Gel composition of red cabbage extract with formaldehyde discoloration properties

Abstract

The present application discloses a kind of purple cabbage extract gel compositions with formaldehyde discoloring performance, the purple cabbage extract gel compositions include the following components: 0.1-1% mass fraction of purple cabbage extract, 0.3-3% mass fraction of hydroxylamine salt, 0.5-5% mass fraction of gelling agent and and the rest mass fraction of water.The purple cabbage extract gel compositions can react to remove formaldehyde pollutants in air, while producing obvious color change, can be used to absorb and indicate formaldehyde.Compared with prior art, the purple cabbage extract gel compositions of the present application are based on natural extracts, have the beneficial effects of being friendly and safe to home environment, being useful for air purification, being sensitive to formaldehyde discoloring and having simple and mild preparation process.

Description

Technical Field

[0001] This invention belongs to the field of daily chemical air purification products, specifically relating to a purple cabbage extract gel composition with formaldehyde color-changing properties, its preparation method, application, and a formaldehyde color-changing indicator containing the same. Background Technology

[0002] Formaldehyde is a colorless gas with a strong, pungent odor. Short-term exposure to high concentrations of formaldehyde can irritate the skin, mucous membranes, and respiratory tract, potentially causing symptoms such as tearing, sore throat, cough, shortness of breath, and difficulty breathing. Long-term exposure to low doses of formaldehyde can cause chronic respiratory diseases, nasopharyngeal carcinoma, colon cancer, brain tumors, menstrual disorders, gene mutations in cell nuclei, DNA single-strand cross-linking, DNA-protein cross-linking, inhibition of DNA damage repair, pregnancy complications, neonatal chromosomal abnormalities, leukemia, and decreased memory and intelligence in adolescents. Formaldehyde ranks second on my country's list of priority controlled toxic chemicals and has been identified by the World Health Organization as a carcinogen and teratogen. It is a recognized allergen and a potential strong mutagen.

[0003] Formaldehyde removal can be achieved through activated carbon adsorption, photocatalysis, catalytic oxidation, and physical ventilation. In recent years, hydrogel materials based on natural extracts for air purification have been gradually introduced. For example, CN105770945A discloses an enzyme-based formaldehyde-removing, deodorizing, and odor-neutralizing agent prepared from the culture broth of microorganisms such as *Isasaccharomyces orientalis*, *Lactobacillus paracasei*, *Pediococcus pentosaceus*, and baker's yeast. CN101804215A provides a method for obtaining a formaldehyde-capturing gel by amino-derived modification of polysaccharides in the hydrolysate of aloe vera gel using natural plant aloe vera as raw material, followed by compounding with amino-modified collagen. CN111974364A provides a rapid and long-lasting air-purifying gel particle and its preparation method, the gel particle including the following raw materials: lemon oil, aloe vera extract, rose oil extract, etc., which can adsorb formaldehyde within 10 minutes at room temperature. However, the above-mentioned natural extract hydrogels lack visual indication function for formaldehyde, a typical indoor air pollutant, which is not conducive to its widespread use in households.

[0004] CN111701439A discloses a formaldehyde-removing color-changing gel with visual appeal. It works by reacting an alkaline alkaline amine compound with formaldehyde, causing a change in the pH of the gel system and resulting in a color change in an acid-base indicator, thus achieving the purpose of formaldehyde removal through color change. However, the alkaline amine compound used in this gel has a strong odor and is not suitable for indoor air purification.

[0005] Therefore, our persistent research goal is to develop a highly sensitive aldehyde-induced color-changing gel that can react with formaldehyde using natural, non-toxic raw materials. Summary of the Invention

[0006] In view of this, the purpose of this invention is to provide a purple cabbage extract gel composition with formaldehyde color-changing properties, so as to solve the technical problems of poor sensitivity of formaldehyde purification gels in the prior art and their own odor, which makes them unsuitable for home use.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] A purple cabbage extract gel composition with formaldehyde-changing properties, the purple cabbage extract gel composition comprising the following components: 0.1-1% by mass of purple cabbage extract, 0.3-3% by mass of hydroxylamine salt, 0.5-5% by mass of gelling agent, and the balance by mass of water.

[0009] Furthermore, the purple cabbage extract gel composition comprises the following components in the indicated mass fractions: 0.1-1% purple cabbage extract, 0.3-3% hydroxylamine salt, 0.5-5% gelling agent, and the balance being water.

[0010] Furthermore, the purple cabbage extract contains anthocyanins at a mass content of ≥5%, preferably 5-30%.

[0011] Furthermore, the hydroxylamine salt is one or more of hydroxylamine sulfate, hydroxylamine hydrochloride, hydroxylamine phosphate, hydroxylamine carboxylate, hydroxylamine acetate, or hydroxylamine oxalate, preferably one or more of hydroxylamine sulfate, hydroxylamine hydrochloride, or hydroxylamine phosphate.

[0012] Furthermore, the gelling agent is one or more of agar, polyvinyl alcohol, gelatin, gellan gum, carrageenan, hyaluronic acid, hydroxypropyl cellulose, or soluble starch, preferably one or more of agar, polyvinyl alcohol, and hyaluronic acid.

[0013] Furthermore, the preparation method of the purple cabbage extract gel composition is as follows: first, the gelling agent is pre-dissolved in water at 20-90°C and stirred until clear; then, purple cabbage extract and hydroxylamine salt are added and mixed, and stirred evenly to obtain the gel composition.

[0014] Furthermore, the purple cabbage extract gel composition provided by the present invention can react with formaldehyde in the air, remove formaldehyde pollutants from the air, and produce a significant color change, so it can be used to absorb and indicate formaldehyde pollutants.

[0015] The present invention also provides a formaldehyde color-changing indicator, the indicator comprising the above-mentioned purple cabbage extract gel composition having formaldehyde color-changing properties, wherein the indicator changes color after absorbing formaldehyde, generally from cyan or green to purple or red, indicating the presence of formaldehyde in the air.

[0016] In this invention, purple cabbage (Brassica oleracea L. var. capitala f. rubra), also known as red cabbage or crimson cabbage, is commonly called purple cabbage. Purple cabbage leaves are rich in anthocyanins (anthocyanins), the main components of which are glycosides and acylated compounds of cyanidin [Food Chemistry, 2008, 109:219]. Numerous studies have shown that anthocyanins possess strong antioxidant activity. Anthocyanins can accelerate microvascular circulation to reduce free radical damage to the eyes and can also help activate and enhance the regenerative capacity of rhodopsin. Extraction methods for purple cabbage rich in anthocyanins include pressing, enzymatic extraction, solvent extraction, microwave-assisted extraction, ultrasound-assisted extraction, and supercritical CO2 extraction [food and bioproducts processing 90(2012)615–623]. Purple cabbage extract is commercially available.

[0017] The core component of purple cabbage extract, anthocyanin, contains a 2-phenylbenzopyranium salt unit substituted with a polyphenolic hydroxyl group, exhibiting acid-base isomerism. This involves tautomerism between two different conjugated structures: the pyranium form (purple-red) and the quinone isomer (blue-green). Based on this, the applicant discovered that combining it with hydroxylamine salts produces an aldehyde-induced color change effect. Specifically, formaldehyde first reacts with the hydroxylamine salt to release a proton, which then binds to the blue-green quinone form of anthocyanin, transforming it into the purple-red pyranium form (e.g., ...). Figure 1 As shown), thus achieving the aldehyde-induced color-changing function (as shown). Figure 2 (As shown).

[0018] This invention, based on natural product chemistry and formulation science, abandons the single-substance approach used in traditional detection methods. Addressing the convenience requirements of home use, it cleverly incorporates the acid-base color-changing properties of anthocyanins in purple cabbage extract, and introduces an acid proton donor—hydroxylamine salt—to create a gel-type formaldehyde detection indicator. Compared to existing technologies, this invention offers the following advantages: the gel composition is based on natural extracts, making it environmentally friendly and safe; it has excellent formaldehyde absorption performance, can be used for air purification, is highly sensitive to formaldehyde color changes, and has a simple and gentle preparation process. It effectively solves the technical problems of poor sensitivity and unpleasant odor in existing formaldehyde purification gels. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the reaction between anthocyanins and formaldehyde in a purple cabbage extract gel composition.

[0020] Figure 2 These are comparative photographs showing the formaldehyde color change in Example 1 and Comparative Example 1. Detailed Implementation

[0021] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way.

[0022] It should be noted that, for those skilled in the art, several changes and improvements can be made without departing from the concept of the present invention, including any combination of the various examples.

[0023] Example 1

[0024] A purple cabbage extract gel composition with formaldehyde-sensitive color-changing properties, comprising the following components: 0.5% by mass of purple cabbage extract (commercially available, anthocyanin content 10%), 1% by mass of hydroxylamine sulfate, 1% by mass of agar and 97.5% by mass of water.

[0025] The preparation method is as follows: First, agar is pre-dissolved in water at 70°C and stirred until clear. Then, purple cabbage extract and hydroxylamine sulfate are added and mixed, and stirred evenly to obtain the gel composition.

[0026] When the gel composition was placed in an air detection chamber at a formaldehyde concentration of 10 mg / L, its color changed from bluish-green to purplish-red after 10 minutes (see appendix). Figure 2 (Left picture) It achieved a significant formaldehyde color change effect.

[0027] Example 2

[0028] A purple cabbage extract gel composition with formaldehyde-sensitive color-changing properties, comprising the following components: 0.1% by mass of purple cabbage extract (commercially available, anthocyanin content 25%), 0.3% by mass of hydroxylamine hydrochloride, 5% by mass of polyvinyl alcohol, and 94.6% by mass of water.

[0029] The preparation method is as follows: Polyvinyl alcohol is first pre-dissolved in water at 90°C and stirred until clear. Then, purple cabbage extract and hydroxylamine sulfate are added and mixed, and stirred evenly to obtain the gel composition.

[0030] When the gel composition was placed in an air detection chamber, under the condition of a formaldehyde concentration of 10 mg / L, the color of the gel composition changed from light blue to pink after 10 minutes, achieving a significant formaldehyde color change effect.

[0031] Example 3

[0032] A purple cabbage extract gel composition with formaldehyde-sensitive color-changing properties, comprising the following components: 1% by mass of purple cabbage extract (commercially available, anthocyanin content 5%), 3% by mass of hydroxylamine phosphate, 0.5% by mass of hyaluronic acid, and 95.5% by mass of water.

[0033] The preparation method is as follows: First, hyaluronic acid is pre-dissolved in water at 20°C and stirred until clear. Then, purple cabbage extract and hydroxylamine sulfate are added and mixed, and stirred evenly to obtain the gel composition.

[0034] When the gel composition was placed in an air detection chamber, under the condition of a formaldehyde concentration of 10 mg / L, the color of the gel composition changed from cyan to red after 10 minutes, achieving a significant formaldehyde color change effect.

[0035] Comparative Example 1

[0036] A purple cabbage extract gel composition with formaldehyde-sensitive color-changing properties, comprising the following components: 0.5% by mass of purple cabbage extract (commercially available, anthocyanin content 10%), 1% by mass of agar, and 98.5% by mass of water.

[0037] The preparation method is as follows: First, agar is pre-dissolved in water at 70°C and stirred until clear. Then, purple cabbage extract is added and mixed, and stirred evenly to obtain the gel composition.

[0038] When the gel composition was placed in an air detection chamber at a formaldehyde concentration of 10 mg / L, its blue-green color remained unchanged for 100 minutes. (See attached image.) Figure 2 The image on the right shows the color-changing effect without formaldehyde.

[0039] It is evident that in a system without hydroxylamine salts, the green quinone form of anthocyanins cannot undergo a color change reaction to convert into a purplish-red pyranonium form, thus failing to achieve the function of absorbing and indicating formaldehyde.

[0040] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A purple cabbage extract gel composition with formaldehyde-sensitive color-changing properties, characterized in that, The purple cabbage extract gel composition comprises the following components: 0.1-1% by mass of purple cabbage extract, 0.3-3% by mass of hydroxylamine salt, 0.5-5% by mass of gelling agent, and the balance being water; wherein the purple cabbage extract contains anthocyanins at a mass fraction ≥ 5%; The preparation method of the formaldehyde-changing purple cabbage extract gel composition includes: first, pre-dissolving the gelling agent in water at 20-90°C, stirring until clear, then adding purple cabbage extract and hydroxylamine salt, mixing, and stirring evenly to obtain the gel composition; The hydroxylamine salt is one or more of hydroxylamine sulfate, hydroxylamine hydrochloride, hydroxylamine phosphate, hydroxylamine carbamate, hydroxylamine acetate, or hydroxylamine oxalate.

2. The purple cabbage extract gel composition with formaldehyde-changing properties according to claim 1, characterized in that, The purple cabbage extract gel composition comprises the following components in the indicated mass fractions: 0.1-1% purple cabbage extract, 0.3-3% hydroxylamine salt, 0.5-5% gelling agent, and the balance being water.

3. The purple cabbage extract gel composition with formaldehyde-changing properties according to claim 1, characterized in that, The gelling agent is one or more of agar, polyvinyl alcohol, gelatin, gellan gum, carrageenan, hyaluronic acid, hydroxypropyl cellulose, or soluble starch.

4. The method for preparing the formaldehyde-sensitive purple cabbage extract gel composition according to any one of claims 1 to 3, characterized in that, The method includes: first, pre-dissolving the gelling agent in water at 20-90°C, stirring until clear, then adding purple cabbage extract and hydroxylamine salt, mixing, and stirring evenly to obtain the gel composition.

5. The use of the purple cabbage extract gel composition with formaldehyde-changing properties according to any one of claims 1 to 3 in the absorption and indication of formaldehyde.

6. A formaldehyde color-changing indicator, the indicator comprising the purple cabbage extract gel composition with formaldehyde color-changing properties as described in any one of claims 1 to 3, wherein the indicator changes color after absorbing formaldehyde.

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