Color fixative for improving thermal stability of cochineal pigment and method thereof
Technical Field
The invention belongs to the technical field of natural pigments, and relates to a color fixative for improving thermal stability of cochineal red pigment and a method thereof.
Background
Cochineal pigment is an anthraquinone natural pigment, is an excellent colorant for food, cosmetics, medicines and textiles, and is the only natural pigment which is allowed by the FDA to be used for food, medicines and cosmetics. Although cochineal pigment is stable, when used in other product processing, it tends to fade when heated, and the effect of conventional monoclonal antibody oxidants is not very apparent.
Disclosure of Invention
Aiming at the technical problems, the invention provides the color fixative for improving the thermal stability of the cochineal color and the method thereof, and the color fixative can protect the stability of the cochineal color under the heating condition and prevent the cochineal color from fading under the synergistic action of the antioxidant and other substances.
The specific technical scheme is as follows:
firstly, the color fixative for improving the thermal stability of cochineal pigment is prepared from the following raw materials: tea polyphenol, papaya flavone and glucomannan, wherein the tea polyphenol is 0.1-0.4 part by mass, the papaya flavone is 0.02-0.05 part by mass, and the glucomannan is 0.5-1.5 parts by mass, and the raw materials are dispersed in a mixed solvent to obtain the color fixative.
Wherein the mixed solvent comprises 20-40 parts of propylene glycol and 50-80 parts of water.
The method for improving the thermal stability of the cochineal color is also provided, and the color fixative is added into the cochineal color and is uniformly mixed to form a mixture of the cochineal color and the color fixative.
The content of cochineal acid in the mixture of the cochineal pigment and the color fixative is 1-20 wt%.
Tea polyphenol has stronger antioxidation, especially ester catechin EGCG, and the reducibility of the tea polyphenol can even reach 100 times of that of L-erythorbic acid. And the oxidation resistance is enhanced along with the rise of the temperature, so that the heat stability of the cochineal is improved. The papaya flavone has good heat resistance and antioxidant activity, and has strong activity of eliminating active oxygen free radicals.
The invention utilizes the mixture of glucomannan, papaya flavone and tea polyphenol as the color fixative, which has the synergistic effect, and the tea polyphenol and papaya flavone have the functions of antioxidation and coloring cochineal pigment. Glucomannan belongs to soluble hemicellulose, and has various unique physicochemical properties of water solubility, water retention thickening, stability, suspension, gelation, adhesion, film formation and the like, so that the glucomannan has wide application and development values. Glucomannan is a vegetable gum, but has a higher viscosity than other natural gums such as xanthan gum, guar gum, locust bean gum, etc., and remains stable without settling when the PH is reduced below 3.8. The invention particularly utilizes the film forming property of glucomannan to form a film outside tea polyphenol and pawpaw flavone, and utilizes the adhesion and gelation properties to contact with cochineal component to form a stable composite structure, which can protect and release the antioxidant substances coated by the film, so that the antioxidant substances of tea polyphenol and bamboo leaf antioxidant can play a good role in antioxidation in the whole product, thereby protecting the cochineal pigment.
The color fixative provided by the invention utilizes glucomannan to form a film outside the cochineal pigment, the cochineal pigment is partially or wholly coated, so that the cochineal pigment is not easily influenced by temperature, oxidant and illumination to obtain enough stability, and the tea polyphenol and the pawpaw flavone have high thermal stability, and the oxidation resistance is enhanced along with the rise of temperature, so that the thermal stability of the cochineal pigment can be obviously improved.
The color fixative for improving the thermal stability of the cochineal color and the method thereof can effectively improve the thermal stability of the cochineal color, avoid the fading of the cochineal color caused by heating in the processing and storage processes, and simultaneously slowly release the tea polyphenol and the papaya flavone antioxidant under the action of glucomannan, thereby effectively prolonging the effective period of the color fixative.
Detailed Description
The present invention will be further understood from the following specific examples of the present invention, which should not be construed as limiting the scope of the present invention.
Example 1
The color fixative for improving the thermal stability of the cochineal red pigment is prepared from the following raw materials: tea polyphenol, papaya flavone and glucomannan, wherein the tea polyphenol is 0.24 part by mass, the papaya flavone is 0.03 part by mass, and the glucomannan is 0.87 part by mass, and the raw materials are dispersed in a mixed solvent to obtain the color fixative. The mixed solvent comprises 34 parts of propylene glycol and 68 parts of water.
Example 2
The color fixative for improving the thermal stability of the cochineal red pigment is prepared from the following raw materials: tea polyphenol, papaya flavone and glucomannan, wherein the tea polyphenol is 0.37 part by mass, the papaya flavone is 0.02 part by mass, and the glucomannan is 0.93 part by mass, and the raw materials are dispersed in a mixed solvent to obtain the color fixative. The mixed solvent comprises 25 parts of propylene glycol and 75 parts of water.
Example 3
The color fixative for improving the thermal stability of the cochineal red pigment is prepared from the following raw materials: tea polyphenol, papaya flavone and glucomannan, wherein the tea polyphenol is 0.19 part by mass, the papaya flavone is 0.03 part by mass, and the glucomannan is 1.26 parts by mass, and the raw materials are dispersed in a mixed solvent to obtain the color fixative. The mixed solvent comprises 20-40 parts of propylene glycol and 50-80 parts of water.
Example 4
The color fixative for improving the thermal stability of the cochineal red pigment is prepared from the following raw materials: tea polyphenol, papaya flavone and glucomannan, wherein the tea polyphenol is 0.1-0.4 part by mass, the papaya flavone is 0.02-0.05 part by mass, and the glucomannan is 0.5-1.5 parts by mass, and the raw materials are dispersed in a mixed solvent to obtain the color fixative. The mixed solvent comprises 20-40 parts of propylene glycol and 50-80 parts of water.
The color fixative of examples 1 to 4 was mixed with cochineal color to form a mixture of cochineal color and color fixative. The content of cochineal acid in the mixture of cochineal pigment and color fixative is 5 wt%, 10 wt%, 15 wt% and 20 wt% in sequence.
The thermal stability of the mixture of cochineal red pigment and color fixative was tested by:
weighing 0.1 g and 98.9 g of anhydrous citric acid and 1 g of the mixture of the cochineal color and the color fixative, and uniformly stirring to obtain an acidic cochineal solution.
The absorbance A1 was measured at 520nm with a spectrophotometer, the cochineal acid solution was kept at a constant temperature for 2 hours in a water bath at 90 ℃ and the absorbance A2 was measured at 520nm with a spectrophotometer, resulting in a pigment retention of A2/A1 at 100%.
The pigment retention of the four samples was tested as in table 1.
TABLE 1 pigment Retention
Examples
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Example 1
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Example 2
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Example 3
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Example 4
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Retention rate of pigment
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91.4%
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90.7%
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88.2%
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87.6% |
The detection result shows that the natural antioxidants of tea polyphenol and papaya flavone selected by the invention have a synergistic effect, and the thermal stability of cochineal is obviously improved.
Although the present invention has been described in detail by the above examples, such description is for illustrative purposes only and should not be construed as limiting the spirit and scope of the present invention as claimed in the appended claims. In addition, the above-described embodiments are for illustrative purposes only, and various modifications may be made thereto, and those skilled in the art will appreciate that the modifications also fall within the scope of the present invention.