Preparation method of high-oleic peanut oil with high removal of aflatoxin

Abstract

The present application relates to the technical field of edible oil production, in particular to a preparation method of high-oleic peanut oil with high removal efficiency of aflatoxin, which comprises five core steps of two-stage low-temperature drying pretreatment of high-oleic peanut raw material, low-temperature and moderate-temperature gradient steaming and frying and pressing, coupling of nanometer composite adsorbent and gradient microwave field for synergistic removal of aflatoxin, precise separation and low-temperature physical refining, online quality control and nitrogen filling preservation. The present application realizes accurate regulation and control of process parameters through aflatoxin dynamic adsorption rate model and microwave synergistic detoxification efficiency formula, can make the removal rate of aflatoxin B1 be greater than or equal to 99.5%, the retention rate of oleic acid be greater than or equal to 98%, the content of aflatoxin B1 in finished oil be less than or equal to 0.1 μg / kg, and the generation amount of trans fatty acids be less than or equal to 0.15%, and the present application is suitable for industrialized continuous production, effectively guarantees the edible safety and nutritional quality of products.

Description

Technical Field

[0001] This invention relates to the field of edible oil production technology, specifically to a method for preparing high-oleic peanut oil with efficient removal of aflatoxin. Background Technology

[0002] High-oleic peanut oil, due to its high oleic acid content, good oxidative stability, and excellent nutritional properties, has become a key development category in the edible vegetable oil sector. However, peanuts are highly susceptible to aflatoxin contamination during planting, harvesting, storage, and initial processing. Aflatoxin B1, in particular, is a potent carcinogen and a core indicator for peanut oil food safety control. Furthermore, oleic acid in high-oleic peanut oil is an unsaturated fatty acid, which is prone to oxidation and isomerization during traditional detoxification and refining processes, leading to oleic acid loss and trans fatty acid formation, thus damaging the oil's nutritional quality and flavor characteristics. Therefore, developing a preparation process that efficiently removes aflatoxin while effectively retaining high-oleic acid components is a key technological focus and research challenge in this field.

[0003] Currently, domestic and international technologies for removing aflatoxin from peanut oil are mainly divided into three categories: chemical degradation, biodegradation, and physical adsorption. Chemical degradation requires sophisticated equipment, easily leaves chemical residues, and poses food safety risks. Biodegradation has a long reaction cycle and poor process controllability, making it difficult to adapt to continuous industrial production. Physical adsorption, due to its simple operation, high safety, and relatively small impact on oil quality, has become the most widely used detoxification technology in the industry. Patent document CN202110553815.2 discloses an adsorbent for removing aflatoxin B1 from traditionally pressed peanut oil and its preparation method. This method uses talc, kaolin, diatomaceous earth, and calcium-based bentonite as core raw materials, which are compounded in a fixed ratio. The compound adsorbent is prepared through acid activation, alkali neutralization, high-temperature calcination, and pulverization and sieving. In use, the adsorbent is mixed with peanut oil in a specific ratio, and aflatoxin B1 is removed through sedimentation or centrifugation. The raw materials used in this solution are all processing aids used in the food industry, which meet the food processing safety requirements. It is characterized by simple operation, readily available raw materials, and low cost. It can be adapted to small and medium-sized processing scenarios and the detoxification treatment of traditionally pressed peanut oil, and to a certain extent solves the problem of excessive aflatoxin in peanut oil from traditional small workshops and the difficulty of detoxification.

[0004] However, the technical solutions in the aforementioned comparative documents still have significant technical defects and cannot meet the requirements for the refined and high-quality preparation of high-oleic peanut oil. Firstly, the compound adsorbent in these documents is a conventional micron-sized powder with limited specific surface area and pore volume, resulting in significant limitations in adsorption capacity and rate. For peanut oil contaminated with high concentrations of aflatoxin, 2% to 5% of the oil weight of adsorbent needs to be added, and a static settling time of more than 24 hours is required to achieve detoxification. The removal efficiency is low, and the high amount of adsorbent added can easily cause adsorption loss of neutral oils, reducing the product's oil yield. Secondly, these documents only employ a single physical static adsorption method, which can only remove free aflatoxin from the oil and cannot degrade and remove bound aflatoxin. This poses a risk of incomplete detoxification and makes it difficult to stably control the aflatoxin B1 content in the finished oil at an extremely low level below 0.1 μg / kg, failing to meet the quality control requirements of high-end edible oils. Third, the prior art document did not adapt the process to the heat-sensitive and easily oxidized characteristics of high-oleic peanut oil. The 550℃ high-temperature calcination process in the adsorbent preparation process and the lack of a full-process low-temperature protection in the oil processing can easily lead to the oxidation and isomerization of unsaturated fatty acids in high-oleic peanut oil, resulting in a decrease in oleic acid content and the formation of trans fatty acids. This makes it impossible to achieve efficient preservation of high-oleic acid nutrients and the inherent flavor of the oil, and is therefore unsuitable for the industrial production of high-oleic peanut oil. Fourth, the process in the prior art document lacks a precise parameter control model, making it impossible to adjust the process conditions in real time according to key parameters such as the initial concentration of aflatoxin in the raw materials and the oleic acid content of the oil. The process stability and raw material compatibility are poor, making it difficult to achieve continuous and large-scale stable production. Therefore, developing a high-oleic peanut oil preparation method with high aflatoxin removal efficiency, good oleic acid retention, controllable process parameters, and suitability for continuous industrial production has significant application value and practical significance. Summary of the Invention

[0005] The purpose of this invention is to provide a highly efficient method for preparing high-oleic peanut oil with aflatoxin removal, so as to solve the problems mentioned in the background art, such as incomplete detoxification of high-oleic peanut oil, easy loss of oleic acid, and poor process controllability.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A method for preparing high-oleic peanut oil with efficient removal of aflatoxin includes the following steps: 1) Pretreatment of high oleic acid peanut raw materials: Peanut kernels with oleic acid content ≥75% are cleaned, graded, color sorted, and subjected to two-stage low-temperature drying to control the moisture content to 3.5%-4.5%; 2) Low-temperature pressing: The pre-treated peanut kernels are crushed, pressed into embryos, and steamed in a gradient manner. They are then pressed at a low temperature of 65-85℃ to obtain high-oleic peanut crude oil. 3) Synergistic removal of aflatoxin: Dynamic adsorption and degradation are achieved by coupling a nanocomposite adsorbent with a gradient microwave field. The adsorption process follows the dynamic adsorption rate model of aflatoxin. ; in, The adsorption rate, The rate constant is For a moment aflatoxin concentration, Let be the reaction order. For activation energy, The gas constant is Thermodynamic temperature; 4) Precision separation and refining: The finished oil is obtained through plate and frame filtration, centrifugal separation, dehydration and degumming, deacidification, deodorization and dewaxing; 5) Online quality control and nitrogen-filled preservation: Online HPLC real-time detection is used, and the aflatoxin B1 removal rate is ≥99.5% and the oleic acid retention rate is ≥98%.

[0007] Preferably, the two-stage low-temperature drying in step 1) is as follows: the first stage is drying at 50-55℃ to a moisture content of 6%-7%, and the second stage is drying at 40-45℃ to the target moisture content. The drying process satisfies the moisture uniformity algorithm. ; in, For moisture uniformity, For single-point moisture, Average moisture content Number of detection points; requirements .

[0008] Preferably, step 2) involves gradient steaming and frying using a horizontal, closed steaming and frying device. Nitrogen gas is introduced throughout the entire steaming and frying process to isolate oxygen, constituting a three-stage gradient temperature-controlled conditioning process. The first stage temperature control is 45℃-50℃, the relative humidity of the steaming and frying chamber is controlled at 55%-65%, the heat preservation time is 15min-25min, the material layer thickness is controlled at 8cm-12cm, and the stirring speed is 30r / min-50r / min. The second stage temperature control is 65℃-70℃, the relative humidity of the steaming and frying chamber is controlled at 35%-45%, the heat preservation time is 15min-25min, and the stirring speed is 40r / min-60r / min; The third stage involves temperature control at 78℃-80℃, relative humidity in the steaming and frying chamber at 15%-25%, heat preservation time at 15min-25min, and stirring speed at 50r / min-70r / min. After steaming and frying, the residual oil rate of peanut embryos is ≤18%, the protein denaturation rate is ≤12%, and the moisture content is controlled at 2.5%-3.5%.

[0009] Preferably, the nanocomposite adsorbent in step 3) is a core-shell structured composite powder, which is composed of acid-modified montmorillonite, lipophilic modified nano-silica, and chitosan quaternary ammonium salt with a degree of quaternization ≥90% in a dry basis mass ratio of 6:3:1. The acid-modified montmorillonite is prepared by reflux modification of sodium-based montmorillonite with 0.8 mol / L-1.2 mol / L hydrochloric acid at 75℃-85℃ for 4-6 hours, followed by washing with deionized water until neutral, drying at 105℃, and grinding through an 800-mesh sieve. The lipophilic modified nano-silica is prepared by surface modification of fumed nano-silica with silane coupling agent KH570, with a native particle size of 15nm-30nm; the nanocomposite adsorbent has a particle size distribution of 50nm-200nm and a specific surface area ≥350m². 2 / g, pore volume ≥0.8cm 3 / g, with pore size distribution concentrated in 2nm-10nm.

[0010] Preferably, in step 3), the amount of nanocomposite adsorbent added is 0.5%-1.5% of the weight of the peanut oil to be treated. The adsorption process adopts a closed jacketed stirred reactor with nitrogen protection throughout the process. The adsorption temperature is controlled at 45℃-65℃. The stirring device adopts a double-layer propeller-type stirring paddle with a stirring speed controlled at 60r / min-120r / min. The adsorbent is added in two equal amounts. The first addition is added at the beginning of adsorption, and the second addition is added 10min-20min after adsorption. The total adsorption time is controlled at 20min-40min. The pressure inside the reactor is controlled at atmospheric pressure during the adsorption process.

[0011] Preferably, the gradient microwave field in step 3) consists of three power gradients: 200W→400W→300W, each lasting 3-8 minutes, with a microwave frequency of 2450MHz, and satisfies the microwave synergistic detoxification efficiency formula: ; in, To improve detoxification efficiency, , These are the initial and final toxin concentrations. , The average and maximum microwave power.

[0012] Preferably, the precision separation in step 4) employs a two-stage cascade filtration process. The first stage is a plate and frame pressure filtration using 200-300 mesh polypropylene filter cloth as the filter media. During the filtration process, 0.1%-0.3% of diatomaceous earth filter aid by weight of oil is added. The filtration pressure is controlled at 0.2MPa-0.4MPa, and the filtration temperature is controlled at 45℃-55℃. The second stage is an inorganic ceramic membrane cross-flow fine filtration using alumina as the ceramic membrane material. The membrane pore size is controlled at 0.1μm-0.5μm, the cross-flow velocity is controlled at 1.5m / s-3.0m / s, the transmembrane pressure difference is controlled at 0.1MPa-0.3MPa, and the filtration temperature is controlled at 50℃-60℃. During the fine filtration process, an online air-water backwash lasting 10s-30s is performed every 30-60 minutes. After filtration, the solid impurity content in the oil is ≤0.01%.

[0013] As a preferred option, the refining process in step 4) adopts a low-temperature physical refining process, which includes dehydration and degumming, deacidification and deodorization, and dewaxing in sequence. The dehydration and degumming process employs phosphoric acid hydration degumming, with phosphoric acid added at 0.05%-0.15% of the oil weight, a phosphoric acid concentration of 85%, hydration temperature controlled at 70℃-80℃, hydration time at 20-30 minutes, dehydration temperature controlled at 90℃-100℃, vacuum residual pressure ≤500Pa, and dehydration until the water content in the oil is ≤0.05%. The deacidification and deodorization process adopts a packed deodorization tower, the deacidification and deodorization temperature is controlled at 160℃-180℃, the vacuum residual pressure inside the tower is ≤200Pa, the direct steam consumption is 0.3%-0.6% of the oil weight, and the total deacidification and deodorization time is controlled at 40min-60min. The dewaxing process employs a gradient cooling crystal growth process. The initial oil temperature is controlled at 50℃-60℃, then reduced to 18℃-22℃ at a cooling rate of 1℃ / h-2℃ / h for 10h-14h. The temperature is then further reduced to 5℃-8℃ at a cooling rate of 0.5℃ / h-1℃ / h for 18h-24h. After crystal growth, the wax is separated by plate and frame filtration, with the filtration temperature controlled at 5℃-8℃ and the filtration pressure ≤0.3MPa. The amount of trans fatty acids generated during the deacidification and deodorization process is ≤0.15%.

[0014] Preferably, in step 5), the online HPLC detection wavelength is 365 nm, the detection accuracy is ≤0.1 μg / kg, and the detection data is input into the process control model. ; in, The optimal adsorption time is [not specified]. This is the process coefficient. To handle traffic, This refers to the amount of adsorbent used.

[0015] Preferably, the final product oil obtained meets the following indicators: oleic acid content ≥75%, linoleic acid content ≤8%, linolenic acid content ≤0.3%, and palmitic acid content ≤6.5%; The aflatoxin B1 content is ≤0.1μg / kg, and the total content of aflatoxin B2, G1, and G2 is ≤0.2μg / kg; Acid value ≤ 0.2 mg KOH / g, peroxide value ≤ 0.15 g / 100 g, moisture and volatile content ≤ 0.05%, insoluble impurity content ≤ 0.01%, solvent residue not detectable, smoke point ≥ 215℃, oxidation induction period ≥ 18 h at 25℃.

[0016] Compared with the prior art, the beneficial effects of the present invention are: This invention employs a synergistic detoxification method combining nanocomposite adsorbents and gradient microwave fields. By integrating a dynamic adsorption rate model for aflatoxin and a microwave-assisted detoxification efficiency formula, precise control of process parameters is achieved, effectively removing aflatoxin from high-oleic peanut oil. Compared to traditional single-stage detoxification processes, this synergistic detoxification method can control the aflatoxin B1 removal rate to over 99.5%. It allows for precise control of key parameters such as temperature, adsorbent dosage, and microwave power during the detoxification process, avoiding damage to oil quality caused by incomplete detoxification or overtreatment. This ensures that the aflatoxin B1 content in the finished oil is stably controlled below 0.1 μg / kg, meeting relevant food safety standards.

[0017] This invention employs a full-process low-temperature design, from two-stage low-temperature drying and low-temperature pressing of raw materials to subsequent low-temperature physical refining. Combined with real-time optimization using moisture uniformity algorithms and process control models, it effectively preserves the oleic acid content in high-oleic peanuts, maintaining an oleic acid retention rate consistently above 98%. Simultaneously, the low-temperature process reduces the formation of trans fatty acids during deacidification and deodorization, controlling the trans fatty acid content below 0.15%. This effectively preserves the nutritional components and inherent flavor of peanut oil, avoiding problems such as oleic acid loss, oil quality deterioration, and flavor impairment that are easily caused by traditional high-temperature processes.

[0018] The preparation process of this invention is clear, with well-defined and controllable parameters at each stage. The nanocomposite adsorbent used can be prepared using conventional raw materials and mature processes, ensuring cost control and preventing secondary pollution of the oil. The two-stage cascade filtration and gradient cooling crystal growth processes further remove solid impurities and waxes from the oil, improving the purity and storage stability of the finished oil. The entire process enables continuous production, adapting to industrial applications. The combination of online HPLC detection and nitrogen-filled preservation technology allows for real-time control of the finished oil quality, extending its shelf life and ensuring product quality stability. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are explained in detail together with the embodiments of the invention, but do not constitute a limitation thereof.

[0020] Figure 1 This invention illustrates the entire process flow diagram for efficiently removing aflatoxin from high-oleic peanut oil, from the pretreatment of high-oleic peanut raw materials to the final finished oil product. Figure 2 This is a diagram illustrating the pretreatment and low-temperature pressing process for high-oleic peanut raw materials according to the present invention. Figure 3 This is a diagram illustrating the synergistic removal of aflatoxin and the precise separation and refining process of this invention; Figure 4 This is a diagram illustrating the online quality control and nitrogen-filling preservation process of this invention. Detailed Implementation

[0021] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0022] Unless otherwise specified, all raw materials and reagents involved in this invention are commercially available conventional products; all testing equipment involved are conventional technical means in this field.

[0023] like Figures 1-4 The diagram shows the overall implementation flow of the preparation method of this invention. The preparation method of this invention includes five core steps in sequence: pretreatment of high oleic acid peanut raw materials, low-temperature and suitable-temperature pressing, synergistic removal of aflatoxin, precision separation and refining, and online quality control and nitrogen-filled preservation. The specific implementation details of each step are as follows: Step 1: Pretreatment of high-oleic peanut raw materials The high oleic acid peanut kernels used in this invention have an oleic acid content of ≥75%. High oleic acid peanut varieties that are harvested in the current year, free from mold and insect infestation are preferred, including Huayu 963, Kainong 176, and Jihua 16.

[0024] The cleaning process uses a combination of air separation and vibrating screen to remove impurities such as dust, gravel, stems and leaves, shriveled kernels, and moldy kernels from the peanut kernels; the grading process uses a drum grading screen to separate the kernels into four grades according to particle size, selecting uniform peanut kernels with a particle size of 8mm-12mm; the color sorting process uses a CCD color sorter to remove discolored kernels, broken kernels, and slightly moldy kernels, with a color sorting accuracy of ≥99.9%.

[0025] The two-stage low-temperature drying process utilizes a hot air circulating low-temperature drying oven, with nitrogen gas supplied throughout to prevent oxidative rancidity of the peanut kernels. The first stage drying temperature is 50℃-55℃, with a hot air velocity of 1.5m / s-2.0m / s, drying until the peanut kernel moisture content reaches 6%-7%. The second stage drying temperature is 40℃-45℃, with a hot air velocity of 1.0m / s-1.5m / s, drying until the final peanut kernel moisture content reaches 3.5%-4.5%. During the drying process, peanut kernel samples are collected from 6-12 locations every 30 minutes to test moisture content. Drying uniformity is controlled using a moisture uniformity algorithm, the expression of which is: ; in, For moisture uniformity, For single-point moisture, Average moisture content Number of detection points; requirements This ensures that the moisture distribution of the peanut kernels is uniform, avoiding fluctuations in oil yield or excessive protein denaturation during subsequent pressing.

[0026] Step 2: Low-temperature pressing The crushing process uses a double-roll crusher to crush the pre-treated peanut kernels into 2-4 pieces with a crushing degree of ≥95%, thus avoiding the generation of too much fine powder.

[0027] The pressing process uses a hydraulic pressing mill with a roller spacing of 0.3mm-0.5mm. After pressing, the peanut embryos are of uniform thickness, with a thickness of 0.3mm-0.5mm and a powder content of ≤5%.

[0028] The gradient steaming and roasting process utilizes a horizontal, closed steaming and roasting equipment. Nitrogen gas is introduced throughout the process to isolate oxygen, employing a three-stage gradient temperature control and conditioning process. The first stage maintains a temperature of 45℃-50℃, a relative humidity of 55%-65% in the steaming and roasting chamber, a holding time of 15-25 minutes, a material layer thickness of 8cm-12cm, and a stirring speed of 30-50 rpm. The second stage maintains a temperature of 65℃-70℃, a relative humidity of 35%-45% in the steaming and roasting chamber, a holding time of 15-25 minutes, and a stirring speed of 40-60 rpm. The third stage maintains a temperature of 78℃-80℃, a relative humidity of 15%-25% in the steaming and roasting chamber, a holding time of 15-25 minutes, and a stirring speed of 50-70 rpm. After steaming and roasting, the residual oil rate of the peanut embryos is ≤18%, the protein denaturation rate is ≤12%, and the moisture content is 2.5%-3.5%.

[0029] Low-temperature pressing uses a twin-screw low-temperature oil press, with the pressing chamber temperature controlled between 65℃ and 85℃ throughout the process, the main shaft speed between 25r / min and 35r / min, and the pressing chamber pressure between 8MPa and 12MPa. High-oleic peanut crude oil is obtained by pressing. Most of the cake residue is removed by primary filtration, which uses an 80-100 mesh filter screen at a filtration temperature of 40℃ to 50℃.

[0030] Step 3: Synergistic removal of aflatoxin The nanocomposite adsorbent is a core-shell structured composite powder, composed of acid-modified montmorillonite, lipophilic-modified nano-silica, and chitosan quaternary ammonium salt with a quaternization degree ≥90% in a dry weight ratio of 6:3:1. The preparation process of the acid-modified montmorillonite is as follows: sodium-based montmorillonite is added to a 0.8 mol / L-1.2 mol / L hydrochloric acid solution at a solid-liquid ratio of 1:10, and refluxed at 75℃-85℃ for 4-6 hours. After modification, the filtrate is washed with deionized water until neutral, dried in a 105℃ forced-air drying oven to constant weight, and then ground using an air jet mill and passed through an 800-mesh sieve. The preparation process of lipophilic modified nano-silica is as follows: Vapor-phase nano-silica with a native particle size of 15nm-30nm is added to an anhydrous ethanol system at a solid-liquid ratio of 1:20. Silane coupling agent KH570 is added at an amount of 15%-20% of the nano-silica mass. The mixture is stirred at 60℃-70℃ for 4-6 hours. After the reaction, the mixture is centrifuged, washed three times with anhydrous ethanol, and dried to constant weight. The composite process of the nanocomposite adsorbent is as follows: Acid-modified montmorillonite, lipophilic modified nano-silica, and chitosan quaternary ammonium salt are added to an anhydrous ethanol system at a solid-liquid ratio of 1:15. The mixture is stirred at high speed at 40℃-50℃ for 2-3 hours at a stirring speed of 3000r / min-5000r / min. After the reaction, the mixture is centrifuged, washed until neutral, freeze-dried under vacuum, and ground through a 1000-mesh sieve. The prepared nanocomposite adsorbent has a particle size distribution of 50nm-200nm, a specific surface area of ​​≥350m² / g, a pore volume of ≥0.8cm³ / g, and a pore size distribution concentrated in the range of 2nm-10nm.

[0031] The synergistic detoxification process is as follows: High-oleic peanut oil after initial filtration is fed into a sealed, jacketed stirred reactor under nitrogen protection throughout the process. A nanocomposite adsorbent is added at a rate of 0.5%-1.5% of the weight of the peanut oil to be treated. The adsorption temperature is controlled at 45℃-65℃. A double-layer propeller-type stirring device is used, with a stirring speed of 60-120 r / min. The adsorbent is added in two equal parts: the first addition is at the initial stage of adsorption, and the second addition is 10-20 minutes into adsorption, for a total adsorption time of 20-40 minutes. The pressure inside the reactor during the adsorption process is atmospheric pressure. Simultaneously, a gradient microwave field is activated to assist detoxification during the adsorption process. The microwave frequency is 2450 MHz, and a three-stage power gradient control is used: the first stage power is 200 W, with an action time of 3-8 minutes; the second stage power is 400 W, with an action time of 3-8 minutes; and the third stage power is 300 W, with an action time of 3-8 minutes. The dynamic adsorption rate model expression for aflatoxin during the adsorption process is as follows: ; in, The adsorption rate, The rate constant is For a moment aflatoxin concentration, Let be the reaction order. For activation energy, The gas constant is The temperature is the thermodynamic temperature. The detoxification efficiency of the microwave-assisted detoxification process is calculated in real time using the microwave-assisted detoxification efficiency formula, which is expressed as follows: ; in, To improve detoxification efficiency, , These are the initial and final toxin concentrations. , The average and maximum microwave power.

[0032] Step 4: Precision Separation and Refining The precision separation process employs a two-stage cascade filtration process. The first stage is a plate and frame pressure filtration using 200-300 mesh polypropylene filter cloth as the filter media. During the filtration process, 0.1%-0.3% of diatomaceous earth filter aid by weight of oil is added. The filtration pressure is 0.2MPa-0.4MPa, and the filtration temperature is 45℃-55℃. The second stage is an inorganic ceramic membrane cross-flow fine filtration using alumina ceramic membrane with a pore size of 0.1μm-0.5μm, a cross-flow velocity of 1.5m / s-3.0m / s, a membrane pressure difference of 0.1MPa-0.3MPa, and a filtration temperature of 50℃-60℃. During the fine filtration process, an online air-water backwash lasting 10-30 seconds is performed every 30-60 minutes. After filtration, the solid impurity content in the oil is ≤0.01%.

[0033] The low-temperature physical refining process includes dehydration and degumming, deacidification and deodorization, and dewaxing. The dehydration and degumming process uses phosphoric acid hydration degumming. The filtered peanut oil is fed into a hydration degumming tank and heated to 70℃-80℃. Food-grade phosphoric acid with a concentration of 85% is added at a rate of 0.05%-0.15% of the oil weight. The stirring speed is 60-80 rpm, and the hydration reaction lasts 20-30 minutes. After the reaction, the oil is centrifuged to remove gum and impurities. The centrifuged oil is then fed into a dehydration tank and dehydrated at 90℃-100℃ under a vacuum residual pressure ≤500Pa until the water content in the oil is ≤0.05%. The deacidification and deodorization process uses a packed deodorization tower. The dehydrated oil is fed into the tower, where the temperature is controlled at 160℃-180℃, the vacuum residual pressure is ≤200Pa, and direct steam is introduced at a rate of 0.3%-0.6% of the oil weight. The total deacidification and deodorization time is 40-60 minutes, and the amount of trans fatty acids generated during the process is ≤0.15%. The dewaxing process uses a gradient cooling crystal growth process. The deacidified and deodorized oil is fed into a crystal growth tank. The initial oil temperature is controlled at 50℃-60℃, and then reduced to 18℃-22℃ at a cooling rate of 1℃ / h-2℃ / h. Crystal growth is maintained at this temperature for 10-14 hours, followed by a further reduction to 5℃-8℃ at a cooling rate of 0.5℃ / h-1℃ / h, and then maintained at this temperature for 18-24 hours. After crystal growth, plate and frame filtration is used to separate the wax. The filtration temperature is controlled at 5℃-8℃, and the filtration pressure is ≤0.3MPa, yielding the finished oil.

[0034] Step 5: Online quality control and nitrogen-filled preservation An online HPLC system was used to perform real-time detection of the finished oil product. The detection wavelength was 365 nm, and the detection accuracy was ≤0.1 μg / kg. Key indicators such as aflatoxin content and oleic acid content in the oil were detected in real time. The detection data was integrated into the process control model to optimize process parameters in real time. The process control model expression is as follows: ; in, The optimal adsorption time is [not specified]. This is the process coefficient. To handle traffic, This refers to the amount of adsorbent used. The qualified finished oil is sent to a sterile storage tank and preserved using a nitrogen-filled process. The top of the tank is filled with food-grade nitrogen with a purity ≥99.99%, and the residual oxygen content inside the tank is ≤0.5%. It is stored at room temperature and protected from light. The final finished oil has an aflatoxin B1 removal rate ≥99.5% and an oleic acid retention rate ≥98%.

[0035] The present invention will be further described in detail below with reference to specific embodiments. The following embodiments are only used to illustrate the present invention and are not intended to limit the scope of protection of the present invention.

[0036] Example 1 This embodiment provides a method for preparing high-oleic peanut oil with efficient removal of aflatoxin. The specific implementation process is as follows: 1. Pretreatment of high-oleic peanut raw materials Peanut kernels from the current year's Huayu 963 variety, with an oleic acid content of 76.2%, were selected. Impurities were removed through air separation and vibrating sieve cleaning. The kernels were then graded by drum screening to obtain uniform kernels with a particle size of 8mm-12mm. A CCD color sorter was used to remove discolored and moldy kernels, achieving a color sorting accuracy of 99.92%. A two-stage low-temperature drying process was employed. The first stage dried the kernels at 52℃ with a hot air velocity of 1.8m / s until the moisture content reached 6.5%. The second stage dried the kernels at 42℃ with a hot air velocity of 1.2m / s until the final moisture content reached 4.0%. Moisture content was measured at 8 points every 30 minutes during the drying process, and a moisture uniformity algorithm was used to control the moisture uniformity. =0.962, which meets the requirement of ≥0.95.

[0037] ; 2. Low-temperature and suitable-temperature pressing Pre-treated peanut kernels were crushed into 2-4 pieces using a double-roll crusher, with a crushing degree of 95.8%. A hydraulic pressing mill was then used to press the kernels, with a roll gap of 0.4 mm, a kernel thickness of 0.4 mm, and a powder content of 3.2%. A horizontal, closed steaming and roasting equipment was used, with nitrogen protection throughout the process. The three-stage gradient steaming and roasting process was employed: the first stage maintained a temperature of 48℃, a relative humidity of 60% in the steaming and roasting chamber, held for 20 minutes, with a material layer thickness of 10 cm and a stirring speed of 40 r / min; the second stage maintained a temperature of 68℃, a relative humidity of 40% in the steaming and roasting chamber, held for 20 minutes, and a stirring speed of 50 r / min; the third stage maintained a temperature of 79℃, a relative humidity of 20% in the steaming and roasting chamber, held for 20 minutes, and a stirring speed of 60 r / min. After steaming and roasting, the peanut kernels had a residual oil rate of 16.8%, a protein denaturation rate of 10.2%, and a moisture content of 3.0%. The oil was pressed using a twin-screw low-temperature oil press at a pressing chamber temperature of 75℃, a main shaft speed of 30r / min, and a pressing chamber pressure of 10MPa to obtain high-oleic peanut crude oil. The oil was then pre-filtered through a 100-mesh filter at a filtration temperature of 45℃.

[0038] 3. Synergistic elimination of aflatoxin Preparation of nanocomposite adsorbent: Acid-modified montmorillonite, lipophilic-modified nano-silica, and chitosan quaternary ammonium salt with a quaternization degree of 92% were weighed at a dry basis mass ratio of 6:3:1. The acid-modified montmorillonite was prepared by reflux modification of sodium-based montmorillonite with 1.0 mol / L hydrochloric acid at 80℃ for 5 h, followed by washing with water until neutral, drying at 105℃, and grinding through an 800-mesh sieve. The lipophilic-modified nano-silica was prepared by fumed silica with a native particle size of 20 nm, modified with KH570 at 18% of the silica mass. The resulting nanocomposite adsorbent had a particle size distribution of 80 nm-150 nm, a specific surface area of ​​382 m² / g, a pore volume of 0.92 cm³ / g, and a pore size concentrated in the range of 3 nm-8 nm.

[0039] The pre-filtered crude oil was fed into a sealed stirred reactor under nitrogen protection throughout the process. The amount of nanocomposite adsorbent added was 1.0% of the oil weight. The adsorption temperature was 55℃, and the stirring speed of the double-layer propeller was 90 r / min. The adsorbent was added in two equal parts: the first addition at the beginning of adsorption and the second addition after 15 minutes of adsorption, for a total adsorption time of 30 minutes. The reactor was kept at atmospheric pressure. A gradient microwave field was simultaneously activated at a frequency of 2450 MHz, with three power gradients: 200 W for 5 minutes, 400 W for 5 minutes, and 300 W for 5 minutes. The adsorption process followed the dynamic adsorption rate model for aflatoxin. ; In this embodiment, k=0.028, n=1.2, Ea=22.4kJ / mol, R=8.314J / (mol·K), and T=328.15K. The microwave-assisted detoxification efficiency is calculated using the following formula: In this embodiment, C0 = 52.6 μg / kg, Ct = 0.21 μg / kg, Pavg = 300 W, Pmax = 400 W, calculated as follows: =99.6%.

[0040] 4. Precision separation and refining A two-stage cascade filtration system is employed: the first stage is a plate and frame filter with 250-mesh polypropylene filter cloth as the filter media, and 0.2% diatomaceous earth filter aid by weight of oil is added. The filtration pressure is 0.3 MPa, and the filtration temperature is 50℃. The second stage is an alumina ceramic membrane fine filter with a membrane pore size of 0.2 μm, a cross-flow velocity of 2.2 m / s, a transmembrane pressure difference of 0.2 MPa, and a filtration temperature of 55℃. An online air-water backwash is performed every 45 minutes for 20 seconds. The solid impurity content in the filtered oil is 0.006%.

[0041] Low-temperature physical refining: In the dehydration and degumming process, the oil is heated to 75℃, and 85% phosphoric acid is added at 0.1% of the oil weight. The stirring speed is 70 r / min, and hydration is carried out for 25 minutes, followed by centrifugal degumming. The dehydration temperature is 95℃, and the vacuum residual pressure is 400 Pa, until the water content reaches 0.03%. In the deacidification and deodorization process, a packed deodorization tower is used at 170℃ and a vacuum residual pressure of 150 Pa. Direct steam is used at 0.45% of the oil weight, and the deacidification and deodorization time is 50 minutes, resulting in 0.12% trans fatty acid formation. In the dewaxing process, the initial oil temperature is 55℃, then cooled to 20℃ at a rate of 1.5℃ / h, and crystallized for 12 hours. The temperature is then further reduced to 6℃ at a rate of 0.8℃ / h, and crystallized for 22 hours. The mixture is then filtered through a plate and frame filter at 6℃ and 0.25 MPa to obtain the finished oil.

[0042] 5. Online quality control and nitrogen-filled preservation Online HPLC detection, detection wavelength 365nm, detection accuracy 0.08μg / kg, detection data. ; In this embodiment, K=0.12, C0=52.6μg / kg, Q=200L / h. =2kg, calculated as follows =31.56min, which matches the actual adsorption time of 30min well. The qualified finished oil is nitrogen-filled for preservation, with nitrogen purity of 99.99% and residual oxygen content in the tank of 0.3%, and is stored at room temperature away from light.

[0043] Example 2 This embodiment provides a method for preparing high-oleic peanut oil with efficient removal of aflatoxin. The specific implementation process is as follows: 1. Pretreatment of high-oleic peanut raw materials Peanut kernels from the current year's harvest of the Kainong 176 variety, with an oleic acid content of 78.5%, were selected. Impurities were removed through air separation and vibrating sieve cleaning. The kernels were then graded by drum screening to obtain uniform kernels with a particle size of 8mm-12mm. A CCD color sorter was used to remove discolored and moldy kernels, achieving a color sorting accuracy of 99.95%. A two-stage low-temperature drying process was employed. The first stage dried the kernels at 50℃ with a hot air velocity of 1.5m / s until the moisture content reached 7.0%. The second stage dried the kernels at 40℃ with a hot air velocity of 1.0m / s until the final moisture content reached 4.5%. Moisture content was measured at six points every 30 minutes during the drying process, and a moisture uniformity algorithm was used to control the moisture uniformity. =0.958, which meets the requirement of ≥0.95.

[0044] ; 2. Low-temperature and suitable-temperature pressing Pre-treated peanut kernels were crushed into 2-4 pieces using a double-roll crusher, with a crushing degree of 96.2%. A hydraulic pressing mill was then used to press the kernels, with a roll gap of 0.5 mm, a kernel thickness of 0.5 mm, and a powder content of 4.5%. A horizontal, closed steaming and roasting equipment was used, with nitrogen protection throughout the process. The three-stage gradient steaming and roasting process was employed: the first stage maintained a temperature of 45℃, a relative humidity of 65% in the steaming and roasting chamber, held for 25 minutes, with a material layer thickness of 12 cm and a stirring speed of 30 r / min; the second stage maintained a temperature of 65℃, a relative humidity of 45% in the steaming and roasting chamber, held for 25 minutes, and a stirring speed of 40 r / min; the third stage maintained a temperature of 78℃, a relative humidity of 25% in the steaming and roasting chamber, held for 25 minutes, and a stirring speed of 50 r / min. After steaming and roasting, the peanut kernels had a residual oil content of 17.5%, a protein denaturation rate of 11.6%, and a moisture content of 3.5%. The oil was pressed using a twin-screw low-temperature oil press with a pressing chamber temperature of 65℃, a main shaft speed of 25r / min, and a pressing chamber pressure of 8MPa to obtain high-oleic peanut crude oil. The oil was then pre-filtered through an 80-mesh filter at a filtration temperature of 40℃.

[0045] 3. Synergistic elimination of aflatoxin Preparation of nanocomposite adsorbent: Acid-modified montmorillonite, lipophilic-modified nano-silica, and chitosan quaternary ammonium salt with a quaternization degree of 90% were weighed at a dry basis mass ratio of 6:3:1. The acid-modified montmorillonite was prepared by reflux modification of sodium-based montmorillonite with 0.8 mol / L hydrochloric acid at 75℃ for 6 h, followed by washing with water until neutral, drying at 105℃, and grinding through an 800-mesh sieve. The lipophilic-modified nano-silica was prepared by fumed silica with a native particle size of 30 nm, modified with KH570 at 15% of the silica mass. The resulting nanocomposite adsorbent had a particle size distribution of 50 nm-180 nm, a specific surface area of ​​356 m² / g, a pore volume of 0.81 cm³ / g, and a pore size concentrated in the range of 2 nm-10 nm.

[0046] The initially filtered crude oil was fed into a sealed stirred reactor under nitrogen protection throughout the process. The amount of nanocomposite adsorbent added was 0.5% of the oil weight. The adsorption temperature was 45℃, and the stirring speed of the double-layer propeller was 60 r / min. The adsorbent was added in two equal parts: the first addition at the beginning of adsorption and the second addition after 10 minutes of adsorption, for a total adsorption time of 20 minutes. The reactor was kept at atmospheric pressure. A gradient microwave field was simultaneously activated at a frequency of 2450 MHz, with three power gradients: 200 W for 3 minutes, 400 W for 3 minutes, and 300 W for 3 minutes. The adsorption process followed the aflatoxin dynamic adsorption rate model. ; In this embodiment, k=0.019, n=1.1, =24.1 kJ / mol, R=8.314 J / (mol·K), T=318.15 K. The microwave-assisted detoxification efficiency is calculated using the following formula: In this embodiment, C0 = 28.3 μg / kg, Ct = 0.14 μg / kg. =300W, =400W, calculated as follows =99.5%.

[0047] 4. Precision separation and refining A two-stage cascade filtration system is employed: the first stage is a plate and frame filter with 200-mesh polypropylene filter cloth as the filter media, and 0.1% diatomaceous earth filter aid by weight of oil is added. The filtration pressure is 0.2 MPa, and the filtration temperature is 45℃. The second stage is an alumina ceramic membrane fine filter with a membrane pore size of 0.5 μm, a cross-flow velocity of 1.5 m / s, a transmembrane pressure difference of 0.1 MPa, and a filtration temperature of 50℃. An online air-water backwash is performed every 30 minutes for 10 seconds. The solid impurity content in the filtered oil is 0.009%.

[0048] Low-temperature physical refining: In the dehydration and degumming process, the oil is heated to 70℃, and 85% phosphoric acid is added at 0.05% of the oil weight. The stirring speed is 60 r / min, and hydration is carried out for 20 minutes, followed by centrifugal degumming. The dehydration temperature is 90℃, and the vacuum residual pressure is 500 Pa, until the water content reaches 0.04%. In the deacidification and deodorization process, a packed deodorization tower is used at 160℃ and a vacuum residual pressure of 200 Pa. Direct steam is used at 0.3% of the oil weight, and the deacidification and deodorization time is 40 minutes, resulting in 0.08% trans fatty acid formation. In the dewaxing process, the initial oil temperature is 50℃, then cooled to 18℃ at a rate of 1℃ / h, and crystallized for 14 hours. The temperature is then further reduced to 5℃ at a rate of 0.5℃ / h, and crystallized for 24 hours. The mixture is then filtered through a plate and frame filter at 5℃ and 0.2 MPa to obtain the finished oil.

[0049] 5. Online quality control and nitrogen-filled preservation Online HPLC detection, detection wavelength 365nm, detection accuracy 0.05μg / kg, detection data integrated into process control model: ; In this embodiment, K=0.12, C0=28.3μg / kg, Q=200L / h. =1kg, calculated as follows =20.38min, which matches the actual adsorption time of 20min well. The qualified finished oil is nitrogen-filled for preservation, with nitrogen purity of 99.99% and residual oxygen content in the tank of 0.4%, and is stored at room temperature away from light.

[0050] Example 3 This embodiment provides a method for preparing high-oleic peanut oil with efficient removal of aflatoxin. The specific implementation process is as follows: 1. Pretreatment of high-oleic peanut raw materials Peanut kernels of the current year's harvest, Jihua No. 16 variety, with an oleic acid content of 75.1%, were selected. Impurities were removed through air separation and vibrating sieve cleaning. The kernels were then graded by drum screening to obtain uniform kernels with a particle size of 8mm-12mm. A CCD color sorter was used to remove discolored and moldy kernels, achieving a color sorting accuracy of 99.91%. A two-stage low-temperature drying process was employed. The first stage dried the kernels at 55℃ with a hot air velocity of 2.0m / s until the moisture content reached 6.0%. The second stage dried the kernels at 45℃ with a hot air velocity of 1.5m / s until the final moisture content reached 3.5%. Moisture content was measured at 12 points every 30 minutes during the drying process, and a moisture uniformity algorithm was used to control the moisture uniformity. =0.971, which meets the requirement of ≥0.95.

[0051] ; 2. Low-temperature and suitable-temperature pressing Pre-treated peanut kernels were crushed into 2-4 pieces using a double-roll crusher, with a crushing degree of 95.3%. A hydraulic pressing mill was then used to press the kernels, with a roll gap of 0.3 mm, a kernel thickness of 0.3 mm, and a powder content of 2.8%. A horizontal, closed steaming and roasting equipment was used, with nitrogen protection throughout the process. The three-stage gradient steaming and roasting process was employed: the first stage maintained a temperature of 50℃, a relative humidity of 55% in the steaming and roasting chamber, held for 15 minutes, with a material layer thickness of 8 cm and a stirring speed of 50 r / min; the second stage maintained a temperature of 70℃, a relative humidity of 35% in the steaming and roasting chamber, held for 15 minutes, and a stirring speed of 60 r / min; the third stage maintained a temperature of 80℃, a relative humidity of 15% in the steaming and roasting chamber, held for 15 minutes, and a stirring speed of 70 r / min. After steaming and roasting, the peanut kernels had a residual oil content of 15.2%, a protein denaturation rate of 8.7%, and a moisture content of 2.5%. The oil was pressed using a twin-screw low-temperature oil press with a pressing chamber temperature of 85℃, a main shaft speed of 35r / min, and a pressing chamber pressure of 12MPa to obtain high-oleic peanut crude oil. The oil was then pre-filtered through a 100-mesh filter at a filtration temperature of 50℃.

[0052] 3. Synergistic elimination of aflatoxin Preparation of nanocomposite adsorbent: Acid-modified montmorillonite, lipophilic-modified nano-silica, and chitosan quaternary ammonium salt with a quaternization degree of 95% were weighed at a dry basis mass ratio of 6:3:1. The acid-modified montmorillonite was prepared by reflux modification of sodium-based montmorillonite with 1.2 mol / L hydrochloric acid at 85℃ for 4 h, followed by washing with water until neutral, drying at 105℃, and grinding through an 800-mesh sieve. The lipophilic-modified nano-silica was prepared by fumed silica with a native particle size of 15 nm, modified with KH570 at a concentration of 20% of the silica mass. The resulting nanocomposite adsorbent had a particle size distribution of 60 nm-200 nm, a specific surface area of ​​405 m² / g, a pore volume of 1.05 cm³ / g, and a pore size concentrated in the range of 2 nm-8 nm.

[0053] The initially filtered crude oil was fed into a sealed stirred reactor under nitrogen protection throughout the process. The amount of nanocomposite adsorbent added was 1.5% of the oil weight. The adsorption temperature was 65℃, and the stirring speed of the double-layer propeller was 120 r / min. The adsorbent was added in two equal parts: the first addition at the beginning of adsorption and the second addition after 20 minutes of adsorption, for a total adsorption time of 40 minutes. The reactor was kept at atmospheric pressure. A gradient microwave field was simultaneously activated at a frequency of 2450 MHz, with three power gradients: 200 W for 8 minutes, 400 W for 8 minutes, and 300 W for 8 minutes. The adsorption process followed the aflatoxin dynamic adsorption rate model. ; In this embodiment, k=0.035, n=1.3, Ea=20.7kJ / mol, R=8.314J / (mol·K), and T=338.15K. The microwave-assisted detoxification efficiency is calculated using the following formula: ; In this embodiment, C0 = 108.4 μg / kg, Ct = 0.32 μg / kg. =300W, =400W, calculated as follows =99.7%.

[0054] 4. Precision separation and refining A two-stage cascade filtration system is employed: the first stage is a plate and frame filter with 300-mesh polypropylene filter cloth as the filter media, and 0.3% diatomaceous earth filter aid by weight of oil is added. The filtration pressure is 0.4 MPa, and the filtration temperature is 55℃. The second stage is an alumina ceramic membrane fine filter with a membrane pore size of 0.1 μm, a cross-flow velocity of 3.0 m / s, a transmembrane pressure difference of 0.3 MPa, and a filtration temperature of 60℃. An online air-water backwash is performed every 60 minutes for 30 seconds. The solid impurity content in the filtered oil is 0.003%.

[0055] Low-temperature physical refining: In the dehydration and degumming process, the oil is heated to 80℃, and 85% phosphoric acid is added at 0.15% of the oil weight. The stirring speed is 80 r / min, and hydration is carried out for 30 minutes, followed by centrifugal degumming. The dehydration temperature is 100℃, and the vacuum residual pressure is 300 Pa, until the water content reaches 0.02%. In the deacidification and deodorization process, a packed deodorization tower is used at 180℃ and a vacuum residual pressure of 100 Pa. Direct steam is used at 0.6% of the oil weight, and the deacidification and deodorization time is 60 minutes, resulting in 0.14% trans fatty acid formation. In the dewaxing process, the initial oil temperature is 60℃, then cooled to 22℃ at a rate of 2℃ / h, and crystallized for 10 hours. The temperature is then further reduced to 8℃ at a rate of 1℃ / h, and crystallized for 18 hours. The mixture is then filtered through a plate and frame filter at 8℃ and 0.3 MPa to obtain the finished oil.

[0056] 5. Online quality control and nitrogen-filled preservation Online HPLC detection, detection wavelength 365nm, detection accuracy 0.06μg / kg, detection data integrated into process control model: ; In this embodiment, K=0.12, C_0=108.4μg / kg, Q=200L / h. =3kg, calculated as follows =39.42min, which matches the actual adsorption time of 40min well. The qualified finished oil is nitrogen-filled for preservation, with nitrogen purity of 99.99% and residual oxygen content of 0.2% in the tank. It is stored at room temperature and away from light.

[0057] This invention employs a synergistic detoxification method combining nanocomposite adsorbents and gradient microwave fields. By integrating a dynamic adsorption rate model for aflatoxin and a microwave-assisted detoxification efficiency formula, precise control of process parameters is achieved, effectively removing aflatoxin from high-oleic peanut oil. Compared to traditional single-stage detoxification processes, this synergistic detoxification method can control the aflatoxin B1 removal rate to over 99.5%. It allows for precise control of key parameters such as temperature, adsorbent dosage, and microwave power during the detoxification process, avoiding damage to oil quality caused by incomplete detoxification or overtreatment. This ensures that the aflatoxin B1 content in the finished oil is stably controlled below 0.1 μg / kg, meeting relevant food safety standards.

[0058] This invention employs a full-process low-temperature design, from two-stage low-temperature drying and low-temperature pressing of raw materials to subsequent low-temperature physical refining. Combined with real-time optimization using moisture uniformity algorithms and process control models, it effectively preserves the oleic acid content in high-oleic peanuts, maintaining an oleic acid retention rate consistently above 98%. Simultaneously, the low-temperature process reduces the formation of trans fatty acids during deacidification and deodorization, controlling the trans fatty acid content below 0.15%. This effectively preserves the nutritional components and inherent flavor of peanut oil, avoiding problems such as oleic acid loss, oil quality deterioration, and flavor impairment that are easily caused by traditional high-temperature processes.

[0059] The preparation process of this invention is clear, with well-defined and controllable parameters at each stage. The nanocomposite adsorbent used can be prepared using conventional raw materials and mature processes, ensuring cost control and preventing secondary pollution of the oil. The two-stage cascade filtration and gradient cooling crystal growth processes further remove solid impurities and waxes from the oil, improving the purity and storage stability of the finished oil. The entire process enables continuous production, adapting to industrial applications. The combination of online HPLC detection and nitrogen-filled preservation technology allows for real-time control of the finished oil quality, extending its shelf life and ensuring product quality stability.

[0060] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing high-oleic peanut oil with efficient removal of aflatoxin, characterized in that, Includes the following steps: 1) Pretreatment of high oleic acid peanut raw materials: Peanut kernels with oleic acid content ≥75% are cleaned, graded, color sorted, and subjected to two-stage low-temperature drying to control the moisture content to 3.5%-4.5%; 2) Low-temperature pressing: The pre-treated peanut kernels are crushed, pressed into embryos, and steamed in a gradient manner. They are then pressed at a low temperature of 65-85℃ to obtain high-oleic peanut crude oil. 3) Synergistic removal of aflatoxin: Dynamic adsorption and degradation are achieved by coupling a nanocomposite adsorbent with a gradient microwave field. The adsorption process follows the dynamic adsorption rate model of aflatoxin. ； in, The adsorption rate, The rate constant is For a moment aflatoxin concentration, Let be the reaction order. For activation energy, The gas constant is Thermodynamic temperature; 4) Precision separation and refining: The finished oil is obtained through plate and frame filtration, centrifugal separation, dehydration and degumming, deacidification, deodorization and dewaxing; 5) Online quality control and nitrogen-filled preservation: Online HPLC real-time detection is used, and the aflatoxin B1 removal rate is ≥99.5% and the oleic acid retention rate is ≥98%.

2. The method for preparing high-oleic peanut oil with efficient aflatoxin removal according to claim 1, characterized in that, Step 1) The two-stage low-temperature drying process consists of: the first stage drying at 50-55℃ to a moisture content of 6%-7%, and the second stage drying at 40-45℃ to the target moisture content. The drying process satisfies the moisture uniformity algorithm. ； in, For moisture uniformity, For single-point moisture, Average moisture content Number of detection points; requirements .

3. The method for preparing high-oleic peanut oil with efficient aflatoxin removal according to claim 1, characterized in that, Step 2) The gradient steaming and frying process uses a horizontal, closed steaming and frying equipment. Nitrogen gas is introduced throughout the entire steaming and frying process to isolate oxygen. It is a three-stage gradient temperature control and conditioning process. The first stage temperature control is 45℃-50℃, the relative humidity of the steaming and frying chamber is controlled at 55%-65%, the heat preservation time is 15min-25min, the material layer thickness is controlled at 8cm-12cm, and the stirring speed is 30r / min-50r / min. The second stage temperature control is 65℃-70℃, the relative humidity of the steaming and frying chamber is controlled at 35%-45%, the heat preservation time is 15min-25min, and the stirring speed is 40r / min-60r / min; The third stage involves temperature control at 78℃-80℃, relative humidity in the steaming and frying chamber at 15%-25%, heat preservation time at 15min-25min, and stirring speed at 50r / min-70r / min. After steaming and frying, the residual oil rate of peanut embryos is ≤18%, the protein denaturation rate is ≤12%, and the moisture content is controlled at 2.5%-3.5%.

4. The method for preparing high-oleic peanut oil with efficient aflatoxin removal according to claim 1, characterized in that, Step 3) The nanocomposite adsorbent is a core-shell structured composite powder, which is composed of acid-modified montmorillonite, lipophilic modified nano-silica, and chitosan quaternary ammonium salt with a degree of quaternization ≥90% in a dry basis mass ratio of 6:3:

1. The acid-modified montmorillonite is prepared by reflux modification of sodium-based montmorillonite with 0.8 mol / L-1.2 mol / L hydrochloric acid at 75℃-85℃ for 4-6 hours, followed by washing with deionized water until neutral, drying at 105℃, and grinding through an 800-mesh sieve. The oleophilic modified nano-silica is prepared by surface modification of fumed nano-silica with silane coupling agent KH570, with a native particle size of 15nm-30nm; the nanocomposite adsorbent has a particle size distribution of 50nm-200nm, a specific surface area ≥350m² / g, a pore volume ≥0.8cm³ / g, and a pore size distribution concentrated in the range of 2nm-10nm.

5. The method for preparing high-oleic peanut oil with efficient aflatoxin removal according to claim 1 or 4, characterized in that, In step 3), the amount of nanocomposite adsorbent added is 0.5%-1.5% of the weight of the peanut oil to be treated. The adsorption process adopts a closed jacketed stirred reactor with nitrogen protection throughout the process. The adsorption temperature is controlled at 45℃-65℃. The stirring device adopts a double-layer propeller, and the stirring speed is controlled at 60r / min-120r / min. The adsorbent is added in two equal amounts. The first addition is added at the beginning of adsorption, and the second addition is added 10min-20min after adsorption. The total adsorption time is controlled at 20min-40min. The pressure inside the reactor is controlled at atmospheric pressure during the adsorption process.

6. The method for preparing high-oleic peanut oil with efficient aflatoxin removal according to claim 1, characterized in that, Step 3) The gradient microwave field consists of three power gradients: 200W→400W→300W, each lasting 3-8 minutes, with a microwave frequency of 2450MHz, and satisfies the microwave synergistic detoxification efficiency formula: ； in, To improve detoxification efficiency, , These are the initial and final toxin concentrations. , The average and maximum microwave power.

7. The method for preparing high-oleic peanut oil with efficient aflatoxin removal according to claim 1, characterized in that, Step 4) The precision separation adopts a two-stage series filtration process. The first stage is a plate and frame pressure filtration, using 200-300 mesh polypropylene filter cloth as the filter material. During the filtration process, 0.1%-0.3% of diatomaceous earth filter aid by weight of oil is added. The filtration pressure is controlled at 0.2MPa-0.4MPa, and the filtration temperature is controlled at 45℃-55℃. The second stage is an inorganic ceramic membrane cross-flow fine filtration. The ceramic membrane material is alumina, the membrane pore size is controlled at 0.1μm-0.5μm, the cross-flow velocity is controlled at 1.5m / s-3.0m / s, the membrane pressure difference is controlled at 0.1MPa-0.3MPa, and the filtration temperature is controlled at 50℃-60℃. During the fine filtration process, an online air-water backwash lasting 10s-30s is performed every 30min-60min. After filtration, the solid impurity content in the oil is ≤0.01%.

8. The method for preparing high-oleic peanut oil with efficient aflatoxin removal according to claim 1, characterized in that, Step 4) The refining process adopts a low-temperature physical refining process, which includes dehydration and degumming, deacidification and deodorization, and dewaxing in sequence. The dehydration and degumming process employs phosphoric acid hydration degumming, with phosphoric acid added at 0.05%-0.15% of the oil weight, a phosphoric acid concentration of 85%, hydration temperature controlled at 70℃-80℃, hydration time at 20-30 minutes, dehydration temperature controlled at 90℃-100℃, vacuum residual pressure ≤500Pa, and dehydration until the water content in the oil is ≤0.05%. The deacidification and deodorization process adopts a packed deodorization tower, the deacidification and deodorization temperature is controlled at 160℃-180℃, the vacuum residual pressure inside the tower is ≤200Pa, the direct steam consumption is 0.3%-0.6% of the oil weight, and the total deacidification and deodorization time is controlled at 40min-60min. The dewaxing process employs a gradient cooling crystal growth process. The initial oil temperature is controlled at 50℃-60℃, then reduced to 18℃-22℃ at a cooling rate of 1℃ / h-2℃ / h for 10h-14h. The temperature is then further reduced to 5℃-8℃ at a cooling rate of 0.5℃ / h-1℃ / h for 18h-24h. After crystal growth, the wax is separated by plate and frame filtration, with the filtration temperature controlled at 5℃-8℃ and the filtration pressure ≤0.3MPa. The amount of trans fatty acids generated during the deacidification and deodorization process is ≤0.15%.

9. The method for preparing high-oleic peanut oil with efficient aflatoxin removal according to claim 1, characterized in that, Step 5) The online HPLC detection wavelength is 365nm, the detection accuracy is ≤0.1μg / kg, and the detection data is input into the process control model: ； in, The optimal adsorption time is [not specified]. This is the process coefficient. To handle traffic, This refers to the amount of adsorbent used.

10. The method for preparing high-oleic peanut oil with efficient aflatoxin removal according to claim 1, characterized in that, The final product oil obtained meets the following indicators: oleic acid content ≥75%, linoleic acid content ≤8%, linolenic acid content ≤0.3%, and palmitic acid content ≤6.5%; The aflatoxin B1 content is ≤0.1μg / kg, and the total content of aflatoxin B2, G1, and G2 is ≤0.2μg / kg; Acid value ≤ 0.2 mg KOH / g, peroxide value ≤ 0.15 g / 100 g, moisture and volatile content ≤ 0.05%, insoluble impurity content ≤ 0.01%, solvent residue not detectable, smoke point ≥ 215℃, oxidation induction period ≥ 18 h at 25℃.

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