Treatment method for directionally removing lead and arsenic in vegetable oil

Abstract

The invention discloses a treatment method for directionally removing lead and arsenic in vegetable oil. The treatment method comprises the following steps: S10, taking materials; s20, taking oil; s30, primary feeding and adsorption; s40, material preparation; s50, secondary feeding and adsorption; s60, sealing is conducted; the method has the beneficial effects that heavy metal pollutants such as lead and arsenic in the vegetable oil can be efficiently removed through the method, the technological process is scientific, the arsenic is mainly removed through first adsorption, the lead is mainly removed through second adsorption, directional removal of different heavy metals is achieved, the treatment pertinence is improved, and the treatment cost is reduced. Therefore, the vegetable oil with the lead and arsenic content reaching safety limit values, high oxidation stability and high nutritional value can be conveniently prepared.

Description

Technical Field

[0001] The invention relates to a treatment method for directionally removing lead and arsenic from vegetable oil. Background Art

[0002] Vegetable oils are oils extracted from seeds, fruits or other parts of plants and are commonly used in cooking, food processing and industrial applications. Common vegetable oils include olive oil, rapeseed oil, soybean oil, sunflower oil, etc. They contain a variety of fatty acids, mainly monounsaturated and polyunsaturated fatty acids, which help provide energy and support health.

[0003] Lead and arsenic are typical heavy metal pollutants in vegetable oils. Affected by the oil, processing, and storage conditions, the lead and arsenic in vegetable oils may exceed the limit values ​​of "GB 2762-2022 National Food Safety Standard Limits of Contaminants in Food", resulting in safety hazards in oil products. Conventional heavy metal removal methods are mainly achieved in the bleaching section of oil refining through the adsorption of adsorbents such as white clay; but at the same time, it is easy to adsorb other antioxidant trace substances (such as tocopherol, etc.) and break unsaturated double bonds, resulting in reduced oxidative stability of oil products and the appearance of a "white clay" taste. In order to remove this unpleasant flavor, a strict deodorization section is required afterwards, which further leads to the loss of antioxidant trace substances and greatly reduces the nutritional value of the oil. In view of this, the present invention proposes a treatment method for directional removal of lead and arsenic in vegetable oil to solve the above problems. Summary of the invention

[0004] The object of the present invention is to provide a treatment method for directional removal of lead and arsenic in vegetable oil to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A treatment method for directional removal of lead and arsenic in vegetable oil comprises the following steps:

[0007] S10, taking materials:

[0008] Take appropriate amounts of attapulgite, activated clay and activated carbon, and store the attapulgite, activated clay and activated carbon separately;

[0009] S20. Get oil:

[0010] Put the vegetable oil to be processed into a storage container, and make the storage container sealed;

[0011] S30, one step of adding material for adsorption:

[0012] Adding the attapulgite in S10 into a storage container, and making the storage container in an unsealed state, and performing a heating treatment on the storage container;

[0013] S40, ingredients:

[0014] Mix activated clay and activated carbon together and stir thoroughly to form an adsorption mixture;

[0015] S50, Secondary feeding adsorption:

[0016] Cooling the storage container that has been heated once in S30, adding the adsorption mixture in S40 to the storage container, and performing a secondary heating on the storage container after the addition is completed;

[0017] S60, Sealing:

[0018] After S50 is completed, the storage container is cooled so that the vegetable oil is at room temperature, and the storage container is sealed.

[0019] As an improvement of the above technical solution, in S10, the specific surface area of ​​the attapulgite is 80 to 200 m 2 / g, pore volume is 0.1~0.3cm 3 / g, average pore size is 6.0~10.0nm;

[0020] The specific surface area of ​​activated clay is 150~220m 2 / g, pore volume is 0.1~0.3cm 3 / g, average pore size is 4.5~8.0nm;

[0021] The specific surface area of ​​activated carbon is 850~1200m 2 / g, pore volume is 0.6~1.0cm 3 / g, the average pore size is 2.5~6.0nm.

[0022] As an improvement of the above technical solution, during the one-time heating in S30, the reaction temperature of the vegetable oil is 90-130° C., and the reaction time is 20-60 min.

[0023] As an improvement of the above technical solution, during the secondary heating in S50, the reaction temperature of the vegetable oil is 80-100° C., and the reaction time is 10-40 min.

[0024] As an improvement of the above technical solution, in S40, the composite mass ratio of activated clay and activated carbon is 5:1 to 20:1.

[0025] As an improvement of the above technical solution, the amount of attapulgite added to the vegetable oil is 1.5% to 5.0% of the mass of the vegetable oil, and in S50, the amount of the adsorption mixture added is 0.5% to 1.5% of the mass of the vegetable oil.

[0026] As an improvement of the above technical solution, during the one-time heating in S30, the following steps are also included:

[0027] S31, heating the vegetable oil to 50° C. and stirring at a stirring speed of 60 RPM for 2 min;

[0028] S32, then heating the vegetable oil to 70° C. and stirring at a stirring speed of 100 RPM for 5 minutes;

[0029] S33. Finally, the vegetable oil is heated to 90-130° C. and stirred at a speed of 150 RPM for 20-60 min.

[0030] As an improvement of the above technical solution, during the secondary heating treatment in S50, the following steps are also included:

[0031] S51, heating the vegetable oil to 50° C. and stirring at a speed of 80 RPM for 2 min;

[0032] S52, then heating the vegetable oil to 70° C. and stirring at a stirring speed of 120 RPM for 5 minutes;

[0033] S53. Finally, the vegetable oil is heated to 80-100° C. and stirred at a speed of 150 RPM for 10-40 minutes.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] The above method can be used to efficiently remove heavy metal pollutants such as lead and arsenic in vegetable oil, and the process flow is reasonable. The first adsorption mainly removes arsenic, and the second adsorption mainly removes lead, thereby achieving directional removal of different heavy metals and improving the targeted treatment, thereby facilitating the production of vegetable oil with lead and arsenic content reaching safe limits and high oxidation stability and high nutritional value, while avoiding the use of excessive kaolin. Under the premise of ensuring that lead and arsenic reach safe levels, the loss of antioxidant trace substances is minimized, and the flavor and oxidation stability of the oil are stabilized. The process method has the technical effects of scientificity, high efficiency, high quality preservation, good controllability, economy and practicality, and is suitable for promotion and application in the deep removal of heavy metals in vegetable oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Schematic diagram of the removal effect of lead and arsenic in vegetable oil by the two-step adsorption process of the present invention. DETAILED DESCRIPTION

[0037] 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.

[0038] Example:

[0039] like Figure 1 As shown, this embodiment proposes a treatment method for directional removal of lead and arsenic in vegetable oil, comprising the following steps:

[0040] S10, taking materials:

[0041] Take appropriate amounts of attapulgite, activated clay and activated carbon, and store the attapulgite, activated clay and activated carbon separately;

[0042] S20. Get oil:

[0043] Put the vegetable oil to be processed into a storage container, and make the storage container sealed;

[0044] S30, one step of adding material for adsorption:

[0045] Adding the attapulgite in S10 into a storage container, and making the storage container in an unsealed state, and performing a heating treatment on the storage container;

[0046] S40, ingredients:

[0047] Mix activated clay and activated carbon together and stir thoroughly to form an adsorption mixture;

[0048] S50, Secondary feeding adsorption:

[0049] Cooling the storage container that has been heated once in S30, adding the adsorption mixture in S40 to the storage container, and performing a secondary heating on the storage container after the addition is completed;

[0050] S60, Sealing:

[0051] After S50 is completed, the storage container is cooled so that the vegetable oil is at room temperature, and the storage container is sealed.

[0052] In this embodiment, the above method can be used to efficiently remove heavy metal pollutants such as lead and arsenic in vegetable oil, and the process flow is reasonable. The first adsorption mainly removes arsenic, and the second adsorption mainly removes lead, thereby achieving directional removal of different heavy metals and improving the targeted treatment, thereby facilitating the preparation of vegetable oil with lead and arsenic content reaching safe limits and high oxidation stability and high nutritional value, while avoiding the use of excessive white clay. Under the premise of ensuring that lead and arsenic reach safe levels, the loss of antioxidant trace substances is minimized as much as possible, and the flavor and oxidation stability of the oil are stabilized. The process method has technical effects such as high efficiency, high quality preservation, good controllability, economy and practicality, and is suitable for promotion and application in the deep removal of heavy metals in vegetable oil.

[0053] Specifically, in S10, the specific surface area of ​​attapulgite is 80 to 200 m 2 / g, pore volume is 0.1~0.3cm 3 / g, average pore size is 6.0~10.0nm;

[0054] The specific surface area of ​​activated clay is 150~220m 2 / g, pore volume is 0.1~0.3cm 3 / g, average pore size is 4.5~8.0nm;

[0055] The specific surface area of ​​activated carbon is 850~1200m 2 / g, pore volume is 0.6~1.0cm 3 / g, the average pore size is 2.5~6.0nm.

[0056] Specifically, during the primary heating in S30, the reaction temperature of the vegetable oil is 90 to 130°C, and the reaction time is 20 to 60 minutes.

[0057] Specifically, during the secondary heating in S50, the reaction temperature of the vegetable oil is 80 to 100° C., and the reaction time is 10 to 40 minutes.

[0058] Specifically, in S40, the composite mass ratio of activated clay to activated carbon is 5:1 to 20:1.

[0059] Specifically, in S30, the amount of attapulgite added to the vegetable oil is 1.5% to 5.0% by weight of the vegetable oil, and in S50, the amount of the adsorption mixture added is 0.5% to 1.5% by weight of the vegetable oil.

[0060] Specifically, during the primary heating in S30, the following steps are also included:

[0061] S31, heating the vegetable oil to 50° C. and stirring at a stirring speed of 60 RPM for 2 min;

[0062] S32, then heating the vegetable oil to 70° C. and stirring at a stirring speed of 100 RPM for 5 minutes;

[0063] S33. Finally, the vegetable oil is heated to 90-130° C. and stirred at a speed of 150 RPM for 20-60 min.

[0064] Specifically, during the secondary heating treatment in S50, the following steps are also included:

[0065] S51, heating the vegetable oil to 50° C. and stirring at a speed of 80 RPM for 2 min;

[0066] S52, then heating the vegetable oil to 70° C. and stirring at a stirring speed of 120 RPM for 5 minutes;

[0067] S53. Finally, the vegetable oil is heated to 80-100° C. and stirred at a speed of 150 RPM for 10-40 minutes.

[0068] In this embodiment, the above-mentioned gradual heating and stirring method can promote uniform heat distribution, reduce local overheating, improve the contact efficiency between the adsorbent and the oil, and enhance the heavy metal removal effect. In addition, step-by-step heating ensures stable reaction conditions and reduces side reactions. At the same time, the temperature and mixing are effectively controlled to reduce the loss of nutrients and avoid the adverse factors caused by sudden temperature changes. That is, while promoting full contact between the adsorbent and the oil, the slow rise in temperature can protect the nutrients in the oil from being excessively destroyed, which can effectively reduce the risk of thermal degradation of the oil.

[0069] Embodiment 1:

[0070] The rapeseed oil with a lead content of 0.5 mg / kg (more than 6 times the standard) and an arsenic content of 1.55 mg / kg (more than 15 times the standard) was used as the experimental object. A two-pass adsorption process was adopted. The first pass of adsorption used attapulgite (specific surface area of ​​120 m 2 / g, pore volume is 0.15cm 3 / g, average pore size of 6.5nm), the addition amount in vegetable oil is 1.8%, the reaction temperature is 105℃, and the time is 22min. At this time, a large amount of arsenic is removed and part of lead is removed, as shown in Table 1 and Figure 1 .

[0071] Table 1 Removal effect of heavy metals by the second adsorption process

[0072]

[0073] Then the second adsorption was carried out using activated clay (specific surface area 165m 2 / g, pore volume is 0.21cm 3 / g, average pore size 5.2nm) and activated carbon (specific surface area 1058m 2 / g, pore volume is 0.78cm 3 / g, average pore size of 4.2nm), the mass ratio of the two was 10:1, the addition amount in the vegetable oil was 0.9%, the reaction temperature was 95℃, and the reaction time was 20min, achieving a large amount of lead removal. The lead and arsenic content of the obtained vegetable oil was lower than the corresponding limit values ​​of GB 2762-2022 National Food Safety Standard Limits of Contaminants in Food (lead ≤ 0.08mg / kg; arsenic ≤ 0.10mg / kg), see Table 1 and Figure 1 .

[0074] Embodiment 2:

[0075] The experimental subjects were rapeseed oil with a lead content of 0.5 mg / kg (more than 6 times the standard) and an arsenic content of 1.55 mg / kg (more than 15 times the standard). 2 / g, pore volume is 0.21cm 3 / g, with an average pore size of 5.2nm) as the adsorbent, the traditional adsorption process was adopted, the addition amount in the vegetable oil was 2.7%, the reaction temperature was 110℃, and the time was 40min. At this time, a large amount of arsenic and lead were removed, as shown in Table 2.

[0076] Table 2 Removal effect of heavy metals by traditional processes

[0077]

[0078] The yield and quality of the refined rapeseed oil obtained in Example 1 and Example 2 are compared in Table 3.

[0079] Table 3 Yield and quality of refined rapeseed oil obtained in Example 1 and Example 2

[0080]

[0081] It can be seen that the present invention can achieve efficient removal of heavy metal lead and arsenic, while retaining tocopherol to the greatest extent and improving the antioxidant capacity of oil products.

[0082] 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 directional removal of lead and arsenic from vegetable oil, characterized in that: The following steps are involved: S10, taking materials: Take appropriate amounts of attapulgite, activated clay and activated carbon, and store the attapulgite, activated clay and activated carbon separately; S20. Get oil: Put the vegetable oil to be processed into a storage container, and make the storage container sealed; S30, one step of adding material for adsorption: Adding the attapulgite in S10 into a storage container, and making the storage container in an unsealed state, and performing a heating treatment on the storage container; S40, Ingredients: Mix activated clay and activated carbon together and stir thoroughly to form an adsorption mixture; S50, Secondary feeding adsorption: Cooling the storage container that has been heated once in S30, adding the adsorption mixture in S40 to the storage container, and performing a secondary heating on the storage container after the addition is completed; S60, Sealing: After S50 is completed, the storage container is cooled so that the vegetable oil is at room temperature, and the storage container is sealed.

2. A method for directional removal of lead and arsenic from vegetable oil according to claim 1, characterized in that: In S10, the specific surface area of ​​attapulgite is 80-200 m² / g, the pore volume is 0.1-0.3 cm³ / g, and the average pore size is 6.0-10.0 nm; The specific surface area of ​​activated clay is 150-220m² / g, the pore volume is 0.1-0.3cm³ / g, and the average pore diameter is 4.5-8.0nm; The specific surface area of ​​activated carbon is 850-1200m² / g, the pore volume is 0.6-1.0cm³ / g, and the average pore diameter is 2.5-6.0nm.

3. The method for directional removal of lead and arsenic from vegetable oil according to claim 1, characterized in that: During the primary heating in S30, the reaction temperature of the vegetable oil is 90 to 130°C, and the reaction time is 20 to 60 minutes.

4. A method for directional removal of lead and arsenic from vegetable oil according to claim 3, characterized in that: During the secondary heating in S50, the reaction temperature of the vegetable oil is 80-100°C, and the reaction time is 10-40 minutes.

5. A method for directional removal of lead and arsenic from vegetable oil according to claim 4, characterized in that: In S40, the composite mass ratio of activated clay to activated carbon is 5:1 to 20:

1.

6. A method for directional removal of lead and arsenic from vegetable oil according to claim 1, characterized in that: The amount of attapulgite added to the vegetable oil is 1.5% to 5.0% of the mass of the vegetable oil. In S50, the amount of the adsorption mixture added is 0.5% to 1.5% of the mass of the vegetable oil.

7. The method for directional removal of lead and arsenic from vegetable oil according to claim 1, characterized in that: During the primary heating in S30, the following steps are also included: S31, heating the vegetable oil to 50°C and stirring at a stirring speed of 60RPM for 2 min; S32, then heating the vegetable oil to 70° C. and stirring at a stirring speed of 100 RPM for 5 minutes; S33. Finally, the vegetable oil is heated to 90-130° C. and stirred at a speed of 150 RPM for 20-60 min.

8. A method for directional removal of lead and arsenic from vegetable oil according to claim 2, characterized in that: During the secondary heating treatment in S50, the following steps are also included: S51, heating the vegetable oil to 50°C and stirring at a stirring speed of 80RPM for 2 min; S52, then heating the vegetable oil to 70° C. and stirring at a stirring speed of 120 RPM for 5 minutes; S53. Finally, the vegetable oil is heated to 80-100° C. and stirred at a speed of 150 RPM for 10-40 minutes.

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