the product.

[0006] Optionally, the concentration of the cellulase aqueous solution is 0.1%-0.5% (m / m), the solid-liquid ratio is m / v=1:2, the enzymolysis temperature is 40-45°C, and the enzymolysis time is 3h-5h.

[0007] Optionally, the fermentation conditions are to add 0.5%-1.0% (m / m) aqueous solution of Saccharomyces cerevisiae to the cellulase hydrolysate, and ferment at 35°C for 4-5 days, during which the fermentation is sealed for 12 hours and open for ventilation for 10-20 minutes to maintain intermittent aerobic fermentation.

[0008] Optionally, the method for extracting the pigment of the fermentation product in S4 is: Use 3-5 times the amount of pure water of the fermentation product, stir at room temperature to extract the pigment of the fermentation product 3 times, each time for 2-3 hours, centrifuge and filter, and combine the extracts.

[0009] Optionally, the S4 further includes: Post-treatment of pigment extraction: add 0.1%-0.5% (m / m) ferrous sulfate of the raw material to the extract, stir for 10 minutes, adjust the pH to 9.0 with calcium hydroxide water, let stand for 0.5h-1h, centrifuge and filter to obtain the liquid, adjust the pH of the clear liquid to 7.0-7.5 with dilute hydrochloric acid, let stand for 0.5h-1h, centrifuge and filter to obtain the liquid, concentrate the clear liquid under reduced pressure and freeze-dry to obtain the product.

[0010] Optionally, the product obtained by the preparation method is a black to dark blue solid powder, the solubility in room temperature neutral water is greater than 10g / 100ml, and the room temperature neutral aqueous solution is dark blue. The product is prepared into a 0.5% (m / m) aqueous solution, and the coloring effect under different pH conditions is: Butterfly pea flower: below pH 2.3 is purple, pH 2.5-11.5 is blue, pH 11.8-12.5 is green; Purple cabbage: PH below 2.0 is purple, PH2.3-PH10.5 is blue, and PH10.8-PH12.5 is green.

[0011] Optionally, the centrifugal condition is 5000r / min and the time is 20min.

[0012] Optionally, the pH adjustment step uses 3.5% (m / m) dilute hydrochloric acid. Compared with the prior art, the present invention provides a method for preparing an acidic anthocyanidin blue pigment, which has the following beneficial effects: 1. The preparation method of the acidic anthocyanidin blue pigment is simple to operate, safe and reliable, and can obtain anthocyanidin pigments better; the obtained butterfly pea flower (purple cabbage) blue pigment has a good blue coloring effect under the acidic condition of relatively low pH=2.5, and expands the application scope of anthocyanidin blue pigments; the obtained butterfly pea flower blue pigment has a good and stable blue coloring effect in a wide range of pH2.5-PH11.5 (purple cabbage blue pigment is in pH2.3-PH10.5).

[0013] 2. The preparation method of the acidic anthocyanidin blue pigment, the obtained butterfly pea flower (purple cabbage) blue pigment is a solid powder with good dispersibility, which provides a source of acidic anthocyanidin blue pigment for the pigment industry and the food processing industry, expands the application range of butterfly pea flower (purple cabbage), and improves the comprehensive economic value of butterfly pea flower (purple cabbage). DETAILED DESCRIPTION

[0014] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0015] Example 1 The present embodiment is an embodiment of directly extracting butterfly pea flower blue pigment from butterfly pea flower raw material.

[0016] The dried butterfly pea flower raw material is sorted and removed for use. Weigh 200g of butterfly pea flower raw material, add it to 1000ml of water, stir and extract for 2h, centrifuge and filter, and retain the liquid; repeat the above operation for the solid and continue to extract 2 times. Combine the 3 extracts, concentrate under reduced pressure to an extract, and freeze-dry to obtain the butterfly pea flower blue pigment product.

[0017] Example 2 The present embodiment is an embodiment in which the butterfly pea flower raw material is first hydrolyzed with cellulase and then the butterfly pea flower blue pigment is extracted.

[0018] Pick and remove the dried butterfly pea flower raw materials for later use. Weigh 200g butterfly pea flower raw materials, add 1000ml water, add 0.5% (m / m) cellulose aqueous solution under 40-45℃ water bath conditions, stir and enzymolyze for 3h-5h; centrifuge and filter, retain the liquid; repeat the above operation for the solid, and continue to extract 2 times. Combine the 3 extracts, reduce pressure and concentrate to extract, freeze-dry, and obtain the butterfly pea flower blue pigment product.

[0019] Example 3 The present embodiment is an embodiment of preparing butterfly pea flower raw material by enzymolysis with 0.5% cellulase, fermentation with 0.5% saccharomyces cerevisiae, and finally water extraction of butterfly pea flower blue pigment.

[0020] The dried butterfly pea flower raw material is sorted and removed for use. Weigh 200g of butterfly pea flower raw material, add 0.5% (m / m) cellulose aqueous solution under 40-45℃ water bath conditions, and stir for enzymolysis for 3h-5h; add 0.5% (m / m) saccharomyces cerevisiae aqueous solution to the butterfly pea flower enzymolyzate, and ferment at 35℃ for 4-5d. During this period, the sealed fermentation is carried out for 12h, and the open ventilation is required for 10-20min to maintain intermittent aerobic fermentation. After the fermentation is completed, sterilize; add the butterfly pea flower fermentation to 1000ml of water, stir and extract for 2h, centrifuge and filter, and retain the liquid. Repeat the above operation for the solid and continue to extract twice. Combine the three extracts, concentrate the clear liquid under reduced pressure and freeze-dry, and obtain the product under reduced pressure and concentrate to an extract, freeze-dry, and obtain the butterfly pea flower blue pigment product.

[0021] Example 4 The present embodiment is an embodiment in which the butterfly pea flower raw material is successively hydrolyzed with 0.5% cellulase, then fermented with 0.5% saccharomyces cerevisiae, and finally the butterfly pea flower blue pigment extract is treated with ferrous salt / calcium hydroxide.

[0022] Pick and remove the dried butterfly pea flower raw materials for later use. Weigh 200g butterfly pea flower raw materials, add 0.5% (m / m) cellulose aqueous solution under 40-45℃ water bath conditions, stir and hydrolyze for 3h-5h; add 0.5% (m / m) saccharomyces cerevisiae aqueous solution to the butterfly pea flower hydrolysate, ferment at 35℃ for 4-5d, during which every 12h of sealed fermentation, open ventilation for 10-20min, and maintain intermittent aerobic fermentation. After fermentation, sterilize; add butterfly pea flower fermentation to 1000ml water, stir and extract for 2h, centrifuge and filter, and retain the liquid. Repeat the above operation for the solid and continue to extract twice. Combine the three extracts, add 0.2 g of ferrous sulfate to the extract, stir for 10 minutes, adjust the pH to 9.0 with calcium hydroxide water, let stand for 0.5h-1h, centrifuge and filter to obtain the liquid, adjust the pH of the clear liquid to 7.0-7.5 with dilute hydrochloric acid, let stand for 0.5h-1h, centrifuge and filter to obtain the liquid, concentrate the clear liquid under reduced pressure and then freeze-dry to obtain the product under reduced pressure to an extract, freeze-dry to obtain a butterfly pea flower blue pigment product.

[0023] Example 5 The present embodiment is an embodiment in which the butterfly pea flower raw material is successively hydrolyzed with 0.1% cellulase, then fermented with 1.0% saccharomyces cerevisiae, and finally the butterfly pea flower blue pigment extract is treated with ferrous salt / calcium hydroxide.

[0024] Pick and remove the dried butterfly pea flower raw materials for later use. Weigh 200g butterfly pea flower raw materials, add 0.1% (m / m) cellulose aqueous solution under 40-45℃ water bath conditions, stir and hydrolyze for 3h-5h; add 1.0% (m / m) saccharomyces cerevisiae aqueous solution to the butterfly pea flower hydrolysate, ferment at 35℃ for 4-5d, during which every 12h of sealed fermentation, open ventilation for 10-20min, and maintain intermittent aerobic fermentation. After fermentation, sterilize; add butterfly pea flower fermentation to 1000ml water, stir and extract for 2h, centrifuge and filter, and retain the liquid. Repeat the above operation for the solid and continue to extract twice. Combine the three extracts, add 1.0 g of ferrous sulfate to the extract, stir for 10 minutes, adjust the pH to 9.0 with calcium hydroxide water, let stand for 0.5h-1h, centrifuge and filter to obtain the liquid, adjust the pH of the clear liquid to 7.0-7.5 with dilute hydrochloric acid, let stand for 0.5h-1h, centrifuge and filter to obtain the liquid, concentrate the clear liquid under reduced pressure and then freeze-dry to obtain the product, concentrate under reduced pressure to an extract, freeze-dry, and obtain the butterfly pea flower blue pigment product.

[0025] Example 6 This embodiment is an embodiment of directly extracting purple cabbage blue pigment from purple cabbage raw material.

[0026] Pick and crush the fresh purple cabbage raw material for later use. Weigh 200g of purple cabbage raw material, add it to 1000ml of water, stir and extract for 2h, centrifuge and filter, and keep the liquid; repeat the above operation for the solid and continue to extract 2 times. Combine the 3 extracts, concentrate under reduced pressure to extract, and freeze-dry to obtain the purple cabbage blue pigment product.

[0027] Example 7 This embodiment is an embodiment of enzymolysis of purple cabbage raw materials with 0.1% cellulase, then fermentation with 1.0% saccharomyces cerevisiae, and finally treatment of purple cabbage blue pigment extract with ferrous salt / calcium hydroxide.

[0028] Pick and crush the fresh purple cabbage raw materials for later use. Weigh 200g of purple cabbage raw materials, add 0.1% (m / m) cellulose aqueous solution under 40-45℃ water bath conditions, stir and hydrolyze for 3h-5h; add 1.0% (m / m) saccharomyces cerevisiae aqueous solution to the purple cabbage hydrolysate, ferment at 35℃ for 4-5d, and open for ventilation for 10-20min every 12h of sealed fermentation to maintain intermittent aerobic fermentation. After fermentation, sterilize; add the purple cabbage fermentation to 1000ml water, stir and extract for 2h, centrifuge and filter, and retain the liquid. Repeat the above operation for the solid and continue to extract twice. Combine the three extracts, add 1.0 g of ferrous sulfate to the extract, stir for 10 minutes, adjust the pH to 9.0 with calcium hydroxide water, let stand for 0.5h-1h, centrifuge and filter to obtain the liquid, adjust the pH of the clear liquid to 7.0-7.5 with dilute hydrochloric acid, let stand for 0.5h-1h, centrifuge and filter to obtain the liquid, concentrate the clear liquid under reduced pressure and then freeze-dry to obtain the product, concentrate under reduced pressure to an extract, freeze-dry to obtain the purple cabbage blue pigment product.

[0029] The color contrast of the butterfly pea flower blue pigment obtained in Example 1 to Example 5 at different pH values ​​when the concentration is 0.5% (m / m) (adjusted with 0.05% dilute hydrochloric acid) is shown in Table 1: Table 1: Comparison of pigment color at different pH PH Example 1 Example 2 Example 3 Example 4 Example 5 PH=11.8 green green green green green PH=11.5 green green Blue Blue Blue PH=11.0 green green Indigo Indigo Indigo PH=10.5 green green blue blue blue PH=10.0 green green blue blue blue PH=9.0 green green blue blue blue PH=8.0 blue blue blue blue blue PH=7.0 blue blue blue blue blue PH=6.5 blue blue blue blue blue PH=6.0 blue blue blue blue blue PH=5.5 blue blue blue blue blue PH=5.0 Blue Purple Blue Purple blue blue blue PH=4.5 Blue Purple Blue Purple blue blue blue PH=4.0 Purple Purple blue blue blue PH=3.5 Purple Purple blue blue blue PH=3.0 Purple Purple blue blue blue PH=2.8 Purple Purple blue blue blue PH=2.5 Purple Purple blue blue blue PH=2.3 Purple Purple red red red As can be seen from Table 1, compared with Example 1-Example 5, the butterfly pea flower blue pigment obtained by the method described in Example 3-Example 5 is blue (system) at pH 2.5-PH11.5, while the butterfly pea flower pigment obtained by direct extraction in Example 1 and extraction after enzymatic hydrolysis in Example 2 is green at pH greater than PH9.0, blue at pH 8.0-PH5.5, blue-purple at pH 5.0-PH4.5, and purple below pH 4.0.

[0030] The color contrast of the purple cabbage blue pigment obtained in Example 6-Example 7 at different pH values ​​when the concentration is 0.5% (m / m) (adjusted with 0.05% dilute hydrochloric acid) is shown in Table 2: Table 2: Comparison of pigment color at different pH PH Example 6 Example 7 PH=10.5 green green PH=10.0 Blue Purple blue PH=9.0 Blue Purple blue PH=8.0 Blue Purple blue PH=7.0 Blue Purple blue PH=6.5 Blue Purple blue PH=6.0 Blue Purple blue PH=5.5 Blue Purple blue PH=5.0 Purple blue PH=4.5 Purple blue PH=4.0 Purple blue PH=3.5 Purple blue PH=3.0 Purple blue PH=2.5 Purple blue PH=2.3 Purple blue PH=2.0 Purple red As can be seen from Table 2, comparing Example 6 and Example 7, the purple cabbage blue pigment obtained by the method described in Example 7 is blue (series) at pH 2.3-PH10.5, while the purple cabbage pigment directly extracted in Example 6 is green at pH greater than 10.5, blue-purple at pH 10.0-PH5.5, and purple-red below pH 5.0.

[0031] The solid appearance of the blue pigment obtained in Example 1-Example 7 is shown in Table 3: Table 3: Comparison of blue pigment solid appearance states obtained in different embodiments Example Solid Color Solid state Dispersibility Example 1 black Asphalt none Example 2 black Asphalt none Example 3 Black to dark blue Sticky solid none Example 4 Blue Black powder good Example 5 Blue Black powder good Example 6 Blue Black Asphalt none Example 7 Blue Black powder good As can be seen from Table 3, the solid states of the butterfly pea flower blue pigment obtained in Examples 1 to 3 and the purple cabbage pigment obtained in Example 6 are asphalt-like or viscous solids with no dispersibility, while the butterfly pea flower blue pigment obtained in Examples 4 to 5 and the purple cabbage pigment solids obtained in Example 7 are solid powders with good dispersibility.

[0032] As an application of this embodiment: the preparation method of the acidic anthocyanin blue pigment is simple to operate, safe and reliable, and can obtain anthocyanin pigments better; the obtained butterfly pea flower (purple cabbage) blue pigment has a good blue coloring effect under a relatively low acidic condition of PH=2.5, which expands the application scope of anthocyanin blue pigments; the obtained butterfly pea flower blue pigment has a good and stable blue coloring effect in a wide range of PH2.5-PH11.5 (purple cabbage blue pigment is in PH2.3-PH10.5).

[0033] The above generally describes the present invention in detail, but it is obvious to a person skilled in the art that some modifications or improvements can be made to the present invention. Therefore, modifications or improvements that do not depart from the spirit of the present invention are within the scope of protection of the present invention.

Claims

1. A method for preparing an acidic anthocyanidin blue pigment, characterized in that: The preparation method comprises the following steps: S1. Pick and remove the impurities of dried butterfly pea flowers or fresh purple cabbage, and crush them appropriately for later use; S2. Mix the raw materials with 0.1%-0.5% (m / m) cellulose aqueous solution at 40-45°C and stir for enzymolysis for 3h-5h; S3, add 0.5%-1.0% (m / m) aqueous solution of brewer's yeast to the enzymatic hydrolysate, ferment at 35°C for 4-5 days, seal and ferment for 12 hours, open for ventilation for 10-20 minutes every time, maintain intermittent aerobic fermentation, and sterilize after fermentation; S4, extract the pigment of the fermentation product with 3-5 times the amount of pure water at room temperature for 3 times, each time for 2-3 hours, centrifuge and filter, and combine the extracts; S5. Add 0.1%-0.5% (m / m) ferrous sulfate as the raw material to the extract, stir for 10 minutes, adjust the pH to 9.0 with calcium hydroxide water, let stand for 0.5h-1h, centrifuge and filter to obtain the liquid, adjust the pH of the clear liquid to 7.0-7.5 with dilute hydrochloric acid, let stand for 0.5h-1h, centrifuge and filter to obtain the liquid, concentrate the clear liquid under reduced pressure and freeze-dry to obtain the product.

2. The method for preparing an acidic anthocyanidin blue pigment according to claim 1, characterized in that: The concentration of the cellulase aqueous solution is 0.1%-0.5% (m / m), the solid-liquid ratio is m / v=1:2, the enzymolysis temperature is 40-45°C, and the enzymolysis time is 3h-5h.

3. The method for preparing an acidic anthocyanidin blue pigment according to claim 1, characterized in that: The fermentation conditions are as follows: adding 0.5%-1.0% (m / m) aqueous solution of saccharomyces cerevisiae to the hydrolyzate of cellulose, and fermenting at 35°C for 4-5 days, during which the fermentation is sealed for 12 hours and then opened for ventilation for 10-20 minutes to maintain intermittent aerobic fermentation.

4. The method for preparing an acidic anthocyanidin blue pigment according to claim 1, characterized in that: The method for extracting the pigment of the fermentation product in S4 is as follows: Use 3-5 times the amount of pure water of the fermentation product, stir at room temperature to extract the pigment of the fermentation product 3 times, each time for 2-3 hours, centrifuge and filter, and combine the extracts.

5. The method for preparing an acidic anthocyanidin blue pigment according to claim 1, characterized in that: The S4 further comprises: Post-treatment of pigment extraction: add 0.1%-0.5% (m / m) ferrous sulfate of the raw material to the extract, stir for 10 minutes, adjust the pH to 9.0 with calcium hydroxide water, let stand for 0.5h-1h, centrifuge and filter to obtain the liquid, adjust the pH of the clear liquid to 7.0-7.5 with dilute hydrochloric acid, let stand for 0.5h-1h, centrifuge and filter to obtain the liquid, concentrate the clear liquid under reduced pressure and freeze-dry to obtain the product.

6. The method for preparing an acidic anthocyanidin blue pigment according to claim 1, characterized in that: The product obtained by the preparation method is a black to dark blue solid powder, the solubility in room temperature neutral water is greater than 10g / 100ml, and the room temperature neutral aqueous solution is dark blue. The product is prepared into a 0.5% (m / m) aqueous solution, and the coloring effect under different pH conditions is: Butterfly pea flower: below pH 2.3 is purple, pH 2.5-11.5 is blue, pH 11.8-12.5 is green; Purple cabbage: PH below 2.0 is purple, PH2.3-PH10.5 is blue, and PH10.8-PH12.5 is green.

7. The method for preparing an acidic anthocyanidin blue pigment according to claim 1, characterized in that: The centrifugal condition is 5000 r / min and the time is 20 min.

8. The method for preparing an acidic anthocyanidin blue pigment according to claim 1, characterized in that: The pH adjustment step uses 3.5% (m / m) dilute hydrochloric acid.