Method for decoloring and deodorizing edible oil

Abstract

The present application relates to a kind of edible oil decolorization and deodorization method, comprising the following steps: S1. under vacuum condition, to the crude product of edible oil, heating and stirring are added adsorbent, after filtration, obtain intermediate product;S2. intermediate product is transferred into deodorization tower, and deodorization treatment is carried out, and the edible oil of decolorization and deodorization is obtained;By the reaction of acrylic resin containing epoxy group and carboxylated bentonite and carboxylated activated carbon, the modified activated carbon-bentonite composite material with adsorption function is obtained, not only improve the specific surface area and porosity of modified activated carbon-bentonite composite material, and a large number of carbonyl, carboxyl group and other groups are introduced to the surface of modified activated carbon-bentonite composite material, can form synergistic effect, more effectively adsorb pigment and odor molecule in edible oil, to improve adsorption performance, enhance adsorption efficiency, and raw material is safe and environmentally friendly, easy to separate after adsorption, less residue, can effectively improve the color and stability of oil.

Description

Technical Field

[0001] This invention belongs to the field of oil refining, and specifically relates to a method for decolorizing and deodorizing edible oil. Background Technology

[0002] In the refining process of edible oils, decolorization and deodorization are crucial steps that determine the quality of the oil. Traditional decolorization processes typically use adsorbents such as activated carbon and natural bentonite to remove pigments and impurities from the oil through physical adsorption. However, while activated carbon has a high specific surface area and adsorption capacity, its non-selective adsorption characteristics easily lead to the loss of beneficial components such as unsaturated fatty acids in the oil (usually reaching 3-5%). In addition, natural bentonite, due to its limited surface functional groups, has insufficient chemical adsorption capacity for polar pigment molecules (such as chlorophyll derivatives and monaditis red), resulting in low decolorization efficiency, especially for heat-stable pigments, where the removal rate is often below 85%.

[0003] In deodorization processes, high-temperature steam distillation (230-250℃) is widely used to remove volatile odor substances. However, high temperatures easily trigger the formation of trans fatty acids and lead to significant losses of heat-sensitive nutrients such as vitamin E (loss rates can reach over 40%). Furthermore, in traditional processes, decolorization and deodorization must be carried out in separate steps. After decolorization, the temperature needs to be raised back to the required deodorization temperature, resulting in energy waste (energy consumption increases by approximately 30%) and the accumulation of byproducts of thermal oxidation of oils.

[0004] The core problems of existing technologies include: (1) insufficient chemical adsorption capacity of adsorbents for pigments, resulting in limited decolorization efficiency due to reliance on physical adsorption; (2) non-selective interaction between adsorbents and oil components increases nutrient loss; (3) mismatch between decolorization and deodorization process conditions, with repeated heating exacerbating oil oxidation and nutrient destruction; and (4) poor synergistic effect of adsorbents, with traditional mechanical mixing methods leading to low interfacial compatibility and difficulty in efficiently utilizing adsorption sites. These problems limit the development of high-nutritional-value edible oils, necessitating the development of an efficient and low-consumption integrated decolorization and deodorization technology through material modification and process optimization.

[0005] Therefore, there is an urgent need to find a technical solution that can overcome the shortcomings of existing technologies. Summary of the Invention

[0006] This invention discloses a method for decolorizing and deodorizing edible oil, comprising the following steps:

[0007] S1. Under vacuum conditions, an adsorbent is added to the crude edible oil product, heated and stirred, and then filtered to obtain an intermediate product;

[0008] S2. The intermediate product is transferred to a deodorization tower for deodorization treatment to obtain decolorized and deodorized edible oil;

[0009] The adsorbent is a modified activated carbon-bentonite composite material;

[0010] The modified activated carbon-bentonite composite material is obtained by reacting activated carbon, bentonite, and acrylic resin containing epoxy groups.

[0011] Furthermore, in step S1, the heating temperature is 100-110℃.

[0012] Furthermore, in step S2, the deodorization temperature is 100-120℃.

[0013] Furthermore, the amount of adsorbent added is 10-15% of the weight of the edible oil.

[0014] Furthermore, the preparation method of the adsorbent includes the following steps:

[0015] L1. Epoxidized soybean oil, acrylic acid, and polymerization inhibitor are mixed and heated to react under the action of a catalyst to obtain an intermediate product;

[0016] L2. Mix the intermediate product, tetraethylene glycol diacrylate, n-propanol, 1,4-butanediol, initiator and emulsifier, emulsify, add polyglycidyl methacrylate, mix evenly, react at room temperature, and then heat to react to obtain an acrylic resin containing epoxy groups.

[0017] L3. Under the protection of an inert gas, an epoxy-containing acrylic resin, carboxylated activated carbon, carboxylated bentonite, and a catalyst are mixed and heated to obtain a modified activated carbon-bentonite composite material.

[0018] Furthermore, in step L1, the temperature of the heating reaction is 100-120°C.

[0019] Further, in step L2, the emulsifier is a mixture of sodium dodecyl sulfate, polyvinyl alcohol, and water.

[0020] Furthermore, in step L3, the temperature of the heating reaction is 100-120°C.

[0021] Furthermore, in step L3, the mass ratio of the carboxylated activated carbon to the carboxylated bentonite is 1-5:1-3.

[0022] The present invention has the following beneficial effects:

[0023] This invention utilizes a modified activated carbon-bentonite composite material as an adsorbent for edible oil. First, epoxidized soybean oil and acrylic acid are reacted under the action of a catalyst and a polymerization inhibitor to obtain an intermediate product with epoxy groups. Then, the intermediate product is used as a monomer, tetraethylene glycol diacrylate as a crosslinking agent, and poly(glycidyl methacrylate) as a seed emulsion for polymerization to obtain an epoxy-containing acrylic resin with adsorption function. Next, the epoxy-containing acrylic resin is reacted and crosslinked with carboxylated bentonite and carboxylated activated carbon to obtain a modified activated carbon-bentonite composite material with adsorption function. This not only increases the specific surface area and porosity of the modified activated carbon-bentonite composite material but also introduces a large number of carbonyl and carboxyl groups onto the surface of the composite material, forming a synergistic effect that more effectively adsorbs pigments and odor molecules in edible oil, thereby improving adsorption performance and efficiency. Furthermore, the raw materials are safe and environmentally friendly, and the adsorbed material is easily separated with minimal residue, effectively improving the color and stability of the oil. Detailed Implementation

[0024] To more clearly illustrate the technical solution of the present invention, the following embodiments are provided. Unless otherwise stated, the raw materials, reactions, and post-processing methods appearing in the embodiments are all commercially available raw materials and technical methods well known to those skilled in the art.

[0025] In this embodiment, the crude edible oil product is a crude peanut oil product.

[0026] Hydroquinone, a polymerization inhibitor.

[0027] Triphenylphosphine, catalyst.

[0028] Azobisisobutyronitrile (AIBN), initiator.

[0029] Epoxidized soybean oil, CAS: 8013-07-8, purchased from Shandong Ranxi Chemical Technology Co., Ltd.

[0030] Polyglycidyl methacrylate, P757736, purchased from Maclean's.

[0031] Polyvinyl alcohol (PVA), with an average degree of polymerization of 1750, was purchased from Tianjin Tianda Chemical Reagent Factory.

[0032] Activated clay was purchased from Jinan Tonghui Chemical Co., Ltd.

[0033] Example 1

[0034] A method for decolorizing and deodorizing edible oil includes the following steps:

[0035] S1. Under vacuum conditions, the crude edible oil product is heated to 85°C, and then 10% of the weight of the edible oil adsorbent is added to the crude edible oil product. The mixture is heated to 105°C and stirred for 30 minutes. After filtration, the intermediate product is obtained.

[0036] S2. The intermediate product is transferred to a deodorization tower, heated to 100°C, and deodorized for 3 hours under vacuum conditions and a pressure of 0.3 MPa by directly introducing steam accounting for 15% of the weight of the intermediate product to obtain decolorized and deodorized edible oil.

[0037] The adsorbent is a modified activated carbon-bentonite composite material;

[0038] The preparation method of the adsorbent includes the following steps:

[0039] L1. Epoxidized soybean oil, acrylic acid and polymerization inhibitor are mixed and heated to 110°C for 2 hours under the action of a catalyst to obtain an intermediate product;

[0040] The mass ratio of the epoxidized soybean oil, acrylic acid, polymerization inhibitor, and catalyst is 8:1:0.1:0.1.

[0041] L2. Mix 10g of intermediate product, 10ml of tetraethylene glycol diacrylate, 10ml of n-propanol, 10ml of 1,4-butanediol, 0.5g of initiator and 200ml of emulsifier. After emulsification, add 12ml of polyglycidyl methacrylate, mix well, react at room temperature for 16h, then heat to 70℃ and continue to react for 16h. After filtration and washing, obtain an acrylic resin containing epoxy groups.

[0042] The emulsifier is a mixture of sodium dodecyl sulfate, polyvinyl alcohol, and water, wherein the content of sodium dodecyl sulfate is 0.2 wt% and the content of polyvinyl alcohol is 0.5 wt%.

[0043] L3-1. Activated carbon was soaked in 7 mol / L nitric acid solution, heated to 80℃ and reacted for 8 h. After washing and drying, carboxylated activated carbon was obtained.

[0044] L3-2. Bentonite was soaked in a 1.5 mol / L dopamine hydrochloride solution with a pH of 8.5, heated to 80°C and reacted for 8 hours, then washed and dried to obtain polydopamine-bentonite.

[0045] L3-3. Using glycerol as a solvent, polydopamine-bentonite and potassium bicarbonate were mixed evenly (mass ratio 1:5), heated to 180℃ and reacted for 30 min. After washing and drying, carboxylated bentonite was obtained.

[0046] L3-4. Under nitrogen protection, acrylic resin containing epoxy groups, carboxylated activated carbon, carboxylated bentonite, and catalyst were mixed and heated to 110℃ for 9 hours to obtain modified activated carbon-bentonite composite material.

[0047] The mass ratio of the epoxy-containing acrylic resin, carboxylated activated carbon, carboxylated bentonite, and catalyst is 1:1:1:0.1.

[0048] Example 2

[0049] A method for decolorizing and deodorizing edible oil includes the following steps:

[0050] S1. Under vacuum conditions, the crude edible oil product is heated to 85°C, and then 10% of the weight of the edible oil adsorbent is added to the crude edible oil product. The mixture is heated to 105°C and stirred for 30 minutes. After filtration, the intermediate product is obtained.

[0051] S2. The intermediate product is transferred to a deodorization tower, heated to 100°C, and deodorized for 3 hours under vacuum conditions and a pressure of 0.3 MPa by directly introducing steam accounting for 15% of the weight of the intermediate product to obtain decolorized and deodorized edible oil.

[0052] The adsorbent is a modified activated carbon-bentonite composite material;

[0053] The preparation method of the adsorbent includes the following steps:

[0054] L1. Epoxidized soybean oil, acrylic acid and polymerization inhibitor are mixed and heated to 110°C for 2 hours under the action of a catalyst to obtain an intermediate product;

[0055] The mass ratio of the epoxidized soybean oil, acrylic acid, polymerization inhibitor, and catalyst is 8:1:0.1:0.1.

[0056] L2. Mix 10g of intermediate product, 10ml of tetraethylene glycol diacrylate, 10ml of n-propanol, 10ml of 1,4-butanediol, 0.5g of initiator and 200ml of emulsifier. After emulsification, add 12ml of polyglycidyl methacrylate, mix well, react at room temperature for 16h, then heat to 70℃ and continue to react for 16h. After filtration and washing, obtain an acrylic resin containing epoxy groups.

[0057] The emulsifier is a mixture of sodium dodecyl sulfate, polyvinyl alcohol, and water, wherein the content of sodium dodecyl sulfate is 0.2 wt% and the content of polyvinyl alcohol is 0.5 wt%.

[0058] L3-1. Activated carbon was soaked in 7 mol / L nitric acid solution, heated to 80℃ and reacted for 8 h. After washing and drying, carboxylated activated carbon was obtained.

[0059] L3-2. Bentonite was soaked in a 1.5 mol / L dopamine hydrochloride solution with a pH of 8.5, heated to 80°C and reacted for 8 hours, then washed and dried to obtain polydopamine-bentonite.

[0060] L3-3. Using glycerol as a solvent, polydopamine-bentonite and potassium bicarbonate were mixed evenly (mass ratio 1:5), heated to 180℃ and reacted for 30 min. After washing and drying, carboxylated bentonite was obtained.

[0061] L3-4. Under nitrogen protection, acrylic resin containing epoxy groups, carboxylated activated carbon, carboxylated bentonite, and catalyst were mixed and heated to 110℃ for 9 hours to obtain modified activated carbon-bentonite composite material.

[0062] The mass ratio of the epoxy-containing acrylic resin, carboxylated activated carbon, carboxylated bentonite, and catalyst is 1:1:1:0.1.

[0063] Example 3

[0064] A method for decolorizing and deodorizing edible oil includes the following steps:

[0065] S1. Under vacuum conditions, the crude edible oil product is heated to 85°C, and then 10% of the weight of the edible oil adsorbent is added to the crude edible oil product. The mixture is heated to 105°C and stirred for 30 minutes. After filtration, the intermediate product is obtained.

[0066] S2. The intermediate product is transferred to a deodorization tower, heated to 100°C, and deodorized for 3 hours under vacuum conditions and a pressure of 0.3 MPa by directly introducing steam accounting for 15% of the weight of the intermediate product to obtain decolorized and deodorized edible oil.

[0067] The adsorbent is a modified activated carbon-bentonite composite material;

[0068] The preparation method of the adsorbent includes the following steps:

[0069] L1. Epoxidized soybean oil, acrylic acid and polymerization inhibitor are mixed and heated to 110°C for 2 hours under the action of a catalyst to obtain an intermediate product;

[0070] The mass ratio of the epoxidized soybean oil, acrylic acid, polymerization inhibitor, and catalyst is 8:1:0.1:0.1.

[0071] L2. Mix 10g of intermediate product, 10ml of tetraethylene glycol diacrylate, 10ml of n-propanol, 10ml of 1,4-butanediol, 0.5g of initiator and 200ml of emulsifier. After emulsification, add 12ml of polyglycidyl methacrylate, mix well, react at room temperature for 16h, then heat to 70℃ and continue to react for 16h. After filtration and washing, obtain an acrylic resin containing epoxy groups.

[0072] The emulsifier is a mixture of sodium dodecyl sulfate, polyvinyl alcohol, and water, wherein the content of sodium dodecyl sulfate is 0.2 wt% and the content of polyvinyl alcohol is 0.5 wt%.

[0073] L3-1. Activated carbon was soaked in 7 mol / L nitric acid solution, heated to 80℃ and reacted for 8 h. After washing and drying, carboxylated activated carbon was obtained.

[0074] L3-2. Bentonite was soaked in a 1.5 mol / L dopamine hydrochloride solution with a pH of 8.5, heated to 80°C and reacted for 8 hours, then washed and dried to obtain polydopamine-bentonite.

[0075] L3-3. Using glycerol as a solvent, polydopamine-bentonite and potassium bicarbonate were mixed evenly (mass ratio 1:5), heated to 180℃ and reacted for 30 min. After washing and drying, carboxylated bentonite was obtained.

[0076] L3-4. Under nitrogen protection, acrylic resin containing epoxy groups, carboxylated activated carbon, carboxylated bentonite, and catalyst were mixed and heated to 110℃ for 9 hours to obtain modified activated carbon-bentonite composite material.

[0077] The mass ratio of the epoxy-containing acrylic resin, carboxylated activated carbon, carboxylated bentonite, and catalyst is 1:1:1:0.1.

[0078] Comparative Example 1

[0079] A method for decolorizing and deodorizing edible oil. The difference between this comparative example and Example 1 is that step L2 is deleted, and the acrylic resin containing epoxy groups is replaced with an intermediate product. Other components and preparation methods are the same.

[0080] Comparative Example 2

[0081] A method for decolorizing and deodorizing edible oil. The difference between this comparative example and Example 1 is that the modified bentonite in this comparative example is replaced with a mixture of carboxylated activated carbon and carboxylated bentonite in a mass ratio of 1:1. Other components and preparation methods are the same.

[0082] Test Example 1

[0083] Decolorization rate test: The decolorization rate was determined by scanning the edible oil with a UV-1900i UV-Vis spectrophotometer to determine the maximum absorption wavelength. Then, the absorbance of the edible oils in Example 1 and Comparative Examples 1-2 before and after decolorization and deodorization was measured at this wavelength, and the decolorization rate was calculated.

[0084] Wherein, decolorization rate = (A0-A1) / A0×100%; A0 is the absorbance before refining; A1 is the absorbance after refining.

[0085] Odor test: The odor of the edible oils after the decolorization and deodorization methods of Example 1 and Comparative Examples 1-2 was evaluated.

[0086] The test results are shown in Table 1.

[0087] Table 1. Results of color and odor tests on edible oils from Examples 1 and 1-2.

[0088]

[0089] As can be seen from Table 1, the edible oil decolorization and deodorization method of the present invention can effectively remove the off-odors and pigments from edible oils, thereby improving the product quality of edible oils.

[0090] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0091] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for decolorizing and deodorizing edible oil, characterized in that, Includes the following steps: S1. Under vacuum conditions, an adsorbent is added to the crude edible oil product, heated and stirred, and then filtered to obtain an intermediate product; S2. The intermediate product is transferred to a deodorization tower for deodorization treatment to obtain decolorized and deodorized edible oil; The adsorbent is a modified activated carbon-bentonite composite material; The preparation method of the adsorbent includes the following steps: L1. Epoxidized soybean oil, acrylic acid, and polymerization inhibitor are mixed and heated to react under the action of a catalyst to obtain an intermediate product; L2. Mix the intermediate product, tetraethylene glycol diacrylate, n-propanol, 1,4-butanediol, initiator and emulsifier, emulsify, add polyglycidyl methacrylate, mix evenly, react at room temperature, and then heat to react to obtain an acrylic resin containing epoxy groups. L3. Under the protection of an inert gas, an epoxy-containing acrylic resin, carboxylated activated carbon, carboxylated bentonite, and a catalyst are mixed and heated to obtain a modified activated carbon-bentonite composite material.

2. The method for decolorizing and deodorizing edible oil according to claim 1, characterized in that, In step S1, the heating temperature is 100-110℃.

3. The method for decolorizing and deodorizing edible oil according to claim 1, characterized in that, In step S2, the deodorization temperature is 100-120℃.

4. The method for decolorizing and deodorizing edible oil according to claim 1, characterized in that, The amount of adsorbent added is 10-15% of the weight of the edible oil.

5. The method for decolorizing and deodorizing edible oil according to claim 1, characterized in that, In step L1, the temperature of the heating reaction is 100-120℃.

6. The method for decolorizing and deodorizing edible oil according to claim 1, characterized in that, In step L2, the emulsifier is a mixture of sodium dodecyl sulfate, polyvinyl alcohol, and water.

7. The method for decolorizing and deodorizing edible oil according to claim 1, characterized in that, In step L2, the temperature of the heating reaction is 60-80℃.

8. The method for decolorizing and deodorizing edible oil according to claim 1, characterized in that, In step L3, the temperature of the heating reaction is 100-120℃.

9. The method for decolorizing and deodorizing edible oil according to claim 1, characterized in that, In step L3, the mass ratio of the carboxylated activated carbon to the carboxylated bentonite is 1-5:1-3.

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