Method for removing benzopyrene in linseed oil by molecular sieve technology

Abstract

The invention belongs to the technical field of linseed oil, and discloses a method for removing benzopyrene in linseed oil by using a molecular sieve technology, which comprises the following steps: heating and regenerating: putting a molecular sieve into a drying oven, setting the temperature at 300-600 DEG C, in the process, volatilizing and decomposing benzopyrene molecules due to high temperature, releasing the benzopyrene molecules into the environment, and after heating is completed, waiting for natural cooling of the molecular sieve so as to remove benzopyrene in the linseed oil; benzopyrene can be dissolved by selecting ethanol and a solvent without damaging a molecular sieve structure, the molecular sieve and the solvent are mixed and stirred, and a large number of micropore structures are formed in the surface of the molecular sieve through cooperation of the zeolite molecular sieve, separation, filtration, stirring and regeneration molecular sieves, so that benzopyrene molecules in the linseed oil can be captured and removed, and the removal efficiency is high; the molecular sieve can remove benzopyrene, the regeneration of the molecular sieve comprises solvent extraction and dichloromethane selection, the molecular sieve adsorbing benzopyrene is mixed with an extraction solvent, and the solvent is in full contact with the molecular sieve through ultrasonic treatment.

Description

Technical Field

[0001] The invention belongs to the technical field of sesame oil, and specifically relates to a method for removing benzopyrene from sesame oil by using molecular sieve technology. Background Art

[0002] Sesame oil may contain benzopyrene, which is a typical polycyclic aromatic hydrocarbon with strong carcinogenicity, so it needs to be removed from the oil. During the oil production process, if the oil (such as sesame) is baked and refined at high temperature, especially in the traditional baking process, it may lead to the formation of polycyclic aromatic hydrocarbons. If contaminated soil and water sources are used in the oil cultivation process, and if it is exposed to pollution sources during transportation and storage, sesame oil may also contain a certain amount of benzopyrene. Benzopyrene is a known carcinogen and is harmful to health. Especially when eating oils containing benzopyrene for a long time, it may increase the risk of cancer and cardiovascular disease. The modern food industry usually uses quality control measures to minimize and remove the content of benzopyrene in food.

[0003] However, the existing molecular sieve technology for removing benzopyrene from sesame oil is not perfect and still has certain defects: Traditional methods for removing benzopyrene from sesame oil mostly use activated carbon as an adsorbent. However, the regeneration process of the adsorbent may be limited, and the adsorbent needs to be replaced regularly, which not only increases labor costs, but also has a poor removal effect on benzopyrene in sesame oil. Therefore, a method for removing benzopyrene from sesame oil using molecular sieve technology is designed. Summary of the invention

[0004] The object of the present invention is to provide a method for removing benzopyrene from sesame oil using molecular sieve technology to solve the problem that the adsorbent proposed in the above background technology needs to be replaced regularly, which not only increases labor costs but also has a poor removal effect on benzopyrene in sesame oil.

[0005] In order to achieve the above object, the present invention provides the following technical solution: a method for removing benzopyrene from sesame oil using molecular sieve technology, comprising the following removal steps: S1. Raw material selection Selection of molecular sieve and oil sample: zeolite molecular sieve and sesame oil sample are selected, the pore size of zeolite molecular sieve is 0.3-1 nanometer, and the usage ratio of zeolite molecular sieve and sesame oil sample is 1:10; S2. Activation of molecular sieves Before using the molecular sieve, the molecular sieve is activated (pretreated) to remove moisture and impurities on its surface; After washing the molecular sieve with ethanol, the solvent is removed by drying; S3, molecular sieve and oil sample mixture Add the pretreated molecular sieve into sesame oil. The amount of molecular sieve used should be determined according to the concentration of benzopyrene and the volume of oil. S4. Adsorption process The temperature during the adsorption process is controlled between 50°C. Heating to 40°C helps to increase the adsorption rate of the molecular sieve. The adsorption time is 30 minutes to 2 hours. Heating the temperature of sesame oil to 50°C can reduce the viscosity and improve the adsorption effect, avoiding the viscosity of sesame oil slowing down the contact between the molecular sieve and the oil sample, resulting in reduced adsorption efficiency. S5. Stirring After the molecular sieve is added to the sesame oil, in order to make the two mixed evenly, a stirrer is used to stir the two to ensure the contact time between the molecular sieve and the oil sample. The stirring rate of the magnetic stirrer is between 100-500 rpm; S6. Separation and Filtration Prepare the filtering equipment: Choose filter paper that can block the molecular sieve particles; Mixing oil and molecular sieve: Mix the oil adsorbed with benzopyrene and the molecular sieve evenly to ensure that the molecular sieve is in full contact with the oil sample; Filtration: Pour the mixed liquid into the filter device and use gravity to let the oil pass through the filter medium. The molecular sieve particles will be retained on the filter medium; Separation of molecular sieve: After filtration, the filter paper will retain the molecular sieve adsorbed with benzopyrene, and the clean oil will flow out through the filter medium; S7, regenerated molecular sieve Heating regeneration: Place the molecular sieve in an oven and set the temperature between 300°C and 600°C. During this process, the molecules of benzopyrene will volatilize and decompose due to the high temperature and be released into the environment. After heating is completed, wait for the molecular sieve to cool naturally. Washing and regeneration: choose ethanol, the solvent can dissolve benzopyrene and will not damage the molecular sieve structure, mix and stir the molecular sieve with the solvent, and wash out the adsorbed benzopyrene, separate the solvent from the molecular sieve by filtering and centrifugation, and separate the benzopyrene dissolved in the solvent; S8. Analysis and evaluation The treated oil samples were analyzed and the changes in the benzopyrene content were detected using gas chromatography and liquid chromatography instruments; S9. Optimization and Adjustment According to the adsorption effect of the molecular sieve, the type, dosage and contact time of the molecular sieve and the oil can be adjusted for further optimization.

[0006] Preferably, the activation temperature of the molecular sieve is 300-500° C., the heating time is 4 hours, and the stirring time of the molecular sieve and the sesame oil sample is 45 minutes, which increases the contact time between the molecular sieve and the sesame oil sample and can adsorb benzopyrene in the sesame oil.

[0007] Preferably, the molecular sieve and the sesame oil sample are stirred at a temperature of 40-50° C., and a magnetic stirrer is used for stirring the two.

[0008] Preferably, before cleaning the molecular sieve, the molecular sieve needs to be soaked in ethanol for 5 hours to ensure that the impurities on its surface are dissolved and removed. The cleaned molecular sieve is placed in an oven with a temperature set at 100°C-300°C and dried for 3 hours until there is no residual solvent on the surface of the molecular sieve.

[0009] Preferably, the separation and filtration include centrifugation, usually using a high-speed centrifuge with a rotation speed set between 3000-5000 rpm. Centrifugal separation: pour the mixed solution into a centrifuge tube and put it into a centrifuge for high-speed centrifugation. The molecular sieve will settle to the bottom of the centrifuge tube, while the oil will float to the upper layer. Collect the oil: After the centrifugation is completed, carefully pour the upper clear liquid into another container, and the molecular sieve precipitate at the bottom will be left behind. Clean the molecular sieve: In order to remove the oil attached to the molecular sieve, the precipitated molecular sieve can be cleaned with a solvent and then dried.

[0010] Preferably, after washing and regeneration, the molecular sieve is further cleaned with clean water to remove residual solvent. The cleaned molecular sieve needs to be dried and placed in an oven heated to 100° C. to remove moisture and residual solvent.

[0011] Preferably, the regeneration of the molecular sieve includes solvent extraction, wherein dichloromethane is selected, the molecular sieve adsorbed with benzopyrene is mixed with the extraction solvent, and the solvent is fully contacted with the molecular sieve by ultrasonic treatment.

[0012] The beneficial effects of the present invention are as follows: 1. The present invention provides a zeolite molecular sieve, separation and filtration, stirring and regeneration of the molecular sieve. The surface of the molecular sieve has a large number of microporous structures, which can capture and remove benzopyrene molecules in sesame oil with high removal efficiency. The molecular sieve can not only remove benzopyrene, but also remove heavy metals and impurities to ensure the purity of the oil. The molecular sieve can be used repeatedly. After regeneration, the adsorption performance can be restored, and the production cost is reduced. The solvent is separated from the molecular sieve by filtering and centrifugation, and the benzopyrene dissolved in the solvent is separated. The regeneration of the molecular sieve includes solvent extraction, selecting dichloromethane, mixing the molecular sieve adsorbed with benzopyrene with the extraction solvent, and making the solvent fully contact with the molecular sieve by ultrasonic treatment.

[0013] 2. The present invention adopts the steps of baking oven, cleaning, molecular sieve activation and ethanol soaking. Before cleaning the molecular sieve, the molecular sieve needs to be soaked in ethanol for 5 hours to ensure that impurities on its surface are dissolved and removed. The cleaned molecular sieve is placed in an baking oven, and the baking oven is set at a temperature of 100°C-300°C for 3 hours until there is no residual solvent on the surface of the molecular sieve. The temperature of molecular sieve activation is 300-500°C, and the heating time is 4 hours. The stirring time of molecular sieve and sesame oil sample is 45 minutes, which increases the contact time between molecular sieve and sesame oil sample and enables adsorption of benzopyrene in sesame oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The figure is a flow chart of removing benzopyrene according to the present invention. DETAILED DESCRIPTION

[0015] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] like Figure 1 As shown, the embodiment of the present invention provides a technical solution for a method for removing benzopyrene from sesame oil using molecular sieve technology, which includes the following removal steps: S1. Raw material selection Selection of molecular sieve and oil sample: zeolite molecular sieve and sesame oil sample are selected, the pore size of zeolite molecular sieve is 0.3-1 nanometer, and the usage ratio of zeolite molecular sieve and sesame oil sample is 1:10; S2. Activation of molecular sieves Before using the molecular sieve, the molecular sieve is activated (pretreated) to remove moisture and impurities on its surface; After washing the molecular sieve with ethanol, the solvent is removed by drying; S3, molecular sieve and oil sample mixture Add the pretreated molecular sieve into sesame oil. The amount of molecular sieve used should be determined according to the concentration of benzopyrene and the volume of oil. S4. Adsorption process The temperature during the adsorption process is controlled between 50°C. Heating to 40°C helps to increase the adsorption rate of the molecular sieve. The adsorption time is 30 minutes to 2 hours. Heating the temperature of sesame oil to 50°C can reduce the viscosity and improve the adsorption effect, avoiding the viscosity of sesame oil slowing down the contact between the molecular sieve and the oil sample, resulting in reduced adsorption efficiency. S5. Stirring After the molecular sieve is added to the sesame oil, in order to make the two mixed evenly, a stirrer is used to stir the two to ensure the contact time between the molecular sieve and the oil sample. The stirring rate of the magnetic stirrer is between 100-500 rpm; S6. Separation and Filtration Prepare the filtering equipment: Choose filter paper that can block the molecular sieve particles; Mixing oil and molecular sieve: Mix the oil adsorbed with benzopyrene and the molecular sieve evenly to ensure that the molecular sieve is in full contact with the oil sample; Filtration: Pour the mixed liquid into the filter device and use gravity to let the oil pass through the filter medium. The molecular sieve particles will be retained on the filter medium; Separation of molecular sieve: After filtration, the filter paper will retain the molecular sieve adsorbed with benzopyrene, and the clean oil will flow out through the filter medium; S7, regenerated molecular sieve Heating regeneration: Place the molecular sieve in an oven and set the temperature between 300°C and 600°C. During this process, the molecules of benzopyrene will volatilize and decompose due to the high temperature and be released into the environment. After heating is completed, wait for the molecular sieve to cool naturally. Washing and regeneration: choose ethanol, the solvent can dissolve benzopyrene and will not damage the molecular sieve structure, mix and stir the molecular sieve with the solvent, and wash out the adsorbed benzopyrene, separate the solvent from the molecular sieve by filtering and centrifugation, and separate the benzopyrene dissolved in the solvent; S8. Analysis and evaluation The treated oil samples were analyzed and the changes in the benzopyrene content were detected using gas chromatography and liquid chromatography instruments; S9. Optimization and Adjustment According to the adsorption effect of the molecular sieve, the type, dosage and contact time of the molecular sieve and the oil can be adjusted for further optimization.

[0017] The molecular sieve activation temperature is 300-500°C, the heating time is 4 hours, the stirring time of the molecular sieve and the sesame oil sample is 45 minutes, which increases the contact time between the molecular sieve and the sesame oil sample, and can adsorb benzopyrene in the sesame oil. The molecular sieve and the sesame oil sample are stirred at a temperature of 40-50°C, and a magnetic stirrer is used for stirring. Before cleaning the molecular sieve, the molecular sieve needs to be immersed in ethanol for 5 hours to ensure that the impurities on its surface are dissolved and removed. The molecular sieve is placed in an oven with a temperature set at 100°C-300°C and dried for 3 hours until there is no residual solvent on the surface of the molecular sieve. The molecular sieve can be used repeatedly. After regeneration, the adsorption performance can be restored, which reduces the production cost. The solvent is separated from the molecular sieve by filtering and centrifugation, and the benzopyrene dissolved in the solvent is separated. The regeneration of the molecular sieve includes solvent extraction, selecting dichloromethane, mixing the molecular sieve adsorbed with benzopyrene with the extraction solvent, and making the solvent fully contact with the molecular sieve by ultrasonic treatment.

[0018] Among them, separation and filtration include centrifugation, usually using a high-speed centrifuge with a speed set between 3000-5000 rpm. Centrifugal separation: Pour the mixed liquid into a centrifuge tube and put it into a centrifuge for high-speed centrifugation. The molecular sieve will settle to the bottom of the centrifuge tube, while the oil will float to the upper layer. Collect the oil: After the centrifugation is completed, carefully pour the upper clear liquid into another container. The molecular sieve sediment at the bottom will be left behind. Clean the molecular sieve: In order to remove the oil attached to the molecular sieve, the precipitated molecular sieve can be cleaned with a solvent and then dried. After washing and regeneration, use clean water to further clean the molecular sieve to remove the residual solvent. The cleaned molecular sieve needs to be dried and placed The mixture is heated to 100°C in an oven to remove moisture and residual solvent. The molecular sieve is regenerated by solvent extraction. Dichloromethane is selected to mix the molecular sieve adsorbed with benzopyrene with the extraction solvent. The solvent is fully contacted with the molecular sieve by ultrasonic treatment. The cleaned molecular sieve is placed in an oven with a temperature set at 100°C-300°C. The mixture is dried for 3 hours until there is no residual solvent on the surface of the molecular sieve. The activation temperature of the molecular sieve is 300-500°C. The heating time is 4 hours. The stirring time of the molecular sieve and the sesame oil sample is 45 minutes. Working principle and use process of the present invention: sesame oil may contain benzopyrene, which is a typical polycyclic aromatic hydrocarbon with strong carcinogenicity, so it needs to be removed from oil. In the production process of oil, if oil (such as sesame) is baked and refined at high temperature, especially in the traditional baking process, it may lead to the formation of polycyclic aromatic hydrocarbons. If contaminated soil and water sources are used in the cultivation of oil, and if it is exposed to pollution sources during transportation and storage, sesame oil may also contain a certain amount of benzopyrene. Benzopyrene is a known carcinogen and is harmful to health, especially in Long-term consumption of oils containing benzopyrene may increase the risk of cancer and cardiovascular disease. Modern food industry usually takes quality control measures to minimize and remove the content of benzopyrene in food. Traditional methods for removing benzopyrene from sesame oil mostly use activated carbon as an adsorbent, but the regeneration process of the adsorbent may be limited, and the adsorbent needs to be replaced regularly, which not only increases labor costs, but also has a poor removal effect on benzopyrene in sesame oil. Therefore, a method for removing benzopyrene from sesame oil using molecular sieve technology is designed. Zeolite molecular sieves and sesame oil samples are selected. The pore size of the zeolite molecular sieve is 0.3-1 nanometers, the dosage ratio of zeolite molecular sieve and sesame oil sample is 1:10. Before using the molecular sieve, the molecular sieve is activated (pretreated) to remove moisture and impurities on its surface. After cleaning the molecular sieve with ethanol, the solvent is removed by drying, and the pretreated molecular sieve is added to the sesame oil. The dosage of the molecular sieve needs to be determined according to the concentration of benzopyrene and the volume of the oil. The temperature during the adsorption process is controlled between 50°C. Heating to 40°C helps to increase the adsorption rate of the molecular sieve. The adsorption time is 30 minutes-2 hours. Heating the temperature of the sesame oil to 50°C can reduce the viscosity and improve the adsorption effect, avoiding the viscosity of the sesame oil slowing down the contact between the molecular sieve and the oil sample, resulting in a decrease in adsorption efficiency. After the molecular sieve is added to the sesame oil, in order to make the two mixed evenly, a stirrer is used to stir the two to ensure the contact time between the molecular sieve and the oil sample. The stirring rate of the magnetic stirrer is 100-500 rpm, prepare the filtering equipment: select filter paper, which can block the molecular sieve particles, mix the oil and molecular sieve adsorbed with benzopyrene: mix the oil and molecular sieve adsorbed with benzopyrene evenly, and ensure that the molecular sieve is in full contact with the oil sample; filter: pour the mixed liquid into the filter device, and use gravity to let the oil pass through the filter medium, and the molecular sieve particles will be retained on the filter medium; separate the molecular sieve: after filtration, the filter paper will retain the molecular sieve adsorbed with benzopyrene, and the clean oil will flow out through the filter medium, heat regeneration: put the molecular sieve into the oven, and set the temperature between 300℃ and 600℃. During this process, the molecules of benzopyrene will be It volatilizes and decomposes at high temperature and is released into the environment. After heating, wait for the molecular sieve to cool naturally and wash and regenerate: choose ethanol, the solvent can dissolve benzopyrene and will not damage the structure of the molecular sieve. Mix the molecular sieve with the solvent and wash out the adsorbed benzopyrene. Separate the solvent from the molecular sieve by filtering and centrifugation. The benzopyrene dissolved in the solvent is separated. Analyze the treated oil sample and use gas chromatography and liquid chromatography instruments to detect the change of benzopyrene content. According to the adsorption effect of the molecular sieve, the type, dosage and contact time of the molecular sieve can be adjusted for further optimization.

[0019] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for removing benzopyrene from sesame oil using molecular sieve technology, comprising the following removal steps: S1. Raw material selection Selection of molecular sieve and oil sample: zeolite molecular sieve and sesame oil sample are selected, the pore size of zeolite molecular sieve is 0.3-1 nanometer, and the usage ratio of zeolite molecular sieve and sesame oil sample is 1:10; S2. Activation of molecular sieves Before using the molecular sieve, the molecular sieve is activated (pretreated) to remove moisture and impurities on its surface; After washing the molecular sieve with ethanol, the solvent is removed by drying; S3, molecular sieve and oil sample mixture Add the pretreated molecular sieve into sesame oil. The amount of molecular sieve used should be determined according to the concentration of benzopyrene and the volume of oil. S4. Adsorption process The temperature during the adsorption process is controlled between 50°C. Heating to 40°C helps to increase the adsorption rate of the molecular sieve. The adsorption time is 30 minutes to 2 hours. Heating the temperature of sesame oil to 50°C can reduce the viscosity and improve the adsorption effect, avoiding the viscosity of sesame oil slowing down the contact between the molecular sieve and the oil sample, resulting in reduced adsorption efficiency. S5. Stirring After the molecular sieve is added to the sesame oil, in order to make the two mixed evenly, a stirrer is used to stir the two to ensure the contact time between the molecular sieve and the oil sample. The stirring rate of the magnetic stirrer is between 100-500 rpm; S6. Separation and Filtration Prepare the filtering equipment: Choose filter paper that can block the molecular sieve particles; Mixing oil and molecular sieve: Mix the oil adsorbed with benzopyrene and the molecular sieve evenly to ensure that the molecular sieve is in full contact with the oil sample; Filtration: Pour the mixed liquid into the filter device and use gravity to let the oil pass through the filter medium. The molecular sieve particles will be retained on the filter medium. Separation of molecular sieves: After filtration, the filter paper will retain the molecular sieve adsorbed with benzopyrene, and the clean oil will flow out through the filter medium. S7, regenerated molecular sieve Heating regeneration: Place the molecular sieve in an oven and set the temperature between 300°C and 600°C. During this process, the molecules of benzopyrene will volatilize and decompose due to the high temperature and be released into the environment. After heating is completed, wait for the molecular sieve to cool naturally. Washing and regeneration: choose ethanol, the solvent can dissolve benzopyrene and will not damage the molecular sieve structure, mix and stir the molecular sieve with the solvent, and wash out the adsorbed benzopyrene, separate the solvent from the molecular sieve by filtering and centrifugation, and separate the benzopyrene dissolved in the solvent; S8. Analysis and evaluation The treated oil samples were analyzed and the changes in the benzopyrene content were detected using gas chromatography and liquid chromatography instruments; S9. Optimization and Adjustment According to the adsorption effect of the molecular sieve, the type, dosage and contact time of the molecular sieve and the oil can be adjusted for further optimization.

2. The method for removing benzopyrene from sesame oil by molecular sieve technology according to claim 1, characterized in that: The activation temperature of the molecular sieve is 300-500°C, the heating time is 4 hours, and the stirring time of the molecular sieve and the sesame oil sample is 45 minutes, which increases the contact time between the molecular sieve and the sesame oil sample and can adsorb benzopyrene in the sesame oil.

3. The method for removing benzopyrene from sesame oil by molecular sieve technology according to claim 2, characterized in that: The molecular sieve and the sesame oil sample are stirred at a temperature of 40-50° C., and a magnetic stirrer is used for stirring the two.

4. The method for removing benzopyrene from sesame oil by molecular sieve technology according to claim 1, characterized in that: Before cleaning the molecular sieve, soak it in ethanol for 5 hours to ensure that the impurities on its surface are dissolved and removed. Place the cleaned molecular sieve in an oven with a temperature set at 100°C-300°C and dry it for 3 hours until there is no residual solvent on the surface of the molecular sieve.

5. The method for removing benzopyrene from sesame oil by molecular sieve technology according to claim 1, characterized in that: The separation and filtration include centrifugation, usually using a high-speed centrifuge with a speed set between 3000-5000 rpm. Centrifugal separation: Pour the mixed liquid into a centrifuge tube and put it into a centrifuge for high-speed centrifugation. The molecular sieve will settle to the bottom of the centrifuge tube, while the oil will float to the upper layer. Collect the oil: After the centrifugation is completed, carefully pour the upper clear liquid into another container, and the molecular sieve precipitate at the bottom will be left behind. Clean the molecular sieve: In order to remove the oil attached to the molecular sieve, the precipitated molecular sieve can be cleaned with a solvent and then dried.

6. The method for removing benzopyrene from sesame oil by molecular sieve technology according to claim 1, characterized in that: After washing and regeneration, the molecular sieve is further cleaned with clean water to remove residual solvent. The cleaned molecular sieve needs to be dried and placed in an oven heated to 100°C to remove moisture and residual solvent.

7. The method for removing benzopyrene from sesame oil by molecular sieve technology according to claim 1, characterized in that: The regeneration of the molecular sieve includes solvent extraction, selecting dichloromethane, mixing the molecular sieve adsorbed with benzopyrene with the extraction solvent, and making the solvent fully contact with the molecular sieve through ultrasonic treatment.

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