Purification method, purification system and detection method of aflatoxin in spiny jujube seeds

Abstract

The invention belongs to the technical field of aflatoxin removal, and discloses a method for purifying aflatoxin in Chinese jujube seeds, a purification system, and a detection method. Chlorine dioxide is diluted to obtain a chlorine dioxide solution; the surface of a Chinese medicinal material is sprayed with the chlorine dioxide solution, and the sprayed medicinal material is stirred while spraying. The sprayed medicinal material is kept for 12 hours, and then placed in a dark environment to dry or dry to obtain the treated Chinese medicinal material. An acetic acid aqueous solution is sprayed on the surface of the Chinese jujube seeds for acidification and degradation treatment to obtain an acidified and degraded Chinese jujube seeds; a sodium bicarbonate aqueous solution is sprayed on the surface of the acidified and degraded Chinese jujube seeds for neutralization treatment. The present invention uses a chlorine dioxide solution to reduce aflatoxin and further uses the acidity of the acetic acid aqueous solution to degrade the aflatoxin in the Chinese jujube seeds. The sodium bicarbonate aqueous solution can neutralize the acetic acid aqueous solution remaining in the Chinese jujube seeds, so that the Chinese jujube seeds maintain their original appearance and smell.

Description

Technical Field

[0001] The invention belongs to the technical field of aflatoxin removal, and in particular relates to a purification method, a purification system and a detection method for aflatoxin in spinach jujube seeds. Background Art

[0002] At present, the research on aflatoxin is becoming more and more in-depth, and Ziziphus jujuba seed is a variety of Chinese medicinal materials with relatively heavy aflatoxin contamination. In order to reveal the main source of aflatoxin contamination in Ziziphus jujuba seed and identify the toxin-producing fungi, 32 Ziziphus jujuba seed samples from the harvesting, processing and storage processes were collected. The aflatoxin content was determined by immunoaffinity column-HPLC post-column photochemical derivatization method, and the contaminated fungi were isolated by dilution plate method. The strains were identified by combining morphological and molecular biological characteristics. The results showed that aflatoxin was detected in 28 samples, and the contaminated samples were distributed in each production link from harvesting to storage. Among them, only aflatoxin B1 (AFB1) exceeded the limit standard of the Chinese Pharmacopoeia in 3 samples, and AFB1 and total aflatoxins (AFs) exceeded the limit in 2 samples, which were samples after water rinsing and storage. The highest detection levels of AFB1 and AFs in the samples after water rinsing reached 94.79 and 121.43 μg kg, respectively. -1 All samples were contaminated with fungi, and the total number of contaminated fungi in freshly harvested sour jujube kernels was the lowest, at 2.20×102 CFU·g -1 , gradually increased with the progress of the processing, and the total number of fungi in the sample after water leaching rose to 1.16×106CFU·g -1 A total of 321 fungi belonging to 17 genera were isolated and identified. The main source of aflatoxin contamination in sour jujube kernels was Aspergillus flavus in the harvesting and processing environment, and one of them was confirmed to produce AFB1 and AFB2. The number of fungi increased significantly during the retting process after sour jujube was harvested, and Aspergillus fungi became the dominant flora on the jujube kernels after the endocarp was removed. The retting and water leaching processes increased the risk of aflatoxin contamination. Sixteen kinds of Chinese medicinal materials commonly used by pharmaceutical companies in Guizhou Province were selected as the research objects. 130 samples from pharmaceutical and decoction slice production companies in Guizhou Province in 2016 were collected. Immunoaffinity column chromatography and high performance liquid chromatography were used to determine the aflatoxin B1, B2, G1 and G2 contained in them. The contamination status of aflatoxin in commonly used Chinese medicinal materials in Guizhou Province was understood, and data reference was provided for the quality control of Chinese medicinal materials in Guizhou Province. Among them, the aflatoxin contamination level of Chinese medicinal materials in peels and fruits such as tangerine peel and jujube is generally low, while Chinese medicinal materials in seeds and kernels (such as pine nuts and betel nuts) and animal medicinal materials (such as centipedes and silkworms) are highly contaminated and should be taken seriously.

[0003] Conventional strategies for reducing mycotoxins include prevention and decontamination strategies. Decontamination of aflatoxins has been an ongoing challenge for the food industry. New processing methods are constantly being explored to achieve complete degradation of aflatoxins in food. Scope and methods.

[0004] Aflatoxin is a strong toxin. So far, the International Agency for Research on Cancer has classified aflatoxin as a carcinogen. Common types of aflatoxins include AFB1, AFB2, AFG1, AFG2, AFM1 and AFM2, etc., more than a dozen compounds with similar structures. Their structural characteristics are that they all contain a bifuran ring and a oxa-naphthoketone. Aflatoxin is easily soluble in organic solvents such as methanol and chloroform, but not easily soluble in water. Aflatoxin can damage human organs and suppress the body's immune function. Among aflatoxins, AFB1 is the most toxic and is a type of mycotoxin that causes very serious harm to human health.

[0005] Aflatoxin detection method

[0006] At present, the detection methods of aflatoxin include thin layer chromatography, microcolumn chromatography, high performance liquid chromatography, immunological methods, and electrochemical immunoassay. Among them, thin layer chromatography requires a long time for sample processing and has weak anti-interference ability; microcolumn chromatography requires separation of sample components; when using high performance liquid chromatography to determine aflatoxin, the chemical reagents and treatment methods used in the experiment will affect the experimental results, and the technical level required is relatively high; while the electrochemical immunoassay is simple to operate, has good detection sensitivity and good selective activity, and is more suitable for the detection of trace elements.

[0007] Through the above analysis, the problems and defects of the existing technology are as follows: the methods for removing and purifying aflatoxin in sour jujube in the existing technology are immature, the removal effect needs to be improved, and the purification system is imperfect.

[0008] Aflatoxin is highly toxic and has relatively high detection requirements. How to find the simplest and least costly method to detect aflatoxin to solve the problem that the existing technology cannot accurately detect the aflatoxin removal effect. Summary of the invention

[0009] In view of the problems existing in the prior art, the present invention provides a purification method, a purification system and a detection method for aflatoxin in spiny jujube seeds.

[0010] The present invention is achieved in this way: a purification system for aflatoxin in Chinese jujube seeds, comprising a Chinese jujube seed washing area, a Chinese jujube seed washing area and a Chinese jujube seed rinsing area, wherein the Chinese jujube seed rinsing area is also connected to a surface spraying area of ​​the Chinese jujube seeds; the spraying area is sequentially connected to a drying area, an acidification and degradation area, a neutralization area and a drying area;

[0011] An aflatoxin detection device is installed in the neutralization zone;

[0012] The aflatoxin detection device comprises an aflatoxin detection sensor; a polished gold electrode is heated to 0.3M to 0.6M H 2 SO 4 Perform medium sweep cyclic voltammetry until the electrode is stable, dry it, and drop 5-8 μL of Au / PANI / GN nanohybrid solution on the electrode surface, and dry it at room temperature; wash it with double distilled water, dry it at room temperature to form a film, drop 8-12 μL of 100 μg / mL anti-AFB1 solution on the electrode surface, and incubate it at 37°C for 20-50 min; wash it with double distilled water, continue to drop 6-12 μL of 3.0% bovine serum albumin BSA solution on the electrode surface to block nonspecific active sites, incubate it at 37°C for 20-40 min, and wash it clean; use a series of different concentrations of aflatoxin antigens for specific recognition with antibodies, incubate it at 37°C for 10-40 min, wash it clean with double distilled water, and store it in a refrigerator at 4°C for use;

[0013] The jujube kernel washing area is connected to the washing area through a washing circulation pump, the jujube kernel washing area is connected to the washing area through a washing circulation pump, and the jujube kernel rinsing area is connected to the rinsing area through a rinsing circulation pump;

[0014] The drainage outlet of the washing area is connected to the sour jujube kernel washing area;

[0015] The drain outlet of the washing area is connected to the sour jujube kernel washing area;

[0016] The spraying area is used to spray the surface of the wild jujube kernels;

[0017] The drying area is used to place the wild jujube seeds in a dark environment to air dry or dry;

[0018] The acidification and degradation zone is used to spray acetic acid aqueous solution on the surface of the wild jujube kernels for acidification and degradation to obtain acidified and degraded wild jujube kernels;

[0019] The neutralization zone is used to neutralize the acidified liquid in the acidified degradation zone;

[0020] The drying area is used to complete the drying of the wild jujube kernels.

[0021] Furthermore, the drain outlet of the rinsing area is connected to the sour jujube kernel rinsing area.

[0022] Furthermore, the purification system for aflatoxin in the spiny jujube seeds also includes:

[0023] A heat source providing pipe is respectively connected to the sour jujube seed washing area, the sour jujube seed washing area and the sour jujube seed rinsing area.

[0024] Furthermore, the purification system for aflatoxin in the spiny jujube seeds also includes:

[0025] A first solenoid valve, wherein the heat source supply pipe is connected to the sour jujube seed washing area through the first solenoid valve;

[0026] A second solenoid valve, wherein the heat source supply pipe is connected to the sour jujube kernel washing area through the first solenoid valve;

[0027] A third solenoid valve, wherein the heat source supply pipe is connected to the sour jujube kernel rinsing area through the third solenoid valve;

[0028] A PLC is electrically connected to the first solenoid valve, the second solenoid valve and the third solenoid valve, and is used to control the water temperature of the sour jujube kernel washing area, the sour jujube kernel washing area and the sour jujube kernel rinsing area;

[0029] A first water level sensor is installed in the sour jujube kernel washing area and is used to detect the liquid level in the sour jujube kernel washing area;

[0030] A second water level sensor is installed in the sour jujube kernel washing area and is used to detect the liquid level in the sour jujube kernel washing area;

[0031] A third water level sensor is installed in the sour jujube kernel rinsing area and is used to detect the liquid level in the sour jujube kernel rinsing area;

[0032] The PLC is also electrically connected to the first water level sensor, the second water level sensor and the third water level sensor, and is used to control the water inlet into the sour jujube seed washing area, the sour jujube seed washing area and the sour jujube seed rinsing area.

[0033] Another object of the present invention is to provide a method for detecting aflatoxin in sour jujube seeds using the aflatoxin purification system in sour jujube seeds, the method for detecting aflatoxin in sour jujube seeds comprising:

[0034] Different types of prepared nanomaterials were modified on the surface of gold electrodes to construct different types of electrochemical sensors, and the electrochemical properties of the sensors were detected using the electrochemical impedance spectroscopy and cyclic voltammetry.

[0035] The aflatoxin detection sensor was constructed by first drop-coating gold / polyaniline / graphene (Au / PANI / GN) composite nanomaterials on the surface of the gold electrode, drying it to form a film, then incubating it with anti-AFB1, and then blocking the nonspecific active sites with bovine serum albumin solution. Then, a series of aflatoxin antigens with different concentrations were incubated for specific recognition with antibodies. Square wave cyclic voltammetry was used to optimize the concentration and incubation time of aflatoxin antibodies, the pH of the buffer solution and the immune response time of the AFB1 antigen, and the optimal conditions were screened.

[0036] Under the optimal conditions, the AC impedance method and square wave cyclic voltammetry were used to quantitatively analyze and determine aflatoxin of different concentrations.

[0037] Another object of the present invention is to provide a method and system for purifying aflatoxin in spiny jujube seeds, which specifically comprises the following steps:

[0038] Step 1: Prepare the Chinese jujube kernels that have been placed at room temperature for 3 months, dilute the chlorine dioxide to 0.1-5ppm, and obtain a chlorine dioxide solution; again, spray the surface of the Chinese jujube kernels with a chlorine dioxide solution with a concentration of 0.1-5ppm, stirring while spraying, keep the sprayed medicinal materials for 1-2 hours, and then place them in a dark environment to dry or bake.

[0039] Step 2: spraying an acetic acid aqueous solution on the surface of the sour jujube kernel to perform an acidification and degradation treatment to obtain an acidified and degraded sour jujube kernel;

[0040] Step three: spraying a sodium bicarbonate aqueous solution on the surface of the acidified and degraded spinach kernels for neutralization treatment.

[0041] Preferably, the mass concentration of the acetic acid aqueous solution is 5.0-10.0%; the dosage ratio of the acetic acid aqueous solution to the spinach seed is 20mL:100g.

[0042] The mass concentration of the sodium bicarbonate aqueous solution is 2.0-4.0%; the dosage ratio of the sodium bicarbonate aqueous solution to the spiny jujube seeds is 20mL:100g.

[0043] When the content of aflatoxin B1 in the spiny jujube seeds is ≤5 ppb and the total content of aflatoxins is ≤10 ppb, the mass concentration of the acetic acid aqueous solution is 5.0-6.0%, and the mass concentration of the sodium bicarbonate aqueous solution is 2.0-2.5%.

[0044] When the aflatoxin B1 content in the Chinese date seeds is ≤5ppb and 10ppb<the total aflatoxin content is ≤30ppb, or the aflatoxin B1 content is 5ppb<≤20ppb and the total aflatoxin content is ≤30ppb, the mass concentration of the acetic acid aqueous solution is 6.0-8.0%, and the mass concentration of the sodium bicarbonate aqueous solution is 2.5-3.5%.

[0045] When the aflatoxin B1 content in the Chinese date seeds is ≤20ppb and 30ppb<total aflatoxin content ≤50ppb, or 20ppb<aflatoxin B1 content ≤30ppb and total aflatoxin content ≤50ppb, the mass concentration of the acetic acid aqueous solution is 8.0-10.0%, and the mass concentration of the sodium bicarbonate aqueous solution is 3.5-4.0%.

[0046] The acidification degradation treatment is carried out under light-proof conditions, the temperature of the acidification degradation treatment is room temperature, and the time is 30 to 60 minutes; the neutralization treatment is carried out under light-proof conditions, the temperature of the neutralization treatment is room temperature, and the time is 5 to 10 minutes.

[0047] Step 4: Drying. The drying temperature is preferably 40-50° C. and the drying time is preferably 3-5 hours. Specifically, the seeds are turned over every 30 minutes during the drying process to ensure that the seeds are fully and evenly dried. Drying is completed when the moisture content of the seeds is less than 9%.

[0048] The present invention can also oxidize some active metabolites of microorganisms such as aflatoxin to achieve the purpose of detoxification or passivation.

[0049] Combined with all the above technical solutions, the advantages and positive effects of the present invention are as follows: the present invention adopts the above method for reducing aflatoxin in Chinese medicinal materials, which can kill microorganisms, and can also oxidize some microbial active metabolites such as aflatoxin, to achieve the purpose of detoxification or passivation, and reduce the content of aflatoxin in Chinese medicinal materials. The present invention utilizes the acidity of acetic acid aqueous solution to degrade aflatoxin in Chinese jujube seeds, and sodium bicarbonate aqueous solution can neutralize the acetic acid aqueous solution remaining in Chinese jujube seeds, so that Chinese jujube seeds maintain their original appearance and smell. The method provided by the present invention has the advantages of good detoxification effect and high efficiency, and has little effect on the smell, color and efficacy of Chinese jujube seeds.

[0050] The present invention adopts Au / PANI / GN composite nanomaterials to construct an electrochemical immunosensor to detect AFB1, and optimizes the conditions such as anti-AFB1 concentration, solution pH, anti-AFB1 incubation time, AFB1 immune response time, etc. during the experiment. The experimental results show that the constructed immunosensor has a wide linear range and a low detection limit, successfully realizes the detection of AFB1, and is expected to be applied to other foods or fruit crops.

[0051] The first solenoid valve of the present invention, the heat source providing pipe is connected to the sour jujube kernel washing area through the first solenoid valve; the second solenoid valve, the heat source providing pipe is connected to the sour jujube kernel washing area through the first solenoid valve; the third solenoid valve, the heat source providing pipe is connected to the sour jujube kernel rinsing area through the third solenoid valve; PLC, which is electrically connected to the first solenoid valve, the second solenoid valve and the third solenoid valve, is used to control the water temperature of the sour jujube kernel rinsing area, the sour jujube kernel washing area and the sour jujube kernel rinsing area.

[0052] The first water level sensor is installed in the sour jujube kernel washing area and is used to detect the liquid level in the sour jujube kernel washing area; the second water level sensor is installed in the sour jujube kernel washing area and is used to detect the liquid level in the sour jujube kernel washing area; the third water level sensor is installed in the sour jujube kernel rinsing area and is used to detect the liquid level in the sour jujube kernel rinsing area; the PLC is electrically connected to the first water level sensor, the second water level sensor and the third water level sensor, and is used to control the water inlet into the sour jujube kernel washing area, the sour jujube kernel washing area and the sour jujube kernel rinsing area.

[0053] The invention can completely clean aflatoxin in the spinach jujube seeds after three cleanings, and has the characteristics of simple structure and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 The present invention provides a flowchart of a method for purifying aflatoxin in spiny jujube seeds according to an embodiment of the present invention.

[0055] Figure 2 It is a schematic diagram of a purification system for aflatoxin in spiny jujube seeds provided in an embodiment of the present invention.

[0056] Figure 2 In: 1. Flushing unit; 2. Washing unit; 3. Rinse unit; 4. Chinese jujube kernel flushing area; 5. Chinese jujube kernel washing area; 6. Chinese jujube kernel rinsing area; 7. Flushing circulation pump; 8. Washing circulation pump; 9. Rinse circulation pump; 10. Heat source supply pipe; 11. First solenoid valve; 12. Second solenoid valve; 13. Third solenoid valve; 14. First water level sensor; 15. Second water level sensor; 16. Third water level sensor; 17. Drain pipe; 18. Steam trap; 19. Water inlet valve.

[0057] Figure 3 The purification system provided by an embodiment of the present invention also includes a connection schematic diagram of an aflatoxin detection device.

[0058] In the figure: 20, spraying area; 21, drying area; 22, acidification and degradation area; 23, neutralization area; 24, drying area; 25, aflatoxin detection device. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0060] By comparing the treatment effects with traditional methods (nano-montmorillonite adsorption method, ozone aqueous solution treatment method, ClO 2 aqueous solution treatment method), a method for purifying aflatoxin in spiny jujube seeds was proposed.

[0061] like Figure 1 As shown, the method for purifying aflatoxin in spiny jujube seeds provided in the embodiment of the present invention specifically comprises the following steps:

[0062] Step 1: Prepare the Chinese jujube kernels that have been placed at room temperature for 3 months, and spray the surface of the Chinese jujube kernels with a chlorine dioxide solution with a concentration of 0.1-5ppm, stirring while spraying, and keep the medicinal materials after spraying for 1-2 hours.

[0063] Step 2: Place it in a dark environment to dry or tumble dry.

[0064] Step 3: spraying an acetic acid aqueous solution on the surface of the sour jujube kernel to perform an acidification and degradation treatment to obtain an acidified and degraded sour jujube kernel;

[0065] Step 4: Spraying sodium bicarbonate aqueous solution on the surface of the acidified and degraded spinach kernels for neutralization treatment.

[0066] Step 5: Drying. The drying temperature is preferably 40-50° C. and the drying time is preferably 3-5 hours. Specifically, the seeds are turned over every 30 minutes during the drying process to ensure that the seeds are fully and evenly dried. Drying is completed when the moisture content of the seeds is less than 9%.

[0067] Preferably, the mass concentration of the acetic acid aqueous solution is 5.0-10.0%; the dosage ratio of the acetic acid aqueous solution to the spinach seed is 20mL:100g.

[0068] Preferably, the mass concentration of the sodium bicarbonate aqueous solution is 2.0-4.0%; the dosage ratio of the sodium bicarbonate aqueous solution to the spiny jujube seeds is 20mL:100g.

[0069] The application principle of the present invention is described in detail below in conjunction with specific experiments;

[0070] The method provided by the present invention is compared with the traditional method in the prior art, wherein:

[0071] Traditional method 1 (nano-montmorillonite adsorption method): Nano-montmorillonite (purity>95%, cation exchange capacity (CEC)=110 mol / kg) and Chinese jujube kernel are fully mixed at a mass ratio of 1:500 (m / m) and placed in the dark for 24 hours.

[0072] Traditional method 2 (ozone aqueous solution treatment method): spray ozone aqueous solution (concentration of 10ppm, the ratio of ozone aqueous solution to the treated sour jujube kernel is 20mL:100g) on ​​the surface of sour jujube kernel, gently stir while spraying, and after spraying, place the sour jujube kernel with the ozone aqueous solution sprayed on the surface in a light-proof, ventilated, clean and hygienic environment, and perform ozone degradation treatment at 20°C for 15min to obtain ozone-degraded sour jujube kernel; dry at 45°C for 4h under ventilation conditions, turn over every 30min during the drying process to ensure that the sour jujube kernel is fully and evenly dried, and the moisture content of the sour jujube kernel is less than 9% after drying.

[0073] Traditional method three (ClO2 aqueous solution treatment method): spray ClO2 aqueous solution (mass concentration of 5.0%, ClO2 aqueous solution to treated jujube kernels in a ratio of 20mL:100g) on ​​the surface of the jujube kernels, gently stir while spraying, and place the jujube kernels with the ClO2 aqueous solution sprayed on the surface in a light-proof, ventilated, clean and sanitary environment after spraying, and perform ClO2 degradation treatment at 20°C for 15min to obtain ClO2-degraded jujube kernels; dry at 45°C for 4h under ventilation conditions, turn over every 30min during the drying process to ensure that the jujube kernels are fully dried, and the moisture content of the jujube kernels is less than 9% after drying.

[0074] HPLC was used to determine the contents of AFB1 and AFS in the wild jujube seeds obtained by the above three traditional detoxification methods. At the same time, a colorimeter was used to determine the color change of wild jujube seeds (L represents brightness, and an increase in L value indicates an increase in brightness; a represents red-green, and an increase in a value indicates an increase in red value and a darkening and browning of the color; b represents yellow-blue, and an increase in b value indicates an increase in yellow). The odor change of wild jujube seeds was determined by sensory evaluation through nose smelling. The specific results are listed in Table 1.

[0075] Table 1 Comparison of the detoxification effects of aflatoxin in spiny jujube seeds using different treatment methods

[0076]

[0077] As shown in Table 1, compared with the nano-montmorillonite adsorption method, ozone aqueous solution treatment method, ClO 2 Compared with the aqueous solution treatment method, the method provided by the present invention has the advantages of good detoxification effect and high efficiency, and has little effect on the smell, color and efficacy of the spinach seeds.

[0078] like Figure 2 As shown, the cleaning equipment provided by the embodiment of the present invention includes: a flushing unit 1, a washing unit 2 and a rinsing unit 3 arranged in sequence, and also includes a Chinese jujube kernel flushing area 4, a Chinese jujube kernel washing area 5 and a Chinese jujube kernel rinsing area 6; the Chinese jujube kernel flushing area 4 is connected to the flushing unit 1 through a flushing circulation pump 7, the Chinese jujube kernel washing area 5 is connected to the washing unit 2 through a washing circulation pump 8, and the Chinese jujube kernel rinsing area 6 is connected to the rinsing unit 3 through a rinsing circulation pump 9.

[0079] When in use, first open the Chinese jujube kernel washing area 4 and the washing circulation pump 7, use the water in the Chinese jujube kernel washing area 4 to wash the Chinese jujube kernel placed in the washing unit 1, then transfer the Chinese jujube kernel to the washing unit 2, and open the Chinese jujube kernel washing area 5 and the washing circulation pump 8, and continue to rinse the Chinese jujube kernel with the water in the Chinese jujube kernel washing area 5. Next, transfer the Chinese jujube kernel to the rinsing unit 3, then open the Chinese jujube kernel rinsing area 6 and the rinsing circulation pump 9, and rinse the Chinese jujube kernel with the water in the Chinese jujube kernel rinsing area 6. After three washes, the Chinese jujube kernel can be thoroughly cleaned and disinfected, and the device has the characteristics of simple structure and low cost.

[0080] The drain outlet of the flushing unit 1 is connected to the sour jujube kernel flushing area 4. Preferably, the drain outlet of the washing unit 2 is connected to the sour jujube kernel washing area 5. Preferably, the drain outlet of the rinsing unit 3 is connected to the sour jujube kernel rinsing area 6. In this way, a part of the flushing unit 1 / washing unit 2 / rinsing unit 3 can be recycled into the sour jujube kernel flushing area 4 / sour jujube kernel washing area 5 / sour jujube kernel rinsing area 6, thereby achieving the purpose of recycling water resources. At the same time, a part of the water discharged from the flushing unit 1 / washing unit 2 / rinsing unit 3 can also be directly discharged through the drain pipe 17. In particular, the sour jujube kernel flushing area 4 / sour jujube kernel washing area 5 / sour jujube kernel rinsing area 6 are also respectively provided with anti-overflow drain holes, which are respectively connected to the drain pipe 17 through the drain valve 18.

[0081] The cleaning equipment also includes a heat source supply pipe 10, which is respectively connected to the jujube kernel washing area 4, the jujube kernel washing area 5 and the jujube kernel rinsing area 6. The water temperature in the washing water tank 4 / the jujube kernel washing area 5 / the jujube kernel rinsing area 6 can be adjusted by the heat source supply pipe 10. For example, when the water temperature is too low (for example, 42 degrees Celsius, etc.), the heat source supply pipe 10 is opened, and when the water temperature rises to a predetermined value (for example, 55 degrees Celsius, etc.), the heat source supply pipe 10 is closed. This process can be automatically controlled by PLC.

[0082] It also includes: a first solenoid valve 11, through which the heat source supply pipe 10 is connected to the solanine jujube kernel washing area 4; a second solenoid valve 12, through which the heat source supply pipe 10 is connected to the solanine jujube kernel washing area 5; a third solenoid valve 13, through which the heat source supply pipe 10 is connected to the solanine jujube kernel rinsing area 6; a PLC, which is electrically connected to the first solenoid valve 11, the second solenoid valve 12 and the third solenoid valve 13, and is used to control the water temperature of the solanine jujube kernel washing area 4, the solanine jujube kernel washing area 5 and the solanine jujube kernel rinsing area 6.

[0083] The system also includes: a first water level sensor 14, installed in the sour jujube kernel washing area 4, for detecting the liquid level in the sour jujube kernel washing area 4; a second water level sensor 15, installed in the sour jujube kernel washing area 5, for detecting the liquid level in the sour jujube kernel washing area 5; a third water level sensor 16, installed in the sour jujube kernel rinsing area 6, for detecting the liquid level in the sour jujube kernel rinsing area 6;

[0084] The PLC is electrically connected to the first water level sensor 14, the second water level sensor 15 and the third water level sensor 16, and is used to control the water inlet of the jujube seed washing area 4, the jujube seed washing area 5 and the jujube seed rinsing area 6. For example, when it is detected that the liquid level is too low, the PLC opens the water inlet valve 19 arranged on the corresponding water inlet pipeline to achieve water inlet; when the liquid level reaches a predetermined value, the PLC closes the water inlet valve 19, so that the liquid level in the washing unit 1 / washing unit 2 / rinsing unit 3 can always be kept within a predetermined range.

[0085] The cleaning device of the present invention is a large-capacity, manual-door cleaning device, which is mainly used for cleaning Chinese date seeds. It can be widely used in the fields of chemical industry, pharmacy, food, biology and medical treatment. The spray arm of the flushing unit 1 / washing unit 2 / rinsing unit 3 adopts a high-pressure water nozzle spray mode, thereby ensuring that all energy acts on it from any angle.

[0086] like Figure 3 As shown, the purification system also includes:

[0087] The jujube kernel rinsing zone 6 is also connected to the surface spraying zone 20 of the jujube kernel; the spraying zone is sequentially connected to the drying zone 21, the acidification and degradation zone 22, the neutralization zone 23 and the drying zone 24;

[0088] The neutralization zone 23 is provided with an aflatoxin detection device 25;

[0089] The aflatoxin detection device comprises an aflatoxin detection sensor; a polished gold electrode is heated to 0.3M to 0.6M H 2 SO 4Perform medium sweep cyclic voltammetry until the electrode is stable, dry it, and drop 5-8 μL of Au / PANI / GN nanohybrid solution on the electrode surface, and dry it at room temperature; wash it with double distilled water, dry it at room temperature to form a film, drop 8-12 μL of 100 μg / mL anti-AFB1 solution on the electrode surface, and incubate it at 37°C for 20-50 min; wash it with double distilled water, continue to drop 6-12 μL of 3.0% bovine serum albumin BSA solution on the electrode surface to block nonspecific active sites, incubate it at 37°C for 20-40 min, and wash it clean; use a series of different concentrations of aflatoxin antigens for specific recognition with antibodies, incubate it at 37°C for 10-40 min, wash it clean with double distilled water, and store it in a refrigerator at 4°C for use;

[0090] The jujube kernel washing area is connected to the washing area through a washing circulation pump, the jujube kernel washing area is connected to the washing area through a washing circulation pump, and the jujube kernel rinsing area is connected to the rinsing area through a rinsing circulation pump;

[0091] The drainage outlet of the washing area is connected to the sour jujube kernel washing area;

[0092] The drain outlet of the washing area is connected to the sour jujube kernel washing area;

[0093] The spraying area is used to spray the surface of the wild jujube kernels;

[0094] The drying area is used to place the wild jujube seeds in a dark environment to air dry or dry;

[0095] The acidification and degradation zone is used to spray acetic acid aqueous solution on the surface of the wild jujube kernels for acidification and degradation to obtain acidified and degraded wild jujube kernels;

[0096] The neutralization zone is used to neutralize the acidified liquid in the acidified degradation zone;

[0097] The drying area is used to complete the drying of the wild jujube kernels.

[0098] The present invention also provides a method for detecting aflatoxin in spiny jujube seeds using the aflatoxin purification system in spiny jujube seeds, comprising:

[0099] Different types of prepared nanomaterials were modified on the surface of gold electrodes to construct different types of electrochemical sensors, and the electrochemical properties of the sensors were detected using the electrochemical impedance spectroscopy and cyclic voltammetry.

[0100] The aflatoxin detection sensor was constructed by first drop-coating gold / polyaniline / graphene (Au / PANI / GN) composite nanomaterials on the surface of the gold electrode, drying it to form a film, then incubating it with anti-AFB1, and then blocking the nonspecific active sites with bovine serum albumin solution. Then, a series of aflatoxin antigens with different concentrations were incubated for specific recognition with antibodies. Square wave cyclic voltammetry was used to optimize the concentration and incubation time of aflatoxin antibodies, the pH of the buffer solution and the immune response time of the AFB1 antigen, and the optimal conditions were screened.

[0101] Under the optimal conditions, the AC impedance method and square wave cyclic voltammetry were used to quantitatively analyze and determine aflatoxin of different concentrations.

[0102] Preferably, the Au / PANI / GN preparation method comprises:

[0103] Preparation of Au / PANI / GN composite nanomaterials with different gold loading rates:

[0104] Accurately weigh 10 mg of PANI / GN in a beaker, disperse by ultrasonic, and add 10 mg and 40 mg of HAuCl 4 .2H 2 O and 14.705 mg of trisodium citrate, add water to 20 mL, disperse by ultrasound, and add dropwise 0.6 mL of 0.1 mol / L NaBH 4 After the reaction is complete after stirring for 12 hours, the Au / PANI / GN composite nanomaterial is washed by centrifugation with double distilled water and is ready for use.

[0105] The reducing agents used in the preparation of the Au / PANI / GN composite nanomaterial include sodium borohydride and ascorbic acid.

[0106] In the preparation of the Au / PANI / GN composite nanomaterial, the mass ratios of PANI / GN and chloroauric acid in the reaction raw materials are 1:1 and 1:4 respectively.

[0107] The concentrations of AFB1 were 0.025 ng / mL, 0.05 ng / mL, 5 ng / mL, 10 ng / mL, 15 ng / mL, 20 ng / mL, and 25 ng / mL;

[0108] The characterization of Au / PANI / GN composite nanomaterials includes: using UV spectroscopy to characterize the prepared materials, and using transmission electron microscopy to characterize the morphology of Au / PANI / GN composite nanomaterials with different gold nanoparticle loading rates;

[0109] The electrochemical performance of the sensor was characterized by AC impedance spectroscopy and cyclic voltammetry. 6 3- / 4-As redox probes, electrochemical impedance spectroscopy and cyclic voltammetry were used to analyze the electrochemical properties of electrodes modified with different materials in 10.0 mM Fe(CN) solution containing 0.1 M KCl. 6 3- / 4- Cyclic voltammetric behavior in solution;

[0110] The optimization method for anti-AFB1 concentration is:

[0111] 7 μL GN / PANI / Au was modified on the gold electrode and incubated with different concentrations of anti-AFB1 (10 μL 25 μg.mL -1 , 50μg.mL -1 , 100μg.mL -1 , 150μg.mL -1 , 200μg.mL -1 ), the optimal conditions were screened by measuring the change of current response with concentration by square wave cyclic voltammetry, 150 μg mL -1 is the optimal anti-AFB1 concentration;

[0112] The optimization method of phosphate buffer solution (PBS) pH is:

[0113] The fixed concentration of anti-AFB1 was 150 μg.mL -1 , square wave cyclic voltammetry was performed at different pH values. Based on the principle that the activity of the protein is related to the pH of the solution, the pH of the electrolyte was controlled between 5.0 and 8.0. The response current value of the electrochemical immunosensor reaction under different pH solutions was measured, and the optimal pH of the solution was optimized. pH = 7.0 was the best solution.

[0114] The optimization method for anti-AFB1 incubation time is:

[0115] The fixed anti-AFB1 concentration was 150 μg mL -1 , incubated in a PBS solution of pH 7.0 for 20min, 30min, 40min, 50min, and 60min, respectively, and the relationship between the current response value and the incubation time of the electrochemical immunosensor was determined by square wave cyclic voltammetry to optimize the optimal incubation time of anti-AFB1, which was 50min;

[0116] The optimization method of anti-AFB1 immunization time is:

[0117] An AFB1 / BSA / anti-AFB1 / Au / PANI / GN / Au immunosensor was constructed. In a PBS solution with a pH of 7.0, the immunoreaction times of AFB1 and anti-AFB1 were 20 min, 30 min, 40 min, 50 min and 60 min, respectively. The immunoreaction time was optimized based on the condition that the square wave cyclic voltammetry peak current of the immunosensor reached the minimum value and was on a relatively stable platform. 50 min was the optimal immunoreaction time.

[0118] The detection method of AFB1 is:

[0119] An electrochemical immunosensor was constructed under the optimal conditions for detecting aflatoxin B1. 7μL Au / PANI / GN composite nanomaterials were modified on the electrode surface and dried at room temperature. The electrode was washed with double distilled water and dried at room temperature to form a film. 10μL 150μg / mL anti-AFB1 solution was dripped on the electrode surface and incubated at 37°C for 40min. The electrode was washed with double distilled water and 10μL 2.0% bovine serum albumin BSA solution was dripped on the electrode surface to block nonspecific active sites. The electrode was incubated at 37°C for 40min and washed clean. A series of AFB1 antigens with different concentrations were used for specific recognition with antibodies. The samples were incubated at 37°C for 30min, washed with double distilled water, and stored in a refrigerator at 4°C for future use. The constructed immunosensors were respectively placed in 0.01M KCl in 10.0mM Fe(CN) 6 3- / 4- The AC impedance was measured in the solution, and then the square wave cyclic voltammetry was used to detect different concentrations of AFB1. The standard curve was drawn with the immune reaction current response value as the ordinate and the AFB1 concentration as the abscissa. The detection linear range was 0.05ng / mL-25ng / mL, the detection limit was 0.017ng / mL, the linear equation was y=-0.177x+4.28, and the linear correlation coefficient was R 2 =0.9916.

[0120] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A purification system for aflatoxin in Chinese jujube seeds, comprising a Chinese jujube seed washing area, a Chinese jujube seed washing area and a Chinese jujube seed rinsing area, characterized in that: The jujube kernel rinsing area is also connected to a spraying area on the surface of the jujube kernel; the spraying area is sequentially connected to a drying area, an acidification and degradation area, a neutralization area and a drying area; An aflatoxin detection device is installed in the neutralization zone; The aflatoxin detection device comprises an aflatoxin detection sensor; a polished gold electrode is subjected to cyclic voltammetry in 0.3M-0.6M H2SO4 until the electrode is stable, dried, 5-8μL Au / PANI / GN nanohybrid solution is dripped on the electrode surface, and dried at room temperature; washed with double distilled water, dried at room temperature to form a film, 8-12μL 100μg / mL anti-AFB1 solution is dripped on the electrode surface, and incubated at 37°C for 20-50min; washed with double distilled water, 6-12μL 3.0% bovine serum albumin BSA solution is continuously dripped on the electrode surface to block non-specific active sites, incubated at 37°C for 20-40min, and cleaned; a series of aflatoxin antigens of different concentrations are used for specific recognition with antibodies, incubated at 37°C for 10-40min, washed with double distilled water, and stored in a refrigerator at 4°C for standby use; The jujube kernel washing area is connected to the washing area through a washing circulation pump, the jujube kernel washing area is connected to the washing area through a washing circulation pump, and the jujube kernel rinsing area is connected to the rinsing area through a rinsing circulation pump; The drainage outlet of the washing area is connected to the sour jujube kernel washing area; The drain outlet of the washing area is connected to the sour jujube kernel washing area; The spraying area is used to spray the surface of the wild jujube kernels; The drying area is used to place the wild jujube seeds in a dark environment to air dry or dry; The acidification and degradation zone is used to spray acetic acid aqueous solution on the surface of the wild jujube kernels for acidification and degradation to obtain acidified and degraded wild jujube kernels; The neutralization zone is used to neutralize the acidified liquid in the acidified degradation zone; The drying area is used to complete the drying of the wild jujube kernels.

2. The purification system for aflatoxin in spiny jujube seeds according to claim 1, characterized in that: The drain outlet of the rinsing area is connected to the sour jujube kernel rinsing area.

3. The purification system for aflatoxin in spiny jujube seeds according to claim 1, characterized in that: The purification system of aflatoxin in the spiny jujube seeds also includes: A heat source providing pipe is respectively connected to the sour jujube seed washing area, the sour jujube seed washing area and the sour jujube seed rinsing area.

4. The purification system for aflatoxin in spiny jujube seeds according to claim 3, characterized in that: The aflatoxin purification system in the spiny jujube seeds also includes: A first solenoid valve, wherein the heat source supply pipe is connected to the sour jujube seed washing area through the first solenoid valve; A second solenoid valve, wherein the heat source supply pipe is connected to the sour jujube kernel washing area through the first solenoid valve; A third solenoid valve, wherein the heat source supply pipe is connected to the sour jujube kernel rinsing area through the third solenoid valve; A PLC is electrically connected to the first solenoid valve, the second solenoid valve and the third solenoid valve, and is used to control the water temperature of the sour jujube kernel washing area, the sour jujube kernel washing area and the sour jujube kernel rinsing area; A first water level sensor is installed in the sour jujube kernel washing area and is used to detect the liquid level in the sour jujube kernel washing area; A second water level sensor is installed in the sour jujube kernel washing area and is used to detect the liquid level in the sour jujube kernel washing area; A third water level sensor is installed in the sour jujube kernel rinsing area and is used to detect the liquid level in the sour jujube kernel rinsing area; The PLC is also electrically connected to the first water level sensor, the second water level sensor and the third water level sensor, and is used to control the water inlet into the sour jujube seed washing area, the sour jujube seed washing area and the sour jujube seed rinsing area.

5. A method for detecting aflatoxin in spiny jujube seeds using the purification system for aflatoxin in spiny jujube seeds according to claim 1, characterized in that: The method for detecting aflatoxin in the spiny jujube seeds comprises: Different types of prepared nanomaterials were modified on the surface of gold electrodes to construct different types of electrochemical sensors, and the electrochemical properties of the sensors were detected using the electrochemical impedance spectroscopy and cyclic voltammetry. The aflatoxin detection sensor was constructed by first drop-coating gold / polyaniline / graphene (Au / PANI / GN) composite nanomaterials on the surface of the gold electrode, drying it to form a film, then incubating it with anti-AFB1, and then blocking the nonspecific active sites with bovine serum albumin solution. Then, a series of aflatoxin antigens with different concentrations were incubated for specific recognition with antibodies. Square wave cyclic voltammetry was used to optimize the concentration and incubation time of aflatoxin antibodies, the pH of the buffer solution and the immune response time of the AFB1 antigen, and the optimal conditions were screened. Under the optimal conditions, the AC impedance method and square wave cyclic voltammetry were used to quantitatively analyze and determine aflatoxin of different concentrations.

6. A method for purifying aflatoxin in spiny jujube seeds, characterized in that: The system for purifying aflatoxin in the spiny jujube seeds according to claim 1 is used, and the method for purifying aflatoxin in the spiny jujube seeds comprises the following steps: Step 1: Prepare the Chinese date kernels at room temperature, and spray the surface of the Chinese date kernels with a chlorine dioxide solution with a concentration of 0.1-5ppm, stirring while spraying, and keep the sprayed medicinal materials for 1-2 hours; Step 2: Place it in a dark environment to dry or dry; Step 3: spraying an acetic acid aqueous solution on the surface of the sour jujube kernel to perform an acidification and degradation treatment to obtain an acidified and degraded sour jujube kernel; Step 4: spraying a sodium bicarbonate aqueous solution on the surface of the acidified and degraded spinach kernels for neutralization treatment; Step 5: Turn the jujube kernels over during the drying process to ensure they are fully and evenly dried.

7. The method for purifying aflatoxin in spiny jujube seeds according to claim 6, characterized in that: In the step 3, the mass concentration of the acetic acid aqueous solution is 5.0-10.0%; the dosage ratio of the acetic acid aqueous solution to the spinach seed is 20mL:100g.

8. The method for purifying aflatoxin in spiny jujube seeds according to claim 6, characterized in that: The mass concentration of the sodium bicarbonate aqueous solution in step 4 is 2.0-4.0%; the dosage ratio of the sodium bicarbonate aqueous solution to the spiny jujube seeds is 20mL:100g.

9. The method for purifying aflatoxin in spiny jujube seeds according to claim 6, characterized in that: In the step 5, the drying temperature is 40-50°C.

10. The method for purifying aflatoxin in spiny jujube seeds according to claim 6, characterized in that: In the step 5, the drying time is 3 to 5 hours; the drying is completed when the moisture content of the sour jujube kernel is less than 9%.

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