A composite aerogel for patulin detoxification, a continuous flow biocatalytic detoxification device and its application

Abstract

This invention discloses a composite aerogel for patulin detoxification, a continuous flow biocatalytic detoxification device, and their applications, belonging to the field of food biocatalytic detoxification technology. The composite aerogel of this invention comprises chitosan aerogel and PPL@COF-LZU1 dispersed within the chitosan aerogel; the PPL@COF-LZU1 is a complex formed by encapsulating porcine pancreatic lipase within a covalent organic framework COF-LZU1. To overcome the shortcomings of existing patulin detoxification technologies, such as poor stability of the free enzyme, difficulty in recovery, inconvenience in handling powdered immobilized enzyme materials, and the difficulty in achieving continuous operation of existing detoxification methods, this invention provides a composite aerogel for patulin detoxification, a continuous flow biocatalytic detoxification device, and their applications, offering a new technical solution for the efficient, safe, and continuous removal of patulin from apple juice, demonstrating promising application prospects.

Description

Technical Field

[0001] This invention relates to the field of food biocatalytic detoxification technology, and in particular to a composite aerogel for patulin detoxification, a continuous flow biocatalytic detoxification device, and its application. Background Technology

[0002] Apple juice is highly favored by consumers for its unique flavor and rich nutritional value, but its quality and safety have always been a major concern. Patulin (PAT), a secondary metabolite produced by various fungi, is a common harmful mycotoxin in apple juice production. PAT has high hepatotoxicity, nephrotoxicity, gastrointestinal tract toxicity, neurotoxicity, and immunotoxicity; even low-dose long-term intake can pose a serious threat to human health. Therefore, developing efficient methods for removing PAT from apple juice is of great significance for protecting consumer health and promoting the high-quality development of the apple juice industry.

[0003] Traditional physical adsorption or chemical detoxification methods often suffer from poor selectivity, easily damage the nutritional quality of apple juice, or introduce secondary pollution, making it difficult to meet the urgent needs of the modern food industry for efficient, green, and safe technologies. In contrast, biodetoxification methods based on enzyme biocatalytic degradation have advantages such as mild conditions, high substrate specificity, high catalytic efficiency, and products that are usually safe and non-toxic. Theoretically, they can precisely remove toxins while preserving the natural quality of apple juice to the greatest extent, thus showing unique application potential in PAT degradation.

[0004] Studies have shown that porcine pancreatic lipase (PPL) exhibits highly efficient degradation capabilities for PAT. Combined with its inherent safety and economic viability, PPL holds great potential for PAT removal. However, directly applying free enzymes to complex food systems still faces significant engineering challenges. First, free enzymes exhibit extremely poor stability; the low pH of apple juice and the wide temperature variations during processing easily lead to enzyme denaturation and inactivation. Second, free enzymes are difficult to recover and reuse, increasing the cost of juice processing. These inherent limitations severely restrict the industrial application of enzymatic detoxification technology.

[0005] Covalent organic frameworks (COFs), as a novel class of crystalline porous materials, possess outstanding advantages such as tunable pore regularity, ultra-high specific surface area, and good thermochemical stability, showing promising potential in the field of biomolecule immobilization. Existing research has disclosed the encapsulation of lactate dehydrogenase in hollow COF-42 using a mild method; the hollow structure provides a suitable microenvironment, enhancing biocatalytic activity. Other studies have combined glucose oxidase with COF capsules, which protect the enzyme from high temperatures, acids, and organic solvents. Nevertheless, these powdered enzyme@COF composites still face challenges in practical applications, including inconvenient handling, difficulty in recycling, and secondary pollution. Incorporating COF particles into porous aerogels is a common strategy. Aerogels, as highly porosity and ultralight materials, are widely used for pollutant adsorption. Studies have synthesized covalently bonded MOF / COF aerogels for the decomposition of nerve agent mimics, avoiding catalysis-related secondary pollution. The choice of substrate is crucial for constructing structurally stable and functionally synergistic aerogel catalytic materials. Chitosan (CS), as a green and safe natural polymer material, provides ample space for the embedding of enzyme@COF nanoparticles due to its abundant porous structure. However, existing CS-based composite aerogels still lack systematic research on continuous flow operation, long-term operational stability, and detoxification performance in actual fruit juice systems, and industrially feasible continuous detoxification devices have not yet been developed. Summary of the Invention

[0006] The purpose of this invention is to provide a composite aerogel for patulin detoxification, a continuous flow biocatalytic detoxification device, and its application, to solve the aforementioned problems in the background art. To overcome the shortcomings of existing patulin detoxification technologies, such as poor stability of free enzymes, difficulty in recovery, inconvenience in handling powdered immobilized enzyme materials, and the difficulty in achieving continuous operation of existing detoxification methods, this invention provides a composite aerogel for patulin detoxification, a continuous flow biocatalytic detoxification device, and its application. This provides a new technical solution for the efficient, safe, and continuous removal of patulin from apple juice, demonstrating promising application prospects.

[0007] To achieve the above objectives, the present invention provides the following technical solution: One of the technical solutions of the present invention is to provide a composite aerogel for patulin detoxification, wherein the composite aerogel contains chitosan aerogel and PPL@COF-LZU1 dispersed in the chitosan aerogel; wherein PPL@COF-LZU1 is a complex formed by encapsulating porcine pancreatic lipase in a covalent organic framework COF-LZU1.

[0008] Preferably, the COF-LZU1 is formed by the condensation polymerization of p-phenylenediamine (PPDA) and 1,3,5-trimethylbenzaldehyde (BTCA).

[0009] The second technical solution of the present invention provides a method for preparing the above-mentioned composite aerogel for patulin detoxification, comprising the following steps: (1) Dissolve 1,3,5-pyromellitic aldehyde in a solvent, then add acetic acid, porcine pancreatic lipase solution and p-phenylenediamine solution, encapsulate the reaction, and collect PPL@COF-LZU1; (2) Chitosan is dissolved in an acidic solution, and then PPL@COF-LZU1, polyethyleneimine solution and epichlorohydrin solution are added to obtain a mixture. The mixture is then gelled to obtain the composite aerogel.

[0010] Preferably, in step (1), the concentration of the porcine pancreatic lipase solution is 10 mg / mL; the concentration of the p-phenylenediamine solution is 10 mg / mL. The ratio of 1,3,5-trimethylbenzaldehyde, porcine pancreatic lipase solution, and p-phenylenediamine solution is 5 mg:1 mL:1 mL.

[0011] Preferably, the encapsulation reaction includes the following steps: after stirring for 10 min, adjusting the pH of the system to 4, and then continuing to stir for 10 min.

[0012] Preferably, in step (2), the ratio of chitosan to acidic solution is 1.0 g: 50 mL, the acidic solution is a 2 wt% acetic acid solution; the concentration of the polyethyleneimine solution is 4 wt%; and the concentration of the epichlorohydrin solution is 2 wt%. The ratio of chitosan, PPL@COF-LZU1, polyethyleneimine solution, and epichlorohydrin is 1.0 g:30 mg:25 mL:1 mL.

[0013] Preferably, the gelation reaction is carried out by heating at 60°C for 5 hours.

[0014] The third technical solution of the present invention provides a continuous flow biocatalytic detoxification device, including a reaction packing column, an inlet / outlet pump and a central controller; the central controller is used to set and adjust the flow rate, and the inlet / outlet pump drives the liquid to flow through the reaction packing column; the above-mentioned composite aerogel is used as the filling material of the reaction packing column.

[0015] The fourth technical solution of the present invention provides an application of the above-mentioned composite aerogel or the above-mentioned continuous flow biocatalytic detoxification device in the field of patulin detoxification.

[0016] The fifth technical solution of the present invention provides a method for detoxifying patulin, which utilizes the above-mentioned continuous flow biocatalytic detoxification device to detoxify patulin in apple juice, including the following steps: continuously flowing the apple juice to be treated through the reaction packing column of the continuous flow biocatalytic detoxification device for detoxification treatment, collecting the effluent to obtain detoxified apple juice.

[0017] Preferably, the liquid flow rate in the inlet and outlet pumps is 0.05-0.5 mL / min.

[0018] Chitosan (CS), as a green and safe natural polymer material, provides ample space for the embedding of enzyme@COF nanoparticles due to its abundant porous structure. The numerous amino and hydroxyl groups on the CS molecular chain can firmly lock the nanocomposite within the network through cross-linking. The covalent organic framework COF-LZU1, with its regular and tunable pore structure, high specific surface area, and good biocompatibility, is an ideal carrier for enzyme immobilization. This invention uses COF-LZU1 as a carrier and employs a mild in-situ encapsulation method to encapsulate PPL within the pores of COF-LZU1, obtaining a PPL@COF-LZU1 composite. This composite is then incorporated into a CS aerogel to prepare a CS@PPL@COF-LZU1 composite aerogel. In this composite aerogel, the COF-LZU1 framework effectively maintains the active conformation of PPL, significantly improving the enzyme's thermal stability and pH tolerance. Simultaneously, the porous structure of the chitosan aerogel exhibits excellent adsorption capacity for PAT, forming an adsorption-catalytic synergistic detoxification effect with the catalytic degradation of PPL. Furthermore, this invention uses the composite aerogel as the column filling material to construct a continuous flow biocatalytic detoxification device, which can achieve continuous and efficient detoxification of PAT in apple juice.

[0019] The beneficial technical effects of the present invention are as follows: To overcome the shortcomings of existing patulin detoxification technologies, such as poor stability of free enzymes, difficulty in recovery, inconvenience in handling powdered immobilized enzyme materials, and difficulty in achieving continuous operation of existing detoxification methods, this invention provides a composite aerogel for patulin detoxification, a continuous flow biocatalytic detoxification device, and its application. This provides a new technical solution for the efficient, safe, and continuous removal of patulin from apple juice and shows good application prospects.

[0020] This invention utilizes COF-LZU1 as a carrier to encapsulate porcine pancreatic lipase (PPL) within the pores of COF-LZU1 via a mild in-situ encapsulation method, which is then embedded into a chitosan aerogel, successfully constructing a CS@PPL@COF-LZU1 composite aerogel. The confinement effect of the COF-LZU1 framework effectively maintains the active conformation of PPL, significantly improving the enzyme's thermal stability and pH tolerance, overcoming the defect of easy inactivation of free enzymes in the acidic environment of apple juice. Simultaneously, the porous structure of the chitosan aerogel endows the material with excellent adsorption capacity for patulin, synergistically enhancing the adsorption-catalytic detoxification effect with the catalytic degradation of PPL, significantly improving detoxification efficiency.

[0021] Furthermore, a continuous-flow biocatalytic detoxification device constructed using this composite aerogel as the filling material achieved continuous detoxification of PAT in apple juice. Under optimized conditions, the device achieved a detoxification rate of 89.67% for PAT in 30 mL of apple juice, reducing the residual concentration to 0.21 μg / mL. In addition, the composite aerogel exhibited good reusability and storage stability, and combined the advantages of simple operation and high safety, providing reliable technical support for the efficient, safe, and continuous removal of patulin from fruit juice. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 CLSM image of PPL@COF-LZU1 powder prepared in Example 1; Figure 2 The FTIR spectra of PPL@COF-LZU1 powder, CS@PPL@COF-LZU1 aerogel, and CS aerogel in Example 1 are shown. Figure 3 The results of the reusability test for the CS@PPL@COF-LZU1 aerogel prepared in Example 1; Figure 4 This is a schematic diagram of the composition of the continuous flow biocatalytic detoxification device in Example 2; Figure 5 Here is a photograph of the continuous flow biocatalytic detoxification device from Example 2; Figure 6For Example 3, under the conditions of a flow rate of 0.05 mL / min and different numbers of aerogels (a: n=3; b: n=2; c: n=1), the PAT concentration and detoxification rate corresponding to different outflow volumes were determined. Figure 7 Example 4 shows the PAT concentration and detoxification rate corresponding to different outflow volumes under conditions of aerogel loading n=3 and different flow rates (v=0.5 mL / min, 0.25 mL / min or 0.05 mL / min). Detailed Implementation

[0024] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention. It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the present invention.

[0025] Furthermore, regarding the numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, are also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0026] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. It should be noted that any aspects of this invention not described in detail are conventional practices in the art and are not the focus of this invention.

[0027] The terms “comprising,” “including,” “having,” “containing,” etc., used in this invention are all open-ended terms, meaning that they include but are not limited to. This invention discloses a method for preparing a composite aerogel (CS@PPL@COF-LZU1 composite aerogel) for patulin detoxification, comprising the following steps: Step 1, Preparation of PPL@COF-LZU1: BTCA (5 mg; 1,3,5-trimethylbenzaldehyde) was dissolved in DMF (250 µL; N,N-dimethylformamide) to form a solution. This solution was then transferred to deionized water (10 mL) and sonicated for 5 min. Next, glacial acetic acid (1 mL) and PPL enzyme solution (1 mL, 10 mg / mL) were added sequentially to obtain a mixture. While stirring, PPDA (p-phenylenediamine) solution (1 mL, 10 mg / mL) was added to the mixture, and the reaction was allowed to proceed for 10 min. Afterward, the pH of the system was adjusted to 4 using NaOH solution (1 mL, 4 mol / L), and stirring was continued at room temperature for another 10 min. After the reaction was complete, the precipitate was collected by centrifugation, washed three times with deionized water, and the resulting nanoparticles were freeze-dried to obtain PPL@COF-LZU1 powder. Step 2: CS (1.0 g; chitosan) was added to acetic acid solution (50 mL, concentration 2 wt%) and mechanically stirred at room temperature for 1 h to obtain CS solution; then, the above CS solution was mixed with PEI (polyethyleneimine) solution (25 mL, concentration 4 wt%) and the above PPL@COF-LZU1 powder (30 mg) and stirred for 2 h; next, epichlorohydrin solution (1 mL, concentration 2 wt%) was added and stirring was continued for 1 h; then the mixture was transferred to a 24-well plate (2 mL per well) and placed in a 60℃ oven for 5 h; after the reaction, it was washed with deionized water and finally freeze-dried for 24 h to obtain CS@PPL@COF-LZU1 composite aerogel.

[0028] The present invention also discloses a method for detoxifying patulin, which utilizes the above-mentioned composite aerogel.

[0029] The following is an experiment on the removal of patulin using CS@PPL@COF-LZU1 composite aerogel: Step 1: The removal capacity of the above CS@PPL@COF-LZU1 composite aerogel for PAT (patulin) was determined by high performance liquid chromatography (HPLC); the aerogel sample was placed in PAT solution (3 mL, concentration 5 μg / mL) and reacted at 25℃ for 24 h; after the reaction, the supernatant was taken and the residual PAT concentration was detected at a wavelength of 276 nm; the sample was washed three times with ultrapure water, and the above operation was repeated. Step 2: Using CS@PPL@COF-LZU1 composite aerogel as the packing material, a chromatography column (5 mL, 69.3 × 12.3 mm, column volume 5.53 mL) was packed to prepare a continuous flow detoxification device; a silicone tube was connected to allow the PAT solution to flow through, and the chromatography column was fixed vertically throughout; apple juice containing PAT (2 μg / mL) was pumped into the chromatography column packed with CS@PPL@COF-LZU1 composite aerogel at a constant flow rate controlled by a central controller; different flow rates and aerogel packing quantities were set, and different volumes of effluent were collected; the effluent apple juice was extracted three times with an equal volume of ethyl acetate, the extracts were combined, dried under nitrogen, and then resuspended in citric acid solution (1 mL, pH 3.5); the residual PAT concentration was determined by HPLC system at a wavelength of 276 nm.

[0030] Unless otherwise specified, "room temperature" in this invention refers to 10-30°C.

[0031] All raw materials used in the following embodiments and comparative examples of the present invention are commercially available products.

[0032] The technical solution of the present invention will be further illustrated by the following embodiments.

[0033] Example 1 A method for preparing CS@PPL@COF-LZU1 composite aerogel, comprising the following steps: Step 1, Preparation of PPL@COF-LZU1: BTCA (5 mg; 1,3,5-trimethylbenzaldehyde) was dissolved in DMF (250 µL; N,N-dimethylformamide) to form a solution. This solution was then transferred to deionized water (10 mL) and sonicated for 5 min. Next, glacial acetic acid (1 mL) and PPL enzyme solution (1 mL, 10 mg / mL) were added sequentially to obtain a mixture. While stirring, PPDA (p-phenylenediamine) solution (1 mL, 10 mg / mL) was added to the mixture, and the reaction was allowed to proceed for 10 min. Afterward, the pH of the system was adjusted to 4 using NaOH solution (1 mL, 4 mol / L), and stirring was continued at room temperature for another 10 min. After the reaction was complete, the precipitate was collected by centrifugation, washed three times with deionized water, and the resulting nanoparticles were freeze-dried to obtain PPL@COF-LZU1 powder. Step 2: CS (1.0 g; chitosan) was added to acetic acid solution (50 mL, concentration 2 wt%) and mechanically stirred at room temperature for 1 h to obtain CS solution; then, the above CS solution was mixed with PEI (polyethyleneimine) solution (25 mL, concentration 4 wt%) and the above PPL@COF-LZU1 powder (30 mg) and stirred for 2 h; next, epichlorohydrin solution (1 mL, concentration 2 wt%) was added and stirring was continued for 1 h; then the mixture was transferred to a 24-well plate (2 mL per well) and placed in a 60℃ oven for 5 h; after the reaction, it was washed with deionized water and finally freeze-dried for 24 h to obtain CS@PPL@COF-LZU1 composite aerogel.

[0034] Comparative Example 1 (without PPL@COF-LZU1) CS (1.0 g) was added to acetic acid solution (50 mL, concentration 2 wt%) and mechanically stirred at room temperature for 1 h to obtain CS solution; transferred to 24-well plate (2 mL per well) and placed in 60℃ oven for 5 h reaction; after the reaction was completed, washed with deionized water and finally freeze-dried for 24 h to obtain CS aerogel.

[0035] Figure 1 The image shows a CLSM image of the PPL@COF-LZU1 powder prepared in Example 1, where PPL is marked with FITC (fluorescein isothiocyanate, red). The image shows that PPL is encapsulated within COF-LZU1, proving that PPL@COF-LZU1 was successfully synthesized.

[0036] Figure 2 The PPL@COF-LZU1 powder, CS@PPL@COF-LZU1 aerogel, and CS aerogel (i.e., the powder, CS@PPL@COF-LZU1 aerogel, and CS aerogel) are from Example 1. Figure 2 The FTIR spectrum of the "CS aerogel" shows that the CS@PPL@COF-LZU1 composite aerogel has a wavelength of 1612 cm⁻¹. -1 The presence of a characteristic absorption peak at the point is attributed to the amide I band of PPL (C=O stretching vibration), confirming that PPL has been successfully loaded into the composite aerogel.

[0037] Deactivation experiment of patulin by CS@PPL@COF-LZU1 composite aerogel: To investigate the reproducibility of the aerogel, high-performance liquid chromatography (HPLC) was used to determine the removal capacity of the CS@PPL@COF-LZU1 composite aerogel for PAT (patulin). 170 mg of the aerogel sample was placed in 3 mL of PAT solution (concentration 5 μg / mL) and reacted at 25 °C for 24 h. After the reaction, the supernatant was collected and the residual PAT concentration was measured at 276 nm to calculate the detoxification rate. The used CS@PPL@COF-LZU1 composite aerogel was washed three times with ultrapure water, and the above operation was repeated. The formula for calculating the detoxification rate is as follows: In the formula, C0 (μg / mL) and C t (μg / mL) represent the initial and detoxified concentrations of PAT, respectively.

[0038] Figure 3 The reusability test results of the CS@PPL@COF-LZU1 aerogel prepared in Example 1 show that the aerogel can maintain a detoxification rate of more than 80% after being used more than 8 times.

[0039] Example 2 Constructing a continuous flow biocatalytic detoxification device: Using the CS@PPL@COF-LZU1 composite aerogel prepared in Example 1 as the packing material, a chromatography column (5 mL, 69.3 × 12.3 mm, column volume 5.53 mL) was packed to prepare a continuous flow detoxification device (chromatographic column); a silicone tube was connected to allow the PAT solution to flow through, and the chromatography column was fixed vertically throughout; apple juice containing PAT (2 μg / mL) was pumped into the chromatography column packed with CS@PPL@COF-LZU1 composite aerogel at a constant flow rate controlled by a central controller; different flow rates and aerogel packing quantities were set, and different volumes of effluent were collected; the effluent apple juice was extracted three times with an equal volume of ethyl acetate, the extracts were combined, dried under nitrogen, and then resuspended in citric acid solution (1 mL, pH 3.5); the residual PAT concentration was determined by HPLC system at a wavelength of 276 nm.

[0040] Figure 4 and Figure 5 The images show schematic diagrams and photographs of the continuous flow biocatalytic detoxification device based on the CS@PPL@COF-LZU1 aerogel from Example 1.

[0041] Example 3 Based on Example 2, relevant tests were conducted by simply modifying the number of CS@PPL@COF-LZU1 composite aerogels used as packing materials in the chromatography column (1, 2, and 3 respectively).

[0042] Figure 6 In Example 3, under conditions of a flow rate of 0.05 mL / min and different numbers of aerogels packed (a: n=1; b: n=2; c: n=3), the PAT detoxification efficiency in 5 mL of effluent increased from 56.7% in a to 80.34% in c, with a corresponding PAT concentration of 0.39 μg / mL in the effluent. This improvement is attributed to the increase in PPL@COF-LZU1, resulting in a richer concentration of active sites.

[0043] Example 4 Based on the aerogel filling method of Example 3, which involves filling three aerogels, relevant tests were conducted by simply modifying the flow rate of the apple juice to be processed to 0.05-0.5 mL / min (specifically v=0.5 mL / min, 0.25 mL / min, or 0.05 mL / min).

[0044] Figure 7 Example 4 shows the PAT concentration and detoxification rate corresponding to different effluent volumes under conditions of aerogel loading volume n=3 and different flow rates (a: v=0.05 mL / min; b: 0.25 mL / min; c: 0.5 mL / min). It can be seen that the PAT concentration and detoxification rate corresponding to different effluent volumes are related to the flow rate. Reducing the flow rate prolongs the reaction time of PAT in the CS@PPL@COF-LZU1 aerogel, thereby significantly improving the detoxification effect. When 30 mL of effluent is collected, the PAT detoxification rate increases from 62.91% for c to 89.67% for a, and the corresponding PAT residual concentration decreases to 0.21 μg / mL.

[0045] This invention proposes a continuous flow biocatalytic detoxification device based on CS@PPL@COF-LZU1 composite aerogel for the efficient removal of PAT from apple juice. Thanks to the confinement effect of COF-LZU1 and the adsorption-catalytic synergy of CS aerogel, the stability and detoxification efficiency of PPL enzyme are significantly improved, providing a reliable platform for continuous PAT detoxification. Compared with traditional physical adsorption or free enzyme treatment methods, the composite aerogel prepared in this invention can effectively maintain enzyme activity during long-term storage and has good reusability. Under optimal operating conditions (flow rate 0.05 mL / min, aerogel packing number 3), the PAT detoxification rate can reach 89.67%, and the residual PAT concentration is reduced to 0.21 μg / mL, providing a new technical solution for the efficient removal of PAT from apple juice.

[0046] The CS@PPL@COF-LZU1 composite aerogel and continuous flow detoxification device of the present invention have the advantages of high detoxification rate, good repeatability and simple operation for the removal of PAT in apple juice. It not only provides a new method for the efficient detoxification of PAT in apple juice, but also expands the application of composite aerogel in the field of food safety processing.

[0047] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A composite aerogel for patulin detoxification, characterized in that, The composite aerogel contains chitosan aerogel and PPL@COF-LZU1 dispersed in the chitosan aerogel; PPL@COF-LZU1 is a complex formed by encapsulating porcine pancreatic lipase in a covalent organic framework COF-LZU1.

2. The composite aerogel for patulin detoxification according to claim 1, characterized in that, The COF-LZU1 is formed by the condensation polymerization of p-phenylenediamine and 1,3,5-trimethylbenzenealdehyde.

3. A method for preparing the composite aerogel for patulin detoxification according to any one of claims 1-2, characterized in that, Includes the following steps: (1) Dissolve 1,3,5-pyromellitic aldehyde in a solvent, then add acetic acid, porcine pancreatic lipase solution and p-phenylenediamine solution, encapsulate the reaction, and collect PPL@COF-LZU1; (2) Chitosan is dissolved in an acidic solution, and then PPL@COF-LZU1, polyethyleneimine solution and epichlorohydrin solution are added to obtain a mixture. The mixture is then gelled to obtain the composite aerogel.

4. The preparation method according to claim 3, characterized in that, In step (1), the concentration of the porcine pancreatic lipase solution is 10 mg / mL; the concentration of the p-phenylenediamine solution is 10 mg / mL. The ratio of 1,3,5-trimethylbenzaldehyde, porcine pancreatic lipase solution, and p-phenylenediamine solution is 5 mg:1 mL:1 mL.

5. The preparation method according to claim 3, characterized in that, The encapsulation reaction The process includes the following steps: after stirring for 10 minutes, adjust the pH of the system to 4, and then continue stirring for another 10 minutes.

6. The preparation method according to claim 3, characterized in that, In step (2), the ratio of chitosan to acidic solution is 1.0 g: 50 mL, the acidic solution is a 2 wt% acetic acid solution; the concentration of the polyethyleneimine solution is 4 wt%; and the concentration of the epichlorohydrin solution is 2 wt%. The ratio of chitosan, PPL@COF-LZU1, polyethyleneimine solution, and epichlorohydrin is 1.0 g:30 mg:25 mL:1 mL.

7. The preparation method according to claim 3, characterized in that, The gelation reaction was carried out by heating at 60°C for 5 hours.

8. A continuous flow biocatalytic detoxification device, characterized in that, It includes a reaction-packed column, inlet and outlet pumps, and a central controller; the central controller is used to set and adjust the flow rate, and the inlet and outlet pumps drive the liquid to flow through the reaction-packed column; the composite aerogel according to any one of claims 1-2 is used as the filling material of the reaction-packed column.

9. The application of the composite aerogel according to any one of claims 1-2 or the continuous flow biocatalytic detoxification device according to claim 8 in the field of patulin detoxification.

10. A method for detoxifying patulin, characterized in that, The method of detoxifying patulin in apple juice using the continuous flow biocatalytic detoxification device according to claim 8 includes the following steps: continuously passing the apple juice to be treated through the reaction packing column of the continuous flow biocatalytic detoxification device for detoxification treatment, and collecting the effluent to obtain the detoxified apple juice.

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