A method for reducing chloropropanol ester substances in fats and oils

Abstract

The present application provides a method for reducing chloropropanol ester substances in oil and fat, and belongs to the technical field of food processing, and aims to solve the technical problem of low adsorption removal rate of activated carbon on chloropropanol ester in oil and fat. The method is to mix modified activated carbon with oil and fat for adsorption, and then separate the modified activated carbon; the modified activated carbon is prepared by mixing and reacting surfactant and activated carbon. The prepared adsorbent has the advantages of easy raw material, simple process and low cost. The specific surface area of the modified activated carbon prepared by surfactant modification is large, the pore size is small, and the 3-chloropropanol ester in the oil and fat can be effectively removed, and the removal rate is as high as 80% or more.

Description

Technical Field

[0001] This invention belongs to the technical field of food processing, and particularly relates to a method for reducing chloropropanol esters in oils and fats. Background Technology

[0002] 3-Chloropropanol esters (3-MCPDEs) are a class of compounds formed by the esterification of 3-chloropropanol (3-MCPD) and fatty acids. They can also be formed by replacing the acyl group on a triacylglycerol with a chlorine atom. 3-MCPDEs include 3-chloropropanol-1-monoester, 3-chloropropanol-2-monoester, and 3-chloropropanol diester. As early as 1978, 3-chloropropanol was discovered as a contaminant produced during oil processing or cooking. It is also found in non-hydrolyzed protein foods such as bread, fish, cheese, and cakes, but it did not attract much attention at the time. It wasn't until 2004 that 3-chloropropanol esters were found in various processed foods, and in 2006, they were first discovered in edible oils. The International Agency for Research on Cancer (IARC) classified it as a possible carcinogen (Group 2B), meaning there is conclusive evidence that it may be carcinogenic. In addition, the European Food Safety Authority (EFSA) has listed the potential adverse effects of 3-MCPDE on the kidneys, male fertility, testes, and immune system.

[0003] 3-Chloropropanol esters (MCPDEs) are heat-induced process contaminants commonly found in refined vegetable oils. They are also widely present in smoked ham, coffee, rye malt, nuts, meat products, fried foods, and infant formula. To ensure the quality and safety of edible oil products and protect consumer health, many countries and regions have imposed strict limits on the content of 3-chloropropanol esters in oil products. In 2020, the European Union, in Commission Regulation (EU) 2020 / 1322, explicitly stipulated that the limit for 3-chloropropanol esters in sunflower oil, soybean oil, corn oil, rapeseed oil, palm kernel oil, coconut oil, and olive oil is 1.25 mg / kg, and the limit in other vegetable oils (including olive pomace oil) is 2.50 mg / kg. Lower permissible concentrations are also specified for infant formula and specific medical applications.

[0004] The formation of 3-chloropropanol esters involves the reaction of lipid components (such as glycerides) with chloride ions. The most common fatty acids that undergo esterification with 3-chloropropanol esters are lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, and linolenic acid. Studies have found that chloride ions are precursors to 3-chloropropanol ester formation. Chemical reagents used in oil refining processes, as well as tap water, can introduce a certain amount of chloride ions. Furthermore, high temperatures and processing conditions during processing can promote the formation of 3-chloropropanol esters. The deodorization process is considered the step in vegetable oil processing that produces the most 3-chloropropanol esters. During thermal processing, the precursor triacylglycerol (TAG) of 3-chloropropanol esters undergoes hydrolysis, losing its ester group to produce diacylglycerol (DAG) or monoacylglycerol (MAG). Both of these react with chloride ions to promote the formation of 3-chloropropanol esters.

[0005] Currently, there are three main methods to control the content of 3-chloropropanol esters in vegetable oils: (1) reducing or eliminating the use of chlorine-containing fertilizers and pesticides during oil crop cultivation can reduce the chlorine-containing compounds in crude oil; and removing precursor substances (chloride ions) from crude oil during the vegetable oil refining process to form 3-chloropropanol esters; (2) controlling process parameters such as deodorization temperature and time to ensure that the degradation rate of 3-chloropropanol esters is greater than the formation rate; and (3) adding antioxidants (tert-butylhydroquinone, butylated hydroxyanisole, α-tocopherol, tea polyphenols, etc.) or adsorbents (activated carbon, zeolite, etc.) or applying a coating during processing to reduce the content of 3-chloropropanol esters.

[0006] Activated carbon is an adsorbent material with a highly porous structure, possessing a large specific surface area and adsorption capacity. It is typically made from natural materials (such as wood, coconut shells, and coal) or synthetic materials, and undergoes a series of physical or chemical treatments. Based on its source, activated carbon can be classified into coal-based activated carbon, wood-based activated carbon, fruit shell activated carbon, and biomass activated carbon from other raw materials. The reason for activated carbon's enormous adsorption capacity is its well-developed pore structure. Activated carbon contains macropores, mesopores distributed within the macropores, and micropores distributed within the mesopores. Currently, oil processing plants commonly use activated carbon to adsorb and remove 3-chloropropanol esters from vegetable oils. However, based on current applications, it has been found that the removal rate of 3-chloropropanol esters by activated carbon is only between 20% and 35%, which is low, leaving a large amount of 3-chloropropanol ester residue in the final product. The source, preparation, porosity, distribution, and surface chemical properties of activated carbon all affect its adsorption performance. Summary of the Invention

[0007] To address the technical problem of low adsorption and removal rates of chloropropanol esters in oils by activated carbon, this invention proposes a method for reducing chloropropanol esters in oils. The modified activated carbon used has a large specific surface area, small pore size, and a simple and low-cost preparation process, while avoiding the introduction of new harmful residues and secondary pollution. After using this composite adsorbent to treat edible oils (vegetable oils), the 3-chloropropanol ester content is significantly reduced. The treated edible oil is far below national standards and meets EU standards, with a significant improvement in oil transparency. Due to the small amount of adsorbent used, the loss of neutral oil is also low.

[0008] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0009] A method for reducing chloropropanol esters in oils involves mixing modified activated carbon with the oil for adsorption, followed by separation of the modified activated carbon; the modified activated carbon is prepared by reacting a surfactant with activated carbon.

[0010] The oil is a vegetable oil. Palm oil is preferred, as it is considered the oil with the most serious exceedance of chloropropanol esters. The standards used for its determination are mainly 3-chloro-1,2-propanediol palmitate and deuterated 3-chloro-1,2-propanediol palmitate. Other types of oils can also be used; different oils have different fatty acid compositions, resulting in different chloropropanol esters, such as 1,2-dilinoleic acid-3-chloropropanol ester and 1,2-dilauric acid-3-chloropropanol ester.

[0011] The ratio of the oil to the modified activated carbon is 40-50g of the modified activated carbon per 1kg of oil, i.e., 40-50g / kg.

[0012] The adsorption conditions are stirring at 40–100°C for 20–90 min.

[0013] The modified activated carbon is prepared by mixing surfactant, activated carbon and solvent to form a mixture for reaction. The mixture after reaction is filtered, washed and ground to obtain modified activated carbon.

[0014] The surfactant is a nonionic surfactant.

[0015] The nonionic surfactant is Tween, and the Tween is Tween 80; the solvent is water.

[0016] The concentration of surfactant in the mixed solution is 40–550 mg / L, and the concentration of activated carbon is 40–50 g / L.

[0017] Preferably, the concentration of the surfactant in the mixed solution is 40-50 mg / L.

[0018] The mass concentration of different types of surfactants in a mixed solution varies greatly, and can also be expressed as critical micelle concentration, that is, the surfactant in the mixed solution reaches 1 to 3 critical micelle concentrations.

[0019] The reaction strip is prepared by stirring at 20–40°C for 5–10 hours.

[0020] The activated carbon is acid-washed to remove impurities before being modified with surfactants.

[0021] The beneficial effects of this invention are as follows: This invention uses abundant and inexpensive activated carbon as raw material, and requires only a small amount, which aligns with my country's strategic requirements for sustainable development and extending the agricultural industry chain. The modified activated carbon obtained by this invention has a small pore size (2-50 nm) and a large specific surface area (1800-2000 m²). 2 The activated carbon modified with Tween-80 ( / g) effectively removes 3-chloropropanol esters from vegetable oils, achieving a removal rate of 82.6%–86.5%. Furthermore, under the same conditions, the removal rates of 3-MCPDE by activated carbon modified with cationic surfactants (CTAB), anionic surfactants (SDBS), and nonionic surfactants (TX-100) were only 60.7%, 64.8%, and 60.8%, respectively, all lower than the removal rate of Tween-80. This demonstrates the superior adsorption performance of the Tween-modified activated carbon. The adsorption effect of an adsorbent on toxins is generally related to its pore size distribution, the number of surface functional groups, specific surface area, and pore volume. According to the classification of nitrogen adsorption isotherms by the International Union of Theoretical and Applied Chemistry (IUPAC), the nitrogen adsorption isotherms of both the activated carbon and Tween-80 modified activated carbon samples belong to Type IV and exhibit an H4 hysteresis loop, indicating the presence of microporous and mesoporous structures within the adsorbent. As can be seen from the pore size parameters in Table 1, the activated carbon modified with Tween-80 has a large specific surface area and total pore volume. During the modification process, the surfactant is loaded onto the outer surface and internal channels of the adsorbent. Although this reduces the number of micropores or the average pore size, it also increases the surface functional group density and coordination sites of the activated carbon, transforming the activated carbon from the original physical adsorption to a complex physical-chemical combined adsorption, thereby improving the activated carbon's adsorption capacity for toxins. Attached Figure Description

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

[0023] Figure 1 This is a schematic diagram of the process for preparing modified activated carbon.

[0024] Figure 2 Nitrogen adsorption isotherms and pore size parameters of activated carbon and prepared modified activated carbon samples. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Example 1

[0027] The preparation process of surfactant-modified activated carbon adsorbent is as follows: Figure 1 As shown, it includes the following steps:

[0028] (1) Take about 10g of activated carbon in a beaker, add a 4mol / L phosphoric acid solution and soak overnight to remove metal ions. Wash with distilled water until the washing solution is neutral. Then place the washed activated carbon in an oven (105℃) to dry and grind it through a 200-mesh sieve for later use.

[0029] (2) Dissolve 10 mg of surfactant Tween-80 in 200 mL of water to prepare a solution with a concentration of 50 mg / L;

[0030] (3) Add 10g of the purified activated carbon obtained in step (1) to the surfactant solution prepared in step (2), shake in a shaker at 30°C for 7h, then filter the resulting mixture, wash with distilled water until no foam is generated, then place the washed filter cake in an oven (105°C) to dry, grind through a 200-mesh sieve to obtain Tween-80 modified activated carbon adsorbent.

[0031] The method for reducing chloropropanol esters in oils is as follows: Weigh 20g of palm oil (containing 17.4mg / kg of 3-chloropropanol esters) and place it in a three-necked flask. Add 1.0g of the prepared Tween-80 modified activated carbon adsorbent. Heat and stir at an adsorption temperature of 100℃. The maximum stirring speed should not cause oil splashing. After adsorption for 20 minutes, filter to separate the adsorbent, and the adsorbed clean oil is obtained.

[0032] Figure 2 The images show the pore structure characterization data of Tween-80 modified activated carbon before and after treatment. Combined with Table 1, it can be seen that the specific surface area increased from 1317.79 m² / s² to [the original value missing]. 2 / g increased to 1975.57m 2 / g; the average pore size decreased from 6.40nm to 4.45nm, which falls within the mesoporous range. The nitrogen adsorption isotherms all belong to type IV, exhibiting an H4 adsorption hysteresis loop, which corresponds to a hierarchical porous structure. This further indicates that the adsorption performance is enhanced after treatment, and the removal rate can be improved.

[0033] Table 1: Pore size parameters of activated carbon and prepared modified activated carbon samples

[0034]

[0035] Comparative Example 1

[0036] The preparation of surfactant-modified activated carbon adsorbents includes the following steps:

[0037] Weigh 20g of palm oil (containing 17.4mg / kg of 3-chloropropanol ester) and place it in a three-necked flask. Add 1.0g of activated carbon adsorbent and heat and stir at an adsorption temperature of 100℃. The maximum stirring speed should not cause oil splashing. After adsorption for 20 minutes, filter to separate the adsorbent and obtain adsorbed purified oil.

[0038] The 3-chloropropanol ester content in the purified oils obtained in Example 1 and Comparative Example 1 was determined, and the removal rate was calculated. In Comparative Example 1, activated carbon treatment was used, and the removal rate of 3-chloropropanol esters in palm oil was 30.6%. However, in Example 1, the residual amount of 3-chloropropanol esters in palm oil treated with Tween-80 modified activated carbon was determined to be 2.4 mg / kg, and the removal rate of 3-chloropropanol esters in the oil was 86.5%, an increase of 55.9% compared to the unmodified oil.

[0039] Example 2

[0040] The preparation of surfactant-modified activated carbon adsorbents includes the following steps:

[0041] (1) Take about 10g of activated carbon in a beaker, add a 4mol / L phosphoric acid solution and soak overnight to remove metal ions. Wash with distilled water until the washing solution is neutral. Then place the washed activated carbon in an oven (105℃) to dry and grind it through a 200-mesh sieve for later use.

[0042] (2) Dissolve 8 mg of surfactant Tween-80 in 200 mL of water to prepare a solution with a concentration of 40 mg / L;

[0043] (3) Add 8g of the purified activated carbon obtained in step (1) to the surfactant solution prepared in step (2), shake in a shaker at 20°C for 7h, then filter the resulting mixture, wash with distilled water until no foam is generated, then place the washed filter cake in an oven (105°C) to dry, grind through a 200-mesh sieve to obtain Tween-80 modified activated carbon adsorbent.

[0044] The method for reducing chloropropanol esters in oils is as follows: Weigh 20g of palm oil (containing 12.6mg / kg of 3-chloropropanol esters) and place it in a three-necked flask. Add 0.8g of the prepared Tween-80 modified activated carbon adsorbent. Heat and stir at an adsorption temperature of 100℃. The maximum stirring speed should not cause oil splashing. After adsorption for 30 minutes, filter to separate the adsorbent, and the adsorbed clean oil is obtained.

[0045] Comparative Example 2

[0046] Weigh 20g of palm oil (containing 12.6mg / kg of 3-chloropropanol ester) and place it in a three-necked flask. Add 0.8g of activated carbon adsorbent and heat and stir at an adsorption temperature of 100℃. The maximum stirring speed should not cause oil splashing. After adsorption for 30 minutes, filter to separate the adsorbent and obtain adsorbed purified oil.

[0047] The 3-chloropropanol ester content in the purified oils obtained in Example 2 and Comparative Example 2 was determined, and the removal rate was calculated. In Comparative Example 2, activated carbon treatment was used, and the removal rate of 3-chloropropanol esters in the palm oil was 27.8%. However, in Example 2, the residual amount of 3-chloropropanol esters in the palm oil treated with Tween-80 modified activated carbon was determined to be 2.2 mg / kg, and the removal rate of 3-chloropropanol esters in the oil was 82.6%, an increase of 54.8% compared to the removal rate before modification.

[0048] Example 3

[0049] The preparation of surfactant-modified activated carbon adsorbents includes the following steps:

[0050] (1) Take about 10g of activated carbon in a beaker, add a 4mol / L phosphoric acid solution and soak overnight to remove metal ions. Wash with distilled water until the washing solution is neutral. Then place the washed activated carbon in an oven (105℃) to dry and grind it through a 200-mesh sieve for later use.

[0051] (2) Dissolve 67 mg of the surfactant cetyltrimethylammonium bromide (CTAB) in 200 mL of water to prepare a solution with a concentration of 335 mg / L;

[0052] (3) Add 10g of the purified activated carbon obtained in step (1) to the surfactant solution prepared in step (2), shake in a shaker at 40°C for 5h, then filter the resulting mixture, wash with distilled water until no foam is generated, then place the washed filter cake in an oven (105°C) to dry, grind through a 200-mesh sieve to obtain CTAB modified activated carbon adsorbent.

[0053] The method for reducing chloropropanol esters in oils is as follows: Weigh 20g of palm oil (containing 17.4mg / kg of 3-chloropropanol esters) and place it in a three-necked flask. Add 1.0g of the CTAB modified activated carbon adsorbent prepared above. Heat and stir at an adsorption temperature of 100℃. The maximum stirring speed should not cause oil splashing. After adsorption for 40 minutes, filter to separate the adsorbent, and the adsorbed clean oil is obtained.

[0054] Comparative Example 3

[0055] Weigh 20g of palm oil (containing 17.4mg / kg of 3-chloropropanol ester) and place it in a three-necked flask. Add 1.0g of activated carbon adsorbent and heat and stir at an adsorption temperature of 100℃. The maximum stirring speed should not cause oil splashing. After adsorption for 40 minutes, filter to separate the adsorbent and obtain adsorbed purified oil.

[0056] The 3-chloropropanol ester content in the purified oils obtained in Example 3 and Comparative Example 3 was determined, and the removal rate was calculated. In Comparative Example 3, activated carbon treatment was used, and the removal rate of 3-chloropropanol esters in the palm oil was 28.2%. In Example 3, the residual amount of 3-chloropropanol esters in the palm oil treated with CTAB-modified activated carbon was determined to be 6.8 mg / kg, and the removal rate of 3-chloropropanol esters in the oil was 60.7%, an increase of 32.5% compared to the unmodified removal rate.

[0057] Example 4

[0058] The preparation of surfactant-modified activated carbon adsorbents includes the following steps:

[0059] (1) Take about 10g of activated carbon in a beaker, add a 4mol / L phosphoric acid solution and soak overnight to remove metal ions. Wash with distilled water until the washing solution is neutral. Then place the washed activated carbon in an oven (105℃) to dry and grind it through a 200-mesh sieve for later use.

[0060] (2) Dissolve 105 mg of the surfactant sodium dodecylbenzenesulfonate (SDBS) in 200 mL of water to prepare a solution with a concentration of 525 mg / L;

[0061] (3) Add 10g of the purified activated carbon obtained in step (1) to the surfactant solution prepared in step (2), shake in a shaker at 20°C for 10h, then filter the resulting mixture, wash with distilled water until no foam is generated, then place the washed filter cake in an oven (105°C) to dry, grind through a 200-mesh sieve to obtain SDBS modified activated carbon adsorbent.

[0062] The method for reducing chloropropanol esters in oils is as follows: Weigh 20g of palm oil (containing 17.4mg / kg of 3-chloropropanol esters) and place it in a three-necked flask. Add 1.0g of the SDBS modified activated carbon adsorbent prepared above. Heat and stir at an adsorption temperature of 100℃. The maximum stirring speed should not cause oil splashing. After adsorption for 40 minutes, filter to separate the adsorbent, and the adsorbed clean oil is obtained.

[0063] Comparative Example 4

[0064] Weigh 20g of palm oil (containing 17.4mg / kg of 3-chloropropanol ester) and place it in a three-necked flask. Add 1.0g of activated carbon adsorbent and heat and stir at an adsorption temperature of 100℃. The maximum stirring speed should not cause oil splashing. After adsorption for 40 minutes, filter to separate the adsorbent and obtain adsorbed purified oil.

[0065] The 3-chloropropanol ester content in the purified oils obtained in Example 4 and Comparative Example 4 was determined, and the removal rate was calculated. In Comparative Example 4, activated carbon treatment was used, and the removal rate of 3-chloropropanol esters in the palm oil was 28.2%. However, in Example 4, the residual amount of 3-chloropropanol esters in the palm oil treated with SDBS-modified activated carbon was determined to be 6.1 mg / kg, and the removal rate of 3-chloropropanol esters in the oil was 64.8%, an increase of 36.6% compared to the removal rate before modification.

[0066] Example 5

[0067] The preparation of surfactant-modified activated carbon adsorbents includes the following steps:

[0068] (1) Take about 10g of activated carbon in a beaker, add a 4mol / L phosphoric acid solution and soak overnight to remove metal ions. Wash with distilled water until the washing solution is neutral. Then place the washed activated carbon in an oven (105℃) to dry and grind it through a 200-mesh sieve for later use.

[0069] (2) Dissolve 29 mg of surfactant Triton X-100 (TX-100) in 200 mL of water to prepare a solution with a concentration of 145 mg / L;

[0070] (3) Add 10g of the purified activated carbon obtained in step (1) to the surfactant solution prepared in step (2), shake in a shaker at 30°C for 7h, then filter the resulting mixture, wash with distilled water until no foam is generated, then place the washed filter cake in an oven (105°C) to dry, grind through a 200-mesh sieve to obtain TX-100 modified activated carbon adsorbent.

[0071] The method for reducing chloropropanol esters in oils is as follows: Weigh 20g of palm oil (containing 17.4mg / kg of 3-chloropropanol esters) and place it in a three-necked flask. Add 1.0g of the TX-100 modified activated carbon adsorbent prepared above. Heat and stir at an adsorption temperature of 100℃. The maximum stirring speed should not cause oil splashing. After adsorption for 40 minutes, filter to separate the adsorbent, and the adsorbed clean oil is obtained.

[0072] Comparative Example 5

[0073] Weigh 20g of palm oil (containing 17.4mg / kg of 3-chloropropanol ester) and place it in a three-necked flask. Add 1.0g of activated carbon adsorbent and heat and stir at an adsorption temperature of 100℃. The maximum stirring speed should not cause oil splashing. After adsorption for 40 minutes, filter to separate the adsorbent and obtain adsorbed purified oil.

[0074] The 3-chloropropanol ester content in the purified oils obtained in Example 5 and Comparative Example 5 was determined, and the removal rate was calculated. In Comparative Example 5, activated carbon treatment was used, and the removal rate of 3-chloropropanol esters in the palm oil was 28.4%. However, in Example 5, the residual amount of 3-chloropropanol esters in the palm oil treated with TX-100 modified activated carbon was determined to be 6.8 mg / kg, and the removal rate of 3-chloropropanol esters in the oil was 60.8%, an increase of 32.4% compared to the removal rate before modification.

[0075] Example 6

[0076] The preparation of surfactant-modified activated carbon adsorbents includes the following steps:

[0077] (1) Take about 10g of activated carbon in a beaker, add a 4mol / L phosphoric acid solution and soak overnight to remove metal ions. Wash with distilled water until the washing solution is neutral. Then place the washed activated carbon in an oven (105℃) to dry and grind it through a 200-mesh sieve for later use.

[0078] (2) Dissolve 10 mg of surfactant Tween-80 in 200 mL of water to prepare a solution with a concentration of 50 mg / L;

[0079] (3) Add 8g of the purified activated carbon obtained in step (1) to the surfactant solution prepared in step (2), shake in a shaker at 25°C for 10h, then filter the resulting mixture, wash with distilled water until no foam is generated, then place the washed filter cake in an oven (105°C) to dry, grind through a 200-mesh sieve to obtain Tween-80 modified activated carbon adsorbent.

[0080] The method for reducing chloropropanol esters in oils is as follows: Weigh 20g of palm oil (containing 17.4mg / kg of 3-chloropropanol esters) and place it in a three-necked flask. Add 1.0g of the prepared Tween-80 modified activated carbon adsorbent. Heat and stir at an adsorption temperature of 100℃. The maximum stirring speed should not cause oil splashing. After adsorption for 30 minutes, filter to separate the adsorbent, and the adsorbed clean oil is obtained.

[0081] Example 7

[0082] The preparation of surfactant-modified activated carbon adsorbents includes the following steps:

[0083] (1) Take about 10g of activated carbon in a beaker, add a 4mol / L phosphoric acid solution and soak overnight to remove metal ions. Wash with distilled water until the washing solution is neutral. Then place the washed activated carbon in an oven (105℃) to dry and grind it through a 200-mesh sieve for later use.

[0084] (2) Dissolve 8 mg of surfactant Tween-80 in 200 mL of water to prepare a solution with a concentration of 40 mg / L;

[0085] (3) Add 10g of the purified activated carbon obtained in step (1) to the surfactant solution prepared in step (2), shake in a shaker at 40°C for 5h, then filter the resulting mixture, wash with distilled water until no foam is generated, then place the washed filter cake in an oven (105°C) to dry, grind through a 200-mesh sieve to obtain Tween-80 modified activated carbon adsorbent.

[0086] The method for reducing chloropropanol esters in oils is as follows: Weigh 20g of palm oil (containing 17.4mg / kg of 3-chloropropanol esters) and place it in a three-necked flask. Add 0.9g of the prepared Tween-80 modified activated carbon adsorbent. Heat and stir at an adsorption temperature of 40℃. The maximum stirring speed should not cause oil splashing. After adsorption for 90 minutes, filter to separate the adsorbent, and the adsorbed clean oil is obtained.

[0087] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for reducing chloropropanol esters in oils and fats, characterized in that, Modified activated carbon is mixed with oil for adsorption, and then the modified activated carbon is separated; the modified activated carbon is prepared by mixing and reacting surfactant with activated carbon. The oil is a vegetable oil, and the vegetable oil is palm oil; The ratio of the oil to the modified activated carbon is 40-50 g of the modified activated carbon per 1 kg of oil; The adsorption conditions were as follows: stirring at 60–100 °C for 20–90 min. The modified activated carbon is prepared by mixing surfactant, activated carbon and solvent to form a mixture and reacting it. The mixture after reaction is filtered, washed and ground to obtain modified activated carbon. The surfactant is a nonionic surfactant; The nonionic surfactant is Tween, and the Tween is Tween 80; the solvent is water. The concentration of surfactant in the mixture is 40–550 mg / L, and the concentration of activated carbon is 40–50 g / L. The reaction conditions were stirring at 20–40°C for 5–10 h.

2. The method for reducing chloropropanol esters in oils and fats according to claim 1, characterized in that, The activated carbon is acid-washed to remove impurities before being modified with surfactants.

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