Production method of beet red pigment with adjustable color difference b

Abstract

The invention discloses a production method of a beet red pigment with an adjustable color difference b, which comprises the following steps: 1) cleaning fresh red beet, crushing into granules, uniformly mixing the granules with an extraction solvent, extracting, adding food-grade phosphoric acid during extraction to adjust the pH value of an extraction system, and performing solid-liquid separation on an extracting solution for multiple times to obtain a purified solution; (2) adsorbing the purified liquid by using a macroporous resin column until the resin column starts to color, washing the column by using pure water which is two times of the volume of resin in the resin column, and eluting by using an ethanol eluent containing sodium hydroxide to obtain beet red eluent; and 3) carrying out low temperature concentration on the beet red eluent to obtain TC refined paste, and carrying out spray drying to obtain beet red pigment powder.The method can be used for preparing a beet red product with a color difference b value of-10-40.

Description

Technical Field

[0001] This application relates to the field of bio-extraction technology, and in particular to a method for producing beet red pigment with adjustable color difference b. Background Technology

[0002] With the development of the food industry, food colorings are increasingly concerned with their safety, naturalness, and performance in improving food taste, enhancing product quality, and meeting processing requirements. Beetroot red, as a food additive, is widely used in the food and health product industries due to its natural and attractive color and broad application range. Currently, many domestic manufacturers have achieved large-scale industrial extraction of beetroot red pigment. However, most manufacturers offer products with relatively limited color options, which cannot fully meet market demands.

[0003] Existing technologies for producing or preparing beet red in different shades are as follows: CN201210565156.5 discloses a method for changing the color of beet red by adding a color modifier. This method introduces many additives, resulting in a high content of other additives remaining in the product, limiting its application and making it unsuitable for use in food or as a natural pigment. CN201210154734.6 discloses a method for preparing beet red pigments in multiple shades. This method utilizes a specific resin for adsorption, followed by elution with four different concentrations of ethanol solutions to obtain beet red pigments in different shades. This method uses a large amount of ethanol, requires resin adsorption and elution, and involves complex operations. The process is complex, the yield is low, and ethanol loss is significant. CN202211358098.9 discloses a method for producing yellowish beet red, which uses two specific tandem resins for adsorption, followed by elution with ethanol. The eluent is then concentrated to obtain products with different hues. However, it is difficult to consistently control the product to obtain the desired hue during production, and the process is complex, requiring specific resins and resulting in high production costs. Furthermore, the addition of 0.8‰ of the weight of beet sugar as an antioxidant is necessary to prevent hue distortion, indicating poor stability of the obtained pigment and the risk of antioxidant residue, which limits the application of this type of pigment in high-requirement fields such as food.

[0004] The information disclosed in the background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] This application addresses the aforementioned technical problems by providing a method for producing beetroot red pigment with adjustable color difference (b). This method controls the pH value during extraction, utilizing the solubility and color development of other hue components in beetroot red pigment at different pH values. This allows for the controllable acquisition of beetroot red pigment products with different hues during extraction. Simultaneously, the addition of food-grade sodium hydroxide to the eluent effectively improves the elution rate and product stability. This invention allows for the artificially controlled and stable production of beetroot red products with desired hues. Large-scale production verification has demonstrated its high feasibility and stability.

[0006] This application provides a method for producing beet red pigment with adjustable color difference b, comprising the following steps: 1) Fresh red beets are washed and crushed into granules. The granules are mixed evenly with the extraction solvent and then extracted. The extraction solvent is pure water. Food-grade phosphoric acid is added to adjust the pH value of the extraction system before extraction. The extract is purified by multiple solid-liquid separations. 2) Use a macroporous resin column to adsorb the purified solution until the resin column starts to turn pink. Then wash the column with twice the volume of pure water. Elute with ethanol to obtain beetroot red eluent. Preparation of ethanol eluent: Add food-grade sodium hydroxide to ethanol as ethanol eluent. 3) The beet red eluent was concentrated at low temperature to obtain TC extract, and spray-dried to obtain beet red pigment powder; When the pH of the extraction system is below 3.0 and the amount of food-grade sodium hydroxide added in the ethanol eluent is 0.4‰ of the amount of ethanol, the target color difference b value range of the beet red pigment powder is between -10 and -2. When the pH value of the extraction system is between 3.0 and 3.5, and the amount of food-grade sodium hydroxide added in the ethanol eluent is 0.35‰ of the amount of ethanol, the target color difference b value of the beet red pigment powder is between 2 and 6. When the pH value of the extraction system is between 3.5 and 4.0, and the amount of food-grade sodium hydroxide added in the ethanol eluent is 0.3‰ of the amount of ethanol, the target color difference b value of the beet red pigment powder is between 8 and 18. When the pH of the extraction system is between 4.0 and 5.0, and the amount of food-grade sodium hydroxide added to the ethanol eluent is 0.2‰ of the amount of ethanol, the target color difference b value of the beet red pigment powder is between 20 and 40.

[0007] Preferably, the raw material and the extraction solvent are mixed at a mass ratio of 1:3 to 5 for extraction.

[0008] Preferably, the extraction conditions are as follows: extraction is carried out in a multi-functional extraction tank for 1 hour.

[0009] Preferably, the solid-liquid separation in step 1 involves the extract being sequentially separated by a horizontal centrifuge, filtered through an 80-mesh nylon filter, separated by a disc separator, and then finely filtered with diatomaceous earth.

[0010] Preferably, the ethanol concentration of the ethanol eluent used is 50-60%.

[0011] Preferably, when the pH of the extraction system is below 3.0 and the amount of food-grade sodium hydroxide added in the ethanol eluent is 0.4‰ of the amount of ethanol used, the target color difference b value of the beet red pigment powder is -8.78. When the pH value of the extraction system is between 3.0 and 3.5, and the amount of food-grade sodium hydroxide added in the ethanol eluent is 0.35‰ of the amount of ethanol, the target color difference b value of the beet red pigment powder is 3.62. When the pH value of the extraction system is between 3.5 and 4.0, and the amount of food-grade sodium hydroxide added in the ethanol eluent is 0.3‰ of the amount of ethanol, the target color difference b value of the beet red pigment powder is 15.42. When the pH of the extraction system is between 4.0 and 5.0, and the amount of food-grade sodium hydroxide added to the ethanol eluent is 0.2‰ of the amount of ethanol, the target color difference b value of the beet red pigment powder is 31.08.

[0012] The beneficial effects that this application can produce include: 1) The method for producing beet red pigment with adjustable color difference (b) provided in this application does not require the use of specific resins, uses a small amount of ethanol throughout the process, and has a simple procedure. Using fresh red beets as raw material, the raw material is crushed, extracted, the extract is refined with resin, eluted, concentrated at low temperature, and spray-dried to obtain products with different color tones. This method can prepare products with color difference (b) values ​​ranging from -10 to 40. No other food additives are introduced. During the raw material extraction process, different color tones can be obtained by controlling the pH value of the extraction process. The extract is then refined to achieve the purpose of preparing multi-color beet red pigment. Adding sodium hydroxide to the ethanol eluent in the refining process can improve product stability, effectively maintain the product color, and is suitable for large-scale production by various manufacturing enterprises, while also controlling product quality.

[0013] 2) The production method of beet red pigment with adjustable color difference b provided in this application is based on the applicant's research on the performance of pigment components in red beets. Beet red pigment contains beet anthocyanins, which are purplish-red, and betaine flavonoids, which are yellow. Through research and practical verification, it has been found that the solubility of betaine flavonoids, which are yellow, varies greatly in aqueous solutions with different pH values. When the pH value is less than 3.0, beet anthocyanins have the highest solubility, while betaine flavonoids are difficult to dissolve. Therefore, beet red appears purplish-red in such solutions. The color difference b-value is approximately -10 to -2. At pH values ​​of 3 to 3.5, the most soluble pigment component is betalain, while betalain is slightly soluble, so betalain appears red, with a color difference b-value of approximately 2 to 6. At pH values ​​of 3.5 to 4, the most soluble pigment component is betalain, while betalain is soluble, so betalain appears red, with a color difference b-value of approximately 8 to 18. At pH values ​​of 4 to 5, both components in betalain are easily soluble, so betalain appears orange-red, with a color difference b-value of approximately 20 to 40. This allows for the acquisition of different hues of betalain pigment by adjusting the pH of the solution system. Detailed Implementation

[0014] The present invention will be further described in detail below with reference to embodiments, but this does not limit the present invention in any way. Any modifications or improvements made based on the teachings of the present invention shall fall within the protection scope of the present invention.

[0015] Unless otherwise specified, all materials and instruments used in the following embodiments were obtained through commercial channels; and all detection methods used are existing methods unless otherwise specified.

[0016] Example 1 1. Red beet raw material crushing: 6 tons of fresh red beets are washed with a washing device and then crushed with a crusher to obtain particles with a particle size ≤0.5cm. The particles are then transported to a multi-functional extraction tank with the extraction solvent for extraction. 2. Extraction: Add all the extraction solvent to the multi-functional extraction tank for extraction. The extraction solvent is 18 tons of pure water (the mass ratio of raw material to extraction solvent is 1:3). Add food-grade phosphoric acid to control the pH of the extraction system to 2.5-2.7. After stirring for 1 hour, separate the residue and liquid. Discard the residue and collect the filtrate. Separate the filtrate using a horizontal centrifuge, filter it through an 80-mesh nylon screen, a disc separator, and a diatomaceous earth precision filter to obtain the purified liquid. 3. Resin purification: Use a macroporous resin column to adsorb the purified solution until the resin column starts to turn pink. Then, wash the column with twice the volume of pure water. After washing, elute with 50% ethanol. Add food-grade sodium hydroxide to the ethanol solution at a concentration of 0.4‰ of the ethanol volume. Collect the eluent with an ethanol concentration of 10 degrees or higher as the beetroot red eluent. 4. Low-temperature concentration: The beet red eluent is concentrated using a low-temperature concentration device to obtain a concentrated eluent paste called TC extract. The concentration temperature is set at 35-40℃ and the vacuum pressure is 0.06-0.08 MPa. 5. Spray drying: The TC extract was spray-dried to obtain beet red pigment powder. The inlet temperature was set to 175°C, the outlet temperature to 85°C, and the feed flow rate to 18%.

[0017] The product was tested according to the requirements of beetroot red GB1886.111-2015, and the relevant indicators were analyzed. The results are shown in the table below: As can be seen from the table above, when the pH of the extraction system is below 3.0 and the amount of food-grade sodium hydroxide added in the ethanol eluent is 0.4‰, the color difference b value of the obtained beet red pigment powder is -8.78, which is between -10 and -2.

[0018] Example 2 The difference from Example 1 is as follows: The pH of the extraction system in step 2 is 3.1–3.3; In step 3, the amount of food-grade sodium hydroxide added to the ethanol eluent is 0.35‰ of the amount of ethanol used.

[0019] Color value was tested according to GB1886.111-2015, and relevant product indicators were analyzed. The results are shown in the table below: As shown in the table above, when the pH of the extraction system is 3.1 to 3.3 and the amount of food-grade sodium hydroxide added in the ethanol eluent is 0.35‰, the color difference b value of the obtained beet red pigment powder is 3.62, which is between 2 and 6.

[0020] Example 3 The difference from Example 1 is as follows: The pH of the extraction system in step 2 is 3.5–4.0; In step 3, the amount of food-grade sodium hydroxide added to the ethanol eluent is 0.3‰ of the amount of ethanol used.

[0021] Color value was tested according to GB1886.111-2015, and product color difference and other indicators were analyzed. The results are shown in the table below: As can be seen from the table above, when the pH of the extraction system is 3.5 to 4.0 and the amount of food-grade sodium hydroxide added in the ethanol eluent is 0.3‰, the color difference b value of the obtained beet red pigment powder is 15.42, which is between 8 and 18.

[0022] Example 4 The difference from Example 1 is as follows: The pH of the extraction system in step 2 is 4.4–4.6; In step 3, the amount of food-grade sodium hydroxide added to the ethanol eluent is 0.2‰ of the amount of ethanol used.

[0023] Color value was tested according to GB1886.111-2015, and relevant product indicators were analyzed. The results are shown in the table below: As shown in the table above, when the pH of the extraction system is 4.4 to 4.6 and the amount of food-grade sodium hydroxide added in the ethanol eluent is 0.2‰, the color difference b value of the obtained beet red pigment powder is 31.08, which is between 20 and 40.

[0024] Example 5 The difference from Example 1 is as follows: The pH of the extraction system in step 2 is 4.4–4.6, and the mass ratio of raw material to extraction solvent is 1:4. In step 3, the amount of food-grade sodium hydroxide added to the ethanol eluent is 0.2‰ of the amount of ethanol used, and the ethanol concentration is 55%.

[0025] Color value was tested according to GB1886.111-2015, and relevant product indicators were analyzed. The results are shown in the table below: As shown in the table above, when the pH of the extraction system is 4.4 to 4.6, the mass ratio of raw material to extraction solvent is 1:4, the amount of food-grade sodium hydroxide added in the ethanol eluent is 0.2‰, and the ethanol concentration is 55%, the color difference b value of the obtained beet red pigment powder is 32.23, which is between 20 and 40.

[0026] Example 6 The difference from Example 1 is as follows: The pH of the extraction system in step 2 is 4.4–4.6, and the mass ratio of raw material to extraction solvent is 1:5. In step 3, the amount of food-grade sodium hydroxide added to the ethanol eluent is 0.2‰ of the amount of ethanol used, and the ethanol concentration is 60%.

[0027] Color value was tested according to GB1886.111-2015, and relevant product indicators were analyzed. The results are shown in the table below: As shown in the table above, when the pH of the extraction system is 4.4 to 4.6, the mass ratio of raw material to extraction solvent is 1:5, the amount of food-grade sodium hydroxide added in the ethanol eluent is 0.2‰, and the ethanol concentration is 55%, the color difference b value of the obtained beet red pigment powder is 32.11, which is between 20 and 40.

[0028] As can be seen from Examples 1 to 6, the method provided by the present invention can prepare beet red products with different hues (color difference b value), and the various indicators of the products meet the product requirements. The process is simple, does not require specific resins or other materials, and does not introduce other food additives.

[0029] This invention discloses the effect of controlling the pH value of the extraction system solution on controlling the color tone (color difference) of the product, and verifies it through production implementation. The verification results show that this invention can prepare products with different color tones.

[0030] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for producing beet red pigment with adjustable color difference b, characterized in that, Includes the following steps: 1) Fresh red beets are washed and crushed into granules. The granules are mixed evenly with the extraction solvent and then extracted. The extraction solvent is pure water. Food-grade phosphoric acid is added to adjust the pH value of the extraction system before extraction. The extract is purified by multiple solid-liquid separations. 2) Use a macroporous resin column to adsorb the purified solution until the resin column starts to turn pink. Then wash the column with twice the volume of pure water. Elute with ethanol to obtain beetroot red eluent. Preparation of ethanol eluent: Add food-grade sodium hydroxide to ethanol as ethanol eluent. 3) The beet red eluent was concentrated at low temperature to obtain TC extract, and spray-dried to obtain beet red pigment powder; When the pH of the extraction system is below 3.0 and the amount of food-grade sodium hydroxide added in the ethanol eluent is 0.4‰ of the amount of ethanol, the target color difference b value range of the beet red pigment powder is between -10 and -2. When the pH value of the extraction system is between 3.0 and 3.5, and the amount of food-grade sodium hydroxide added in the ethanol eluent is 0.35‰ of the amount of ethanol, the target color difference b value of the beet red pigment powder is between 2 and 6. When the pH value of the extraction system is between 3.5 and 4.0, and the amount of food-grade sodium hydroxide added in the ethanol eluent is 0.3‰ of the amount of ethanol, the target color difference b value of the beet red pigment powder is between 8 and 18. When the pH of the extraction system is between 4.0 and 5.0, and the amount of food-grade sodium hydroxide added to the ethanol eluent is 0.2‰ of the amount of ethanol, the target color difference b value of the beet red pigment powder is between 20 and 40.

2. The method for producing beet red pigment with adjustable color difference b according to claim 1, characterized in that, The raw materials and extraction solvent are mixed at a mass ratio of 1:3~5 for extraction.

3. The method for producing beet red pigment with adjustable color difference b according to claim 1, characterized in that, The extraction conditions were as follows: extraction was carried out in a multi-functional extraction vessel for 1 hour.

4. The method for producing beet red pigment with adjustable color difference b according to claim 1, characterized in that, The solid-liquid separation in step 1 involves the extract being sequentially separated by a horizontal centrifuge, filtered through an 80-mesh nylon filter, separated by a disc separator, and then finely filtered with diatomaceous earth.

5. The method for producing beet red pigment with adjustable color difference b according to claim 1, characterized in that, The ethanol eluent used has an ethanol concentration of 50-60%.

6. The method for producing beet red pigment with adjustable color difference b according to claim 1, characterized in that, When the pH of the extraction system is below 3.0 and the amount of food-grade sodium hydroxide added in the ethanol eluent is 0.4‰ of the amount of ethanol, the target color difference b value of the beet red pigment powder is -8.

78. When the pH value of the extraction system is between 3.0 and 3.5, and the amount of food-grade sodium hydroxide added in the ethanol eluent is 0.35‰ of the amount of ethanol, the target color difference b value of the beet red pigment powder is 3.

62. When the pH value of the extraction system is between 3.5 and 4.0, and the amount of food-grade sodium hydroxide added in the ethanol eluent is 0.3‰ of the amount of ethanol, the target color difference b value of the beet red pigment powder is 15.

42. When the pH of the extraction system is between 4.0 and 5.0, and the amount of food-grade sodium hydroxide added to the ethanol eluent is 0.2‰ of the amount of ethanol, the target color difference b value of the beet red pigment powder is 31.08.

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