PH and biogenic amine dual-response sensing material and application thereof
By using ethyl cellulose and polyethylene glycol as substrates, homemade DL-mandelic acid-based complex nanocrystals as pH-responsive indicators, a sensing material with both pH and bioamine dual response was developed, solving the complexity and cost of detecting freshness of meat foods in the prior art, and achieving high performance, low cost and real-time monitoring effects.
Patent Information
- Application Number
- CN202411956719.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-29
- Publication Date
- 2025-04-04
AI Technical Summary
The prior art has problems such as time-consuming and labor-intensive testing, expensive equipment, complex operation, and inability to detect real-time detection in the detection of the freshness of meat foods. The traditional natural pigments have the disadvantages of complex extraction process, high cost and poor stability.
Using ethyl cellulose and polyethylene glycol as the matrix, homemade DL-mandelic acid-based complex nanocrystals as pH-responsive indicators, a sensing material with dual responses between pH and bioamine was developed.
It has achieved high-performance, low-cost, real-time monitoring of food freshness, and has a wide application value in smart food packaging, sensing materials, ammonia detection, environmental monitoring and safety.
Smart Images
Figure CN119751987A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of polymer composite materials, and in particular relates to a sensing material with dual response to pH and biogenic amines and its application. Background Art
[0002] With the development of modern food industry, packaged meat products have occupied an important position in the market. However, since meat products are encapsulated in packaging, it is difficult for consumers to evaluate their freshness through sensory evaluation. Traditional food freshness detection technologies include gas chromatography, liquid chromatography, electrochemical analysis and microbiological testing, but these detection technologies have the disadvantages of being time-consuming and labor-intensive, requiring expensive equipment, complicated operation, requiring professional operation, unable to detect in real time, and unable to transmit information instantly, making it difficult to meet the requirements of simple, fast and low-cost detection. It is worth mentioning that packaged meat products are prone to deterioration during storage, accompanied by the gradual release of volatile biogenic amines such as dimethylamine, resulting in an increase in pH value. Therefore, sensing materials with pH or biogenic amine response functions have attracted widespread attention in the fields of smart packaging because they can produce reliable color reactions to indicate the deterioration of meat products in storage. At present, many natural pigments mainly extracted from plants have been used as pH-responsive indicators for the manufacture of smart sensing membrane materials for food safety monitoring. However, these natural pigments extracted from plants usually have the disadvantages of relatively complex extraction processes, high costs, and poor stability under light and heat conditions. Therefore, there is still a need to create a new pH / biogenic amine responsive indicator material with high stability, low cost and easy synthesis. On the other hand, when preparing pH / biogenic amine responsive smart sensing materials, bio-based polymers (such as starch, cellulose, sodium alginate, etc.) are often used as the matrix of smart sensing film materials due to their excellent film-forming properties and environmental friendliness. However, these bio-based polymers (such as starch, cellulose, sodium alginate, etc.) usually have poor ductility and toughness, which is not conducive to their practical application in smart sensing materials. Based on this, the present invention uses ethyl cellulose and polyethylene glycol as the matrix and a homemade pH-responsive indicator as the filler to develop a simple, economical, high-performance, low-cost, wide pH response range, fast response speed, biodegradable, and real-time monitoring of food freshness. The new tough sensing material has the characteristics of widening its application in the fields of smart food packaging, sensing materials, ammonia detection, environmental monitoring and safety. Summary of the invention
[0003] The purpose of the present invention is to address the deficiencies of the prior art, and to provide a high-performance sensing material with dual responses to both pH and biogenic amines, using ethyl cellulose and polyethylene glycol as a matrix and a homemade pH-responsive indicator as a filler. The sensing material has the characteristics of a wide pH response range, fast response speed, biodegradability, and toughness, and can effectively monitor the freshness of meat food in real time. The preparation process is simple and environmentally friendly, and the cost is low, which is suitable for mass production.
[0004] The technical solution of the present invention:
[0005] The pH and biogenic amine dual-responsive sensing material is characterized by being composed of the following components in parts by weight: 120 parts of ethyl cellulose, 30 parts of polyethylene glycol, and 1.5-6 parts of a pH-responsive indicator.
[0006] The pH-responsive indicator is a DL-mandelic acid-based complex nanocrystal, and its preparation method comprises the following steps:
[0007] (1) Weigh 15.22 parts of DL-mandelic acid and dissolve it in 5000 parts of ethanol. Stir it at room temperature for 30 min to dissolve it, and obtain a uniform DL-mandelic acid solution for later use.
[0008] (2) Weigh 13.90 parts of ferrous sulfate heptahydrate and dissolve it in 1000 parts of deionized water. Stir it at room temperature for 10 minutes to dissolve it, and obtain a uniform ferrous sulfate solution for later use.
[0009] (3) The ferrous sulfate solution obtained in step (2) is added dropwise to the DL-mandelic acid solution obtained in step (1), and the mixture is stirred at room temperature for 20 min. The mixture is then centrifuged, washed, and vacuum dried to obtain a pH-responsive indicator.
[0010] The method for preparing the sensing material with dual response to pH and biogenic amines comprises the following steps:
[0011] (1) Add 120 parts of ethyl cellulose and 30 parts of polyethylene glycol to 3000 parts of ethanol, stir at room temperature for 10 min, and then stir in a water bath at 55 °C for 30 min to completely dissolve them to obtain a uniform blend solution, cool to room temperature, and set aside;
[0012] (2) Disperse 1.5-6 parts of pH-responsive indicator in 500 parts of ethanol and stir for 20 min to obtain a uniform dispersion for later use;
[0013] (3) adding the dispersion obtained in step (2) to the blended solution obtained in step (1), and stirring at room temperature for 30 min to obtain a uniform film-forming solution for standby use;
[0014] (4) The film-forming solution obtained in step (3) is poured into a flat-bottomed glass dish and dried in a vacuum oven at 55° C. for 48 h to obtain a sensing material with dual response to pH and biogenic amines.
[0015] The present invention has the beneficial effects:
[0016] The pH and biogenic amine dual-responsive sensing material prepared by the present invention is simple, economical, and has the properties of high performance, low cost, no pollution, wide pH response range, fast response speed, long duration, biodegradability, toughness, ultraviolet light blocking, and the ability to achieve real-time monitoring. The deterioration of meat foods such as shrimp during storage can be monitored efficiently, in real time, and intuitively through the color change of the sensing material. The sensing material has a simple preparation process, is environmentally friendly, low cost, and is suitable for large-scale production. It has a wide range of application values in the fields of pH / biogenic amine responsive color-changing materials, ammonia responsive color-changing materials, food packaging, ultraviolet light protection, environmental monitoring and safety, etc. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 This is a scanning electron microscope image of the pH-responsive indicator involved in the present invention;
[0018] Figure 2 This is a physical photo of the sensing material sample prepared in Example 3 of the present invention. DETAILED DESCRIPTION
[0019] The present invention is described in detail below through examples. It is necessary to point out that the examples are only used to further illustrate the present invention and cannot be understood as limiting the scope of the present invention. Those skilled in the art can make some non-essential improvements and adjustments based on the contents of the present invention. The parts of the raw materials are all parts by weight unless otherwise specified.
[0020] In the specific embodiments and comparative example formulas, DL-mandelic acid is an analytically pure reagent provided by Shanghai Yuanye Biotechnology Co., Ltd., ferrous sulfate heptahydrate is an analytically pure reagent provided by Xilong Science Co., Ltd., ethanol is an analytically pure reagent provided by Tianjin Fuyu Fine Chemical Co., Ltd., ethyl cellulose is a product provided by Shanghai MacLean Biochemical Technology Co., Ltd. (item number: E915394-500g), and polyethylene glycol is a product provided by Shanghai Aladdin Biochemical Technology Co., Ltd. (item number: P103730-500g).
[0021] In the following specific examples and comparative examples, the pH-responsive indicator is a DL-mandelic acid-based complex nanocrystal (the scanning electron microscopy image of which is shown in Figure 1), the preparation method of which comprises the following steps: (1) weighing 15.22 parts of DL-mandelic acid and dissolving it in 5000 parts of ethanol, stirring it at room temperature for 30 minutes to dissolve it, to obtain a uniform DL-mandelic acid solution for use; (2) weighing 13.90 parts of ferrous sulfate heptahydrate and dissolving it in 1000 parts of deionized water, stirring it at room temperature for 10 minutes to dissolve it, to obtain a uniform ferrous sulfate solution for use; (3) dropping the ferrous sulfate solution obtained in step (2) into the DL-mandelic acid solution obtained in step (1), stirring the reaction at room temperature for 20 minutes, and then centrifuging, washing, and vacuum drying in sequence to obtain a pH-responsive indicator.
[0022] Example 1
[0023] The pH and biogenic amine dual-responsive sensing material is characterized by being composed of the following components in parts by weight: 120 parts of ethyl cellulose, 30 parts of polyethylene glycol, and 1.5 parts of a pH-responsive indicator.
[0024] The preparation method comprises the following steps:
[0025] (1) Add 120 parts of ethyl cellulose and 30 parts of polyethylene glycol to 3000 parts of ethanol, stir at room temperature for 10 min, and then stir in a water bath at 55 °C for 30 min to completely dissolve them to obtain a uniform blend solution, cool to room temperature, and set aside;
[0026] (2) Disperse 1.5 parts of pH-responsive indicator in 500 parts of ethanol and stir for 20 min to obtain a uniform dispersion for later use;
[0027] (3) adding the dispersion obtained in step (2) to the blended solution obtained in step (1), and stirring at room temperature for 30 min to obtain a uniform film-forming solution for standby use;
[0028] (4) The film-forming solution obtained in step (3) is poured into a flat-bottomed glass dish and dried in a vacuum oven at 55° C. for 48 h to obtain a sensing material with dual response to pH and biogenic amines.
[0029] Example 2
[0030] The pH and biogenic amine dual-responsive sensing material is characterized by being composed of the following components in parts by weight: 120 parts of ethyl cellulose, 30 parts of polyethylene glycol, and 3 parts of a pH-responsive indicator.
[0031] The preparation method comprises the following steps:
[0032] (1) Add 120 parts of ethyl cellulose and 30 parts of polyethylene glycol to 3000 parts of ethanol, stir at room temperature for 10 min, and then stir in a water bath at 55 °C for 30 min to completely dissolve them to obtain a uniform blend solution, cool to room temperature, and set aside;
[0033] (2) Disperse 3 parts of pH-responsive indicator in 500 parts of ethanol and stir for 20 min to obtain a uniform dispersion for later use;
[0034] (3) adding the dispersion obtained in step (2) to the blended solution obtained in step (1), and stirring at room temperature for 30 min to obtain a uniform film-forming solution for standby use;
[0035] (4) The film-forming solution obtained in step (3) is poured into a flat-bottomed glass dish and dried in a vacuum oven at 55° C. for 48 h to obtain a sensing material with dual response to pH and biogenic amines.
[0036] Example 3
[0037] The sensing material with dual response to pH and biogenic amines is characterized by being composed of the following components in parts by weight: 120 parts of ethyl cellulose, 30 parts of polyethylene glycol, and 6 parts of a pH-responsive indicator.
[0038] The preparation method comprises the following steps:
[0039] (1) Add 120 parts of ethyl cellulose and 30 parts of polyethylene glycol to 3000 parts of ethanol, stir at room temperature for 10 min, and then stir in a water bath at 55 °C for 30 min to completely dissolve them to obtain a uniform blend solution, cool to room temperature, and set aside;
[0040] (2) Disperse 6 parts of pH-responsive indicator in 500 parts of ethanol and stir for 20 min to obtain a uniform dispersion for later use;
[0041] (3) adding the dispersion obtained in step (2) to the blended solution obtained in step (1), and stirring at room temperature for 30 min to obtain a uniform film-forming solution for standby use;
[0042] (4) The film-forming solution obtained in step (3) is poured into a flat-bottomed glass dish and dried in a vacuum oven at 55° C. for 48 h to obtain a sensing material with dual response to pH and biogenic amines.
[0043] Comparative Example
[0044] As a comparison standard for each of the above embodiments, the present invention provides a comparative example material prepared without a pH-responsive indicator, comprising the following steps:
[0045] (1) Add 120 parts of ethyl cellulose and 30 parts of polyethylene glycol to 3000 parts of ethanol, stir at room temperature for 10 min, and then stir in a water bath at 55 °C for 30 min to completely dissolve them to obtain a uniform blend solution, cool to room temperature, and set aside;
[0046] (2) adding 500 parts of ethanol to the blended solution obtained in step (1), and stirring at room temperature for 30 minutes to obtain a uniform film-forming solution for later use;
[0047] (3) The film-forming solution obtained in step (2) was poured into a flat-bottomed glass dish and dried in a vacuum oven at 55° C. for 48 h to obtain a comparative example material.
[0048] Performance Testing:
[0049] The performance tests were carried out on the comparative material prepared in the above comparative example and the pH and biogenic amine dual-responsive sensing material prepared in the example, wherein the tensile performance was tested according to GB / T 1040-2006, the UV-visible performance was tested using an UV spectrophotometer, and the average transmittance of ultraviolet rays (UVA, UVB and UVC) was calculated with reference to GB / T18830-2009.
[0050] The ammonia response test method is as follows: expose the sample material to an ammonia environment for 30 seconds, observe and record the color change of the sample material, and calculate the color difference value ∆E of the sample material before and after the ammonia response (Note: ∆E >3 indicates an obvious color change visible to the human eye).
[0051] Shrimp freshness monitoring experiment: Fresh shrimps were purchased from the market, and the shrimps (mass: 100 g) were placed in a glass culture dish and sealed with a culture dish lid. The materials prepared in the comparative example and Example 3 (pre-cut into sample materials with a diameter of 1.2 cm) were pasted under the lid. The shrimp samples were then stored in an oven at 25°C, and the changes in the freshness of the shrimps and the color changes of the sample materials were observed and recorded.
[0052] pH response experiment: The materials prepared in the comparative example and Example 3 were cut into sample materials with a diameter of 1.2 cm, and 5 drops of a buffer solution with a pH value of 10 were dripped on the surface of the sample material to observe its color change.
[0053] Table 1 Performance test data
[0054]
[0055] Table 2 Experimental data of shrimp freshness monitoring (where t is the storage time of fresh shrimp)
[0056]
[0057] The results of the ammonia response test show that the material prepared in the comparative example is colorless and transparent. After being exposed to an ammonia environment for 30 seconds, its color does not change significantly, and it still exhibits colorless and transparent optical properties, and its ∆E value is 0.35 (that is, the color difference is negligible and cannot be distinguished by the human eye); the sensing material prepared in Example 1 is light yellow, and after being exposed to an ammonia environment for 30 seconds, its color changes to light green, and its ∆E value is 22.76 (Note: ∆E >3 indicates an obvious color change visible to the human eye); the sensing material prepared in Example 2 is yellow, and after being exposed to an ammonia environment for 30 seconds, its color changes to dark green, and its ∆E value is 26.87 (Note: ∆E >3 indicates an obvious color change visible to the human eye); the sensing material prepared in Example 3 is dark yellow, and after being exposed to an ammonia environment for 30 seconds, its color changes significantly, and its ∆E value is 34.23 (Note: ∆E >3 indicates an obvious color change visible to the human eye).
[0058] The results of the shrimp experiment show that the sensor material prepared in Example 3 has a color change response to the biogenic amines released by shrimp deterioration (see Table 2), and can efficiently, real-time and intuitively monitor the deterioration of shrimp and other meat products during storage through the color change of the membrane.
[0059] The results of the pH response experiment show that after a buffer solution with a pH value of 10 was added to the surface of the material prepared in the comparative example, its color did not change significantly; after a buffer solution with a pH value of 10 was added to the surface of the material prepared in Example 1, its color changed significantly (from light yellow to light green); after a buffer solution with a pH value of 10 was added to the surface of the material prepared in Example 2, its color changed significantly (from yellow to dark green); after a buffer solution with a pH value of 10 was added to the surface of the material prepared in Example 3, its color changed significantly (from yellow to dark green). The above results show that the sensing material prepared by the present invention has pH response color change performance.
[0060] In summary, it can be seen from the performance test data of the above-mentioned sensor material composite film samples that the composite film material of the sensor material with dual response to pH and biogenic amines prepared by the present invention is simple, economical, and has the properties of high performance, low cost, pollution-free, wide pH response range, fast response speed, long duration, biodegradability, and the ability to achieve real-time monitoring. It can efficiently, in real time, and intuitively monitor the deterioration of meat foods such as shrimp during storage through the color change of the sensor material. The preparation process of the sensor material is simple, environmentally friendly, low-cost, and suitable for large-scale production. It has wide application value in the fields of pH / biogenic amine response color-changing materials, ammonia response color-changing materials, food packaging, ultraviolet protection, environmental monitoring and safety.
[0061] The content of the present invention is not limited to the embodiments listed. A person skilled in the art can make any equivalent changes to the technical solution of the present invention by reading the specification of the present invention, which are all covered by the claims of the present invention.
Claims
1. A sensing material with dual response to pH and biogenic amines, characterized in that: The invention is composed of the following components in parts by weight: 120 parts of ethyl cellulose, 30 parts of polyethylene glycol, and 1.5 to 6 parts of a pH-responsive indicator; The preparation method of the pH-responsive indicator comprises the following steps: (1) Weigh 15.22 parts of DL-mandelic acid and dissolve it in 5000 parts of ethanol. Stir it at room temperature for 30 min to dissolve it, and obtain a uniform DL-mandelic acid solution for later use. (2) Weigh 13.90 parts of ferrous sulfate heptahydrate and dissolve it in 1000 parts of deionized water. Stir it at room temperature for 10 minutes to dissolve it, and obtain a uniform ferrous sulfate solution for later use. (3) The ferrous sulfate solution obtained in step (2) is added dropwise to the DL-mandelic acid solution obtained in step (1), and the mixture is stirred at room temperature for 20 min. The mixture is then centrifuged, washed, and vacuum dried to obtain a pH-responsive indicator.
2. A method for preparing a sensing material having dual response to pH and biogenic amines as claimed in claim 1, characterized in that: The steps include: (1) Add 120 parts of ethyl cellulose and 30 parts of polyethylene glycol to 3000 parts of ethanol, stir at room temperature for 10 minutes, and then stir in a water bath at 55°C for 30 minutes to completely dissolve them to obtain a uniform blend solution, cool to room temperature, and set aside; (2) Disperse 1.5-6 parts of pH-responsive indicator in 500 parts of ethanol and stir for 20 min to obtain a uniform dispersion for later use; (3) adding the dispersion obtained in step (2) to the blended solution obtained in step (1), and stirring at room temperature for 30 minutes to obtain a uniform film-forming solution for standby use; (4) The film-forming solution obtained in step (3) is poured into a flat-bottomed glass dish and dried in a vacuum oven at 55° C. for 48 h to obtain a sensing material with dual response to pH and biogenic amines.
3. An application of the pH and biogenic amine dual-responsive sensing material as claimed in claim 1, characterized in that: It is used in pH sensing, biogenic amine response materials, ammonia response materials, food packaging, visual detection of ammonia, environmental monitoring and safety fields.