Preparation of high-stability natural blue pigment and application of high-stability natural blue pigment in leisure food for children

Abstract

The invention relates to preparation of high-stability natural blue pigment and application of the high-stability natural blue pigment in leisure food for children, which comprises the following steps: preparation of geniposide, purification of geniposide, preparation of natural blue pigment, preparation of jelly containing gardenia blue pigment, and preparation of milk tea containing gardenia blue pigment. The jelly product containing the blue gardenia pigment is creatively prepared by using a macroporous adsorption resin purification geniposide technology, a geniposide enzymolysis technology, ammonia process catalysis of natural blue pigment and sol blending, and the jelly product has the characteristics of easiness in operability, stable pigment, good ornamental value, difficulty in fading and the like.

Description

Technical Field

[0001] The invention relates to the preparation of a high-stability natural blue pigment and the application of the blue pigment in children's leisure food, belonging to the new technical field of food additives. Background Art

[0002] Natural blue pigment has extremely high application value and is now widely used in medicine, cosmetics, printing and dyeing, food and other fields. But in fact, among common natural pigments, the natural source of blue pigment is very limited, which leads to consumers often labeling related blue foods as "artificial blue" and believing that they may have potential health risks. In addition, color often causes consumers to have corresponding visual psychological effects. In the past, researchers have compared the consumption of yellow potatoes and blue potatoes to verify the psychological impact and consumption choices of blue foods on consumers. The results show that only 28% of consumers chose blue potatoes, simply because of their curiosity about new products. However, this phenomenon has basically disappeared in recent years. Blue ice cream, blue cakes and blue candies loved by children can be seen everywhere in the market.

[0003] Gardenia is an evergreen tree of the Rubiaceae family, which is widely cultivated in my country. The fruit is small, orange, oval, and 1.25 to 2.5 cm long. Gardenia glycoside is one of the main iridoid glycoside compounds present in gardenia fruit and can be used as a natural yellow colorant. After gardenia glycoside is extracted from plant raw materials, it is hydrolyzed by β-glucosidase to release genipin and glucose. When genipin reacts with primary amine compounds such as amino acids, blue pigment is generated. When genipin reacts with different amino acids, different blue pigments are generated. Gardenia blue pigment is mainly used in hard candies, beverages, fruit juices, etc. Coloring. In addition, due to the good solubility and strong coloring power of gardenia blue pigment, common metal ions, acids and alkalis have little effect on its hue, so it is also widely used in medicines, cosmetics and biomaterials. Gardenia blue pigment is a safe, non-toxic and natural food pigment made by bioengineering technology. It is a dark blue powder and is easily soluble in water. my country included it in the formulation of new food additives in 1990. It is used for dyeing foods such as protein, sugar and starch, especially in the production of mixed liquor. Gardenia blue is an indispensable component in compound pigments such as pomegranate red. Summary of the invention

[0004] In view of the above problems, the present invention provides a method for preparing a natural blue pigment with high stability and its application in children's leisure food.

[0005] The first technical purpose of the present invention is to provide a method for preparing geniposide which is water-soluble and can be separated and purified to high purity.

[0006] The second technical purpose of the present invention is to provide a method for preparing gardenia blue pigment by enzymatic hydrolysis and amination reaction of geniposide.

[0007] The third technical purpose of the present invention is to provide a method for preparing jelly containing gardenia blue pigment and milk tea containing gardenia blue pigment by using the gardenia blue pigment.

[0008] The invention relates to the preparation of a natural blue pigment with high stability and application thereof in children's leisure food. The preparation method comprises the following steps: preparation of geniposide, purification of geniposide, preparation of natural blue pigment, preparation of jelly containing gardenia blue pigment and preparation of milk tea containing gardenia blue pigment.

[0009] Preferably, step (1) preparation of geniposide The crude powder of Gardenia jasminoides was used to extract geniposide by orthogonal experiments on extraction time, liquid-solid ratio and ethanol concentration. Step (2) Purification of Geniposide For FD 802 The resin was pretreated and wet loaded, the extract was concentrated and dealcoholized, and then diluted with distilled water to different feed concentrations. The feed concentration and column flow rate were used to decolorize the gardenia blue pigment. 802 The resin column liquid is concentrated under reduced pressure to an extract, and ethyl acetate is used as the extraction solvent. The liquid-to-solid volume ratio and the extraction time are used to extract geniposide. The extract is vacuum concentrated to dryness, and acetone is added for hot dissolution. When it is completely dissolved, acetone is slowly added dropwise with an equal volume of ethyl acetate, and then allowed to stand and cool, filtered and dried to obtain white needle-shaped crystals, and the prepared geniposide is used for standby; Step (3) Preparation of natural blue pigment The prepared geniposide is dissolved in water, β-glucosidase is added to heat and enzymolyze, the supernatant after centrifugation and filtration is evaporated and concentrated, a saturated solution of ammonium salt is added dropwise under stirring, and the material is kept until the pigment is generated, and the prepared gardenia blue pigment is set aside; Step (4) Preparation of jelly containing gardenia blue pigment Konjac gum, carrageenan, and agar are uniformly mixed with white granulated sugar in proportion, konjac flour, carrageenan, and agar are slowly added to cold water and soaked, so that the composite gelling agent fully absorbs water and swells, so as to better bring into play the gelling property of the colloid, the colloid is heated in a constant temperature water bath, and is constantly stirred with a spoon to avoid uneven heating and causing caking, when the colloid is completely dissolved in the water and there is no caking, the water bath is heated, and gardenia blue pigment is added in proportion, heated to boiling and dissolved, and stirred evenly, and the bubbles generated in the stirring process are removed, and when the mixed glue solution temperature drops, citric acid and potassium chloride mixed solution are added in proportion while stirring, and a filter cloth is used to filter the sugar-glucoside mixed solution, and then it is dispensed into the jelly cups sterilized in advance and sealed, and the jelly cups after the sealing are sterilized, and the finished gardenia blue jelly is obtained after cooling; Step (5) Preparation of milk tea containing gardenia blue pigment Use boiling water to brew the weighed Fuzhuan tea, then filter the tea leaves with gauze, discard the tea soup, keep the tea leaves, boil the filtered tea leaves, add them into boiling water separately, after pre-boiling, filter the tea soup with gauze, discard the tea leaves, keep the tea soup, weigh the remaining tea soup before adding pure milk, then add corresponding percentages of gardenia blue pigment and pure milk according to the remaining tea soup, weigh the remaining amount of boiled milk tea and add corresponding percentages of salt, which is the finished product of gardenia blue milk tea.

[0010] The first technical purpose of the present invention is achieved through the following technical solutions: Preferably, step (1) preparation of geniposide The crude powder of Gardenia jasminoides was used to extract geniposide by orthogonal experiment on extraction time, liquid-solid ratio and ethanol concentration.

[0011] The advantage of the present invention is that ethanol is a polar solvent and can effectively dissolve a variety of polar and weakly polar compounds, including glycoside compounds such as geniposide.

[0012] Preferably, step (2) purification of geniposide For FD 802 The resin was pretreated and wet loaded, with a loading volume of 30-60 mL. The extract was concentrated and dealcoholized to 1 / 4-1 / 7 of the volume and diluted with distilled water to different feed concentrations. The feed concentration and column flow rate (0.5-3.0 Bv / h) were used to decolorize the gardenia blue pigment. 802 The resin column liquid is concentrated under reduced pressure to an extract with ethyl acetate as the extraction solvent. The temperature effect (30-60°C), liquid-to-solid volume ratio (0.5-3.0) and extraction time (10-40min) have an effect on the extraction of geniposide. The extract is concentrated to dryness in vacuo, and 5-8g of acetone is added for hot dissolution. When it is completely dissolved, acetone is slowly added dropwise in an amount equal to the volume of ethyl acetate, and the mixture is allowed to stand and cool for 24-48h. It is filtered and dried to obtain white needle-shaped crystals, and the prepared geniposide is ready for use.

[0013] The invention has the advantages of separating and purifying geniposide by using the method of organic solvent extraction, macroporous adsorption resin decolorization, ethyl acetate extraction and acetone crystallization, and the process is simple and easy with high purity.

[0014] The second technical purpose of the present invention is achieved through the following technical solutions: Preferably, step (3) preparation of natural blue pigment Dissolve 30-60 g of geniposide in 400-550 mL of water, add 2-5 g of β-glucosidase and heat at 45-60 ° C for enzymolysis for 8-14 hours, take the supernatant after centrifugation and filtration, evaporate and concentrate, and when the temperature reaches 125-155 ° C, add a saturated solution of ammonium salt dropwise under stirring, and then keep the material at about 140-160 ° C until the pigment is generated, and the prepared gardenia blue pigment is ready for use.

[0015] The invention has the advantage that, through the optimized enzyme-catalyzed amination process, the blue pigment obtained has better color stability and safety.

[0016] The third technical objective of the present invention is achieved through the following technical solutions: Preferably, step (4) comprises the preparation of the gardenia blue pigment jelly Evenly mix konjac gum, carrageenan, and agar with 8-14% white sugar in a ratio of 1-2:2-4:1-2. Slowly add konjac powder, carrageenan, and agar to 200-350 mL of cold water and soak for 30-60 min to allow the composite gel to fully absorb water and swell, so as to better exert the gel properties of the colloid. Heat the colloid in a constant temperature water bath at 80-95 ° C, stirring continuously with a spoon to avoid agglomeration caused by uneven heating. When the colloid is completely dissolved in the water without agglomeration, heat the water bath to 100-130 ° C, and add 0.07-0.1% of Add gardenia blue pigment, heat to boiling to dissolve for 10-25 minutes, stir evenly, remove bubbles generated during the stirring process, when the temperature of the mixed glue solution drops to 75-85°C, add citric acid and potassium chloride mixed solution in the proportion of 0.2-0.5% and 0.04-0.07% while stirring, filter the sugar-gum mixed solution with a 60-90 mesh filter cloth, and then dispense it into pre-sterilized jelly cups and seal them, sterilize the sealed jelly cups at 80-100°C for 30-60 minutes, and cool them to obtain the finished gardenia blue jelly.

[0017] The invention has the advantage that the gardenia blue pigment, as a natural pigment with good stability, is applied in jelly to prepare a gardenia blue jelly, which can not only meet the demand for jelly coloring, but also make the jelly product more unique in taste, can meet people's needs to the greatest extent in terms of color and nutritional characteristics, can also prolong the storage time of the product, is beneficial to the storage and transportation of the jelly product, and has broad market prospects.

[0018] Preferably, step (5) comprises the preparation of gardenia blue pigment milk tea Use 100~120℃ boiling water to brew 5~8g Fuzhuan tea, then filter the tea leaves with gauze, discard the tea soup, keep the tea leaves, boil the filtered tea leaves, add them into 350~500ml of 100~120℃ boiling water respectively, after pre-boiling for 2.5~5.5min, filter the tea soup with 100~120 mesh gauze, discard the tea leaves, keep the tea soup, weigh the remaining tea soup before adding pure milk, and then add the corresponding 0.5~2% gardenia blue pigment and 8~14% pure milk according to the remaining tea soup, weigh the remaining amount of boiled milk tea and add the corresponding 0.5~2% salt, which is the finished product of gardenia blue milk tea.

[0019] The invention has the advantages that the brick tea milk tea has a smooth taste, a mellow flavor, is rich in protein, vitamins and various mineral elements, and the gardenia blue pigment, as a natural pigment with good stability, is applied to milk. It combines traditional milk tea with the gardenia blue pigment, giving the beverage a unique blue appearance, and increasing the visual effect and taste.

[0020] In summary, the present invention has the following beneficial effects: 1. The present invention has the advantage that ethanol is a polar solvent that can effectively dissolve a variety of polar and weakly polar compounds, including glycoside compounds such as geniposide; 2. The present invention has the advantages of separating and purifying geniposide by organic solvent extraction, macroporous adsorption resin decolorization, ethyl acetate extraction and acetone crystallization, which has a simple process and high purity; 3. The present invention has the advantage that, through the optimized enzyme-catalyzed amination process, the blue pigment obtained has better color stability and safety; 4. The invention has the advantages that the gardenia blue pigment is a natural pigment with good stability. When it is applied to jelly to make a gardenia blue jelly, it can not only meet the demand for jelly coloring, but also make the jelly product more unique in taste. It can meet people's needs to the greatest extent in terms of color and nutritional characteristics, and can also extend the storage time of the product, which is beneficial to the storage and transportation of the jelly product, and has broad market prospects. 5. The advantage of adopting the present invention is that the brick tea milk tea has a smooth taste, a mellow flavor, is rich in protein, vitamins and various mineral elements, and the gardenia blue pigment, as a natural pigment with good stability, is applied to milk. It combines traditional milk tea with the gardenia blue pigment, giving the drink a unique blue appearance, increasing the visual effect and taste. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The present invention is a preparation flow chart of a natural blue pigment with high stability. DETAILED DESCRIPTION

[0022] The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention. Without departing from the spirit and substance of the present invention, modifications or substitutions made to the methods, steps or conditions of the present invention are within the scope of the present invention.

[0023] If not specifically stated, the technical means used in the examples are conventional means known to those skilled in the art. In addition, all the raw materials used in the examples are known commercial products. Example 1

[0024] Step (1) Preparation of Geniposide 5 g of Gardenia jasminoides powder was taken and geniposide was extracted by orthogonal experiment at 75°C with the extraction time of 0.5 h, liquid-solid ratio of 6:1 and ethanol concentration (mass fraction 30%).

[0025] Step (2) Purification of Geniposide For FD 802 The resin was pretreated and wet loaded into the column, with a loading volume of 30 mL. The extract was concentrated and dealcoholized to 1 / 4 of the volume and diluted with distilled water to different feed concentrations. The feed concentration and column flow rate were 0.5 Bv / h to decolorize the gardenia blue pigment. 802 The resin column liquid is concentrated under reduced pressure to an extract, and ethyl acetate is used as the extraction solvent. The temperature effect is 30°C, the liquid-to-solid volume ratio is 0.5, and the extraction time is 10 min to extract geniposide. The extract is vacuum concentrated to dryness, 5 g of acetone is added for hot dissolution, and when it is completely dissolved, acetone equal to the volume of ethyl acetate is slowly added dropwise, and then it is allowed to cool for 24 hours, filtered and dried to obtain white needle-shaped crystals. The prepared geniposide is used for later use.

[0026] Step (3) Preparation of natural blue pigment Dissolve 30g of the prepared geniposide in 400mL of water, add 2g of β-glucosidase and heat at 45℃ for enzymolysis for 8h, take the supernatant after centrifugation and filtration, evaporate and concentrate, when the temperature reaches 125℃, add saturated solution of ammonium salt dropwise under stirring, and then maintain the material at about 140℃ until the pigment is generated, and the prepared gardenia blue pigment is ready for use.

[0027] Step (4) Preparation of jelly containing gardenia blue pigment Konjac gum, carrageenan, agar were uniformly mixed with 8% white sugar in a ratio of 1:2:1. Konjac powder, carrageenan, agar were slowly added to 200 mL of cold water and soaked for 30 min to allow the composite gel to fully absorb water and swell, so as to better exert the gel properties of the colloid. The colloid was heated in a constant temperature water bath at 80 ° C, and stirred continuously with a spoon to avoid agglomeration caused by uneven heating. When the colloid was completely dissolved in the water without agglomeration, the water bath was heated to 100 ° C and 0.07% of the mixture was added. Gardenia blue pigment was heated to boiling and dissolved for 10 minutes, stirred evenly, and bubbles generated during the stirring process were removed. When the temperature of the mixed glue solution dropped to 75°C, citric acid and potassium chloride mixed solution were added at a ratio of 0.2% and 0.04% while stirring. The sugar-gum mixed solution was filtered through a 60-mesh filter cloth, and then divided into pre-sterilized jelly cups and sealed. The sealed jelly cups were sterilized at 80°C for 30 minutes, and the finished gardenia blue jelly was obtained after cooling.

[0028] Step (5) Preparation of milk tea containing gardenia blue pigment Brew 5g of Fuzhuan tea with 100℃ boiling water, filter the tea leaves with gauze, discard the tea soup, keep the tea leaves, boil the filtered tea leaves, add them into 350ml of 100℃ boiling water, pre-boil for 2.5min, filter the tea soup with 100-mesh gauze, discard the tea leaves, keep the tea soup, weigh the remaining tea soup before adding pure milk, then add the corresponding 0.5% gardenia blue pigment and 8% pure milk according to the remaining tea soup, weigh the remaining amount of boiled milk tea and add the corresponding 0.5% salt, which is the finished product of gardenia blue milk tea. Example 2

[0029] Step (1) Preparation of Geniposide Take 6g of Gardenia jasminoides powder and extract geniposide by orthogonal experiment at 80℃ with extraction time of 1.0h, liquid-solid ratio of 9:1 and ethanol concentration of 50%.

[0030] Step (2) Purification of Geniposide For FD 802 The resin was pretreated and wet loaded into the column, with a loading volume of 40 mL. The extract was concentrated and dealcoholized to 1 / 5 of the volume and diluted with distilled water to different feed liquid concentrations, liquid concentrations and column flow rates of 1.0 Bv / h to decolorize gardenia blue pigment. 802 The resin column liquid is concentrated under reduced pressure to an extract, and ethyl acetate is used as the extraction solvent. The temperature effect is 40°C, the liquid-to-solid volume ratio is 1.0, and the extraction time is 20 min to extract geniposide. The extract is concentrated to dryness in vacuo, and 6 g of acetone is added for hot dissolution. When it is completely dissolved, acetone equal to the volume of ethyl acetate is slowly added dropwise, and then it is allowed to cool for 24 hours, filtered and dried to obtain white needle-shaped crystals. The prepared geniposide is used for later use.

[0031] Step (3) Preparation of natural blue pigment Dissolve 40g of the prepared geniposide in 450mL of water, add 3g of β-glucosidase and heat at 50℃ for enzymolysis for 10h, take the supernatant after centrifugation and filtration, evaporate and concentrate, when the temperature reaches 135℃, add saturated solution of ammonium salt dropwise under stirring, and then maintain the material at about 145℃ until the pigment is generated, and the prepared gardenia blue pigment is ready for use.

[0032] Step (4) Preparation of jelly containing gardenia blue pigment Konjac gum, carrageenan, agar were mixed evenly with 10% white sugar in a ratio of 1:2:1. Konjac powder, carrageenan, agar were slowly added to 250 mL of cold water and soaked for 40 min to allow the composite gel to fully absorb water and swell, so as to better exert the gel properties of the colloid. The colloid was heated in a constant temperature water bath at 85 ° C, and stirred continuously with a spoon to avoid agglomeration caused by uneven heating. When the colloid was completely dissolved in the water without agglomeration, the water bath was heated to 110 ° C and 0.08% of the mixture was added. Gardenia blue pigment was heated to boiling and dissolved for 15 minutes, stirred evenly, and bubbles generated during the stirring process were removed. When the temperature of the mixed glue solution dropped to 80°C, citric acid and potassium chloride mixed solution were added at a ratio of 0.3% and 0.05% while stirring. The sugar-gum mixed solution was filtered through a 70-mesh filter cloth, and then divided into pre-sterilized jelly cups and sealed. The sealed jelly cups were sterilized at 85°C for 40 minutes, and the finished gardenia blue jelly was obtained after cooling.

[0033] Step (5) Preparation of milk tea containing gardenia blue pigment Use 100℃ boiling water to brew 6g of Fuzhuan tea, then filter the tea leaves with gauze, discard the tea soup, keep the tea leaves, boil the filtered tea leaves, add them into 400ml of 100℃ boiling water respectively, after pre-boiling for 3.5min, filter the tea soup with 100-mesh gauze, discard the tea leaves, keep the tea soup, weigh the remaining tea soup before adding pure milk, and then add the corresponding 1% gardenia blue pigment and 10% pure milk according to the remaining tea soup, weigh the remaining amount of boiled milk tea and add the corresponding 1% salt, which is the finished product of gardenia blue milk tea. Example 3

[0034] Step (1) Preparation of Geniposide 7 g of Gardenia jasminoides powder was used to extract geniposide at 85°C using an orthogonal experiment with extraction time of 2.0 h, liquid-solid ratio of 12:1 and ethanol concentration of 70%.

[0035] Step (2) Purification of Geniposide For FD 802The resin was pretreated and wet loaded into the column. The loading volume was 50 mL. The extract was concentrated and dealcoholized to 1 / 6 of the volume and diluted with distilled water to different feed concentrations. The feed concentration and column flow rate were 2.0, Bv / h, and the decolorization of gardenia blue pigment was investigated. FD 802 The resin column liquid is concentrated under reduced pressure to an extract, and ethyl acetate is used as the extraction solvent. The temperature effect is 50°C, the liquid-to-solid volume ratio is 2.0, and the extraction time is 30 min to extract geniposide. The extract is concentrated to dryness in vacuo, and 7g of acetone is added for hot dissolution. When it is completely dissolved, acetone equal to the volume of ethyl acetate is slowly added dropwise, and then it is allowed to cool for 48 hours, filtered and dried to obtain white needle-shaped crystals. The prepared geniposide is used for later use.

[0036] Step (3) Preparation of natural blue pigment Dissolve 50g of the prepared geniposide in 500mL of water, add 4g of β-glucosidase and heat at 55℃ for enzymolysis for 12h, take the supernatant after centrifugation and filtration, evaporate and concentrate, when the temperature reaches 145℃, add saturated solution of ammonium salt dropwise under stirring, and then maintain the material at about 150℃ until the pigment is generated, and the prepared gardenia blue pigment is ready for use.

[0037] Step (4) Preparation of jelly containing gardenia blue pigment Konjac gum, carrageenan, agar were uniformly mixed with 12% white sugar in a ratio of 2:4:2. Konjac powder, carrageenan, agar were slowly added to 300 mL of cold water and soaked for 50 min to allow the composite gel to fully absorb water and swell, so as to better exert the gel properties of the colloid. The colloid was heated in a 90°C constant temperature water bath, and stirred continuously with a spoon to avoid agglomeration caused by uneven heating. When the colloid was completely dissolved in the water without agglomeration, the water bath was heated to 120°C and 0.09% of the mixture was added. Gardenia blue pigment was heated to boiling and dissolved for 20 minutes, stirred evenly, and bubbles generated during the stirring process were removed. When the temperature of the mixed glue solution dropped to 85°C, citric acid and potassium chloride mixed solution were added in the proportion of 0.4% and 0.06% while stirring. The sugar-gum mixed solution was filtered through an 80-mesh filter cloth, and then divided into pre-sterilized jelly cups and sealed. The sealed jelly cups were sterilized at 90°C for 50 minutes, and the finished gardenia blue jelly was obtained after cooling.

[0038] Step (5) Preparation of milk tea containing gardenia blue pigment Brew 7g of Fuzhuan tea with 120℃ boiling water, filter the tea leaves with gauze, discard the tea soup, keep the tea leaves, boil the filtered tea leaves, add them into 450ml of 120℃ boiling water, pre-boil for 4.5min, filter the tea soup with 120-mesh gauze, discard the tea leaves, keep the tea soup, weigh the remaining tea soup before adding pure milk, then add the corresponding 1.5% gardenia blue pigment and 12% pure milk according to the remaining tea soup, weigh the remaining amount of boiled milk tea and add the corresponding 1.5% salt, which is the finished product of gardenia blue milk tea. Example 4

[0039] Step (1) Preparation of Geniposide 8 g of Gardenia jasminoides powder was taken and geniposide was extracted by orthogonal experiment at 90°C with the extraction time of 2.0 h, liquid-solid ratio of 12:1 and ethanol concentration (mass fraction 70%).

[0040] Step (2) Purification of Geniposide For FD 802 The resin was pretreated and wet loaded, with a column loading volume of 60 mL. The extract was concentrated and dealcoholized to 1 / 7 of the volume and diluted with distilled water to different feed concentrations. The feed concentration and column flow rate were 3.0, Bv / h to decolorize gardenia blue pigment. FD 802 The resin column liquid is concentrated under reduced pressure to an extract, and ethyl acetate is used as the extraction solvent. The temperature effect is 60°C, the liquid-to-solid volume ratio is 3.0, and the extraction time is 40 min to extract geniposide. The extract is concentrated to dryness in vacuo, and 8 g of acetone is added for hot dissolution. When it is completely dissolved, acetone equal to the volume of ethyl acetate is slowly added dropwise, and then it is allowed to cool for 48 hours, filtered and dried to obtain white needle-shaped crystals. The prepared geniposide is used for later use.

[0041] Step (3) Preparation of natural blue pigment Dissolve 60g of the prepared geniposide in 550mL of water, add 5g of β-glucosidase and heat at 60℃ for enzymolysis for 14h, take the supernatant after centrifugation and filtration, evaporate and concentrate, when the temperature reaches 155℃, add saturated solution of ammonium salt dropwise under stirring, and then keep the material at about 160℃ until the pigment is generated, and the prepared gardenia blue pigment is ready for use.

[0042] Step (4) Preparation of jelly containing gardenia blue pigment Konjac gum, carrageenan, agar were uniformly mixed with 14% white sugar in a ratio of 2:4:2. Konjac flour, carrageenan, agar were slowly added to 350 mL of cold water and soaked for 60 min to allow the composite gel to fully absorb water and swell, so as to better exert the gel properties of the colloid. The colloid was heated in a 95°C constant temperature water bath, and stirred continuously with a spoon to avoid agglomeration caused by uneven heating. When the colloid was completely dissolved in the water without agglomeration, the water bath was heated to 130°C, and gardenia was added at a ratio of 0.1%. Heat the gardenia blue pigment to boiling point for 25 minutes, stir evenly, and remove the bubbles generated during the stirring process. When the temperature of the mixed glue solution drops to 90°C, add citric acid and potassium chloride mixed solution in the proportion of 0.5% and 0.07% while stirring. Use a 90-mesh filter cloth to filter the sugar-gum mixed solution, and then divide it into pre-sterilized jelly cups and seal them. Sterilize the sealed jelly cups at 100°C for 60 minutes. After cooling, the finished gardenia blue jelly is obtained.

[0043] Step (5) Preparation of milk tea containing gardenia blue pigment Brew 8g of Fuzhuan tea with 120℃ boiling water, then filter the tea leaves with gauze, discard the tea soup, keep the tea leaves, boil the filtered tea leaves, add them into 500ml of 120℃ boiling water respectively, pre-boil for 5.5min, filter the tea soup with 120-mesh gauze, discard the tea leaves, keep the tea soup, weigh the remaining tea soup before adding pure milk, then add the corresponding 2% gardenia blue pigment and 14% pure milk according to the remaining tea soup, weigh the remaining amount of boiled milk tea and add the corresponding 2% salt, which is the finished product of gardenia blue milk tea. Comparative Example 1

[0044] Step (1) Preparation of Geniposide 5 g of Gardenia jasminoides powder was taken and geniposide was extracted by orthogonal experiment at 75°C with the extraction time of 0.5 h, liquid-solid ratio of 6:1 and ethanol concentration (mass fraction 30%).

[0045] Step (2) Purification of Geniposide For FD 802 The resin was pretreated and wet loaded into the column, with a loading volume of 30 mL. The extract was concentrated and dealcoholized to 1 / 4 of the volume and diluted with distilled water to different feed concentrations. The feed concentration and column flow rate were 0.5 Bv / h to decolorize the gardenia blue pigment. 802 The resin column liquid is concentrated under reduced pressure to an extract, and ethyl acetate is used as the extraction solvent. The temperature effect is 30°C, the liquid-to-solid volume ratio is 0.5, and the extraction time is 10 min to extract geniposide. The extract is vacuum concentrated to dryness, 5 g of acetone is added for hot dissolution, and when it is completely dissolved, acetone equal to the volume of ethyl acetate is slowly added dropwise, and then it is allowed to cool for 24 hours, filtered and dried to obtain white needle-shaped crystals. The prepared geniposide is used for later use.

[0046] Step (3) Preparation of natural blue pigment Dissolve 30g of the prepared geniposide in 400mL of water, take the supernatant after centrifugation and filtration, evaporate and concentrate, and when the temperature reaches 125°C, add the saturated solution of ammonium salt dropwise under stirring, and then maintain the material at about 140°C until the pigment is generated, and the prepared gardenia blue pigment is ready for use.

[0047] Step (4) Preparation of jelly containing gardenia blue pigment Konjac gum, carrageenan, agar were uniformly mixed with 8% white sugar in a ratio of 1:2:1. Konjac powder, carrageenan, agar were slowly added to 200 mL of cold water and soaked for 30 min to allow the composite gel to fully absorb water and swell, so as to better exert the gel properties of the colloid. The colloid was heated in a constant temperature water bath at 80 ° C, and stirred continuously with a spoon to avoid agglomeration caused by uneven heating. When the colloid was completely dissolved in the water without agglomeration, the water bath was heated to 100 ° C and 0.07% of the mixture was added. Gardenia blue pigment was heated to boiling and dissolved for 10 minutes, stirred evenly, and bubbles generated during the stirring process were removed. When the temperature of the mixed glue solution dropped to 75°C, citric acid and potassium chloride mixed solution were added at a ratio of 0.2% and 0.04% while stirring. The sugar-gum mixed solution was filtered through a 60-mesh filter cloth, and then divided into pre-sterilized jelly cups and sealed. The sealed jelly cups were sterilized at 80°C for 30 minutes, and the finished gardenia blue jelly was obtained after cooling.

[0048] Step (5) Preparation of milk tea containing gardenia blue pigment Brew 5g of Fuzhuan tea with 100℃ boiling water, filter the tea leaves with gauze, discard the tea soup, keep the tea leaves, boil the filtered tea leaves, add them into 350ml of 100℃ boiling water, pre-boil for 2.5min, filter the tea soup with 100-mesh gauze, discard the tea leaves, keep the tea soup, weigh the remaining tea soup before adding pure milk, then add the corresponding 0.5% gardenia blue pigment and 8% pure milk according to the remaining tea soup, weigh the remaining amount of boiled milk tea and add the corresponding 0.5% salt, which is the finished product of gardenia blue milk tea. Comparative Example 2

[0049] Step (1) Preparation of Geniposide 8 g of Gardenia jasminoides powder was taken and geniposide was extracted by orthogonal experiment at 90°C with the extraction time of 2.0 h, liquid-solid ratio of 12:1 and ethanol concentration (mass fraction 70%).

[0050] Step (2) Purification of Geniposide For FD 802The resin was pretreated and wet loaded on the column with a loading volume of 60 mL. The extract was concentrated and dealcoholized to 1 / 7 of the volume and diluted with distilled water to different feed liquid concentrations. The feed liquid concentration and column flow rate were 3.0, Bv / h. Gardenia blue pigment was decolorized and 8 g of acetone was added for hot dissolution. When it was completely dissolved, acetone of an equal volume of ethyl acetate was slowly added dropwise, and then allowed to cool for 48 hours. It was filtered and dried to obtain white needle-shaped crystals. The prepared geniposide was set aside.

[0051] Step (3) Preparation of natural blue pigment Dissolve 60g of the prepared geniposide in 550mL of water, add 5g of β-glucosidase and heat at 60℃ for enzymolysis for 14h, take the supernatant after centrifugation and filtration, evaporate and concentrate, when the temperature reaches 155℃, add saturated solution of ammonium salt dropwise under stirring, and then keep the material at about 160℃ until the pigment is generated, and the prepared gardenia blue pigment is ready for use.

[0052] Step (4) Preparation of jelly containing gardenia blue pigment Konjac gum, carrageenan, agar were uniformly mixed with 14% white sugar in a ratio of 2:4:2. Konjac flour, carrageenan, agar were slowly added to 350 mL of cold water and soaked for 60 min to allow the composite gel to fully absorb water and swell, so as to better exert the gel properties of the colloid. The colloid was heated in a 95°C constant temperature water bath, and stirred continuously with a spoon to avoid agglomeration caused by uneven heating. When the colloid was completely dissolved in the water without agglomeration, the water bath was heated to 130°C, and gardenia was added at a ratio of 0.1%. Heat the gardenia blue pigment to boiling point for 25 minutes, stir evenly, and remove the bubbles generated during the stirring process. When the temperature of the mixed glue solution drops to 90°C, add citric acid and potassium chloride mixed solution in the proportion of 0.5% and 0.07% while stirring. Use a 90-mesh filter cloth to filter the sugar-gum mixed solution, and then divide it into pre-sterilized jelly cups and seal them. Sterilize the sealed jelly cups at 100°C for 60 minutes. After cooling, the finished gardenia blue jelly is obtained.

[0053] Step (5) Preparation of milk tea containing gardenia blue pigment Brew 8g of Fuzhuan tea with 120℃ boiling water, then filter the tea leaves with gauze, discard the tea soup, keep the tea leaves, boil the filtered tea leaves, add them into 500ml of 120℃ boiling water respectively, pre-boil for 5.5min, filter the tea soup with 120-mesh gauze, discard the tea leaves, keep the tea soup, weigh the remaining tea soup before adding pure milk, then add the corresponding 2% gardenia blue pigment and 14% pure milk according to the remaining tea soup, weigh the remaining amount of boiled milk tea and add the corresponding 2% salt, which is the finished product of gardenia blue milk tea.

[0054] Comparison of detection experiments: The preparation of a highly stable natural blue pigment obtained in Examples 1 to 4 and its application in children's leisure food and comparative example products 1 and 2 were tested. The specific testing method is as follows: High performance liquid chromatography Ultra high performance liquid chromatography-photodiode array detection-tandem quadrupole time-of-flight mass spectrometry was used to identify the gardenia blue pigment in jelly containing gardenia blue pigment and milk tea containing gardenia blue pigment. The ultra-high performance liquid chromatography separation of the pigment extract was combined with high-resolution time-of-flight mass spectrometry and ultraviolet-visible absorption spectrum data collected by a diode array detector to achieve faster, more sensitive and more accurate identification of the samples.

[0055] Surface enhanced Raman spectroscopy Surface enhanced Raman spectroscopy was used to determine the gardenia blue pigment in jelly containing gardenia blue pigment and gardenia blue milk tea. The prepared surface enhanced Raman spectroscopy substrate was exposed to the gardenia blue pigment solution to allow the pigment to adsorb to the substrate surface. The sample was evenly coated on the substrate by dripping, dipping or spraying, and the sample was allowed to dry to ensure that the pigment was firmly adsorbed on the substrate. This method is novel, the equipment is simple to operate, the analysis speed is fast, the reproducibility is good, and the sensitivity is relatively high. It can be used to quickly and effectively detect the gardenia blue pigment in gardenia blue pigment jelly and gardenia blue pigment milk tea.

[0056] Table 1 Identification results of gardenia blue pigment in jelly containing gardenia blue pigment and milk tea containing gardenia blue pigment

[0057] As can be seen from Table 1, Example 3 is the best and Comparative Example 1 is relatively poor. The characteristic absorption peak in Example 3 further proves that the sample contains gardenia blue pigment and is very stable. This result is mainly caused by the fact that geniposide was not hydrolyzed by β-glucosidase during the preparation of Comparative Example 1 and macroporous resin decolorization technology was not used during the preparation of geniposide in Comparative Example 2, resulting in such a large difference in the prepared products containing gardenia blue pigment.

[0058] Table 2 Detection results of gardenia blue pigment in jelly containing gardenia blue pigment and milk tea containing gardenia blue pigment

[0059] As can be seen from Table 2, Example 3 is the best, while Comparative Example 1 is relatively poor. This result is mainly due to the fact that geniposide was not hydrolyzed by β-glucosidase during the preparation of Comparative Example 1, and was not decolorized by macroporous resin during the preparation of geniposide in Comparative Example 2. The high sensitivity of surface enhanced Raman spectroscopy technology enables the detection of gardenia blue pigment even at very low concentrations, which is particularly useful for the detection of pigments in food and cosmetics because the content of pigments in these products is usually very low.

[0060] The preparation of a high-stability natural blue pigment obtained in Examples 1 to 4 and its application in children's snack foods and comparative example products 1 and 2 were tested. It was found that the main reason why the example data was better than the comparative example data was that during the preparation of comparative example 1, geniposide was not hydrolyzed by β-glucosidase, and during the preparation of comparative example 2, geniposide was not decolorized by macroporous resin, which ultimately resulted in different experimental results.

[0061] This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art can make non-creative modifications to the present embodiment as needed, but they are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A preparation method of a high-stability natural blue pigment, characterized in that: Preparation of geniposide, purification of geniposide, preparation of natural blue pigment.

2. The preparation of a high-stability natural blue pigment according to claim 1, characterized in that: Step (1) Preparation of Geniposide The crude powder of Gardenia jasminoides was used to extract geniposide by orthogonal experiments on extraction time, liquid-solid ratio and ethanol concentration. Step (2) Purification of Geniposide For FD 802 The resin was pretreated and wet loaded, the extract was concentrated and dealcoholized, and then diluted with distilled water to different feed concentrations. The feed concentration and column flow rate were used to decolorize the gardenia blue pigment. 802 The resin column liquid is concentrated under reduced pressure to an extract, and ethyl acetate is used as the extraction solvent. The liquid-to-solid volume ratio and the extraction time are used to extract geniposide. The extract is vacuum concentrated to dryness, and acetone is added for hot dissolution. When it is completely dissolved, acetone is slowly added dropwise with an equal volume of ethyl acetate, and then allowed to stand and cool, filtered and dried to obtain white needle-shaped crystals, and the prepared geniposide is used for standby; Step (3) Preparation of natural blue pigment The prepared geniposide is dissolved in water, β-glucosidase is added and heated for enzymolysis, the supernatant after centrifugation and filtration is evaporated and concentrated, a saturated solution of ammonium salt is added dropwise under stirring, and the material is maintained until the pigment is generated, and the prepared gardenia blue pigment is set aside.

3. The preparation of a high stability natural blue pigment according to claim 2, characterized in that: Step (1) Preparation of Geniposide The crude powder of Gardenia jasminoides was used to extract geniposide by orthogonal experiment on extraction time, liquid-solid ratio and ethanol concentration.

4. The preparation of a high-stability natural blue pigment according to claim 3 and its application in children's leisure food, characterized in that: Step (2) Purification of Geniposide For FD 802 The resin was pretreated and wet loaded, with a loading volume of 30-60 mL. The extract was concentrated and dealcoholized to 1 / 4-1 / 7 of the volume and diluted with distilled water to different feed concentrations. The feed concentration and column flow rate (0.5-3.0 Bv / h) were used to decolorize the gardenia blue pigment. 802 The resin column liquid is concentrated under reduced pressure to an extract with ethyl acetate as the extraction solvent. The temperature effect (30-60°C), liquid-to-solid volume ratio (0.5-3.0) and extraction time (10-40min) have an effect on the extraction of geniposide. The extract is concentrated to dryness in vacuo, and 5-8g of acetone is added for hot dissolution. When it is completely dissolved, acetone is slowly added dropwise in an amount equal to the volume of ethyl acetate, and the mixture is allowed to stand and cool for 24-48h. It is filtered and dried to obtain white needle-shaped crystals, and the prepared geniposide is ready for use.

5. The preparation of a high-stability natural blue pigment according to claim 4, characterized in that: Step (3) Preparation of natural blue pigment Dissolve 30-60 g of geniposide in 400-550 mL of water, add 2-5 g of β-glucosidase and heat at 45-60 ° C for enzymolysis for 8-14 hours, take the supernatant after centrifugation and filtration, evaporate and concentrate, and when the temperature reaches 125-155 ° C, add a saturated solution of ammonium salt dropwise under stirring, and then keep the material at about 140-160 ° C until the pigment is generated, and the prepared gardenia blue pigment is ready for use.

6. A high-stability natural blue pigment, characterized in that: It is obtained according to the preparation method of a high-stability natural blue pigment according to any one of claims 1 to 5.

7. An application of a high-stability natural blue pigment, characterized in that: The high-stability natural blue pigment described in claim 6 is added and applied in children's snack foods, including the preparation of jelly containing gardenia blue pigment and the preparation of milk tea containing gardenia blue pigment.

8. The use of a high-stability natural blue pigment according to claim 7, characterized in that: Preparation of jelly containing gardenia blue pigment Evenly mix konjac gum, carrageenan, and agar with 8-14% white sugar in a ratio of 1-2:2-4:1-2. Slowly add konjac powder, carrageenan, and agar to 200-350 mL of cold water and soak for 30-60 min to allow the composite gel to fully absorb water and swell, so as to better exert the gel properties of the colloid. Heat the colloid in a constant temperature water bath at 80-95 ° C, stirring continuously with a spoon to avoid agglomeration caused by uneven heating. When the colloid is completely dissolved in the water without agglomeration, heat the water bath to 100-130 ° C, and add 0.07-0.1% of Add gardenia blue pigment, heat to boiling to dissolve for 10-25 minutes, stir evenly, remove bubbles generated during stirring, when the temperature of the mixed glue solution drops to 75-90°C, add citric acid and potassium chloride mixed solution in the proportion of 0.2-0.5% and 0.04-0.07% while stirring, filter the sugar-gum mixed solution with a 60-90 mesh filter cloth, and then dispense it into pre-sterilized jelly cups and seal them, sterilize the sealed jelly cups at 80-100°C for 30-60 minutes, and cool them to obtain the finished gardenia blue jelly.

9. The use of a high-stability natural blue pigment according to claim 7, characterized in that: Step (5) Preparation of milk tea containing gardenia blue pigment Use 100~120℃ boiling water to brew 5~8g Fuzhuan tea, then filter the tea leaves with gauze, discard the tea soup, keep the tea leaves, boil the filtered tea leaves, add them into 350~500ml of 100~120℃ boiling water respectively, after pre-boiling for 2.5~5.5min, filter the tea soup with 100~120 mesh gauze, discard the tea leaves, keep the tea soup, weigh the remaining tea soup before adding pure milk, and then add the corresponding 0.5~2% gardenia blue pigment and 8~14% pure milk according to the remaining tea soup, weigh the remaining amount of boiled milk tea and add the corresponding 0.5~2% salt, which is the finished product of gardenia blue milk tea.

10. The use of a high-stability natural blue pigment according to claim 7, characterized in that: Preparation of jelly containing gardenia blue pigment Konjac gum, carrageenan, and agar are uniformly mixed with white granulated sugar in proportion, konjac flour, carrageenan, and agar are slowly added to cold water and soaked, so that the composite gelling agent fully absorbs water and swells, so as to better bring into play the gelling property of the colloid, the colloid is heated in a constant temperature water bath, and is constantly stirred with a spoon to avoid uneven heating and causing caking, when the colloid is completely dissolved in the water and there is no caking, the water bath is heated, and the gardenia blue pigment is added in proportion, heated to boiling and dissolved, and stirred evenly, and the bubbles generated in the stirring process are removed, and when the mixed glue solution temperature drops, citric acid and potassium chloride mixed solution are added in proportion while stirring, and the sugar glue mixed solution is filtered using a filter cloth, and then it is dispensed into the jelly cups sterilized in advance and sealed, and the jelly cups after the sealing are sterilized, and the cooling is the gardenia blue jelly finished product; Preparation of milk tea containing gardenia blue pigment Use boiling water to brew the weighed Fuzhuan tea, then filter the tea leaves with gauze, discard the tea soup, keep the tea leaves, boil the filtered tea leaves, add them into boiling water separately, after pre-boiling, filter the tea soup with gauze, discard the tea leaves, keep the tea soup, weigh the remaining tea soup before adding pure milk, then add corresponding percentages of gardenia blue pigment and pure milk according to the remaining tea soup, weigh the remaining amount of boiled milk tea and add corresponding percentages of salt, which is the finished product of gardenia blue milk tea.

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