Beta-cyanin- anthocyanin complex pigment composition, dyeing agent and use

Abstract

The present application provides a betalain-cyanidin composite pigment composition, a dyeing agent and application, the composition is combined by cyanidin freeze-dried powder and betalain freeze-dried powder according to the mass ratio of 5:1-5. The betalain-cyanidin composite dyeing agent formed by the composition has good temperature stability and pH stability, and strong coloring power, and can be widely applied to product materials containing kapok, silk, cotton, hemp and the like.

Description

Technical Field

[0001] This invention relates to the field of dyeing technology, specifically to a betalain-anthocyanin complex pigment composition, dyeing agent, and its application. Background Technology

[0002] Artificial pigments are inexpensive, have higher stability and stronger coloring power, but pose significant safety risks. Therefore, natural pigments have attracted much attention due to their high safety and nutritional properties. While performing their color-developing function, they also exhibit various physiological activities, making them a research hotspot in the fields of food additives and dyes / colorants. As natural colorants derived from animals, plants, and microorganisms, natural pigments have become a research focus in the food and pharmaceutical industries due to their safety and bioactivity. Among the many natural pigments, carotenoids, anthocyanins, chlorophyll, quinones, flavonoids, betalains, and curcumin have attracted much attention due to their unique spectral characteristics and physiological functions. They are widely used in food, beverages, cosmetics, textiles, and pharmaceuticals. However, currently, these applications mainly use single natural pigments as colorants, primarily due to the stability challenges of natural pigments. The stability of a single natural pigment (sensitivity to light, heat, pH, and metal ions) is an industry problem. When several are combined, the interaction and stability issues that need to be addressed increase exponentially. This requires substantial R&D investment, increasing technical difficulty and cost. Another issue is the tinting strength, which is a problem that natural pigments urgently need to solve. The tinting strength of a single pigment is already poor. Introducing multiple pigments not only does not help the tinting strength much, but may also cause instability temperature, increase the difficulty of supply and production, and further increase the difficulty of using natural pigments in combination. Summary of the Invention

[0003] In view of this, the purpose of this invention is to overcome the difficulties in using natural pigments in combination, develop natural composite dyes that can improve stability and dyeing performance, and turn some waste materials into treasures, such as kapok. In turn, it provides a betalain-anthocyanin composite pigment composition, dye and application. Experiments have confirmed that the betalain-anthocyanin composite dye has multiple advantages such as good thermal stability, strong coloring power and good pH adaptability.

[0004] To achieve the above technical objectives, the technical solution adopted in this application is as follows: In a first aspect, the present invention provides a betalain-anthocyanin complex pigment composition, wherein the composition is composed of anthocyanin freeze-dried powder and betalain freeze-dried powder in a mass ratio of 5:1 to 5.

[0005] Preferably, the composition is composed of anthocyanin freeze-dried powder and betaine freeze-dried powder in a mass ratio of 5:1 to 3; more preferably, the composition is composed of anthocyanin freeze-dried powder and betaine freeze-dried powder in a mass ratio of 5:1 to 2.

[0006] Preferably, the method for obtaining the anthocyanin freeze-dried powder includes: homogenizing mulberries and extracting them with acidic ethanol to obtain a crude extract; purifying the crude extract with AB-8 macroporous resin to obtain anthocyanins, and then freeze-drying it to obtain the anthocyanin freeze-dried powder.

[0007] Preferably, the method for obtaining the betaine lyophilized powder includes: grinding dried bougainvillea into powder and then extracting it with water to obtain a crude extract; purifying the crude extract using HPD100 macroporous resin and then lyophilizing it to obtain the betaine lyophilized powder.

[0008] In a second aspect, the present invention provides the application of the betaine red pigment-anthocyanin complex pigment composition described in the first aspect in the preparation of dyeing agents.

[0009] Thirdly, the present invention provides a dyeing agent, which is prepared by dissolving the betalain-anthocyanin complex pigment composition described in the first aspect in an aqueous solution with a pH of 3.5 to 4.0 to obtain a solution with a concentration of 8 to 12 mg / mL.

[0010] Preferably, the reagent used to adjust the pH is glacial acetic acid, a buffer salt solution, or acidic ethanol.

[0011] Preferably, the reagent used to adjust the pH is an ammonium acetate-hydrochloric acid buffer solution, wherein the final concentration of ammonium acetate is 0.2~0.3 g / mL and the final concentration of hydrochloric acid is 6~7 mol / L; more preferably, the preparation method of the ammonium acetate-hydrochloric acid buffer solution includes: dissolving ammonium acetate in water, adding hydrochloric acid solution, and then adjusting the pH value to 3.5~4.0 with hydrochloric acid solution or ammonia solution.

[0012] Fourthly, the present invention provides a dyeing material for articles, which is dyed using the dyeing agent described in the third aspect.

[0013] Preferably, the material of the product is yarn; more preferably, the yarn includes: kapok, silk, cotton, and hemp.

[0014] Compared with the prior art, the present invention has the following beneficial effects: Firstly, the total flavonoid content in the betaine-anthocyanin composite dye of the present invention is 6-7% higher than that of anthocyanin alone; the composite dye has better color stability during heat treatment at different times, the addition of betaine promotes red color development and has stronger coloring power; and the pH stability of the composite pigment is enhanced during pH treatment from 3.0 to 5.0, resulting in stable color development and demonstrating better pH adaptability.

[0015] Secondly, the betaine red pigment-anthocyanin composite dye of this invention has a wide range of applications, including in materials such as silk, cotton, and hemp. Taking waste kapok fibers as an example, kapok is more difficult to dye than silk, cotton, and hemp because dyes mainly bind chemically or physically through the "hydroxyl (-OH), carboxyl, and amino" groups on the fibers. Kapok fibers mainly contain lignin, hemicellulose, and waxes, while silk is rich in carboxyl and amino groups, cotton is rich in hydroxyl groups, and hemp is mainly composed of cellulose, similar to cotton. All of these components are relatively easy to bind with dyes. This invention demonstrates that the dyeing process of kapok fibers by the betaine red pigment-anthocyanin composite dye follows a pseudo-second-order kinetic model, and the dyeing equilibrium adsorption amount and rate constant are positively correlated with increasing temperature. Kapok waste can be used to make aesthetically pleasing and functional kapok handicrafts, such as dried flowers.

[0016] Thirdly, the application of the composite dye of the present invention in the dyeing of kapok also provides a technical reference for further exploring the dyeing effect of the composite dye on other waste fiber materials and its potential in the development of functional foods. Attached Figure Description

[0017] The accompanying drawings, which are provided to further illustrate the invention and constitute a part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a picture of the actual cotton fibers of a kapok flower.

[0018] Figure 2 This is the dyeing kinetic curve of anthocyanins, complex pigments and betalains on kapok fibers in Example 3 of the present invention.

[0019] Figure 3 This is a linear fitting curve of the pseudo-first-order kinetic mode of adsorption of the composite pigment on kapok fiber in Example 3 of the present invention.

[0020] Figure 4 This is a linear fitting curve of the pseudo-first-order kinetic mode of anthocyanin adsorption on kapok fiber in Example 3 of the present invention.

[0021] Figure 5 This is a linear fitting curve of the pseudo-first-order kinetic mode of betaine adsorption on kapok fiber in Example 3 of the present invention.

[0022] Figure 6 This is a linear fitting curve of the pseudo-second-order kinetic mode of adsorption of the composite pigment on kapok fiber in Example 3 of the present invention.

[0023] Figure 7 This is a linear fitting curve of the pseudo-second-order kinetic mode of anthocyanin adsorption on kapok fiber in Example 3 of the present invention.

[0024] Figure 8 This is a linear fitting curve of the pseudo-second-order kinetic mode of betaine adsorption on kapok fiber in Example 3 of the present invention.

[0025] Figure 9 The image shows the dyeing effect of the composite pigments of mulberry anthocyanin, betalain and A1 group on kapok cotton fibers in the application example of this invention. A and B represent the dyeing effects at 0 and 24 hours of UV irradiation, respectively.

[0026] Figure 10 This is an example of the dyeing of handicrafts made from kapok wadding using anthocyanins, betalains, and A1 complex pigments in an application example of the present invention, where A to D represent kapok materials of different shapes. Detailed Implementation

[0027] In an embodiment of the present invention, the method for obtaining anthocyanins is as follows: Mulberries are processed in a high-speed homogenizer, and then 200 mL of the homogenized sample is weighed. The sample is diluted to volume with acidic ethanol (1% HCl in 95% ethanol) at a material-to-liquid ratio of 1:39. The solution is dispensed into beakers, shaken well, and then extracted using an ultrasonic cell disruptor at 51°C for 39 min. The mixture is then filtered to obtain a crude extract. Anthocyanins are purified using AB-8 macroporous resin. The pH of the crude extract is 2.54 when loaded, and adsorption is performed at a flow rate of 0.5 mL / min. The desorption solution is a 45% ethanol aqueous solution with a pH of 0.5, and desorption is performed at a flow rate of 2 mL / min to obtain purified anthocyanins. The purified anthocyanins are then freeze-dried to obtain anthocyanin lyophilized powder, which is subsequently stored in a refrigerator.

[0028] The mulberry variety used in the embodiments of the present invention is Yun Sang No. 2, which originates from Yanbian County, Panzhihua City.

[0029] Anthocyanin content determination: Prepare pH 1.0 buffer: 1.49 g potassium chloride was diluted to 100 mL with distilled water, and 1.7 mL of analytical grade hydrochloric acid was diluted to 100 mL. The solutions were mixed at a volume ratio of 25:75, and then the pH was adjusted to 1.0±0.1 with potassium chloride solution. Prepare pH 4.5 buffer: 1.64 g sodium acetate was diluted to 100 mL with distilled water, and the pH was adjusted to 4.5±0.1 with hydrochloric acid. 0.5 g of lyophilized anthocyanin was dissolved in dilute alcohol and diluted to 100 mL. Two 10 mL portions were then transferred and diluted to 100 mL with pH 1.0 and pH 4.5 solutions, respectively. After standing for 60 min, the absorbance was read at 510 nm and 700 nm. The anthocyanin content was calculated using formula (1): Anthocyanin content = (1), In formula (1): A: OD510-OD700 is calculated using the pH differential method, i.e., ε: Extinction coefficient of cyanidin-3-glucoside (26900); L: Optical path length, 1 cm; M W Relative molecular mass of cyanidin-3-glucoside (449.2); DF: dilution factor; V: final volume (ml); Wt: product mass (mg). The obtained anthocyanin content was 2.86 mg / g.

[0030] In an embodiment of the present invention, the method for obtaining betalains is as follows: Fresh bougainvillea 'Xiaoye Zi' (from the nursery of Panzhihua University) is dried in a constant temperature drying oven, then ground into powder using a multi-functional pulverizer, and sieved through a 100-mesh sieve. 200 g of sample powder is weighed, with a material-to-liquid ratio of 1:10 (g / mL), and diluted to 2000 mL with deionized water. The powder is dispensed into conical flasks, shaken well, and placed in a 40℃ water bath in the dark for 100 min. After filtration, a crude extract is obtained. The crude betalain extract is purified using HPD100 macroporous resin. The pH of the crude betalain extract is adjusted to 3.0, and adsorption is performed for 4 hours. The desorption buffer is then a 50% ethanol aqueous solution with a pH of 5.0, and the desorption time is also 4 hours. The purified betalains are then freeze-dried using a freeze dryer to obtain betalain freeze-dried powder, which is subsequently stored in a refrigerator.

[0031] Determination of betalain content: Spectrophotometry was used. The lyophilized betalain powder was diluted 100 times with distilled water. After shaking and stabilization, the absorbance was measured at wavelengths of 537 nm and 600 nm, using distilled water as a reference. The betalain content was calculated according to formula (2): betalain content (mg / L) = (2), In formula (2): A: OD537-OD600; Mw: relative molecular mass of betalain, 550 g / mol; DF: dilution factor of the sample; ε: molar assimilation of betalain, 60000 L / (mol·cm); L: thickness of the cuvette, 1 cm. The obtained betalain content was 0.36 mg / g.

[0032] In the embodiments of this invention, 0.5 g each of lyophilized powder samples, including mulberry anthocyanins, A1-A5, and bougainvillea betalains, were accurately weighed and dissolved in 50 mL of deionized water. The solutions were ultrasonically dispersed for 10 minutes to ensure complete dissolution, yielding sample solutions with a solid content of 10 mg / mL. pH, TSS, and TA were then measured. pH was measured using a pH meter. TSS (Total Soluble Solids) was measured using a handheld saccharimeter. TA (Titratable Acidity) was determined using acid-base titration. The total acidity (TA) is directly related to the organic acid content in the dye solution; the organic acid value of the composite pigment was observed. The experimental procedure was as follows: titration was performed using a calibrated acid burette with 0.1 mol / L NaOH standard solution as the titrant. Add 3 drops of phenolphthalein indicator to the dissolved sample solution. The initial solution is colorless. Add NaOH solution dropwise while stirring continuously until the solution turns slightly red and does not fade within 30 seconds. Record the volume of NaOH consumed. Each experiment is performed in parallel three times, and the average value is taken to reduce error. Formula (3) is: (3), In equation (3), C NaOH V represents the concentration of NaOH (mol / L). NaOH For titration volume (L), the molar mass of mulberry anthocyanin is 449.2 g / mol, the molar mass of bougainvillea betalain is 550 g / mol, and for groups A1-A5, the equivalent mass is calculated by adding the two pigments together and multiplying by the corresponding ratio. K is the molar mass of each pigment, and m is the molar mass of each pigment. 样品 The sample mass is 0.5 g.

[0033] In embodiments of the present invention, the method for determining the total phenol and total flavonoid content is as follows: (1) Quantitative analysis of total phenols was performed according to the Folin-Ciocalteu method. Samples from series A1-A5 were accurately weighed (0.1 g) and transferred to a 50 mL volumetric flask. 9.5 mL of ultrapure water was added and the mixture was shaken to prepare a test solution with a concentration of 10 mg / mL. Then, 0.5 mL of Folin-Ciocalteu colorimetric reagent was added, vortexed for 30 s, and allowed to stand in the dark for 5 min. Next, 1.5 mL of sodium carbonate solution (20%, w / v) was added, and the solution was diluted to the mark with ultrapure water. The mixture was incubated at a constant temperature in the dark for 30 min, and the absorbance was measured at a characteristic wavelength of 765 nm using a UV spectrophotometer. A regression equation was established using a gradient concentration of gallic acid standard solutions (0, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0 μg / mL): y = 9.6414x + 0.1289, R0 2=0.9975, the total phenol content of the sample was calculated by linear fitting.

[0034] (2) The total flavonoid content was determined by spectrophotometry. 1.00 mL of the lyophilized powder solution (concentration 10 mg / mL) was accurately transferred to a 100 mL brown volumetric flask. 1.0 mL of ethanol solution (60%, v / v) and 0.50 mL of sodium nitrite solution (5%, w / v) were added. The mixture was vortexed for 30 s and then allowed to stand in the dark for 6 min (25±0.5℃). Subsequently, 0.50 mL of aluminum nitrate solution (10%, w / v) was added, and the mixture was thoroughly mixed and reacted for 6 min. Then, 4.0 mL of sodium hydroxide solution (4%, w / v) was added, and the mixture was brought to a final volume with 60% ethanol. After the colorimetric system stabilized in the dark for 15 min, the absorbance was measured at 510 nm using a UV spectrophotometer. A linear regression equation was established using rutin standards (standard solution concentration gradients: 0, 5, 15, 20, 25 ug / ml): y = 0.026x - 0.0052, R0 2 =0.9995.

[0035] In an embodiment of the present invention, the method for determining antioxidant activity is as follows: Weigh 0.1152 g of ABTS powder, add 20 mg of K2S2O8, dissolve in 30 mL of 0.1 mol PBS solution with pH 7.4, and store in the dark. When needed, dilute the stock solution with PBS. Measure the absorbance of the stock solution at 734 nm; the absorbance should be 0.7, with a tolerance of 0.02. Then, using the pre-prepared ABTS free radical stock solution, take 20 μL of sample, add 2 mL of ABTS solution, react in the dark for 6 min, and measure the absorbance at 734 nm. Use deionized water as a blank group. The ABTS free radical scavenging rate of the sample is calculated using formula (2-4): (4); In equation (4), A represents the absorbance value.

[0036] In embodiments of the present invention, the color index is determined by using a fully automated colorimeter to perform CIELAB color space analysis on the sample, measuring the lightness L* value (100 for pure white, 0 for pure black); the red-green axis chromaticity a* value (-60 to +60 corresponding to the green-to-red gradient and the yellow-blue axis chromaticity); and the b* value (-60 to +60 corresponding to the blue-to-yellow gradient). The color stability of the dye is significantly negatively correlated with the chromaticity coordinate offset.

[0037] C* represents the color saturation. The color richness is positively correlated with the value, and is calculated according to formula (5): (5); h° (Hueangle) reflects the position of a color on the color wheel through an angular range. 0° or 360° represents a red hue, 90° represents a yellow hue, 180° represents a green hue, and 270° represents a blue hue. Calculated according to formula (6): (6); ∆E is the total color difference value that combines the differences in brightness, red-green, and yellow-blue directions. It is used to measure the overall color difference and is calculated according to formula (7): (7); In equation (7): ∆L* = L1*-L2*, which is the difference in brightness between the two colors; ∆a* = a1*-a2*, which is the difference in brightness between the two colors in the red-green direction; ∆b* = b1* -b2*, which is the difference in brightness between the two colors in the yellow-blue direction.

[0038] In the description of this invention, it should be noted that unless specific conditions are specified in the examples, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0039] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. These descriptions are for illustrative purposes only and not for limiting the scope of protection of the present invention. Furthermore, it should be noted that, unless otherwise stated, the technical or scientific terms used in this application should have the ordinary meaning understood by those skilled in the art.

[0040] Example 1

[0041] This embodiment provides a betaine-anthocyanin complex pigment composition, obtained by mixing anthocyanin freeze-dried powder and betaine freeze-dried powder at mass ratios of 5:1, 5:2, 5:3, 5:4, and 5:5, respectively, and naming them A1, A2, A3, A4, and A5. The relevant physicochemical properties of A1 to A5 were determined, and the detailed determination methods are as described above. The specific determination results are as follows: I. pH, TSS, and TA determination The pH, TSS, and TA results of the complex systems of mulberry anthocyanins and bougainvillea betalains in different proportions are shown in Table 1.

[0042] Table 1. Results of pH, TSS, and TA measurements

[0043] Table 1 shows that the pH of the composite system gradually increased from 3.14 (initially mulberry anthocyanins) to 4.41. The pH values ​​of the composite pigments were all higher than those of mulberry anthocyanins. This is because betalains generally have a pH of around 4.4, anthocyanins around 3.1, and the pH values ​​of the composite pigments fall between these two, increasing with the increase in the proportion of bougainvillea betalains added. The TSS showed the same trend; the TSS of anthocyanins and betalains were similar. The addition of bougainvillea betalains introduced soluble sugars and other substances, thus significantly increasing the TSS of the composite pigments. The TA trend was negatively correlated with pH, ​​rising slightly from 0.66% to 0.81%.

[0044] II. Determination of Total Phenolic and Total Flavonoid Content The total phenolic and total flavonoid contents of the mulberry anthocyanin and bougainvillea betalain complex system at different ratios are shown in Table 2.

[0045] Table 2 Results of determination of total phenols and total flavonoids

[0046] The total phenolic and total flavonoid content of mulberry anthocyanins was significantly higher than that of bougainvillea betalains. The total flavonoid content of the compound pigments was between that of mulberry anthocyanins and bougainvillea betalains, because the concentration of total phenolic and total flavonoids was lower than that of mulberry anthocyanins after the two were combined.

[0047] III. Antioxidant Activity Assay The antioxidant activity of ABTS in different proportions of the mulberry anthocyanin and bougainvillea betalain complex system is shown in Table 3.

[0048] Table 3. Antioxidant activity of ABTS in pigment compositions with different ratios

[0049] Table 3 shows that the detection system exhibits a characteristic blue-green color due to the generation of ABTS free radicals, and the scavenging effect of antioxidants on free radicals can induce a decay in the colorimetric response. Experimental data show that bougainvillea betaine has a low ABTS antioxidant level of 55.48%, while mulberry anthocyanin reaches 92.90%. This dose-response effect indicates that the ABTS antioxidant capacity of the complex pigments is inversely proportional to the increase in the proportion of bougainvillea betaine, further suggesting that the amount of ABTS free radical scavenging substances in mulberry anthocyanin is reduced with the addition of bougainvillea betaine. The ABTS free radical scavenging rates of the A1 and A2 complex pigments are closest to those of mulberry anthocyanin.

[0050] IV. Color Index Measurement The color parameters of the composite systems of mulberry anthocyanins and bougainvillea betalains in different proportions are shown in Table 4.

[0051] Table 4 Color parameters of different proportions of composite pigments

[0052] As shown in Table 4, after adding bougainvillea betalain, the L* values ​​of all samples except A1 decreased, while the b* values ​​generally showed a decreasing trend, and the a* values ​​increased. This indicates that the brightness of the composite pigment gradually decreased compared to mulberry anthocyanin, the color became darker, and the red component was enhanced. The addition of bougainvillea betalain promoted the development of red color. The C* value of mulberry anthocyanin was 9.83, and that of bougainvillea betalain was 28.75. The C* value of the composite pigment was between the two, indicating that the color saturation of the composite pigment was enhanced, suggesting that the pigment was more vibrant. In terms of hue angle, mulberry anthocyanin leaned towards red-yellow, with A1 to A5 turning negative, while bougainvillea betalain leaned towards blue-purple. The addition of bougainvillea betalain caused the sample hue to gradually shift from red-yellow to blue-purple. The change in ΔE showed the same trend as a*, with the A1 composite pigment having a color difference ΔE < 5, indicating the best staining uniformity.

[0053] Considering the above performance, A1 has the lowest pH among the composite pigments, followed by A2 and A3. TSS reflects the total concentration of soluble components in the dye solution, including sugars, organic acids, etc. The TSS of composite pigments increases significantly with the increase of betalain proportion; therefore, conservatively speaking, A1 is the better choice for composite pigments, followed by A2. The determination of TA is directly related to the organic acid content in the dye solution. Acidic conditions can promote the swelling of cellulose fibers and increase the penetration channels of dye molecules, but this did not show a significant change in composite pigments. Regarding total phenol content, group A1 showed the least decrease in total phenol content, while its total flavonoid content was higher than that of proanthocyanidins. The total flavonoid content of A2 was also higher than that of proanthocyanidins. The total phenol and total flavonoid contents of groups A3-A5 all decreased significantly. Mulberry anthocyanins showed a higher ABTS radical scavenging rate than bougainvillea betalains. The results for group A1 were closest to those for mulberry anthocyanins, followed by A2 and A3. A4 and A5 achieved ABTS radical scavenging rates exceeding 75%. Regarding color indicators, A1 composite pigment exhibited the best color difference ΔE < 5, indicating the best staining uniformity. This was followed by A2 and A3, then A4 and A5. Therefore, among these five composite staining agents, A1 was the relatively best choice, followed by A2 and A3, and finally A4 and A5. Further experiments will use A1 for further evaluation.

[0054] Example 2

[0055] This embodiment analyzes the effect of betalain addition on the stability of mulberry anthocyanins, using the A1 group of compound pigments.

[0056] I. Evaluation of the thermal stability of compound pigments Natural colorants such as anthocyanins and betalains are prone to molecular degradation at high temperatures due to their poor thermal stability, leading to a decrease in the color stability of the composite system. To investigate the effect of heat treatment on the color of the composite product and the changes of the two types of pigments during heat treatment, mulberry anthocyanins, bougainvillea betalains, and the A1 group composite pigments were prepared into aqueous solutions with a concentration of 10 mg / mL. These solutions were then heat-treated in a water bath at 70℃ for 2 h. Samples were taken every 20 min to measure color parameters, anthocyanin content, and betalain content. The determination of color parameters is described above, as are the methods for determining anthocyanin and betalain content. The changes in color parameters, anthocyanin retention rate, and betalain retention rate of each pigment under different heat treatment times are shown in Table 5.

[0057] Table 5. Color parameters, anthocyanin retention rate, and betalain retention rate of various pigments under different heat treatment times.

[0058] Mulberry anthocyanins showed a color difference of 5.90 after 20 minutes of heat treatment, with ΔE increasing to 7.64 within 80 minutes. Within 120 minutes, the a* value continuously decreased from 22.95 to 16.39, while the b* value increased from -6.97 to -0.69, a decrease of 89.9% in absolute value, resulting in a 33.76% decrease in the C* value. 0 The value increased from an initial 343.10 to 350.28, gradually approaching 360 (i.e., 0, the pure red baseline), indicating that the proportion of purple tones in the sample gradually decreased, while the proportion of red tones relatively increased, and the overall saturation showed a significant downward trend. During the 120-minute heat treatment, the color difference ΔE of the composite pigment changed from 1.59 to 4.72 and then to 1.67, with relatively small overall color variations. The a* value increased from an initial 16.26 to 18.91 and then to 15.83, with a maximum increase of 16.30%; the C* value fluctuated from 16.40 to 20.12, an increase of 22.68%; h 0 The value increased from 9.64 to 20.39, indicating a gradual shift towards a yellowish-red hue, but the color difference remained below the critical value of 5. The betaine system also showed significant temperature sensitivity, with ΔE reaching 6.87 after 120 min of heat treatment. Notably, the L* value continuously increased with prolonged treatment time. 0 The value shifted from 331.62 to 336.30. Overall, after heating, betalains gradually changed color from a relatively reddish, dark, and bluish hue to a brighter color with reduced red and blue tones. Comprehensive comparison revealed that the compound pigment exhibited the best thermal stability, with the smallest fluctuation in its color parameters.

[0059] After heat treatment at 70℃ for 120 minutes, the composite pigment still retained 77.60% of its anthocyanins. Within the 0-120 minute range, the retention rate slowly decreased with increasing heating time, indicating good thermal stability. In contrast, the retention rate of mulberry anthocyanins dropped to 57.23% after 120 minutes of heating, showing poor thermal stability. The difference in anthocyanin retention rates between mulberry anthocyanins and the composite pigment increased with heating time, indicating that the composite pigment exhibited significantly better thermal stability than mulberry anthocyanins. This is consistent with the same trend in the color hue (a*) and ∆E described in Example 1.

[0060] Under heating conditions, the betalain retention rates of both the composite pigment and the bougainvillea pigment decreased over time. The polysaccharides and proteins in the composite pigment form a physical barrier, reducing heat transfer; the antioxidant components inhibit oxidation reactions, lowering the pigment degradation rate. The faster decrease in bougainvillea betalain retention indicates that the two individual pigments are more sensitive to heat, while the composite formulation provides better stabilization and protection.

[0061] II. Stability evaluation of composite pigments at different pH levels Anthocyanins and betalains exhibit different pH sensitivities. Anthocyanins show good stability around pH 3.0; changes in solution pH alter their structure, leading to color changes. In contrast, betalains maintain a stable red color across a wider pH range (3.0-7.0), making them more suitable for weakly acidic to neutral media. To investigate the changes in the content and color of the two pigments in the anthocyanin-betalain complex under different acidic conditions, aqueous solutions of mulberry anthocyanins, bougainvillea betalains, and the A1 group complex pigment were prepared at a concentration of 10 mg / mL. The pH was adjusted to 1.0–12.0 using 1 mol / L HCl and NaOH, and color indicators were observed. However, due to the molecular structure degradation of anthocyanins and betalains in strongly acidic and alkaline environments, the data were rationalized; therefore, only color indicators, anthocyanin content, and betalain content at pH 3.0–7.0 were examined. The color parameters of each pigment at different pH values ​​are shown in Table 6.

[0062] Table 6. Color parameters of each pigment at different pH levels

[0063] Depend on Figure 6The color patch diagram clearly shows that the color of mulberry anthocyanins changes significantly with pH. At pH 3.0, the patch is pink; at pH 4.0 and 5.0, the patch turns grayish-pink and grayish-gray. In contrast, the color of the composite pigment is not significantly different from that at pH 7.0; it is purplish-red at pH 3.0 and dark purplish-red at pH 4.0 and 5.0. Bougainvillea betaine exhibits a brighter purplish-red color as the pH increases, but its brightness decreases slightly. The color parameters of the composite pigment change less than those of mulberry anthocyanins. When the system environment is pH 3.0-5.0, bougainvillea betaine, due to its stronger stability and color-producing ability at this pH, contributes to the reddish-purple color of the solution. Mulberry anthocyanins exhibit poor stability and significant color difference in a pH range of 3.0-5.0, with a value of 15.98 at pH 3.0, indicating substantial color variation. However, the introduction of bougainvillea betalain complex pigment system demonstrates improved color development performance, showing better results in terms of redness, saturation, and color difference.

[0064] The variation patterns of anthocyanin content and relative amount of betalain under different pH conditions are shown in Table 7.

[0065] Table 7. Relative amounts of anthocyanins and betalains of various pigments under different pH conditions (compared to pH=7.0)

[0066] The trend of relative content shows that the degradation of anthocyanins in the composite pigments is less with increasing pH, and their relative contents are higher than those of mulberry anthocyanins under the same conditions. Furthermore, the fluctuation range of relative content within the pH range of 3.0-5.0 is only 14.69 percentage points. This phenomenon indicates that the synergistic effect among the composite components effectively buffers the impact of pH gradient changes on anthocyanin stability, demonstrating superior pH adaptability compared to single mulberry anthocyanins.

[0067] Example 3

[0068] The kapok tree, belonging to the genus *Ceiba* in the family Malvaceae, is renowned for its tall stature, fiery red flowers, and light, fluffy fibers, making it an important ornamental and ecological tree species in South China. It typically blooms in spring with large flowers, and after flowering, it produces oblong capsules that split open in summer, releasing white, fluffy fibers. After the kapok fruit matures, the fluff is often considered "urban pollen" and is collected. The kapok flower's fluff resembles... Figure 1 As shown, kapok fibers are lightweight and fluffy, white in color, and possess strong absorbency and flexibility. Compared to traditional fiber materials, kapok wadding, due to its lightweight and fluffy characteristics, maintains high breathability and softness after dyeing, making it suitable for making functional filling materials or handicrafts. This expands the application scenarios of kapok wadding and brings multiple benefits.

[0069] This embodiment investigates the staining experiment of kapok using a betalain-anthocyanin composite dye. The kapok substrate was treated with an ultrasonic-ethanol combined degreasing process, with an ethanol concentration of 40% and a treatment time of 15 min. The composite pigment dye was prepared by freeze-drying a mixture of bougainvillea betalain and mulberry anthocyanins according to the ratio specified in group A1.

[0070] I. Staining Kinetics To investigate the adsorption dynamics of anthocyanins, complex pigments, and betalains on kapok fibers, reveal the mechanism of temperature influence on the adsorption process, and provide theoretical support for the formulation optimization and dyeing process parameters of complex pigment dyes, twelve pieces of 1.000 g kapok wadding were accurately weighed. Twenty sets of dye solutions each for anthocyanins, complex pigments, and betalains were prepared (four temperatures, five parallels per temperature), and pre-equilibrated for 20 minutes in a constant-temperature oscillating water bath (temperature gradients set at 40℃, 60℃, 80℃, and 100℃). A quantitative amount of kapok fiber sample was added to the dyeing system for dynamic adsorption experiments (0 to 120 minutes, with sampling at 15-minute intervals). After the sample was removed, the absorbance of the residual liquid was measured at wavelengths of 537 nm (betalain) and 510 nm (complex pigment and anthocyanin) using a UV-Vis spectrophotometer (for calculating Ct, the calculation method is detailed in formulas (1) and (2)). The amount of dye fixed on the fiber surface qt was calculated by formula (8), and a dyeing kinetic model was constructed to characterize the influence mechanism of temperature on the adsorption process.

[0071] (8); In the formula: C0 is the initial mass concentration of anthocyanin, complex pigment and betalain in the dye solution, respectively, mg / L; Ct is the mass concentration of anthocyanin, complex pigment and betalain on the fiber at time t of dyeing, mg / L; V is the total volume of dye solution, mL; W is the fiber mass, g.

[0072] The staining kinetics curves of anthocyanins, complex pigments, and betalains on kapok fibers at different temperatures are shown below. Figure 2As shown, temperature significantly regulates the adsorption rate and equilibrium adsorption capacity of dyes. Within the 40℃~100℃ range, the adsorption rate of all three pigments increases significantly with increasing temperature. Moreover, the composite pigment exhibits the fastest adsorption rate at the same temperature. However, when the temperature rises to 80℃~100℃, the increased adsorption rate is accompanied by the potential risk of dye thermal degradation. The type of pigment has a particularly significant impact on dyeing efficiency. The composite pigment shows a significant synergistic effect, which may originate from the hydrogen bonding between betaine and anthocyanins. This interaction enhances the binding ability of pigment molecules on the surface of kapok fibers, thereby improving dyeing efficiency. At 60℃, the composite pigment achieves a 90% absorbance reduction in just 45 minutes, while single anthocyanins and betaine require 60 minutes and 75 minutes, respectively, to achieve similar results. Furthermore, the equilibrium adsorption capacity of the composite pigment at 80℃ is 15%~20% higher than that of the single pigment, highlighting its advantage in resisting thermal degradation. In contrast, betalains are highly sensitive to temperature, with adsorption decreasing sharply above 80°C, indicating insufficient thermal stability and requiring strict control of the staining temperature.

[0073] II. Staining Kinetic Equations To comprehensively study the dyeing kinetics of anthocyanins, complex pigments, and betaine on kapok fibers, the following two kinetic models were selected. Figure 2 The data in the dataset is fitted.

[0074] (1) Quasi-first-order dynamic equations Assuming that the amount of dye adsorbed on the cotton fiber qt changes exponentially with time t, it means that it has the characteristics of first-order adsorption kinetics. Then, the Lagergren first-order kinetic adsorption equation can be used to calculate its adsorption rate, as shown in formula (9).

[0075] (9); In the formula: q e The values ​​are the contents of anthocyanins, complex pigments, and betalains on the fiber at adsorption equilibrium, respectively, in mg / g; q t The values ​​represent the contents of anthocyanins, complex pigments, and betalains on the fiber at time t, in mg / g; k1 is the first-order kinetic rate constant, in min. -1 Equation (9) is simplified by integrating the critical conditions qt=0 at t=0 and qt=qt at t=t, and then obtaining: (10); In equation (10), ln(q) e -q tPlotting t as the dependent variable and t as the independent variable yields a straight line, from which the reaction rate constant k1 can be calculated. If adsorption occurs at an interface, most experiments follow a pseudo-first-order kinetic model. If the experimental results do not conform to equation (10), it indicates that the process does not conform to the first-order kinetic equation.

[0076] The pseudo-first-order kinetic parameters of the adsorption of compound pigments, anthocyanins, and betalains on kapok fibers are shown in Table 8.

[0077] Table 8. Quasi-first-order kinetic parameters of dyeing compound pigments, anthocyanins, and betalains on kapok fibers.

[0078] Note: q e,exp q represents the equilibrium adsorption amount of the staining solution obtained in the experiment. e,cal The calculated dyeing equilibrium adsorption amount; R 2 The fitting coefficients are denoted as .

[0079] Linear fitting using equation (10) yields the pseudo-first-order kinetic model linear fitting curve of the adsorption of composite pigments on kapok fiber, as shown below. Figure 3 As shown, the results indicate that the adsorption process of the composite pigment is in high agreement with the pseudo-first-order kinetic model, and the goodness of linear fit at various temperatures demonstrates that the model can effectively describe its adsorption mechanism. With increasing temperature, the reaction rate constant k1 increases significantly, consistent with the theoretical expectation of the temperature effect from the Arrhenius equation. Furthermore, the experimental equilibrium adsorption amount q... e,exp Compared with the model calculated value q e,cal The results were close, further validating the model's predictive accuracy.

[0080] Linear fitting using equation (10) yields the pseudo-first-order kinetic model linear fitting curve for the adsorption of anthocyanins on kapok fibers, as shown below. Figure 4 As shown, the pseudo-first-order model for anthocyanins exhibits good applicability, but slight deviations occur in later data points at high temperatures of 80℃ and 100℃, possibly related to the synergistic adsorption effect or surface site competition among the components in the complex system. Although the increasing trend of temperature on the reaction rate constant k1 is consistent with that of the composite pigment, the calculated equilibrium adsorption amount q... e,cal The value is slightly higher than the experimental value, and the adsorption mechanism needs to be further verified by combining a pseudo-second-order kinetic model.

[0081] Linear fitting using equation (10) yields the pseudo-first-order kinetic model linear fitting curve for the adsorption of betaine on kapok fibers, as shown below. Figure 5 As shown, the adsorption kinetics of betalains exhibit a certain degree of complexity. The data points at 40°C and 60°C show a linear distribution, but at higher temperatures, due to the rapid reaching of adsorption equilibrium, the later ln(q)... e -q tThe value approaches negative infinity, leading to a reduction in effective data points. Furthermore, the difference between experimental and calculated values ​​indicates that the pseudo-first-order model has limitations in describing the betalain adsorption process, necessitating the introduction of a pseudo-second-order model to explore its chemisorption mechanism.

[0082] (2) Quasi-second-order dynamic equations The pseudo-second-order kinetic model is based on the assumption that the adsorption rate is determined by the square of the number of unoccupied adsorption vacancies on the fiber surface, and its formula is as follows: (11); In the formula: q e The values ​​are the contents of anthocyanins, complex pigments, and betalains on the fiber at adsorption equilibrium, respectively, in mg / g; q t , respectively, represent the contents of anthocyanins, complex pigments, and betalains on the fiber at time t, in mg / g; k2 is the second-order kinetic rate constant, in g / (mg·min). By integrating equation (11) and substituting the critical conditions qt=0 at t=0 and qt=qt at t=t, we obtain: (12); From equation (12), we can see that k2 and q e Can be directly from t / q t The value of qe is calculated from the intercept and slope of the t-curve. The larger the slope, the smaller the qe, which means the smaller the dyeing equilibrium adsorption amount.

[0083] The pseudo-second-order kinetic parameters of the adsorption of compound pigments, anthocyanins, and betalains on kapok fibers are shown in Table 9.

[0084] Linear fitting using equation (12) yields the pseudo-second-order kinetic model linear fitting curve of the adsorption of composite pigments on kapok fiber, as shown below. Figure 6 As shown.

[0085] Linear fitting using equation (12) yielded the pseudo-second-order kinetic model linear fitting curve for the adsorption of anthocyanins on kapok fibers, as shown below. Figure 7 As shown.

[0086] Linear fitting using equation (12) yields the pseudo-second-order kinetic model linear fitting curve for the adsorption of betaine on kapok fibers, as shown below. Figure 8 As shown, the linear fitting curves for the three pigment staining methods are all linear at different temperatures.

[0087] Table 9. Pseudo-second-order kinetic parameters of dyeing compound pigments, anthocyanins, and betalains on kapok fibers.

[0088] From Table 9, the corresponding parameters q of the pseudo-second-order dynamics model e,caland regression coefficient R 2 It can be seen that the experimental equilibrium adsorption amount q e,exp Compared with the model calculated value q e,cal Very close, and the regression coefficient R0 2 The values ​​are significantly higher than those of the first-order kinetic model, all above 0.99, indicating that the pseudo-second-order kinetic equation can well describe the entire adsorption process. Because the pseudo-second-order model includes all processes of dye adsorption onto the fiber, such as external liquid film diffusion, dye adsorption on the fiber surface, and dye diffusion into the fiber interior, it more realistically and comprehensively reflects the kinetic mechanism of anthocyanin, complex pigments, and betalain dyeing on kapok fibers.

[0089] Table 9 also shows that the reaction rate of dyeing kapok fibers by anthocyanins, compound pigments and betalains all increases with increasing temperature. This is because as the temperature increases, the fiber expansion increases and the thermal motion of the dye becomes more intense, which is conducive to accelerating the dyeing process.

[0090] Application Example 1 In this application example, a complex pigment from mulberry anthocyanins, betalains, and group A1 was dissolved in a pH 3.5 buffer solution to prepare a dyeing agent with a concentration of 10 mg / mL. The buffer solution was prepared as follows: 25 g of ammonium acetate was dissolved in 25 ml of water, then 38 ml of 7 mol / L hydrochloric acid solution was added. The pH was accurately adjusted to 3.5 using 2 mol / L hydrochloric acid solution or 5 mol / L ammonia solution, and then diluted with water to 100 ml. Then, cotton fibers were dyed at a 1:2 bath ratio at 40 ± 1℃ for 120 min, followed by fixing and drying. After irradiation under ultraviolet light for 24 hours, the dyeing process was completed. Figure 9 It can be seen that the composite pigment showed the least fading, while anthocyanins and betalains showed more fading and poor color fixation. The experimental results indicate that the composite pigment provided the best color fixation. The kapok wadding dyed with the composite pigment exhibits a vibrant purplish-red color and can be widely used in handicrafts and functional filling materials.

[0091] The application of dyeing kapok lint exemplifies the concept of "turning waste into treasure." Kapok lint is often overlooked waste, but through research on composite dyes, it has been given new life. By extracting natural betalains and anthocyanins to create a composite dye and exploring its dyeing stability, waste lint can be transformed into unique handicraft materials after dyeing. Figure 10This study investigates the dyeing of handicrafts made from kapok wadding using a complex pigment of anthocyanins, betalains, and A1. From dyeing samples to finished products, each step combines scientific research with resource reuse, activating the value of "waste." It provides practical samples for the research of complex pigment dyes, verifying their feasibility in dyeing natural fibers, and freeing kapok wadding from the label of "waste," transforming it into a carrier of color and creativity. This achieves a win-win situation for ecological protection and scientific innovation, turning kapok "waste into treasure" and contributing to the development of resource recycling and natural dyeing processes.

[0092] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A betaine-anthocyanin complex pigment composition, characterized in that, The composition is made by combining anthocyanin freeze-dried powder and betalain freeze-dried powder in a mass ratio of 5:1 to 5.

2. The betaine red pigment-anthocyanin complex pigment composition according to claim 1, characterized in that, The composition is made by combining anthocyanin freeze-dried powder and betalain freeze-dried powder in a mass ratio of 5:1 to 3; preferably, the composition is made by combining anthocyanin freeze-dried powder and betalain freeze-dried powder in a mass ratio of 5:1 to 2.

3. The betaine red pigment-anthocyanin complex pigment composition according to claim 1 or 2, characterized in that, The method for obtaining the anthocyanin freeze-dried powder includes: homogenizing mulberries and extracting them with acidic ethanol to obtain a crude extract; purifying the crude extract with AB-8 macroporous resin to obtain anthocyanins, and then freeze-drying it to obtain the anthocyanin freeze-dried powder.

4. The betaine red pigment-anthocyanin complex pigment composition according to claim 1 or 2, characterized in that, The method for obtaining the betalain freeze-dried powder includes: grinding dried bougainvillea into powder and extracting it with water to obtain a crude extract; purifying the crude extract with HPD100 macroporous resin and then freeze-drying it to obtain the betalain freeze-dried powder.

5. The use of the betaine red pigment-anthocyanin complex pigment composition according to any one of claims 1 to 4 in the preparation of dyeing agents.

6. A dyeing agent, characterized in that, The betalain-anthocyanin complex pigment composition according to any one of claims 1 to 4 is dissolved in an aqueous solution with a pH of 3.5 to 4.0 to prepare a solution with a concentration of 8 to 12 mg / mL.

7. The staining agent according to claim 6, characterized in that, The reagents used to adjust pH are glacial acetic acid, buffer salt solution, or acidic ethanol.

8. The staining agent according to claim 6 or 7, characterized in that, The reagent used to adjust the pH is an ammonium acetate-hydrochloric acid buffer solution, wherein the final concentration of ammonium acetate is 0.2~0.3 g / mL and the final concentration of hydrochloric acid is 6~7 mol / L; preferably, the preparation method of the ammonium acetate-hydrochloric acid buffer solution includes: dissolving ammonium acetate in water, adding hydrochloric acid solution, and then adjusting the pH value to 3.5~4.0 with hydrochloric acid solution or ammonia solution.

9. A dyeing material, characterized in that, The dyeing agent described in any one of claims 6 to 8 is used to dye the product material.

10. The dyed product material according to claim 8, characterized in that, The material of the product is yarn; preferably, the yarn includes: kapok, silk, cotton, and hemp.

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