A gas sensing material for detecting deterioration in fruit and vegetable quality, its preparation method and application

Abstract

A gas-sensing material for detecting deterioration in fruit and vegetable quality, its preparation method, and its application are disclosed. The steps include (1) preparation of a hydrogel; (2) addition of a reactant; (3) addition of a colorimetric agent; and (4) preparation of a gas-sensitive membrane. This invention utilizes a complex of anthocyanins, curcumin, and red yeast rice pigments combined with laser perforation technology to prepare a gas-sensitive material that synergistically monitors the release of aldehydes in fruits and vegetables, thereby obtaining real-time information on fruit and vegetable quality, reducing economic losses, and preventing food safety issues.

Description

Technical Field

[0001] This invention belongs to the field of food testing technology, specifically relating to a non-climacteric respiratory gas sensing material for fruit and vegetable quality deterioration based on anthocyanins, curcumin, and red yeast rice pigment, its preparation method, and its application. Background Technology

[0002] As consumers become more safety-conscious, they pay closer attention to product information. Fresh food, with its high water and nutrient content, is a natural culture medium for microorganisms, making it susceptible to microbial infection and rapid loss of nutrients. This not only causes economic losses but also poses safety risks to consumers. Currently, technologies for detecting the quality of fresh food include chromatography, nuclear magnetic resonance, electronic nose, electronic tongue, and mass spectrometry. While these technologies can accurately detect the quality of fresh food, they also have disadvantages such as complex pretreatment, the need for specialized knowledge, high cost, and time consumption. Therefore, developing a rapid, inexpensive, easy-to-operate, and consumer-friendly detection technology for real-time monitoring of fresh food quality has broad application scenarios.

[0003] In recent years, smart food packaging technologies have attracted researchers' attention. These sensitive materials can visualize changes in the gases emitted by fresh food and the external environment, allowing consumers to obtain real-time quality information and thus judge the quality of fresh food. Fruits and vegetables exhibit strong respiration and ethylene release during the ripening process. Simultaneously, some fermentation byproducts are produced during this stage, including substances such as ethanol, acetaldehyde, and acetic acid. Therefore, monitoring aldehydes can indirectly reflect the quality of fruits and vegetables.

[0004] Shao Ping (2021) disclosed a method for preparing a hydrophobic film and its application in visually detecting the freshness of fruits and vegetables (Publication No.: CN113527728A), which uses polyvinyl alcohol, ethyl cellulose, and methyl red to visualize the freshness of kiwifruit. The methyl red added in this method is a chemical pigment, which raises significant questions about food safety. Furthermore, fruits and vegetables release relatively little aldehydes, resulting in large errors in the results of a single visualization film. Additionally, the visualization effect of methyl red is weak and it is only suitable for fruits and vegetables with climacteric respiration. The emulsifier is unstable, and white flocculent matter may precipitate.

[0005] Zou Xiaobo (2023) disclosed a method for preparing an intelligent visual food freshness indicator label (Publication No.: CN115782264A). The method involves preparing a film solution using pectin, chitosan, and beeswax, which is then dried to obtain a film sheet. Next, a concentrated natural pigment solution and starch gel are prepared and mixed to obtain a pigment-starch gel. This gel is then placed in a 3D printing material container and 3D printed to obtain a single-layer hydrophobic film indicator label. Finally, the film solution is atomized through a spray system and evenly sprayed onto the single-layer hydrophobic film to obtain a double-layer hydrophobic film indicator label. This method, which utilizes 3D printing combined with a spray system to prepare the indicator label, suffers from disadvantages such as technical difficulties and cumbersome steps. Summary of the Invention

[0006] Technical problem to be solved: In order to overcome the shortcomings of the prior art, the present invention provides a non-catastrophic gas sensing material for the deterioration of fruit and vegetable quality based on anthocyanin-curcumin-red yeast rice pigment, its preparation method and application. The gas sensing material is prepared by using a compound of anthocyanin-curcumin-red yeast rice pigment combined with laser drilling technology to synergistically monitor the release of aldehydes in fruits and vegetables, thereby obtaining real-time information on the quality of fruits and vegetables, reducing economic losses and preventing food safety problems.

[0007] Technical solution: A method for preparing a gas sensing material for detecting the deterioration of fruit and vegetable quality, comprising the following steps: (1) Preparation of hydrogel: Polyvinyl alcohol and soluble starch are dissolved in water, stirred and mixed at 60-80 °C, cooled and then 2% by weight of glycerol is added, and stirring is continued to obtain a hydrogel mixed with polyvinyl alcohol and soluble starch. The mass ratio of polyvinyl alcohol, soluble starch and water is (2-5):(1-3):100; (2) Addition of reactant: Bis(3-aminopropyl)polyethylene glycol is added to the hydrogel obtained in step (1) to obtain a mixed hydrogel. Stir and mix well; wherein the mass ratio of bis(3-aminopropyl)polyethylene glycol to water is (0.07~1.2):100; (3) Addition of color developer: add anthocyanin-curcumin-red yeast rice pigment compound to the mixed hydrogel obtained in step (2), stir to prepare a mixed hydrogel containing anthocyanin-curcumin-red yeast rice pigment compound; wherein the mass ratio of anthocyanin-curcumin-red yeast rice pigment compound to reactant is 0.02~0.06:0.07~1.2; (4) Preparation of gas-sensitive membrane: sonicate the mixed hydrogel obtained in step (3) and cast it into a film, dry it to obtain gas sensing material.

[0008] In step (1), 2-5 g of polyvinyl alcohol and 1-3 g of soluble starch are weighed and dissolved in 100 mL of water. The mixture is stirred at 60-80°C for 3-4 hours to obtain a hydrogel solution.

[0009] In step (3), 0.02–0.06 g of anthocyanin-curcumin-red yeast rice pigment complex is weighed and dissolved in the mixed hydrogel.

[0010] Preferably, the anthocyanin-curcumin-red yeast rice pigment compound is mixed in a mass ratio of 1:0.5:0.5.

[0011] In steps (2) and (3), the color developer and the reactant are added after the hydrogel has been dissolved and cooled.

[0012] In step (4), after the membrane solution cools, it is sonicated at 200W to 500W for 5 to 10 minutes and then dried in an oven at 30 to 45 ℃ for 8 to 12 hours.

[0013] The above preparation method yields a gas sensing material for detecting deterioration in the quality of fruits and vegetables, specifically for fruits and vegetables of the non-rapid respiration type.

[0014] The above-mentioned fruit and vegetable quality deterioration gas sensing material is used to monitor volatile aldehydes in the fruit and vegetable supply chain. It is packaged in a box containing a non-rapid respiration type fruit and vegetable quality deterioration gas sensing material. Its detection accuracy is 99.40-99.92% and the detection speed is 3-5 seconds.

[0015] The material is perforated by laser. The perforation shape is pentagonal, with a side length of 1 to 1.5 mm. A 7×7 matrix pattern is used, with an interval of 0.5 to 1.5 mm.

[0016] The color changes of the gas-sensing material for detecting deterioration in fruit and vegetable quality when monitoring volatile aldehydes showed that when the gas-sensitive membrane was dark brown, the strawberries were fresh; when it was green, the strawberries were not very fresh; and when it was pink, the strawberries were rotten. The color a* of the gas-sensitive membrane varied from 1.23 to 27.74, and the b* varied from -21.11 to 2.34, with a detection accuracy of 99.40% to 99.92%.

[0017] This invention provides the application of the mixed hydrogel membrane prepared according to the above method in the visual detection of the quality of non-breathing climacteric fruits and vegetables. The specific application is as follows: the membrane is placed in the fruit and vegetable packaging or on the packaging box. When the gas sensing material is dark brown, it indicates that the fruit and vegetables are fresh. When the gas sensing material is green, it indicates that the fruit and vegetables are not very fresh. When the membrane is pink, it indicates that the fruit and vegetables are rotten.

[0018] This invention uses an anthocyanin-curcumin-red yeast rice pigment complex as a colorimetric agent. By adjusting the ratio of anthocyanins, curcumin, and red yeast rice pigment, the colorimetric agent can achieve various color changes with pH variations. Red yeast rice pigment is relatively stable between pH 1 and 10 and is not easily affected by pH, thus it can be used as a co-coloring agent to achieve multiple color changes in the anthocyanin-curcumin-red yeast rice pigment complex, enabling real-time monitoring of quality changes in fruits and vegetables during storage. Furthermore, natural pigments do not pose certain food safety issues. The ratio of polyvinyl alcohol and soluble starch is not strictly limited, and both can form films with high mechanical strength. Moreover, the presence of polyvinyl alcohol provides good hydrophobicity to the film. On the other hand, laser perforation technology can improve the permeability of the gas-sensitive membrane, allowing the reactants in the gas-sensitive membrane to react rapidly with volatile aldehydes, thereby achieving rapid color change. Therefore, the gas-sensitive membrane prepared by combining polyvinyl alcohol, soluble starch, and natural pigments with laser perforation technology has broad application prospects in food quality monitoring.

[0019] Beneficial effects: (1) This invention uses natural pigments, which are abundant in nature and easy to obtain. In addition, natural pigments have good antioxidant and chronic disease prevention effects. At present, most inventions use chemically synthesized pigments, which not only have great drawbacks on the human body, but also have carcinogenic side effects. With the increasing attention to safety, some chemical pigments will bring a great psychological burden to people. Therefore, natural pigments are a good color developer.

[0020] (2) The polyvinyl alcohol and soluble starch used in this invention are relatively inexpensive materials, which is beneficial for industrial production and application. The membrane material formed by polyvinyl alcohol and soluble starch has good mechanical strength and will not be easily damaged during fruit and vegetable monitoring. In addition, the material has good waterproof ability, which can prevent water vapor released by fruits and vegetables during respiration and will not affect the accuracy of gas-sensitive materials in monitoring the quality of fruits and vegetables.

[0021] (3) This invention uses anthocyanin / curcumin / red yeast rice pigment complex to prepare a gas-sensitive material, which has a wider pH color change range. This makes the color of the gas-sensitive membrane material diverse, which can bring better visual judgment to people with color weakness or color blindness. At the same time, this gas-sensitive membrane can monitor the entire process of fruits and vegetables from fresh to rotten.

[0022] (4) This invention uses laser to perforate the gas-sensitive membrane, which allows the gas to react rapidly with the membrane, thereby achieving rapid identification of volatile aldehyde gases. This saves reaction time, thus enabling rapid detection of quality changes in fruits and vegetables. At the same time, the gas-sensitive membrane prepared by this laser perforation technology allows the reactants in the membrane to react more thoroughly with the volatile aldehydes in fruits and vegetables, thereby achieving accurate detection of quality changes in fruits and vegetables. Attached Figure Description

[0023] Figure 1 Quality changes of strawberries during storage. A: Sensory evaluation of strawberries during storage. B: Changes in firmness of strawberries during storage. C: Changes in total soluble solids content of strawberries during storage. D: Changes in malondialdehyde content of strawberries during storage.

[0024] Figure 2 Color development mechanism of gas-sensitive membrane in monitoring strawberry quality. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be further described below in conjunction with specific embodiments and comparative examples.

[0026] Example 1

[0027] (1) Weigh 1.5 g of polyvinyl alcohol and soluble starch and dissolve them in 100 mL of water. Stir the mixture at 60 °C and 800 rpm for 2 h on a magnetic stirrer until dissolved. After cooling, add 1% of the mass of the above system of glycerol and continue stirring for 0.7 h to obtain a hydrogel containing polyvinyl alcohol and soluble starch.

[0028] (2) Add 0.07 g of bis(3-aminopropyl)polyethylene glycol to the hydrogel of polyvinyl alcohol and soluble starch obtained in step (1) to obtain a mixed hydrogel, and stir at 900 rpm for 1 h in a magnetic stirrer.

[0029] (3) Add anthocyanin-curcumin-red yeast rice pigment compound to the mixed hydrogel obtained in step (2), and stir at 800 rpm for 1 h in a magnetic stirrer to prepare mixed hydrogels containing anthocyanin-curcumin-red yeast rice pigment compound (the mass ratio of anthocyanin to curcumin to red yeast rice pigment is 1:0.5:0.5); wherein the mass ratio of anthocyanin-curcumin-red yeast rice pigment compound to mixed hydrogel is 0.02:100.

[0030] (4) After sonicating the film-forming solution obtained in step (3) for 5 minutes, pour it into a 90 mm × 15 mm glass culture dish to cast a film, dry it, and obtain the gas sensing membrane material and store it in a constant temperature and humidity chamber.

[0031] (5) The gas-sensitive membrane obtained in step (4) is laser-drilled. The drilling shape is pentagonal with a side length of 1 mm. A 7 (horizontal X) × 7 (vertical Y) matrix pattern is adopted with an interval of 1 mm.

[0032] (6) The gas-sensitive membrane obtained in (5) is used to monitor the quality of strawberries.

[0033] Example 2

[0034] (1) Weigh 2 g of polyvinyl alcohol and soluble starch and dissolve them in 100 mL of water. Stir the mixture on a magnetic stirrer at 70 °C and 700 rpm for 1 h to dissolve it. After cooling, add 2% of the mass of the above system of glycerol and continue stirring for 0.8 h to obtain a hydrogel containing polyvinyl alcohol and soluble starch.

[0035] (2) Add 0.08 g of bis(3-aminopropyl)polyethylene glycol to the hydrogel of polyvinyl alcohol and soluble starch obtained in step (1) to obtain a mixed hydrogel, and stir at 700 rpm for 0.5 h in a magnetic stirrer.

[0036] (3) Add anthocyanin-curcumin-red yeast rice pigment compound to the mixed hydrogel obtained in step (2), and stir at 900 rpm for 0.5 h in a magnetic stirrer to prepare mixed hydrogels containing anthocyanin-curcumin-red yeast rice pigment compound (the mass ratio of anthocyanin to curcumin to red yeast rice pigment is 1:0.5:0.5); wherein the mass ratio of anthocyanin-curcumin-red yeast rice pigment compound to mixed hydrogel is 0.04:100.

[0037] (4) After sonicating the film-forming solution obtained in step (3) for 6 minutes, pour it into a 90 mm × 15 mm glass culture dish to cast a film, and dry it to obtain the gas sensing membrane material.

[0038] (5) The gas-sensitive membrane obtained in step (4) is laser-drilled. The side length of the pentagon is 1.2 mm. A 7 (horizontal X) × 7 (vertical Y) matrix pattern is adopted with an interval of 1.3 mm.

[0039] (6) The gas-sensitive membrane obtained in (5) is used to monitor the quality of strawberries.

[0040] Example 3

[0041] (1) Weigh 3 g of polyvinyl alcohol and 2 g of soluble starch and dissolve them in 100 mL of water. Stir the mixture on a magnetic stirrer at 80 °C and 700 rpm for 1 h to dissolve it. After cooling, add 1.5% of the above system mass of glycerol and continue stirring for 0.5 h to obtain a hydrogel containing polyvinyl alcohol and soluble starch.

[0042] (2) Add 1.2 g of bis(3-aminopropyl)polyethylene glycol to the hydrogel of polyvinyl alcohol and soluble starch obtained in step (1) to obtain a mixed hydrogel, and stir at 700 rpm for 0.8 h in a magnetic stirrer.

[0043] (3) Add anthocyanin-curcumin-red yeast rice pigment compound to the mixed hydrogel obtained in step (2), and stir at 900 rpm for 0.8 h in a magnetic stirrer to prepare mixed hydrogels containing anthocyanin-curcumin-red yeast rice pigment compound (the mass ratio of anthocyanin to curcumin to red yeast rice pigment is 1:0.5:0.5); wherein the mass ratio of anthocyanin-curcumin-red yeast rice pigment compound to mixed hydrogel is 0.06:100.

[0044] (4) After sonicating the film-forming solution obtained in step (3) for 7 min, pour it into a 90 mm × 15 mm glass culture dish to cast a film, and dry it to obtain the gas sensing membrane material.

[0045] (5) The gas-sensitive membrane obtained in step (4) is laser-drilled. The drilling shape is pentagonal with a side length of 1.4 mm. A 7 (horizontal X) × 7 (vertical Y) matrix pattern is adopted with an interval of 1 mm.

[0046] (6) The gas-sensitive membrane obtained in (5) is used to monitor the quality of strawberries.

[0047] Example for comparison:

[0048] The comparative example of this invention uses polyvinyl alcohol and soluble starch to prepare a gas-sensitive membrane, and is compared with the example. The detailed steps are as follows, based on Example 1:

[0049] Compare with Example 1:

[0050] (1) Weigh 1.5 g of polyvinyl alcohol and soluble starch and dissolve them in 100 mL of water. Stir the mixture at 60 °C and 800 rpm for 2 h on a magnetic stirrer until dissolved. After cooling, add 1% of the mass of the above system of glycerol and continue stirring for 0.7 h to obtain a hydrogel containing polyvinyl alcohol and soluble starch.

[0051] (2) Add 0.07 g of bis(3-aminopropyl)polyethylene glycol to the hydrogel of polyvinyl alcohol and soluble starch obtained in step (1) to obtain a mixed hydrogel, and stir at 900 rpm for 1 h in a magnetic stirrer.

[0052] (3) Add anthocyanin-curcumin-red yeast rice pigment compound to the mixed hydrogel obtained in step (2), and stir at 800 rpm for 1 h in a magnetic stirrer to prepare mixed hydrogels containing anthocyanin-curcumin-red yeast rice pigment compound (the mass ratio of anthocyanin, curcumin and red yeast rice pigment is shown in Table 1); wherein the mass ratio of anthocyanin-curcumin-red yeast rice pigment compound to mixed hydrogel is 0.02:100.

[0053] (4) After sonicating the film-forming solution obtained in step (3) for 5 minutes, pour it into a 90 mm × 15 mm glass culture dish to cast a film, dry it, and obtain the gas sensing membrane material and store it in a constant temperature and humidity chamber.

[0054] (5) The gas-sensitive membrane obtained in (4) is used to monitor the quality of strawberries.

[0055] Compare with Example 2:

[0056] (1) Weigh 1.5 g of polyvinyl alcohol and soluble starch and dissolve them in 100 mL of water. Stir the mixture at 60 °C and 800 rpm for 2 h on a magnetic stirrer until dissolved. After cooling, add 1% of the mass of the above system of glycerol and continue stirring for 0.7 h to obtain a hydrogel containing polyvinyl alcohol and soluble starch.

[0057] (2) Add 0.07 g of bis(3-aminopropyl)polyethylene glycol to the hydrogel of polyvinyl alcohol and soluble starch obtained in step (1) to obtain a mixed hydrogel, and stir at 900 rpm for 1 h in a magnetic stirrer.

[0058] (3) Add anthocyanin-curcumin-red yeast rice pigment compound to the mixed hydrogel obtained in step (2), and stir at 800 rpm for 1 h in a magnetic stirrer to prepare mixed hydrogels containing anthocyanin-curcumin-red yeast rice pigment compound (the mass ratio of anthocyanin to curcumin to red yeast rice pigment is 1:0.5:0.5); wherein the mass ratio of anthocyanin-curcumin-red yeast rice pigment compound to mixed hydrogel is 0.02:100.

[0059] (4) After sonicating the film-forming solution obtained in step (3) for 5 minutes, pour it into a 90 mm × 15 mm glass culture dish to cast a film, dry it, and obtain the gas sensing membrane material and store it in a constant temperature and humidity chamber.

[0060] (5) The gas-sensitive membrane obtained in (4) is used to monitor the quality of strawberries.

[0061] Compare with Example 3:

[0062] (1) Weigh 1.5 g of polyvinyl alcohol and soluble starch and dissolve them in 100 mL of water. Stir the mixture at 60 °C and 800 rpm for 2 h on a magnetic stirrer until dissolved. After cooling, add 1% of the mass of the above system of glycerol and continue stirring for 0.7 h to obtain a hydrogel containing polyvinyl alcohol and soluble starch.

[0063] (2) Add 0.07 g of bis(3-aminopropyl)polyethylene glycol to the hydrogel of polyvinyl alcohol and soluble starch obtained in step (1) to obtain a mixed hydrogel, and stir at 900 rpm for 1 h in a magnetic stirrer.

[0064] (3) Add anthocyanin-curcumin-red yeast rice pigment compound to the mixed hydrogel obtained in step (2), and stir at 800 rpm for 1 h in a magnetic stirrer to prepare mixed hydrogels containing anthocyanin-curcumin-red yeast rice pigment compound (the mass ratio of anthocyanin to curcumin to red yeast rice pigment is 1:0.5:0.5); wherein the mass ratio of anthocyanin-curcumin-red yeast rice pigment compound to mixed hydrogel is 0.02:100;

[0065] (4) After sonicating the film-forming solution obtained in step (3) for 5 minutes, pour it into a 90 mm × 15 mm glass culture dish to cast a film, dry it, and obtain the gas sensing membrane material and store it in a constant temperature and humidity chamber.

[0066] (5) The gas-sensitive membrane obtained in step (4) is laser-drilled. The drilling shape is a circular pentagon with a side length of 1 mm. A 7 (horizontal X) × 7 (vertical Y) matrix pattern is adopted with an interval of 1 mm.

[0067] (6) The gas-sensitive membrane obtained in (5) is used to monitor the quality of strawberries.

[0068] In Comparative Example 1, the use of gas-sensitive membranes containing different mass ratios of anthocyanin-curcumin-red yeast rice pigment to monitor quality changes in strawberries during storage was investigated. As shown in Table 1, compared to other ratios, the gas-sensitive membrane with a mass ratio of 1:0.5:0.5 could accurately monitor the entire process of strawberry quality changes during storage, from fresh to slightly fresh and then to rotten. This gas-sensitive membrane exhibited three color changes compared to other ratios of colorimetric reagents. When the gas-sensitive membrane was dark brown, the strawberries were fresh; when it was green, the strawberries were slightly fresh; and when it was pink, the strawberries were rotten. This process was only achieved with a mass ratio of 1:0.5:0.5. When monitoring the quality changes of strawberries during storage, the aldehydes released by the strawberries reacted with (3-aminopropyl)polyethylene glycol, lowering the pH of the environment and causing a color change in the gas-sensitive membrane. Red yeast rice pigment is relatively stable at pH 1 to 10. Therefore, red yeast rice pigment can be used as an auxiliary colorant to achieve the three color changes of the gas-sensitive membrane.

[0069] The differences between Comparative Examples 2-3 and the Examples lie in the absence of laser perforation on the gas-sensitive membrane and the difference in perforation shape. The color changes of the prepared gas-sensitive membranes during strawberry monitoring were compared, as detailed in the table below.

[0070] Table 2 shows the color changes of the three gas-sensitive membranes during the monitoring of strawberry quality. Anthocyanin-curcumin-red yeast rice pigment complex was used as the color developer. The gas-sensitive membranes in the control examples were those with circular perforations created using a laser, and those without laser perforation.

[0071] The results showed that the gas-sensitive membranes prepared by the three methods exhibited the same color change pattern as the quality changes of strawberries during storage. From day 1 to day 2 of strawberry storage, the color of the gas-sensitive membrane did not change noticeably to the naked eye. From day 2 to day 3 of strawberry storage, the color of the gas-sensitive membrane changed visibly from dark brown to green. From day 3 to day 4 of strawberry storage, the color of the gas-sensitive membrane changed from green to pink. However, compared with Control Examples 1 and 2, the color change of the gas-sensitive membrane prepared in Example 1 was more significant and easier to observe with the naked eye. The color change of the gas-sensitive membrane was consistent with the pattern of quality changes of strawberries during storage. When the gas sensing material was dark brown, it indicated that the fruit and vegetables were fresh; when the gas sensing material was green, it indicated that the fruit and vegetables were not very fresh; and when the membrane was pink, it indicated that the fruit and vegetables were rotten. Therefore, the present invention successfully prepared a gas-sensitive membrane that can be used for strawberry quality monitoring.

[0072] Table 1. Color changes of different pigment ratios during strawberry quality monitoring.

[0073]

[0074] Table 2. Color changes of five gas-sensitive membranes during strawberry quality monitoring.

[0075]

[0076] The foregoing illustrative description of the invention and its embodiments is not restrictive. Therefore, if those skilled in the art are inspired by it and design similar structural methods and embodiments without departing from the spirit of the invention, they should all fall within the protection scope of the invention.

Claims

1. A method for preparing a gas sensing material for detecting deterioration in fruit and vegetable quality, characterized in that, Includes the following steps: (1) Preparation of hydrogel: Polyvinyl alcohol and soluble starch are dissolved in water and stirred at 60-80 °C. After cooling, 2% glycerol by mass of the system is added and stirring is continued to obtain a hydrogel mixed with polyvinyl alcohol and soluble starch. The mass ratio of polyvinyl alcohol, soluble starch and water is (2-5):(1-3):100; (2) Addition of reactant: Bis(3-aminopropyl)polyethylene glycol is added to the hydrogel obtained in step (1) to obtain a mixed hydrogel. Stir and mix well; wherein the mass ratio of bis(3-aminopropyl)polyethylene glycol to water is (0.07~1.2):100; (3) Addition of color developer: add anthocyanin-curcumin-red yeast rice pigment compound to the mixed hydrogel obtained in step (2), stir to prepare a mixed hydrogel containing anthocyanin-curcumin-red yeast rice pigment compound; wherein the mass ratio of anthocyanin-curcumin-red yeast rice pigment compound to reactant is 0.02~0.06:0.07~1.2; (4) Preparation of gas-sensitive membrane: sonicate the mixed hydrogel obtained in step (3) and cast it into a film, dry it to obtain gas sensing material.

2. The preparation method of the gas sensing material for detecting deterioration in fruit and vegetable quality according to claim 1, characterized in that, In step (1), 2-5 g of polyvinyl alcohol and 1-3 g of soluble starch are weighed and dissolved in 100 mL of water. The mixture is stirred at 60-80°C for 3-4 hours to obtain a hydrogel solution.

3. The preparation method of the gas sensing material for detecting deterioration in fruit and vegetable quality according to claim 1, characterized in that, In step (3), 0.02–0.06 g of anthocyanin-curcumin-red yeast rice pigment complex is weighed and dissolved in the mixed hydrogel.

4. The method for preparing the gas sensing material for detecting deterioration in fruit and vegetable quality according to claim 1, characterized in that, In step (3), the anthocyanin-curcumin-red yeast rice pigment compound is mixed in a mass ratio of 1:0.5:0.

5.

5. The method for preparing the gas sensing material for detecting deterioration in fruit and vegetable quality according to claim 1, characterized in that, In steps (2) and (3), the color developer and the reactant are added after the hydrogel has been dissolved and cooled.

6. The method for preparing the gas sensing material for detecting deterioration in fruit and vegetable quality according to claim 1, characterized in that, In step (4), after the membrane solution cools, it is sonicated at 200W to 500W for 5 to 10 minutes and then dried in an oven at 30 to 45 ℃ for 8 to 12 hours.

7. The fruit and vegetable quality deterioration gas sensing material prepared by any one of claims 1 to 6, characterized in that, The fruits and vegetables are of the non-climacteric respiration type.

8. The application of the fruit and vegetable quality deterioration gas sensing material of claim 7 in monitoring aldehyde volatile substances in the fruit and vegetable supply chain, characterized in that, The packaging box contains a non-jumping respiration gas sensing material for detecting deterioration in fruit and vegetable quality. Its detection accuracy is 99.40-99.92%, and its detection speed is 3-5 seconds.

9. The application of the fruit and vegetable quality deterioration gas sensing material according to claim 8 in monitoring aldehyde volatile substances in the fruit and vegetable supply chain, characterized in that, The packaging box material is perforated by laser. The perforation shape is pentagonal, with a side length of 1 to 1.5 mm, using a 7×7 matrix pattern and an interval of 0.5 to 1.5 mm.

10. The application of the fruit and vegetable quality deterioration gas sensing material according to claim 8 in monitoring aldehyde volatile substances in the fruit and vegetable supply chain, characterized in that, The color change of the gas sensing material for detecting deterioration in fruit and vegetable quality when monitoring volatile aldehydes is as follows: when the gas-sensitive membrane is dark brown, the strawberries are fresh; when the gas-sensitive membrane is green, the strawberries are not very fresh; when the gas-sensitive membrane is pink, the strawberries are rotten. The color a* of the gas-sensitive membrane varies from 1.23 to 27.74; the color b* varies from -21.11 to 2.34, and its detection accuracy is 99.40% to 99.92%.

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