Efficient degradation method for mycotoxin in corn steep liquor
By combining alkaline solution treatment and heterogeneous ozone oxidation with a microbubble device, the problem of poor degradation of mycotoxins in corn steep liquor was solved, achieving efficient, green, and pollution-free degradation of DON and ZEN, which is suitable for industrial processing of corn steep liquor.
Patent Information
- Application Number
- CN202511317852.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-16
- Publication Date
- 2025-12-23
AI Technical Summary
Existing technologies have poor degradation effects on mycotoxins in corn steep liquor, especially DON and ZEN. Physical methods are inefficient, chemical methods are complex and leave harmful residues, and biological methods are difficult to apply on a large scale.
After neutralizing the corn steep liquor with an alkaline solution, a heterogeneous ozone oxidation and microbubble device are used to form a heterogeneous ozone oxidation reaction using a solid catalyst, which destroys the structure of fungal toxins and generates harmless substances.
It achieves efficient degradation of DON and ZEN in corn steep liquor, reaching over 95%, and is simple to operate, green and pollution-free, making it suitable for industrial applications.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of corn deep processing and detoxification technology, and more specifically to a method for efficient degradation of corn steep liquor mycotoxins. Background Technology
[0002] Corn is one of my country's main food crops, playing an irreplaceable role in feed, food, and chemical industries. Almost all raw corn is contaminated with mycotoxins to varying degrees, with some exceeding safe levels. DON and ZEN, chemically stable and difficult to degrade during corn storage and processing, are the main mycotoxin contaminants in raw corn. my country's corn starch industry primarily uses wet processing, which involves mycotoxins dissolving from raw corn into sulfite leaching solutions, ultimately accumulating in processing byproducts such as corn steep liquor and sprayed corn husks, leading to excessive DON and ZEN levels. Corn steep liquor, a byproduct of deep corn processing, is widely used as a feed ingredient due to its low price. Therefore, reducing the DON and ZEN content in corn steep liquor is crucial for its production.
[0003] Currently, research on the removal of DON and ZEN from corn steep liquor primarily focuses on physical, chemical, and biological methods. Physical methods, including physical adsorption and traditional thermal treatment, suffer from low efficiency, long processing times, and poor degradation effects, and can also negatively impact product quality. Chemical methods, such as using alkaline substances and redox agents to disrupt the toxin structure, can achieve high degradation rates and are relatively inexpensive and easy to operate, making them widely studied; however, chemical reactions are complex and can easily introduce other harmful substances and compromise food quality, requiring careful selection. Biological methods mainly degrade toxins through the bioactive metabolites of microorganisms and cell wall adsorption. While these methods are effective in degrading toxins, they require significant investment, hindering large-scale industrial application.
[0004] Therefore, this paper proposes a method for efficiently and safely degrading mycotoxins, which is essential for the processing and utilization of corn by-products and for ensuring food quality and safety.
[0005] Therefore, providing a method for the efficient degradation of corn steep liquor mycotoxins is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention
[0006] In view of this, the present invention provides a method for the efficient degradation of mycotoxins in corn steep liquor, in order to solve the problem that the treatment effect of degrading major toxins in corn in the prior art needs to be improved.
[0007] To achieve the above objectives, the present invention adopts the following technical solution: A method for efficiently degrading corn steep liquor mycotoxins, characterized by comprising the following steps: (1) After removing solid impurities by the filter, the corn syrup is concentrated to a concentration of 19.0-21.0 Be by an evaporator at a temperature of 93-95℃ to obtain corn syrup concentrate. After cooling to 40-45℃, it is sent to a fermenter, and an alkaline solution is added dropwise to adjust the pH to 6.0-7.0. The mixture is stirred evenly and the reaction continues. The reaction continues for 30-50 minutes, the temperature is controlled at 30-40℃, and the stirring speed is 100-120 rpm.
[0008] (2) Add solid catalyst to corn slurry after step (1), stir evenly, connect microbubble device, soak fully, and obtain mixed solution.
[0009] The amount of solid catalyst added is 2.5-7.5 g / L; the stirring speed is 90-120 rpm; and the soaking time is 2-10 min.
[0010] (3) Ozone is introduced into the above mixed solution, and a heterogeneous ozone oxidation reaction is formed in combination with the catalyst to carry out detoxification treatment.
[0011] The ozone flow rate is 0.5 L / min, the ozone concentration is 90-150 mL / L, and the pressure is 0.2-0.5 MPa.
[0012] The ozone oxidation reaction conditions are as follows: temperature controlled at 30-40℃, stirring speed at 90-120 rpm, and reaction time at 30-60 min.
[0013] (4) Separate and recover the solid catalyst to obtain detoxified corn steep liquor.
[0014] Furthermore, the filter pore size in step (1) is 100µm.
[0015] In this invention, corn slurry is first neutralized with an alkaline solution to make it neutral or weakly alkaline. While exposing the toxins, residual sulfur dioxide reacts to form sulfites, which act as reducing agents to destroy double bonds, ketone groups, and other unsaturated groups in the DON and ZEN structures. Then, a heterogeneous ozone strong oxidation reaction is used, utilizing the strong oxidizing effects of various active substances to destroy double bonds, epoxy rings, hydroxyl groups, and other groups in the structures of vomitoxin and zearalenone toxin, generating products with lower toxicity, thereby achieving the purpose of degradation.
[0016] Furthermore, the alkaline solution mentioned in step (1) is a 30% NaOH solution or a 28% ammonia solution.
[0017] Most toxins rely on stable molecular structures for activity. DON is relatively sensitive to alkaline solutions and can alter the molecular structure of toxins, destroy active sites, or promote decomposition.
[0018] Furthermore, the solid catalyst mentioned in step (2) is a Mg(OH)2 solid catalyst, Ca2Fe2O5 particles, or MnFe2O4 particles.
[0019] Ozone oxidation technology, as an advanced oxidation process, relies on ozone as a strong oxidant to react with inorganic and organic pollutants in water, breaking them down into smaller, simpler molecules. Ozone typically reacts directly with organic matter in molecular form, or in water through a chain reaction to produce highly oxidizing monatomic oxygen (O) and hydroxyl radicals (-OH). These radicals possess extremely high reactivity and non-selectivity, enabling chain reactions that oxidize and degrade large organic molecules, ultimately leading to mineralization.
[0020] Since hydroxyl radicals are unstable, catalysts can be used to increase the concentration of hydroxyl radicals to improve the degradation effect of organic pollutants. According to water solubility, catalysts can be divided into homogeneous catalysts and heterogeneous catalysts. Compared with homogeneous catalysts, heterogeneous catalysts are easier to separate from water and do not cause secondary pollution. The reaction mechanism of heterogeneous catalytic oxidation technology mainly includes three aspects: (1) When ozone dissolves in the liquid phase, the catalyst absorbs and enriches it and activates it, reducing the activation energy of ozone decomposition and generating a large number of hydroxyl radicals; (2) Organic pollutants are adsorbed on the catalyst surface to form surface chelates, which synergistically carry out oxidation reactions with hydroxyl radicals; (3) The mass transfer efficiency between the gas, liquid and solid phases is improved, the reaction time is reduced, and it is more suitable for actual production needs.
[0021] Ozone molecules readily adsorb onto the surface of Ca(OH)2, which has strong alkaline sites. This adsorption allows the catalyst to come into full contact with the ozone molecules, promoting the decomposition of ozone and generating active free radicals.
[0022] Furthermore, the microbubble device described in step (2) generates tiny spherical bubbles with a diameter of less than 50 µm.
[0023] Microbubble ozone oxidation is an upgrade from ozone oxidation alone. It is an advanced water treatment oxidation technology that combines the strong oxidizing properties of ozone with the high mass transfer rate of microbubbles. Microbubble ozone can significantly enhance the ozone mass transfer process, solving the problem of slow mass transfer rates between ozone liquid and catalyst, while accelerating the decomposition of ozone to generate hydroxyl radicals.
[0024] Furthermore, the filter used for separating and recovering the solid catalyst in step (4) has a pore size of 1 mm.
[0025] Furthermore, the catalyst used in step (4) is dried at 110°C and sent back for regeneration.
[0026] In the catalyst of this invention, the support is a drinking water filtration material (such as clay, zeolite, etc.) with good mechanical strength and appropriate particle size, while the catalytically active component uses trace metal elements present in corn steep liquor, eliminating the possibility of poisoning. The catalyst is applied after the catalytically active component is fixed on the surface of certain porous supports through processes such as impregnation, precipitation, and ultra-high temperature sintering. Even after slight loss of active components during long-term use, the excellent catalytic ability can be restored with a simple regeneration operation.
[0027] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a method for highly efficient degradation of corn steep liquor mycotoxins, which has the following beneficial effects: (1) Mycotoxin contamination is a major threat to food safety and human health, therefore, the development of efficient and safe degradation methods is of great significance. This invention employs an alkaline heterogeneous ozone oxidation method to treat corn slurry contaminated with DON and ZEN, achieving the oxidation-reduction degradation of over 95% of DON and ZEN in wheat into other substances, thus realizing efficient degradation. This method is simple to operate, operates under mild conditions, and has great application potential.
[0028] (2) The analysis of the components after the reaction showed that it reached the harmless level. Except for the generation of a small amount of sulfate, ozone can act quickly and automatically decompose into oxygen. After the treatment is completed, no residue will be left in the product. It is green and pollution-free, which is conducive to the further development and utilization of by-products. Detailed Implementation
[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0030] Spherical MnFe2O4 particles, zeolite carrier; spherical Ca2Fe2O5 particles, activated carbon carrier, purchased from Sichuan Shutai Chemical Technology Co., Ltd., with particle diameters of approximately 3-5 mm; spherical Mg(OH)2 solid catalyst, clay carrier, with diameters of approximately 5-7 mm, purchased from Jianghua Environmental Protection Equipment Packing Co., Ltd.
[0031] Example 1 A highly efficient method for degrading corn steep liquor mycotoxins, comprising the following steps: (1) After removing solid impurities by passing the corn syrup through a filter with a pore size of 100µm, it flows into an evaporator at a temperature of 93-95℃ and is concentrated to a concentration of 20.8-21.0Be to obtain corn syrup concentrate. After cooling to 40-45℃, it is sent to a fermenter, and caustic soda (NaOH concentration 30%) is added dropwise to adjust the pH to 6.5. The reaction continues at a temperature of 38-40℃ and uniform stirring at 120rpm for 30min.
[0032] (2) Add Mg(OH)2 catalyst microspheres to the corn slurry after step (1) at a dosage of 3.0 g / L, connect to a microbubble device (to generate tiny spherical bubbles with a diameter of less than 50 µm), stir evenly at 90 rpm for 10 min, and soak thoroughly for 5 min.
[0033] (3) Introduce ozone into the fermenter at a flow rate of 0.5 L / min, an ozone concentration of 100 mL / L, a pressure of 0.35 MPa, a temperature of 38-40 °C, and a stirring speed of 90 rpm; perform strong oxidation reaction for 30 min.
[0034] (4) The solid catalyst was separated and recovered using a filter with a pore size of 1 mm to obtain detoxified corn syrup.
[0035] Example 2 A highly efficient method for degrading corn steep liquor mycotoxins, comprising the following steps: (1) After removing solid impurities by passing the corn syrup through a filter with a pore size of 100µm, it flows into an evaporator at a temperature of 93-95℃ and is concentrated to a concentration of 20.4-20.6Be to obtain corn syrup concentrate. After cooling to 40-45℃, it is sent to a fermenter, ammonia water is added dropwise, the pH is adjusted to 6.0, and the reaction continues: the temperature is 34-35℃, and the mixture is stirred evenly at 110rpm for 45min.
[0036] (2) Add MnFe2O4 catalyst microspheres to the corn slurry after step (1) at a dosage of 2.5 g / L, connect to a microbubble device (to generate tiny spherical bubbles with a diameter of less than 50 µm), stir evenly at 100 rpm for 10 min, and soak thoroughly for 2 min.
[0037] (3) Introduce ozone into the fermenter at a flow rate of 0.5 L / min, an ozone concentration of 150 mL / L, a pressure of 0.2 MPa, a temperature of 34-35 °C, and a stirring speed of 100 rpm; perform strong oxidation reaction for 50 min.
[0038] (4) The solid catalyst was separated and recovered using a filter with a pore size of 1 mm to obtain detoxified corn syrup.
[0039] Example 3 A highly efficient method for degrading corn steep liquor mycotoxins, comprising the following steps: (1) After removing solid impurities by passing the corn syrup through a filter with a pore size of 100µm, it flows into an evaporator at a temperature of 93-95℃ and is concentrated to a concentration of 19.9-20.1 Be to obtain corn syrup concentrate. After cooling to 40-45℃, it is sent to a fermenter, and caustic soda (NaOH concentration 30%) is added dropwise to adjust the pH to 7.0. The reaction continues at a temperature of 35-38℃ and is stirred evenly at 100rpm for 50min.
[0040] (2) Add Ca2Fe2O5 catalyst microspheres to the corn slurry after step (1) at a dosage of 4.0 g / L, connect to a microbubble device (to generate tiny spherical bubbles with a diameter of less than 50 µm), stir evenly at 120 rpm for 15 min, and soak for 10 min.
[0041] (3) Introduce ozone into the fermenter at a flow rate of 0.5 L / min, an ozone concentration of 120 mL / L, a pressure of 0.5 MPa, a temperature of 35-38 °C, and a stirring speed of 120 rpm; perform strong oxidation reaction for 40 min.
[0042] (4) The solid catalyst was separated and recovered using a filter with a pore size of 1 mm to obtain detoxified corn syrup.
[0043] Comparative Example 1 This comparative example did not use a catalyst for heterogeneous strong oxidation when ozone was introduced, and the strong oxidation reaction conditions were increased. The specific implementation operation is as follows: (1) After removing solid impurities by passing the corn syrup through a filter with a pore size of 100µm, it flows into an evaporator at a temperature of 93-95℃ and is concentrated to a concentration of 20.8-21.0Be to obtain corn syrup concentrate. After cooling to 40-45℃, it is sent to a fermenter, and caustic soda (NaOH concentration 30%) is added dropwise to adjust the pH to 6.5. The reaction continues at a temperature of 38-40℃ and uniform stirring at 120rpm for 30min.
[0044] (2) Introduce ozone into the fermenter at a flow rate of 0.5 L / min, an ozone concentration of 150 mL / L, a pressure of 0.4 MPa, a temperature of 38-40 °C, and a stirring speed of 120 rpm; at the same time, connect a microbubble device and perform a strong oxidation reaction for 90 min to obtain detoxified corn syrup.
[0045] Comparative Example 2 This comparative example did not involve synergistic microbubble reaction during the heterogeneous ozone strong oxidation reaction, and the catalyst dosage and strong oxidation reaction conditions were increased. The specific implementation operation is as follows: (1) After removing solid impurities by passing the corn syrup through a filter with a pore size of 100µm, it flows into an evaporator at a temperature of 93-95℃ and is concentrated to a concentration of 20.8-21.0 Be to obtain corn syrup concentrate. After cooling to 40-45℃, it is sent to a fermenter, and caustic soda (NaOH concentration 30%) is added dropwise to adjust the pH to 6.5. The reaction continues at a temperature of 38-40℃ and uniform stirring at 120rpm for 30min.
[0046] (2) Add Mg(OH)2 catalyst microspheres to the pretreated corn syrup at a dosage of 6.5 g / L, stir evenly at 120 rpm for 10 min, and soak thoroughly for 5 min.
[0047] (3) Introduce ozone into the fermenter at a flow rate of 0.5 L / min, an ozone concentration of 100 mL / L, a pressure of 0.35 MPa, a temperature of 38-40 °C, and a stirring speed of 120 rpm; perform strong oxidation reaction for 60 min.
[0048] (4) The solid catalyst was separated and recovered using a filter with a pore size of 1 mm to obtain detoxified corn syrup.
[0049] Comparative Example 3 This comparative example, after corn steep liquor concentration, did not react with an alkaline solution. Instead, the catalyst dosage was increased, and strong oxidation reaction conditions were applied directly for heterogeneous ozone strong oxidation. The specific implementation steps are as follows: (1) After removing solid impurities by passing the corn syrup through a filter with a pore size of 100µm, it flows into an evaporator with a temperature of 93-95℃ and is concentrated to a concentration of 20.8-21.0 Be to obtain corn syrup concentrate. After cooling to 40-45℃, it is sent to a fermenter, where Mg(OH)2 catalyst microspheres are added at a dosage of 7.0g / L. The mixture is stirred evenly at 120rpm for 10min and then soaked for 5min.
[0050] (2) Introduce ozone into the fermenter at a flow rate of 0.5 L / min, an ozone concentration of 120 mL / L, a pressure of 0.35 MPa, a temperature of 38-40 °C, and a stirring speed of 100 rpm; the strong oxidation reaction lasts for 90 min.
[0051] (3) The solid catalyst was separated and recovered using a filter with a pore size of 1 mm to obtain detoxified corn syrup.
[0052] Comparative Example 4 This comparative example did not undergo soaking pretreatment with corn slurry when using the catalyst. The specific implementation procedure is as follows: (1) After removing solid impurities by passing the corn syrup through a filter with a pore size of 100µm, it flows into an evaporator at a temperature of 93-95℃ and is concentrated to a concentration of 20.8-21.0 Be to obtain corn syrup concentrate. After cooling to 40-45℃, it is sent to a fermenter at a temperature of 34-35℃. Sodium hydroxide (NaOH concentration 30%) is added dropwise and the reaction continues. The pH is adjusted to 6.5, the temperature is 38-40℃, and the mixture is stirred evenly at 120rpm for 30min.
[0053] (2) Add Mg(OH)2 catalyst microspheres to the pretreated corn syrup at a dosage of 3.0 g / L, introduce ozone, connect to a microbubble device at a flow rate of 0.5 L / min, ozone concentration of 100 mL / L, pressure of 0.35 MPa, temperature of 38-40℃, and stirring speed of 90 rpm; perform strong oxidation reaction for 30 min.
[0054] (3) The solid catalyst was separated and recovered using a filter with a pore size of 1 mm to obtain detoxified corn syrup.
[0055] The virus-free corn steep liquor from Examples 1-3 and Comparative Examples 1-4 was tested for relevant indicators using the following methods: Zearalenone and vomitoxin levels: Detected using a rapid fluorescence quantitative detection card purchased from Shanghai Feice Biotechnology Co., Ltd.
[0056] Crude protein content: determined by the Kjeldahl method in GB / T 5009.5-2025.
[0057] Crude ash content: Refer to the method for determining crude ash content in GB / T 6438-2007.
[0058] Sulfite content: Refer to GB 1886.4-2015 for the determination of sulfite content.
[0059] Mg 2＋ and Mg 2＋ Detection was performed using inductively coupled plasma atomic emission spectrometry.
[0060] The results are shown in Tables 1 and 2.
[0061] Table 1. Degradation rate of vomitoxin and zearalenone toxin
[0062] Table 2. Comparison of components before and after corn syrup treatment (dry weight)
[0063] Comparing the vomitoxin and zearalenone content in Examples 1-3 and Comparative Examples 1-4, it can be seen that heterogeneous ozone strong oxidation combined with microbubble treatment of corn steep liquor can significantly improve the degradation effect of mycotoxins. Under the same conditions, the degradation efficiency of vomitoxin using a catalyst-based heterogeneous ozone oxidation reaction is significantly higher than that of ozone oxidation alone. On the other hand, the ozone strong oxidation combined with microbubble treatment of the desulfurization reaction of this invention greatly reduces the sulfite content and improves the quality of by-product feed.
[0064] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A method for efficient degradation of corn steep liquor mycotoxins, characterized in that, Includes the following steps: (1) After removing solid impurities by filtering, the corn syrup is concentrated in an evaporator at a temperature of 93-95℃ to a concentration of 19.0-21.0 Be to obtain corn syrup concentrate; after cooling to 40-45℃, it is sent to a fermenter, and an alkaline solution is added dropwise to adjust the pH to 6.0-7.
0. The mixture is stirred evenly and the reaction continues; the reaction continues for 30-50 minutes, the temperature is controlled at 30-40℃, and the stirring speed is 100-120 rpm. (2) Add solid catalyst to the corn slurry after step (1), stir evenly, connect microbubble device, soak thoroughly, and obtain mixed solution; The amount of solid catalyst added is 2.5-7.5 g / L; the stirring speed is 90-120 rpm; and the soaking time is 2-10 min. (3) Ozone is introduced into the above mixed solution, and a heterogeneous ozone oxidation reaction is formed in combination with the catalyst to carry out detoxification treatment; The ozone flow rate is 0.5 L / min, the ozone concentration is 90-150 mL / L, and the pressure is 0.2-0.5 MPa; The ozone oxidation reaction conditions are as follows: temperature controlled at 30-40℃, stirring speed at 90-120 rpm, and reaction time at 30-60 min. (4) Separate and recover the solid catalyst to obtain detoxified corn steep liquor.
2. The method for efficient degradation of corn steep liquor mycotoxins according to claim 1, characterized in that, The filter pore size in step (1) is 100µm.
3. The method for efficient degradation of corn steep liquor mycotoxins according to claim 1, characterized in that, The alkaline solution mentioned in step (1) is a 30% NaOH solution or a 28% ammonia solution.
4. The method for efficient degradation of corn steep liquor mycotoxins according to claim 1, characterized in that, The solid catalyst mentioned in step (2) is Mg(OH)2 solid catalyst, Ca2Fe2O5 particles or MnFe2O4 particles.
5. The method for efficient degradation of corn steep liquor mycotoxins according to claim 1, characterized in that, The microbubble device described in step (2) generates tiny spherical bubbles with a diameter of less than 50 µm.
6. The method for efficient degradation of corn steep liquor mycotoxins according to claim 1, characterized in that, The filter used for separating and recovering the solid catalyst in step (4) has a pore size of 1 mm.