Method for enhancing stability of natural carthamin yellow

Abstract

The invention discloses a method for enhancing the stability of natural carthamin yellow. The method comprises the steps that natural carthamin yellow powder and tea polyphenol are dissolved in water and stirred evenly to obtain a pigment solution, the pigment solution is stored in a dark place at the temperature of 25 DEG C, the mass concentration of natural carthamin yellow in the pigment solution is 0.1%, and the concentration of the tea polyphenol in the pigment solution is 0.1-0.3%. The tea polyphenol has a color protection effect on the natural carthamin yellow, the stability of the natural carthamin yellow can be effectively improved, 0.1% of tea polyphenol has the best color protection effect, and the pigment loss rates are 9.12% and 15.21% respectively after testing for 12 hours under the conditions of strong light irradiation and high temperature of 60 DEG C.

Description

Technical Field

[0001] This invention belongs to the field of pigment technology, specifically relating to a method for enhancing the stability of natural safflower yellow pigment. Background Technology

[0002] As health foods gain increasing attention from consumers, some artificial colorings have been banned or have their use restricted due to their extreme safety risks, making green and healthy natural colorings the new favorites. Pure natural safflower yellow pigment is a type of natural yellow pigment isolated from saffron (Crocus sativus) of the Iridaceae family. Its bright color and various pharmacological and biological activities have made it popular across various fields, especially in the food industry. Compared to other coloring agents, pure natural safflower yellow pigment, as an edible colorant, has advantages such as being milder, more natural, and more appealing, which can entice a wide range of consumers to make purchases. While natural safflower yellow pigment has a bright color and multiple uses, it has traditionally been mainly used as a dye for noodle products. In recent years, due to continuous research and development in the application fields of pure natural safflower yellow pigment, its applications in proteins, starches, etc., have expanded. [3] It is becoming increasingly popular in various fields, and can be used as a coloring agent in various foods such as pastries, candies, flour, beverages, jellies, biscuits, and ice cream. However, pure natural safflower yellow pigment is rich in several unsaturated double bonds, which makes the liquid product very unstable. It is easily affected by external factors and fades, greatly affecting the color and stability of the finished product and the dyed product. Summary of the Invention

[0003] The purpose of this invention is to provide a method for enhancing the stability of natural safflower yellow pigment.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0005] A method to enhance the stability of natural safflower yellow pigment: Dissolve natural safflower yellow pigment powder and tea polyphenols in water, stir evenly to obtain a pigment solution, and store at 25°C in the dark.

[0006] Furthermore, the mass concentration of natural safflower yellow pigment in the pigment solution is 0.1%.

[0007] Furthermore, the mass concentration of tea polyphenols in the pigment solution is 0.1% to 0.3%.

[0008] Preferably, the mass concentration of tea polyphenols in the pigment solution is 0.1%.

[0009] This invention investigates the color-protecting effect of adding natural antioxidants on natural safflower yellow pigment solution. The results show that tea polyphenols have a color-protecting effect on natural safflower yellow pigment and can effectively improve the stability of natural safflower yellow pigment. The color-protecting effect of 0.1% tea polyphenols is the best. After 12 hours of testing under strong light irradiation and high temperature of 60°C, the pigment loss rates are 9.12% and 15.21%, respectively.

[0010] This invention provides new ideas for the practical production and application of pigments. Attached Figure Description

[0011] Figure 1 This study investigates the effect of different concentrations of tea polyphenols on the stability of natural safflower yellow pigment.

[0012] Figure 2 This study investigated the effect of different concentrations of white-backed angelica extract on the stability of natural safflower yellow pigment.

[0013] Figure 3 This study investigated the effect of different concentrations of grape seed extract on the stability of natural safflower yellow pigment.

[0014] Figure 4 This relates to the effect of antioxidants on the stability of pigment solutions under strong light irradiation.

[0015] Figure 5 This relates to the effect of antioxidants on the stability of pigment solutions under indoor natural light.

[0016] Figure 6 This relates to the effect of antioxidants on the stability of pigment solutions under light-protected conditions.

[0017] Figure 7 This relates to the effect of antioxidants on the stability of pigment solutions at 25°C.

[0018] Figure 8 This relates to the effect of antioxidants on the stability of pigment solutions at 55℃.

[0019] Figure 9 The effect of antioxidants on the stability of pigment solutions at 85℃. Detailed Implementation

[0020] Example 1: Selection of Antioxidants and Experimental Conditions

[0021] 1. Materials, Reagents and Instruments

[0022] Natural safflower yellow pigment (≥95%) (Zhuhai Yafuxingyuan Food Industry Co., Ltd.); Tea polyphenols (Hebei Runbu Biotechnology Co., Ltd.); White-backed amaranth extract (laboratory preparation); Grape seed extract (Zhejiang Yicun Biotechnology Co., Ltd.); UV-1800 ultraviolet-visible spectrophotometer (Shanghai Yuanxi Instrument Co., Ltd.); LS-300 light irradiation tester (Shanghai Jingsheng Scientific Instrument Co., Ltd.); Digital display forced-air drying oven (Cangzhou Nalian Instrument Equipment Co., Ltd.); Electric thermostatic incubator (Thermo Fisher Scientific China).

[0023] 2. Experimental Methods

[0024] Each of the following experiments was repeated at least 3 times. The results are expressed as mean ± standard deviation. To represent, SPSS 22.0 statistical software was used for data analysis, and Origin 8.0 software was used for plotting.

[0025] 2.1 Investigation on the color-protecting effect of different concentrations of antioxidants

[0026] Ten portions of natural safflower flavonoid powder, each accurately weighed to 0.1 g, were placed in volumetric flasks numbered 1-10. Different amounts of tea polyphenols were added to volumetric flasks 1-3, resulting in polyphenol concentrations of 0.1%, 0.2%, and 0.3%, respectively. Different amounts of white-backed amaranth extract were added to volumetric flasks 4-6, resulting in extract concentrations of 0.1%, 0.2%, and 0.3%, respectively. Grape seed extract was added to volumetric flasks 7-9, and flask 10 served as a blank. All samples were placed on a laboratory bench at room temperature. At 0, 1, 3, 6, and 12 hours, 1 mL of the corresponding pigment solution was taken and diluted to 25 mL. The absorbance was measured at 401 nm, and the absorbance values ​​were recorded. The pigment loss rate (A) was calculated using formula ① and plotted.

[0027] A = (A0 - A1) × 100% / A0 ①

[0028] In the formula, A0 is the absorbance value before pigment solution treatment, and A1 is the absorbance value after pigment solution treatment.

[0029] (1) The effect of different concentrations of tea polyphenols on the color protection of natural safflower yellow pigment: by Figure 1 It was found that the pigment loss rate of natural safflower yellow pigment without the addition of antioxidant tea polyphenols gradually increased with the increase of treatment time, reaching a maximum of 9.81% after 12 hours of treatment. After adding the antioxidant tea polyphenols, the loss rate of natural safflower yellow pigment decreased after treatment for different time periods. However, there was no significant difference in the antioxidant effect of tea polyphenols at concentrations of 0.1%, 0.2%, and 0.3%. Considering economic efficiency, a concentration of 0.1% tea polyphenols was selected for subsequent experiments.

[0030] (2) Effects of different concentrations of white-backed amaranth extract on the color-protecting properties of natural safflower yellow pigment: Figure 2 It can be seen that, compared with the control group, the loss rate of natural safflower yellow pigment was reduced after adding the antioxidant white-backed safflower extract for different treatment times. However, the antioxidant effect of white-backed safflower extract is not proportional to the concentration. Therefore, considering the economic cost, the concentration of white-backed safflower extract was selected as 0.1% in subsequent experiments.

[0031] (3) Effects of different concentrations of grape seed extract on the color protection of natural safflower yellow pigment: Figure 3 It can be seen that the pigment loss of the pigment solution under the action of the three concentrations of grape seed extract is not significantly related to the concentration. The loss rate of the pigment solution group with a concentration of 0.3% is even higher than that of the blank group, while the pigment solution containing 0.1% concentration of grape seed extract has the best stability.

[0032] The study investigated the effects of three antioxidants at different concentrations on pigment solutions and found that the antioxidant effect was not directly proportional to the concentration. In other words, more antioxidants are not necessarily better. This may be because there is a weak balance in the pigment solution system, and excessive use will disrupt this balance. The specific reason is still unclear.

[0033] 2.2 Investigation on the color-protecting effect of antioxidants under different light intensities

[0034] Four portions of natural safflower yellow pigment powder, each accurately weighed to 0.1g, were added to volumetric flasks numbered 1-4 respectively. A certain amount of tea polyphenols, white-backed amaranth extract, and grape seed extract were added to volumetric flasks numbered 1, 2, and 3 respectively, and the volumes were adjusted to 100mL with water to ensure a final concentration of 0.1% of natural antioxidants in each flask. Flask number 4 was used as a blank. The flasks were placed in a light box, on an experimental table, and in a dark room, respectively, under strong light, natural indoor light, and in the dark. At 0, 1, 3, 6, and 12 hours, 1mL of the corresponding pigment solution was taken and diluted to 25mL. The absorbance was measured at a wavelength of 401nm, and the absorbance values ​​were recorded. The pigment loss rate was calculated using formula ①.

[0035] (1) The investigation of the effects of strong light was conducted by Figure 4 It was found that under strong light irradiation, the antioxidants tea polyphenols, white-backed amaranth extract, and grape seed extract could effectively enhance the stability of the natural safflower yellow pigment solution. Among them, tea polyphenols had the best antioxidant effect, with a natural safflower yellow pigment loss rate of 9.12% after 12 hours of strong light irradiation, which was less than 10% and 55.16% lower than the control group. White-backed amaranth extract had the second best antioxidant effect, with a natural safflower yellow pigment loss rate of 11.14% after 12 hours of strong light irradiation. Grape seed extract had the worst antioxidant effect, with a pigment loss rate of 15.35% after 12 hours of strong light irradiation.

[0036] (2) The investigation of indoor natural light was conducted by Figure 5 It can be seen that after 12 hours of exposure to natural indoor light, the stability of natural antioxidants is as follows: tea polyphenols > white-backed amaranth extract > grape seed extract. Among them, after 12 hours, the pigment loss rate of the tea polyphenol group was only 4.08%, which is about 42% of that of the control group.

[0037] (3) The investigation of the effects of light avoidance was conducted by Figure 6 It can be seen that after being placed in the dark for 12 hours, compared with the control, all three natural antioxidants can significantly reduce the pigment loss rate. Moreover, the three antioxidants have almost the same ability to increase the stability of natural safflower yellow pigment, and can all effectively control the pigment loss to about 3%.

[0038] 2.3 Investigation on the color-protecting effect of antioxidants under different temperature conditions

[0039] Prepare the antioxidant solutions and blank solutions according to method 2.2. Divide each group of solutions into three portions in transparent conical flasks and place them in constant temperature incubators with temperatures set at 25℃, 55℃ and 85℃ respectively. Take 1 mL of the corresponding pigment solution into volumetric flasks at 0, 1, 3, 6 and 12 h, dilute to the mark with water and shake well. Measure the absorbance at a wavelength of 401 nm, record the absorbance value, calculate the pigment loss rate according to formula ① and plot it.

[0040] (1) Results of the study on the color-protecting effect of antioxidants on pigments at 25℃ are as follows: Figure 7 As shown, at a temperature of 25℃, all three antioxidants can effectively improve the stability of natural safflower yellow pigment. The stability effect of the three antioxidants is tea polyphenols > white-backed amaranth extract > grape seed extract. After 12 hours, the pigment loss rates of the tea polyphenol group, white-backed amaranth extract group, and grape seed extract group are 2.01%, 2.41%, and 4.41%, respectively.

[0041] (2) Results of the study on the color-protecting effect of antioxidants on pigments at 55℃ are as follows: Figure 8 As shown, at 55℃, all three natural antioxidants can effectively enhance the stability of the natural safflower yellow pigment solution. After 12 hours, the pigment loss rate of the blank group was 31.25%, the pigment loss rate of the tea polyphenol group was 15.21%, the pigment loss rate of the white-backed safflower extract group was 19.41%, and the pigment loss rate of the grape seed extract group was 20.87%.

[0042] (3) Results of the study on the color-protecting effect of antioxidants on pigments at 85℃ are as follows: Figure 9 As shown, under a high temperature of 80℃, the protective effect of the three natural antioxidants on the safflower yellow pigment solution was no longer significant. After 12 hours, although the pigment loss rate of all three groups was lower than that of the blank group, the pigment loss still reached about 50%.

[0043] This embodiment first investigated the effect of different concentrations of antioxidants on the stability of pigment solutions. The results showed that the antioxidant effect was not directly proportional to the concentration, and the pigment solution containing 0.1% tea polyphenols exhibited the best stability among all concentration groups. Stability tests under light and temperature conditions revealed that all three antioxidants could effectively enhance the stability of natural safflower yellow pigment to a certain extent. After 12 hours of strong light irradiation, the pigment loss rate was 9.12% for the 0.1% tea polyphenol group, 11.14% for the white-backed amaranth extract, and 15.35% for the grape seed extract. Under high temperature (85℃), the protective effect of the three natural antioxidants on the natural safflower yellow pigment solution was not significant, possibly because the high temperature simultaneously damaged the structure of the antioxidants, causing them to lose their protective effect.

[0044] Example 2

[0045] A method for enhancing the stability of natural safflower yellow pigment: Natural safflower yellow pigment powder and tea polyphenols are dissolved in water and stirred until homogeneous to obtain a pigment solution, wherein the mass concentration of natural safflower yellow pigment is 0.1%, and the mass concentration of tea polyphenols is 0.1%, and then stored at 25°C in the dark.

Claims

1. A method for enhancing the stability of natural safflower yellow pigment, characterized in that, Natural safflower flavonoid powder and tea polyphenols were dissolved in water and stirred evenly to obtain a pigment solution, which was then stored at 25°C away from light.

2. The method for enhancing the stability of natural safflower yellow pigment according to claim 1, characterized in that, The pigment solution contains 0.1% natural safflower yellow pigment by mass.

3. The method for enhancing the stability of natural safflower yellow pigment according to claim 1, characterized in that, The mass concentration of tea polyphenols in the pigment solution is 0.1-0.3%.

4. The method for enhancing the stability of natural safflower yellow pigment according to claim 3, characterized in that, The pigment solution contains 0.1% tea polyphenols by mass.

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