Intelligent tag group and preparation method thereof

Abstract

This invention relates to the field of food labeling technology, and more particularly to a smart label assembly and its preparation method. A smart label assembly includes: a substrate layer, a color-developing layer, and a protective layer; the color-developing layer is fixed to the surface of the substrate layer, and the protective layer covers the surface of the color-developing layer; the color-developing layer includes: an amine oxidase-type color-developing area and a glucose oxidase-type color-developing area. When livestock and poultry meat spoils and produces volatile amines and glucose degradation products, these two types of substances are catalyzed by amine oxidase and glucose oxidase, respectively, to produce ammonia and hydrogen peroxide, which then react with indicators on the label to produce color changes. The two types of labels are used together for mutual verification, forming a rapid detection method for livestock and poultry meat spoilage using smart labels, which can directly determine the quality of livestock and poultry meat. This label is simple to prepare, low in cost, and suitable for fresh livestock and poultry meat packaging, allowing monitoring from the freshness stage.

Description

Technical Field

[0001] This invention relates to the field of food labeling technology, and in particular to a smart label set and its preparation method. Background Technology

[0002] As high-protein foods, livestock and poultry meat is susceptible to microbial contamination, leading to spoilage and the production of volatile amines (such as ammonia and trimethylamine) and glucose degradation products, thus affecting food safety and quality. Traditional testing methods, such as sensory evaluation, microbial counting, or chemical analysis, are complex, time-consuming, not intuitive, and unsuitable for real-time monitoring. Existing smart tags are mostly based on pH indicators, nanomaterials, or complex sensors, which are costly, cumbersome to prepare, have limited response, and may introduce heavy metal risks and stability issues.

[0003] Patent CN117343054A describes a method for monitoring the freshness of meat products by preparing fluorescent probes and attaching them to solid supports to form fluorescent tags. However, the preparation process involves multiple chemical reactions, some of which need to be carried out in a nitrogen atmosphere. The preparation steps are complex, and a handheld ultraviolet lamp is required when monitoring the freshness of meat products, making the operation relatively cumbersome.

[0004] Patent CN120484281A describes the preparation of smart gel tags to indicate the freshness of aquatic products. The preparation process requires the addition of chitosan. When anthocyanin aqueous solution is mixed and then calcium sulfate is added and incubated for 12-24 hours, the preparation time is long. When the trimethylamine content is detected, the gel changes from pink to dark gray, and finally to dark brown. The color is not obvious to the naked eye.

[0005] Patent CN111472092A uses a pH indicator dye and an H2S sensitive agent (lead acetate) to create a dual-indicator smart label to identify meat quality. However, when using the pH indicator dye, the enzymatic amplification effect is ignored, resulting in insufficient sensitivity.

[0006] The spoilage process of high-protein foods is highly complex. Monitoring with a single indicator (volatile amines or glucose degradation products) is often insufficient, easily leading to false negatives and false positives. Furthermore, it cannot grade the degree of spoilage, making it difficult to provide scientific quality assurance. During long-distance or cold chain transportation, food is easily affected by temperature; single-indicator monitoring is prone to failure, unable to cover different spoilage pathways, and lacks dynamic real-time monitoring capabilities. Simultaneously, during food storage, such as in supermarket retail packaging or home refrigerators, consumers cannot visually assess the food's condition. Therefore, there is a need for a smart tag that effectively solves these problems, enabling dynamic real-time monitoring of food spoilage and freshness. Summary of the Invention

[0007] The purpose of this invention is to provide a smart tag set and a method for preparing the same. The technical problem to be solved is not limited to the described technical subject matter; other technical subjects not mentioned herein will be clearly understood by those skilled in the art through the following description.

[0008] In a first aspect, the present invention provides a smart label assembly, comprising: a substrate layer, a color developing layer, and a protective layer; the color developing layer is disposed on the surface of the substrate layer, and the protective layer is covered on the surface of the color developing layer; the color developing layer includes mutually independent amine oxidase-type color developing regions and glucose oxidase-type color developing regions.

[0009] In one embodiment, the amine oxidase-type chromogenic region and the glucose oxidase-type chromogenic region are located on the same plane.

[0010] In one embodiment, the amine oxidase-type chromogenic region and the glucose oxidase-type chromogenic region are arranged alternately on the chromogenic layer.

[0011] In one embodiment, the area ratio of the amine oxidase-type chromogenic region to the glucose oxidase-type chromogenic region is 1:1 to 1:5.

[0012] In one embodiment, the amine oxidase-type chromogenic region includes: amine oxidase, a pH-sensitive indicator, and a biocompatible carrier.

[0013] In one embodiment, the pH-sensitive indicator is loaded in the biocompatible carrier.

[0014] In one embodiment, the pH-sensitive indicator is bromocresol green, and the mass fraction of bromocresol green in the chromogenic layer is 0.1-0.5%.

[0015] In one embodiment, the amine oxidase includes, but is not limited to, monoamine oxidase, diamine oxidase, histamine-N-methyltransferase, and polyamine oxidase, with a loading of 0.5-2.0 mg / cm³. 2 .

[0016] In one embodiment, the biocompatible carrier is chitosan or agar.

[0017] In one embodiment, the amine oxidase-type chromogenic region is prepared by the following steps: dissolving amine oxidase and pH-sensitive indicator in an aqueous solution of a biocompatible carrier, coating or impregnating the substrate layer surface, and drying.

[0018] Specifically, the biocompatible carrier aqueous solution has a mass fraction of 1-3% and a pH value of 5.0-6.0.

[0019] Specifically, the drying temperature is 30-50℃ and the time is 1-2 hours.

[0020] In one embodiment, the glucose oxidase-type chromogenic region includes: glucose oxidase, peroxidase, color indicator, and biocompatible carrier.

[0021] In one embodiment, the pH-sensitive indicator is loaded in the biocompatible carrier.

[0022] In one embodiment, the color indicator is o-benzidine, and the mass fraction of o-benzidine in the chromogenic layer is 0.05-0.3%.

[0023] In one embodiment, the glucose oxidase loading is 0.3-1.5 mg / cm³. 2 ;

[0024] In one embodiment, the biocompatible carrier is gelatin or sodium alginate.

[0025] In one embodiment, the glucose oxidase-type chromogenic region is prepared by the following steps: dissolving glucose oxidase, peroxidase, and color indicator in a biocompatible carrier aqueous solution, coating it onto the surface of the substrate layer, and drying it.

[0026] Specifically, the biocompatible carrier aqueous solution has a mass fraction of 2-4% and a pH value of 6.0-7.0.

[0027] Specifically, the drying temperature is 25-45℃ and the time is 0.5-1.5 hours.

[0028] The working principles of the two color rendering zones are as follows: (1) Amine oxidase type color development area: When livestock and poultry meat is fresh, the volatile amines are low, the pH is neutral, and the label is yellow; as the degree of spoilage increases, the color development area reacts with the volatile amines of spoilage products through amine oxidase, catalyzing the production of ammonia, the pH increases, and the color of the color development area gradually changes from yellow (indicating freshness) to blue (indicating spoilage), which makes it easier for users to intuitively judge the quality of food.

[0029] (2) Glucose oxidase type color development area: When livestock and poultry meat is fresh, the amount of spoilage products is low and the label is colorless; when spoiled, the amount of glucose increases, and the label reacts with glucose oxidase through the spoilage products to produce hydrogen peroxide, which then reacts with peroxidase and indicators to cause a color change, gradually changing from colorless (indicating freshness) to brown (indicating spoilage), which is used to visually display the quality of food.

[0030] In one embodiment, the glucose oxidase-type chromogenic region further includes a temperature-sensitive layer, which is coated on the surface of the substrate layer, and the glucose oxidase-type chromogenic region is fixed to the temperature-sensitive layer or the surface of the temperature-sensitive layer and the substrate layer.

[0031] In one embodiment, the temperature-sensitive layer is prepared by coating or impregnating a temperature-sensitive ink onto the surface of a substrate layer to form the temperature-sensitive layer.

[0032] In one embodiment, the detection range of the amine oxidase-type chromogenic region is TVB-N = 15-25 mg / 100g; the detection range of the glucose oxidase-type chromogenic region is TVB-N = 10-30 mg / 100g.

[0033] In one embodiment, the substrate layer is made of a flexible material, including but not limited to at least one of cotton cloth, food-grade cellulose paper, food-grade filter paper, and non-woven fabric, with a thickness of 0.1-0.6 mm.

[0034] In one embodiment, the protective layer has a breathable yet waterproof structure, allowing gas to pass through while blocking moisture, effectively protecting the color-developing layer from contamination. Preferably, the protective layer is a transparent or translucent material to allow observation of color changes in the color-developing layer.

[0035] In one embodiment, the protective layer is at least one of polypropylene film, polyvinyl alcohol film, polyethylene film, and polylactic acid film, with a thickness of 0.03-0.2 mm.

[0036] In one embodiment, the color-developing layer may be formed on the surface of the substrate layer by printing, spraying, screen printing or coating.

[0037] In one embodiment, the smart tag assembly further includes an adhesive layer, with a substrate layer covering the surface of the adhesive layer.

[0038] In one embodiment, the adhesive layer is prepared by applying an adhesive to the surface of a substrate layer to form the adhesive layer.

[0039] In a second aspect, the present invention provides the application of the above-described smart tag group in any of the following: 1) Used for monitoring the freshness or spoilage level of products with high protein content; 2) Used to monitor spoilage products or indicate product freshness during product transportation; 3) Used for visualizing the state of food during product storage.

[0040] In one implementation, the high-protein product is an animal product (including but not limited to: meat, seafood, and dairy products).

[0041] In a third aspect, the present invention provides a product quality detection method, which uses the above-mentioned smart label group and the product in the same sealed space, and judges the product quality based on the color change of the smart label group.

[0042] In one embodiment, the product is a high-protein product; preferably an animal product (including but not limited to: meat, seafood, and dairy products).

[0043] In one implementation, when the amine oxidase-type colorimetric area of ​​the smart label group is yellow and the glucose oxidase-type colorimetric area is colorless, it indicates that the product is fresh; when the amine oxidase-type colorimetric area of ​​the smart label group is blue and the glucose oxidase-type colorimetric area is brown, it indicates that the product is completely spoiled and inedible; when the amine oxidase-type colorimetric area of ​​the smart label group gradually changes from yellow to blue, and / or the glucose oxidase-type colorimetric area gradually shows brown, it indicates that the product is spoiling.

[0044] This invention aims to provide a simple and inexpensive enzymatic colorimetric label assembly. The amine oxidase type colorimetric zone utilizes a natural enzyme and a simple indicator, while the glucose oxidase type colorimetric zone leverages a dual-enzyme system of glucose oxidase and peroxidase to amplify the signal, enabling intuitive quality display starting from fresh meat and more precise spoilage monitoring from freshness, avoiding the shortcomings of existing technologies. This invention uses both amine oxidase and glucose oxidase type colorimetric zones in combination, forming a rapid intelligent label detection method for meat spoilage, improving the accuracy of judging the degree of spoilage. Simultaneously, during the development process, correlation verification was conducted using TVB-N (total volatile basic nitrogen) standard determination. The results of both tests showed a high correlation, and the colorimetric results were correlated with the shelf life of meat products, allowing for direct and intuitive judgment of meat quality, demonstrating intelligent characteristics.

[0045] Because the spoilage process of high-protein perishable foods (meat, seafood, dairy products) is quite complex, it releases amine gases and may be accompanied by sugar metabolites. The label set obtained by this invention uses a dual-indicator approach to grade and display the degree of spoilage (such as "fresh - slightly fresh - spoiled"), providing a more scientific quality assurance.

[0046] During long-distance transportation or cold storage, food quality is affected by temperature, and temperature fluctuations can cause different spoilage pathways (protein decomposition vs. carbohydrate metabolism) to occur sequentially. The label set obtained by this invention uses dual indicators to cover different spoilage pathways, monitors two types of spoilage products at the same time, provides more accurate early predictions, and enables dynamic real-time monitoring.

[0047] Meanwhile, in supermarkets, convenience stores, or home refrigerators, consumers have difficulty visually observing the quality of food, leading to a higher risk of misjudgment. The label set obtained by this invention uses dual indicators in combination, which not only avoids misleading information by using dual colors to visually judge the state of food and improve the user experience, but also avoids being misled by "false freshness" or "false spoilage" due to the deviation of a single detection.

[0048] Compared with existing technologies, the present invention has the following advantages: (1) Simple and inexpensive: the materials are common and no special equipment is required for preparation.

[0049] (2) Safe and environmentally friendly: It uses biological enzymes and natural carriers and is non-toxic.

[0050] (3) High sensitivity: Amine oxidase type: response time < 24 hours, sensitive to changes in TVB-N; Glucose oxidase type: dual enzyme amplification, response time < 12 hours.

[0051] (4) Visual display: color gradient, monitoring from freshness, convenient for consumers to use. Attached Figure Description

[0052] Figure 1 This is a schematic diagram of the structure of the smart tag group obtained by the present invention.

[0053] In the diagram, 1 is the substrate layer; 2 is the color development layer; 3 is the protective layer; 4 is the adhesive layer; and 5 is the temperature-sensitive layer. Detailed Implementation

[0054] The present invention will now be described in further detail with reference to specific embodiments. The given embodiments are merely illustrative of the invention and not intended to limit its scope. The embodiments provided below can serve as a guide for further improvements by those skilled in the art and do not constitute a limitation on the invention in any way.

[0055] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Unless otherwise specified, the materials and reagents used in the following examples are commercially available.

[0056] Commercial sourcing of non-biological materials: Chitosan was purchased from Sinopharm Chemical Reagents (Beijing) Co., Ltd. Glacial acetic acid was purchased from Sinopharm Chemical Reagents (Beijing) Co., Ltd., used to prepare 1% acetic acid. Bromocresol green was purchased from Sinopharm Chemical Reagents (Beijing) Co., Ltd. Filter paper was purchased from Sinopharm Chemical Reagents (Beijing) Co., Ltd. Amine oxidase was purchased from Sigma-Aldrich (Shanghai) Trading Co., Ltd. Histamine-N-methyltransferase was from MedChemExpress LLC. Gelatin was purchased from Beijing Solarbio Technology Co., Ltd. Glucose oxidase was purchased from Sinopharm Chemical Reagents (Beijing) Co., Ltd. Peroxidase was purchased from Sigma-Aldrich (Shanghai) Trading Co., Ltd. o-Benzidine was purchased from Sinopharm Chemical Reagents (Beijing) Co., Ltd. Sodium chloride was purchased from Sinopharm Chemical Reagents (Beijing) Co., Ltd. Polyethylene was purchased from Sigma-Aldrich (Shanghai) Trading Co., Ltd. Polypropylene was purchased from Sigma-Aldrich (Shanghai) Trading Co., Ltd. Dichloromethane was purchased from Sinopharm Chemical Reagents (Beijing) Co., Ltd. Paraffin oil was purchased from Beijing Solarbio Technology Co., Ltd.

[0057] Overview of the preparation steps for 0.1mm polyethylene microporous membrane: Sodium chloride with a particle size sieved (approximately 80-120 mesh) is used as a pore-forming agent and melt-blended with polyethylene at 130℃ and pressed into shape (150℃); the resulting composite membrane is immersed in water for 24-48 hours to completely dissolve the pore-forming agent and then filtered; the membrane is then subjected to gentle drying (vacuum drying at 40℃) and post-treatment to obtain the final product.

[0058] Overview of the preparation steps for 0.08 mm polypropylene nanoporous membrane: Polypropylene is blended with paraffin oil at high temperature (nitrogen protection, 180°C) to form a homogeneous solution; the solution is coated onto a substrate, and the gap is controlled to obtain a wet film, which is then rapidly cooled to room temperature to induce phase separation; the paraffin oil is washed away with dichloromethane; and the membrane is dried in a vacuum drying oven at 40°C for 6 hours to obtain the final product.

[0059] like Figure 1 As shown, the present invention provides a smart label assembly, comprising: a substrate layer 1, a color developing layer 2, a protective layer 3, an adhesive layer 4, and a temperature-sensitive layer 5.

[0060] Substrate layer 1 is covered on the surface of adhesive layer 4, color development layer 2 is disposed on the surface of substrate layer 1, and protective layer 3 is covered on the surface of color development layer 2.

[0061] The chromogenic layer 2 includes an independent amine oxidase-type chromogenic region (located on the left side of the chromogenic layer 2) and a glucose oxidase-type chromogenic region (located on the right side of the chromogenic layer 2). The amine oxidase-type chromogenic region and the glucose oxidase-type chromogenic region are located on the same plane. The area ratio of the amine oxidase-type chromogenic region and the glucose oxidase-type chromogenic region can be 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, etc.

[0062] A temperature-sensitive layer 5 is applied to the surface of the substrate layer 1, and the glucose oxidase-type colorimetric region is fixed to the temperature-sensitive layer 5 or the surface of the temperature-sensitive layer 5 and the substrate layer 1.

[0063] The substrate layer 1 is made of at least one of cotton cloth, food-grade cellulose paper, food-grade filter paper, and non-woven fabric, and its thickness is 0.1-0.6 mm; the protective layer 3 is made of at least one of polypropylene film, polyvinyl alcohol film, polyethylene film, and polylactic acid film, and its thickness is 0.03-0.2 mm.

[0064] Example 1: Amine oxidase-based smart tag (1) Dissolve 2g of chitosan in 100mL of distilled water (containing 1% acetic acid) and adjust the pH to 5.5. Add 1g of amine oxidase (containing 0.25g each of monoamine oxidase, diamine oxidase, histamine-N-methyltransferase and polyamine oxidase) and 0.2g of bromocresol green, and stir for 30min until homogeneous.

[0065] (2) Take food-grade filter paper (10cm×10cm) as the substrate, immerse it in the above solution for 10min, take it out and dry it in an oven at 40℃ for 1.5h to form a color layer.

[0066] (3) A 0.1 mm polyethylene microporous membrane is hot-pressed onto the color development layer as a protective layer.

[0067] (4) Apply food-grade adhesive to the bottom of the substrate to form an adhesion layer and obtain a smart label.

[0068] Example 2: Glucose oxidase-based smart tag (1) Dissolve 3g of gelatin in 100mL of distilled water and adjust the pH to 6.5. Add 0.8g of glucose oxidase, 0.5g of peroxidase and 0.1g of o-benzidine, and stir for 20min until homogeneous.

[0069] (2) Take food-grade cellulose paper (8cm×8cm) as the substrate, print temperature-sensitive ink on the substrate to form a temperature-sensitive layer; continue to spray the above solution, take it out and dry it in an oven at 35℃ for 1 hour to form a color development layer.

[0070] (3) A 0.08 mm polypropylene nanoporous membrane is laminated onto the color development layer as a protective layer to obtain a smart label.

[0071] Example 3: Smart Tag Group (1) Dissolve 2g of chitosan in 100mL of distilled water (containing 1% acetic acid) and adjust the pH to 5.5. Add 1g of amine oxidase (containing 0.25g each of monoamine oxidase, diamine oxidase, histamine-N-methyltransferase and polyamine oxidase) and 0.2g of bromocresol green, stir for 30min until homogeneous, and obtain an amine oxidase-type colorimetric solution.

[0072] (2) Dissolve 3g of gelatin in 100mL of distilled water and adjust the pH to 6.5. Add 0.8g of glucose oxidase, 0.5g of peroxidase and 0.1g of o-benzidine, stir for 20min until homogeneous to obtain glucose oxidase type colorimetric solution.

[0073] (3) Take food-grade cellulose paper (18cm×10cm) as substrate layer 1, immerse the left side of the cellulose paper in amine oxidase type color development solution for 10min, and then drain it. (4) Print temperature-sensitive ink on the right side of the drained cellulose paper to form temperature-sensitive layer 5; continue to spray glucose oxidase type color development solution on temperature-sensitive layer 5 and the right side surface of cellulose paper, take it out and dry it in an oven at 35℃ for 2 hours to form color development layer 2, and the amine oxidase type color development area and the glucose oxidase type color development area are independent of each other, and the area ratio of the amine oxidase type color development area and the glucose oxidase type color development area is 1:1.

[0074] (5) A 0.08 mm polypropylene nanoporous membrane is pressed onto the color development layer 2 as a protective layer 3, and food-grade adhesive is coated on the bottom of the substrate to form an adhesion layer 4, thus obtaining a smart label set.

[0075] Example 4: Tag Performance Test The amine oxidase-type smart label obtained in Example 1 was affixed to fresh chicken packaging (TVB-N = 10 mg / 100 g) and stored in a refrigerator at 4°C. Color changes were observed: yellow (fresh) from 0-24 h; gradually turning green (slight spoilage) from 24-48 h; and blue (spoilage) after >48 h. Compared with standard TVB-N determination, the correlation coefficient between color change and degree of spoilage was >0.95.

[0076] The glucose oxidase-type smart label obtained in Example 2 was placed in fresh beef packaging (TVB-N = 8 mg / 100 g) and stored in a simulated environment at 10°C. Color changes were observed: colorless (fresh) for 0-12 h; gradually turning light brown (slight spoilage) for 12-36 h; and dark brown (spoilage) for >36 h. The correlation coefficient between the color change and the TVB-N standard determination was >0.98.

[0077] Example 5: Monitoring of meat by labeling Similar to Example 4, the amine oxidase-type smart tag obtained in Example 1 was used on fresh pork. The results showed that the tag started as yellow, turned blue when spoiled, had a short response time, and cost 0.05 yuan per tag.

[0078] Similar to Example 4, the glucose oxidase-type smart label obtained in Example 2 was used on fresh chicken. The results showed that the label started as colorless, turned brown when spoiled, responded quickly, cost 0.03 yuan per label, and the temperature-sensitive layer turned red as an additional warning when the temperature was >25°C.

[0079] Example 6: False Negative and False Positive Tests Using 30 batches of fresh beef, the smart label group obtained in Example 3 was placed in the fresh beef packaging and stored in a simulated environment at 10°C. The color change of the color development area was observed within 48 hours.

[0080] Two batches of beef showed no significant color change in the amine oxidase-type chromogenic region (false negative rate 6.7%), while three other different batches of beef showed no significant color change in the glucose oxidase-type chromogenic region (false negative rate 10%). However, the combined assessment of both chromogenic regions reduced the false negative rate to 0%.

[0081] Using 100 batches of fresh chicken (TVB-N ≤ 10 mg / 100 g), the smart label group obtained in Example 3 was placed in the fresh chicken packaging and stored in a refrigerator at 4°C. The color change of the two labels was observed over 3 hours.

[0082] Four batches of chicken packaging showed color changes in the amine oxidase-type chromogenic area (false positive rate 4%); five batches showed color changes in the glucose oxidase-type chromogenic area (false positive rate 5%), with two of these batches also showing color changes in the amine oxidase-type chromogenic area. However, cross-judgment using two chromogenic areas from the label group reduced the false positive rate to 2% (less than 3%).

[0083] The above embodiments demonstrate that the label of the present invention is simple and effective. When used together, the two constitute a rapid detection method for spoilage of livestock and poultry meat using intelligent labels, which is applicable to the quality monitoring of livestock and poultry meat.

[0084] The present invention has been described in detail above. Those skilled in the art will recognize that the invention can be practiced in a wide range of ways with equivalent parameters, concentrations, and conditions without departing from its spirit and scope, and without requiring unnecessary experiments. While specific embodiments have been provided, it should be understood that further modifications can be made to the invention. In summary, according to the principles of the invention, this application is intended to include any changes, uses, or improvements to the invention, including changes made using conventional techniques known in the art that depart from the scope disclosed herein.

Claims

1. A smart label set, characterized in that include: The substrate layer (1), the color developing layer (2), and the protective layer (3) are provided; the color developing layer (2) is disposed on the surface of the substrate layer (1), and the protective layer (3) is covered on the surface of the color developing layer (2); The chromogenic layer (2) includes two independent amine oxidase-type chromogenic regions and glucose oxidase-type chromogenic regions.

2. The smart label set of claim 1, wherein, The amine oxidase-type chromogenic region includes: amine oxidase, pH-sensitive indicator, and biocompatible carrier.

3. The smart label set of claim 2, wherein, The pH-sensitive indicator is bromocresol green, and the mass fraction of bromocresol green in the chromogenic layer (2) is 0.1-0.5%; Preferably, the amine oxidase includes, but is not limited to, monoamine oxidase, diamine oxidase, histamine-N-methyltransferase, polyamine oxidase, and the loading amount thereof is 0.5-2.0 mg / cm 2 ; Preferably, the biocompatible carrier is chitosan or agar.

4. The smart label set of claim 1, wherein, The glucose oxidase-type chromogenic region includes: glucose oxidase, peroxidase, color indicator, and biocompatible carrier.

5. The smart label set of claim 4, wherein, The color indicator is o-benzidine, and the mass fraction of o-benzidine in the colorimetric layer (2) is 0.05-0.3%; Preferably, the glucose oxidase has a loading of 0.3-1.5 mg / cm 2 ; Preferably, the biocompatible carrier is gelatin or sodium alginate.

6. The smart label set of claim 4, wherein, The glucose oxidase-type color development area also includes a temperature-sensitive layer (5), which is covered on the surface of the substrate layer (1). The glucose oxidase-type color development area is fixed on the temperature-sensitive layer (5) or the temperature-sensitive layer (5) and the substrate layer (1).

7. The smart label set of any one of claims 1-6, wherein, The detection range of the amine oxidase type chromogenic region is TVB-N=15-25mg / 100g; the detection range of the glucose oxidase type chromogenic region is TVB-N=10-30mg / 100g.

8. The application of the smart tag group as described in any one of claims 1-7 in any of the following: 1) Used for monitoring the freshness or spoilage level of products with high protein content; 2) Used to monitor spoilage products or indicate product freshness during product transportation; 3) Used for visualizing the state of food during product storage.

9. A method of detecting product quality, characterized by, The product quality is determined by the color change of the smart label group as described in any one of claims 1-7, which is placed in the same sealed space as the product.

10. The detection method according to claim 9, characterized in that, When the amine oxidase type color development area of ​​the smart label group is yellow and the glucose oxidase type color development area is colorless, it indicates that the product is fresh; When the amine oxidase type color development area of ​​the smart label group is blue and the glucose oxidase type color development area is brown, it indicates that the product is completely spoiled and inedible. When the amine oxidase type color development area of ​​the smart label group gradually changes from yellow to blue, or / and the glucose oxidase type color development area gradually turns brown, it indicates that the product is spoiling.

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