Process for removing di (2-ethyl) hexyl phthalate in aromatic peanut oil
By using high-pressure cross-linked porous starch adsorbent in the production of rich-flavor peanut oil, the problem of DEHP removal was solved, the flavor and nutritional components of the oil were maintained, and efficient and safe DEHP removal was achieved.
Patent Information
- Application Number
- CN202510886130.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-30
- Publication Date
- 2025-09-26
AI Technical Summary
How to efficiently remove di(2-ethylhexyl) phthalate (DEHP), a plasticizer that is harmful to the human body and easily migrates into edible oil, while maintaining the natural flavor and nutritional content of rich peanut oil.
High-pressure cross-linked porous starch is used as an adsorbent, and its lipophilicity and hydrophilicity are enhanced through modification. It is added to peanut oil and mixed with peanut kernels, then fried and pressed. Combined with low-temperature filtration and aseptic canning steps, the effective removal of DEHP is ensured.
The method can achieve efficient removal of DEHP from fragrant peanut oil, maintain the oil quality and flavor, and has simple process, safety and harmlessness, and is suitable for large-scale industrial production.
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Abstract
Description
Technical Field
[0001] The invention relates to a process for removing di(2-ethyl)hexyl phthalate from fragrant peanut oil, and belongs to the technical field of fragrant peanut oil processing. Background Art
[0002] Rich-flavor peanut oil is an edible oil made from high-quality peanut kernels through a process of roasting, roasting, and physical pressing. It offers a rich flavor and streamlined processing, preserving the natural active ingredients of peanuts to the greatest extent possible. Compared to refined peanut oil, it is richer in nutrients and flavor. However, due to its high content of natural oils, rich-flavor peanut oil has a strong adsorption capacity for plasticizers. Plasticizers are toxic plastic softeners used in the chemical industry and typically exist as colorless and odorless liquids. Their migration properties make them easily transferable from plastic products into food contact. This is particularly true during the production and storage of edible oil, where plastic containers or pipes are used. Plasticizers can dissolve into the edible oil, contaminating it. Furthermore, plasticizers in the environment, such as those found in soil and water, can also enter edible oil through the food chain.
[0003] Di(2-ethylhexyl) phthalate (DEHP) is a common plasticizer that is highly toxic and widely present. Its detection rate and content in edible oils are both high. Long-term exposure to DEHP or the use of edible oils contaminated with DEHP can cause irreversible and serious damage to the human nervous system.
[0004] Currently, there is considerable research on the removal of DEHP from refined peanut oil, often performed through activated carbon adsorption and high-temperature deodorization. However, to preserve the natural color, aroma, and flavor of rich-flavor peanut oil, hydration, alkali refining, bleaching, and deodorization are generally avoided. Therefore, optimizing processing techniques to efficiently remove DEHP from rich-flavor peanut oil while maintaining its flavor and safety is crucial. Summary of the Invention
[0005] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a process for removing di(2-ethylhexyl) phthalate from rich-flavor peanut oil. By adding high-pressure cross-linked porous starch, DEHP in rich-flavor peanut oil can be efficiently removed.
[0006] In order to solve the above technical problems, the technical solution provided by the present invention is: The process for removing di(2-ethyl)hexyl phthalate from fragrant peanut oil comprises the following steps: (1) Raw material screening: The peanuts are screened by a vibrating screen, cyclone dust collector, stone remover, and color sorter to remove impurities and moldy peanuts, and the screened peanut kernels are obtained; (2) Soaking and adsorption: Add peanut oil to the screened peanut kernels, then add high-pressure cross-linked porous starch, and stir for 40-50 minutes to obtain soaked peanut kernels; (3) Frying: The soaked peanut kernels are placed in a continuous seed frying furnace for frying to obtain fried peanut kernels; (4) Pressing: Add the roasted peanut kernels into the oil press to obtain peanut cakes and pressed crude oil; (5) Low temperature filtration: After the crude oil is precipitated in the crude oil tank, it is pumped into the cooling tank, cooled with cold water under stirring conditions, and then filtered to obtain filtered peanut oil; (6) DEHP determination: Detect the DEHP content of the filtered peanut oil to obtain the fragrant peanut oil; (7) Finished product canning and storage: Filter the fragrant peanut oil through a bag filter, can it with an automatic filling machine, and then conduct light inspection. The qualified fragrant peanut oil should be stored in a cool and dark place.
[0007] Furthermore, in step (1), the impurities include light impurities and heavy impurities. Light impurities include hemp rope, peanut peels, and nylon skins, and heavy impurities include mud, sand, stones, and iron impurities. Screening the raw materials ensures the safety and hygiene of the raw materials.
[0008] Furthermore, in step (2), the preparation method of the high-pressure cross-linked porous starch is: (a) adding sodium phosphate buffer solution to corn starch to prepare corn starch emulsion, placing the corn starch emulsion in a polyethylene bag, vacuum sealing the bag, and pre-treating the bag under high static pressure for 25-35 minutes to obtain a corn starch emulsion pre-treated under high static pressure; (b) heating the corn starch emulsion pretreated with high static pressure in a constant temperature water bath at 50° C. for 8-12 minutes, adding a complex enzyme, reacting for 3-5 hours, inactivating the emulsion, centrifuging, filtering, washing with deionized water three times, drying in a forced air drying oven for 16-20 hours, grinding, and passing through a 100-mesh sieve to obtain high-pressure porous starch; (c) Deionized water is added to the high-pressure porous starch to prepare a starch milk, sodium hydroxide and sodium chloride are added, and the mixture is stirred with a magnetic stirrer until dissolved. The mixture is heated in a water bath at 35-45°C for 1-2 hours, and then sodium trimetaphosphate is added. The mixture is placed in a constant temperature oscillator and reacted at a speed of 140 r / min for 3 hours. The pH is then adjusted to neutral with hydrochloric acid, the mixture is filtered, washed three times, and then dried in a constant temperature drying oven for 16-20 hours. The mixture is ground and passed through a 100-mesh sieve to obtain a high-pressure cross-linked porous starch.
[0009] Furthermore, in step (a), the concentration of the sodium phosphate buffer solution is 0.1 mol / L; the concentration of the corn starch emulsion is 20 wt.%; and the pressure of the high static pressure pretreatment is 180-220 MPa.
[0010] Furthermore, in step (b), the complex enzyme is a mixture of α-amylase and saccharifying enzyme in a mass ratio of 4:1; the added amount of the complex enzyme is 2.0% of the mass of the corn starch.
[0011] Furthermore, in step (b), the inactivation operation is: adding sodium hydroxide to the corn starch milk pretreated at high static pressure; the amount of sodium hydroxide added is 4% of the mass of the corn starch.
[0012] Furthermore, in step (c), the concentration of the starch milk is 20 wt.%.
[0013] Furthermore, in step (c), the amount of sodium hydroxide added is 2% by weight of the corn starch; the amount of sodium chloride added is 6% by weight of the corn starch; and the amount of sodium trimetaphosphate added is 3% by weight of the corn starch. The modified starch of the present invention enhances thermal stability, strengthens lipophilicity and hydrophilicity, and increases adsorption sites, resulting in excellent adsorption performance as an adsorbent without affecting the flavor of peanut oil.
[0014] Furthermore, in step (2), the amount of peanut oil added is 1.5% of the mass of the screened peanut kernels. The peanut oil evenly coats the peanut kernels, allowing the surface of the peanut kernels to be better coated with starch, providing a favorable environment for the removal of di(2-ethyl)hexyl phthalate.
[0015] Furthermore, in step (2), the amount of high-pressure cross-linked porous starch added is 1.5-3.0% of the mass of the screened peanut kernel. High-pressure cross-linked porous starch has a uniform pore structure, a large specific surface area and pore diameter, a destroyed short-range ordered structure, reduced crystallinity, a prominent lipophilic property, and improved adsorption capacity. Under the high-temperature and high-pressure conditions of frying and pressing, it has a strong adsorption capacity for di(2-ethyl)hexyl phthalate, can effectively adsorb and remove di(2-ethyl)hexyl phthalate, and can also adsorb residual small molecular impurities and odors such as free fatty acids in oils and fats, thereby improving the color and flavor of rich-flavor peanut oil.
[0016] Furthermore, in step (3), the discharge temperature of the continuous seed roasting furnace is 145-155° C. The guide plate disc in the seed roasting furnace is continuously pushed to make the soaked peanut kernels undergo uniform heat exchange in the continuous seed roasting furnace.
[0017] Furthermore, in step (3), the frying temperature is 155-160° C., and the frying time is 10-20 min.
[0018] Furthermore, in step (4), the residual oil content in the peanut cake is 5-7%. The oil is separated from the peanut cake by screw extrusion in the oil press.
[0019] Furthermore, in step (5), the specific operations of cooling and filtering are as follows: cooling the pressed crude oil to 20-25°C with cold water once, filtering it once with a plate and frame filter, cooling it to 18-20°C a second time, and then pumping it into the plate and frame filter for secondary filtration.
[0020] Furthermore, in step (7), the filling process requires ozone sterilization to ensure that the entire process is carried out under sterile conditions; the filled product is subjected to light inspection, requiring that there is no oil outside the bottle, no contamination on the label, and no visible impurities in the finished oil in the bottle.
[0021] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention introduces high-pressure cross-linked porous starch into the peanut oil production process. Since the high-pressure cross-linked porous starch has a large specific surface area and pore size, it can efficiently remove DEHP from the rich-flavor peanut oil with a high removal rate. It can also absorb impurities and odors in the oil, thereby improving the quality of the rich-flavor peanut oil.
[0022] (2) The high-pressure cross-linked porous starch added in the present invention can be used as a food additive. After addition, it will not have a negative impact on the flavor of the fragrant peanut oil, nor will it cause harm to the human body. In addition, the preparation method of the high-pressure cross-linked porous starch is simple and inexpensive, which is conducive to reducing production costs.
[0023] (3) The production process of the present invention is simple, easy to operate, and has no complicated steps, which can save manpower and material resources. In addition, the physical method is used to remove DEHP from the fragrant peanut oil, which is green and safe and will not introduce new harmful substances. It is suitable for large-scale industrial production of fragrant peanut oil. DETAILED DESCRIPTION
[0024] Example 1 The process for removing di(2-ethyl)hexyl phthalate from fragrant peanut oil comprises the following steps: (1) Raw material screening: The peanuts are screened by a vibrating screen, cyclone dust collector, stone remover, and color sorter to remove impurities and moldy peanuts, and the screened peanut kernels are obtained; (2) Soaking and adsorption: adding peanut oil to the screened peanut kernels, and then adding high-pressure cross-linked porous starch, stirring for 45 minutes to obtain soaked peanut kernels; the amount of peanut oil added is 1.5% of the mass of the screened peanut kernels, and the amount of high-pressure cross-linked porous starch added is 1.5% of the mass of the screened peanut kernels; The preparation method of the high-pressure cross-linked porous starch is as follows: (a) adding sodium phosphate buffer solution to corn starch to prepare a corn starch emulsion with a concentration of 20 wt.%, putting the corn starch emulsion into a polyethylene bag, vacuum-sealing the bag, and pre-treating the bag under high static pressure at a pressure of 200 MPa for 30 minutes to obtain the pre-treated corn starch emulsion; (b) heating the pre-treated corn starch emulsion in a constant temperature water bath at 50° C. for 10 minutes, adding a complex enzyme consisting of α-amylase and saccharifying enzyme in a mass ratio of 4:1, and adding an amount of the complex enzyme of 2.0% of the mass of the corn starch, reacting for 4 hours, inactivating the emulsion, centrifuging, filtering, washing with deionized water three times, drying the emulsion in an air drying oven for 18 hours, grinding the emulsion, and passing the emulsion through a 100-mesh sieve. (c) adding deionized water to the high-pressure porous starch to prepare a starch emulsion with a concentration of 20 wt.%, adding sodium hydroxide and sodium chloride, stirring with a magnetic stirrer until dissolved, heating in a 40° C. water bath for 1 hour, adding sodium trimetaphosphate, placing in a constant temperature oscillator, reacting at a speed of 140 r / min for 3 hours, then adjusting the pH to neutral with hydrochloric acid, filtering, washing three times, and then drying in a constant temperature drying oven for 18 hours, grinding, and passing through a 100-mesh sieve to prepare a high-pressure cross-linked porous starch; the amount of sodium hydroxide added is 2% by weight of the corn starch; the amount of sodium chloride added is 6% by weight of the corn starch; and the amount of sodium trimetaphosphate added is 3% by weight of the corn starch; (3) Frying: Place the soaked peanut kernels in a continuous seed frying furnace and fry for 10 minutes, controlling the discharge temperature at 145°C to obtain fried peanut kernels; (4) Pressing: Add the roasted peanut kernels to the oil press, and separate the oil from the peanut cake through the action of screw extrusion to obtain peanut cake and pressed crude oil. The residual oil content in the peanut cake is 5-7%; (5) Low temperature filtration: After the crude oil is precipitated in the crude oil tank, it is pumped into the cooling tank and cooled with cold water under stirring. After cooling to 20-25°C, it is filtered using a plate and frame filter. It is then cooled to 18-20°C for the second time and then pumped into a plate and frame filter for the second filtration to obtain filtered peanut oil. (6) DEHP determination: According to the gas chromatography-mass spectrometry (GC-MS) method specified in "GB 5009.271-2016 National Food Safety Standard Determination of Phthalates in Food", the DEHP content of the filtered peanut oil was detected to obtain the fragrant peanut oil; (7) Finished product canning and storage: The fragrant peanut oil is filtered through a bag filter, canned using an automatic filling machine, and sterilized with ozone to ensure that the entire process is carried out under sterile conditions. Then, a light inspection is carried out to ensure that there is no oil outside the bottle, no contamination on the label, and no visible impurities in the finished oil in the bottle. It is then stored in a cool, dark place.
[0025] Example 2 The process for removing di(2-ethyl)hexyl phthalate from fragrant peanut oil comprises the following steps: (1) Raw material screening: The peanuts are screened by a vibrating screen, cyclone dust collector, stone remover, and color sorter to remove impurities and moldy peanuts, and the screened peanut kernels are obtained; (2) Soaking and adsorption: peanut oil is added to the screened peanut kernels, and then high-pressure cross-linked porous starch is added. The preparation method of the high-pressure cross-linked porous starch is the same as that of Example 1. The mixture is stirred for 45 minutes to obtain soaked peanut kernels. The amount of peanut oil added is 1.5% of the mass of the screened peanut kernels, and the amount of high-pressure cross-linked porous starch added is 2.0% of the mass of the screened peanut kernels. (3) Frying: Place the soaked peanut kernels in a continuous seed frying furnace and fry for 15 minutes, controlling the discharge temperature at 145°C to obtain fried peanut kernels; (4) Pressing: Add the roasted peanut kernels to the oil press, and separate the oil from the peanut cake through the action of screw extrusion to obtain peanut cake and pressed crude oil. The residual oil content in the peanut cake is 5-7%; (5) Low temperature filtration: After the crude oil is precipitated in the crude oil tank, it is pumped into the cooling tank and cooled with cold water under stirring. After cooling to 20-25°C, it is filtered using a plate and frame filter. It is then cooled to 18-20°C for the second time and then pumped into a plate and frame filter for the second filtration to obtain filtered peanut oil. (6) DEHP determination: According to the gas chromatography-mass spectrometry (GC-MS) method specified in "GB 5009.271-2016 National Food Safety Standard Determination of Phthalates in Food", the DEHP content of the filtered peanut oil was detected to obtain the fragrant peanut oil; (7) Finished product canning and storage: The fragrant peanut oil is filtered through a bag filter, canned using an automatic filling machine, and sterilized with ozone to ensure that the entire process is carried out under sterile conditions. Then, a light inspection is carried out to ensure that there is no oil outside the bottle, no contamination on the label, and no visible impurities in the finished oil in the bottle. It is then stored in a cool, dark place.
[0026] Example 3 The process for removing di(2-ethyl)hexyl phthalate from fragrant peanut oil comprises the following steps: (1) Raw material screening: The peanuts are screened by a vibrating screen, cyclone dust collector, stone remover, and color sorter to remove impurities and moldy peanuts, and the screened peanut kernels are obtained; (2) Soaking and adsorption: peanut oil is added to the screened peanut kernels, and then high-pressure cross-linked porous starch is added. The preparation method of the high-pressure cross-linked porous starch is the same as that of Example 1. The mixture is stirred for 45 minutes to obtain soaked peanut kernels. The amount of peanut oil added is 1.5% of the mass of the screened peanut kernels, and the amount of high-pressure cross-linked porous starch added is 2.5% of the mass of the screened peanut kernels. (3) Frying: Place the soaked peanut kernels in a continuous seed frying furnace and fry them for 15 minutes. Control the discharge temperature at 150°C to obtain fried peanut kernels. (4) Pressing: Add the roasted peanut kernels to the oil press, and separate the oil from the peanut cake through the action of screw extrusion to obtain peanut cake and pressed crude oil. The residual oil content in the peanut cake is 5-7%; (5) Low temperature filtration: After the crude oil is precipitated in the crude oil tank, it is pumped into the cooling tank and cooled with cold water under stirring. After cooling to 20-25°C, it is filtered using a plate and frame filter. It is then cooled to 18-20°C for the second time and then pumped into a plate and frame filter for the second filtration to obtain filtered peanut oil. (6) DEHP determination: According to the gas chromatography-mass spectrometry (GC-MS) method specified in "GB 5009.271-2016 National Food Safety Standard Determination of Phthalates in Food", the DEHP content of the filtered peanut oil was detected to obtain the fragrant peanut oil; (7) Finished product canning and storage: The fragrant peanut oil is filtered through a bag filter, canned using an automatic filling machine, and sterilized with ozone to ensure that the entire process is carried out under sterile conditions. Then, a light inspection is carried out to ensure that there is no oil outside the bottle, no contamination on the label, and no visible impurities in the finished oil in the bottle. It is then stored in a cool, dark place.
[0027] Example 4 The process for removing di(2-ethyl)hexyl phthalate from fragrant peanut oil comprises the following steps: (1) Raw material screening: The peanuts are screened by a vibrating screen, cyclone dust collector, stone remover, and color sorter to remove impurities and moldy peanuts, and the screened peanut kernels are obtained; (2) Soaking and adsorption: peanut oil was added to the screened peanut kernels, and then high-pressure cross-linked porous starch was added. The preparation method of the high-pressure cross-linked porous starch was the same as that of Example 1. The mixture was stirred for 45 minutes to obtain soaked peanut kernels. The amount of peanut oil added was 1.5% of the mass of the screened peanut kernels, and the amount of high-pressure cross-linked porous starch added was 3.0% of the mass of the screened peanut kernels. (3) Frying: Place the soaked peanut kernels in a continuous seed frying furnace and fry for 20 minutes, controlling the discharge temperature at 155°C to obtain fried peanut kernels; (4) Pressing: Add the roasted peanut kernels to the oil press, and separate the oil from the peanut cake through the action of screw extrusion to obtain peanut cake and pressed crude oil. The residual oil content in the peanut cake is 5-7%; (5) Low temperature filtration: After the crude oil is precipitated in the crude oil tank, it is pumped into the cooling tank and cooled with cold water under stirring. After cooling to 20-25°C, it is filtered using a plate and frame filter. It is then cooled to 18-20°C for the second time and then pumped into a plate and frame filter for the second filtration to obtain filtered peanut oil. (6) DEHP determination: According to the gas chromatography-mass spectrometry (GC-MS) method specified in "GB 5009.271-2016 National Food Safety Standard Determination of Phthalates in Food", the DEHP content of the filtered peanut oil was detected to obtain the fragrant peanut oil; (7) Finished product canning and storage: The fragrant peanut oil is filtered through a bag filter, canned using an automatic filling machine, and sterilized with ozone to ensure that the entire process is carried out under sterile conditions. Then, a light inspection is carried out to ensure that there is no oil outside the bottle, no contamination on the label, and no visible impurities in the finished oil in the bottle. It is then stored in a cool, dark place.
[0028] Comparative Example 1 Refer to the process steps of Example 3, except that step (2) is not performed.
[0029] Comparative Example 2 Refer to the process steps of Example 3, except that the high-pressure cross-linked porous starch in step (2) is replaced with starch, specifically: (2) Soaking and adsorption: peanut oil is added to the screened peanut kernels, and then starch is added, and the mixture is stirred for 45 minutes to obtain soaked peanut kernels; the amount of peanut oil added is 1.5% of the mass of the screened peanut kernels, and the amount of starch added is 2.5% of the mass of the screened peanut kernels.
[0030] Comparative Example 3 Refer to the process steps of Example 3, except that the high-pressure cross-linked porous starch in step (2) is replaced with porous starch, specifically: (2) Soaking and adsorption: peanut oil was added to the screened peanut kernels, and then porous starch was added, and the mixture was stirred for 45 minutes to obtain soaked peanut kernels; the amount of peanut oil added was 1.5% of the mass of the screened peanut kernels, and the amount of porous starch added was 2.5% of the mass of the screened peanut kernels.
[0031] Comparative Example 4 Refer to the process steps of Example 3, except that the high-pressure cross-linked porous starch in step (2) is replaced with cross-linked porous starch, specifically: (2) Soaking and adsorption: peanut oil was added to the screened peanut kernels, and then cross-linked porous starch was added, and the mixture was stirred for 45 minutes to obtain soaked peanut kernels. The amount of peanut oil added was 1.5% of the mass of the screened peanut kernels, and the amount of cross-linked porous starch added was 2.5% of the mass of the screened peanut kernels.
[0032] Comparative Example 5 Refer to the process steps of Example 3, except that the high-pressure cross-linked porous starch in step (2) is replaced with activated carbon, specifically: (2) Soaking and adsorption: peanut oil is added to the screened peanut kernels, and then activated carbon is added, and the mixture is stirred for 45 minutes to obtain soaked peanut kernels; the amount of peanut oil added is 1.5% of the mass of the screened peanut kernels, and the amount of activated carbon added is 2.5% of the mass of the screened peanut kernels.
[0033] Experimental Example 1 The removal rates of DEHP from the fragrant peanut oils in Examples 1-4 were tested, and the test results are listed in Table 1.
[0034] DEHP removal rate = ; Among them, DEHP determination was carried out in accordance with the gas chromatography-mass spectrometry (GC-MS) method specified in "GB 5009.271-2016 National Food Safety Standard Determination of Phthalates in Foods"; the control oil sample was peanut oil in Example 1.
[0035] Table 1. DEHP removal rate of fragrant peanut oil As shown in Table 1, Examples 1-4 all added high-pressure cross-linked porous starch for soaking and adsorption before frying the peanut kernels. The DEHP removal rate of the pressed fragrant peanut oil exceeded 42.95%. In particular, Example 3, when 2.5% (w / w) of high-pressure cross-linked porous starch was added, achieved a DEHP removal rate of 53.61% in the pressed fragrant peanut oil. This indicates that the addition of high-pressure cross-linked porous starch in the present invention can effectively remove DEHP from the fragrant peanut oil. This is because the high-pressure cross-linked porous starch has a uniform pore structure, a large specific surface area and pore diameter, a disrupted short-range ordered structure, reduced crystallinity, and a strong lipophilic property. It possesses strong adsorption capacity, allowing it to evenly coat the peanut kernels. Under the high-temperature and high-pressure conditions of frying and pressing, it exhibits strong adsorption capacity for DEHP.
[0036] Experimental Example 2 The removal rates of DEHP in the fragrant peanut oils of Example 3 and Comparative Examples 1-4 were tested, and the test results are listed in Table 2.
[0037] Table 2. Removal rate of DEHP in fragrant peanut oil Comparative Example 1 did not include high-pressure cross-linked porous starch in the soaking and adsorption step, and the peanut oil prepared from this starch was used as the benchmark for calculation of the removal rate. Comparative Example 2 added starch, and the DEHP removal rate of the pressed fragrant peanut oil was 30.69%; Comparative Example 3 added porous starch, and the DEHP removal rate of the pressed fragrant peanut oil was 32.46%; Comparative Example 4 added cross-linked porous starch, and the DEHP removal rate of the pressed fragrant peanut oil was 34.21%; Comparative Example 5 added activated carbon, and the DEHP removal rate of the pressed fragrant peanut oil was 31.72%. The DEHP removal rate of the fragrant peanut oil in Example 3 was 53.61%. This shows that the present invention, by modifying starch to produce high-pressure cross-linked porous starch and using it in the preparation process for fragrant peanut oil, achieves a high DEHP removal rate for the resulting fragrant peanut oil, demonstrating that the process of the present invention can effectively remove DEHP from fragrant peanut oil.
[0038] Experimental Example 3 Referring to the process steps of Example 3, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, and 3.5% of high-pressure cross-linked porous starch were added in step (2), respectively, to prepare rich-flavor peanut oil. The DEHP removal rate of the rich-flavor peanut oil was tested to explore the effect of the addition amount of high-pressure cross-linked porous starch on the DEHP removal rate of the rich-flavor peanut oil.
[0039] Table 3. Removal rate of DEHP in fragrant peanut oil As can be seen from Table 3, with the increase in the addition amount of high-pressure cross-linked porous starch, the removal rate of DEHP shows a trend of first increasing and then decreasing. When the addition amount of high-pressure cross-linked porous starch is 2.5%, the removal rate of DEHP reaches the highest, which is 53.61%. As can be seen, when the addition amount of high-pressure cross-linked porous starch is too little or too much, the removal rate of DEHP in the fragrant peanut oil will be lower, and the more the addition amount of high-pressure cross-linked starch, the higher the production cost will be. Therefore, the present invention selects the addition amount of high-pressure cross-linked porous starch to be 1.5-3.0%, and now the removal effect of DEHP in peanut oil is the most excellent.
[0040] Experimental Example 4 Refined peanut oil was prepared according to the prior art production process for refined peanut oil. The peanut oil from Comparative Example 1 served as a control group, the peanut oil from Example 3 served as an experimental group, and the DEHP content and flavor compound content of the peanut oils from the blank, control, and experimental groups were measured. The DEHP removal rate was calculated using the peanut oil from the blank group as a control. The results are shown in Table 4.
[0041] Table 4. Content of components in peanut oil As can be seen from Table 4, the control group prepared peanut oil using the production process of refined peanut oil in the prior art. Its DEHP content was low, the DEHP removal rate was high, but the flavor content was low. This is because the process of refining peanut oil usually requires degumming, alkali refining, deacidification, decolorization, and deodorization after pressing. Although its high degree of refining can effectively reduce the DEHP content of peanut oil, it can lead to a serious loss of flavor substances and nutrients. The process steps are cumbersome, requiring a large amount of manpower and material resources, and the production cost is high. The experimental group prepared peanut oil using the process of the present invention. The DEHP content was low, the DEHP removal rate was high, and the flavor content was high. It can be seen that the addition of the high-pressure cross-linked porous starch of the present invention can effectively remove DEHP without affecting the flavor content of the rich-flavor peanut oil. This shows that the process of the present invention can effectively remove DEHP from the rich-flavor peanut oil while retaining a good peanut oil flavor, and the production process is simple.
Claims
1. A process for removing di(2-ethyl)hexyl phthalate from fragrant peanut oil, characterized in that: The following steps are involved: (1) Raw material screening: The peanuts are passed through a vibrating screen, cyclone dust collector, stone remover, and color sorter to remove impurities and moldy peanuts, and the screened peanut kernels are obtained; (2) Soaking and adsorption: Add peanut oil to the screened peanut kernels, then add high-pressure cross-linked porous starch, and stir for 40-50 minutes to obtain soaked peanut kernels; (3) Frying: The soaked peanut kernels are placed in a continuous seed frying furnace for frying to obtain fried peanut kernels; (4) Pressing: Add the roasted peanut kernels into the oil press to obtain peanut cakes and pressed crude oil; (5) Low temperature filtration: After the crude oil is precipitated in the crude oil tank, it is pumped into the cooling tank, cooled with cold water under stirring conditions, and then filtered to obtain filtered peanut oil; (6) DEHP determination: Detect the DEHP content of the filtered peanut oil to obtain the fragrant peanut oil; (7) Finished product canning and storage: Filter the fragrant peanut oil through a bag filter, can it with an automatic filling machine, and then conduct light inspection. The qualified fragrant peanut oil should be stored in a cool and dark place.
2. The process for removing di(2-ethyl)hexyl phthalate from fragrant peanut oil according to claim 1, wherein: In step (2), the amount of peanut oil added is 1.5% of the mass of the screened peanut kernels.
3. The process for removing di(2-ethyl)hexyl phthalate from fragrant peanut oil according to claim 2, wherein: In step (2), the amount of high-pressure cross-linked porous starch added is 1.5-3.0% of the mass of the screened peanut kernels.
4. The process for removing di(2-ethyl)hexyl phthalate from fragrant peanut oil according to claim 3, wherein: In step (2), the preparation method of the high-pressure cross-linked porous starch is: (a) adding sodium phosphate buffer solution to corn starch to prepare corn starch emulsion, placing the corn starch emulsion in a polyethylene bag, vacuum sealing the bag, and pre-treating the bag under high static pressure for 25-35 minutes to obtain a corn starch emulsion pre-treated under high static pressure; (b) heating the corn starch emulsion pretreated with high static pressure in a constant temperature water bath at 50° C. for 8-12 minutes, adding a complex enzyme, reacting for 3-5 hours, inactivating the emulsion, centrifuging, filtering, washing with deionized water three times, drying in a forced air drying oven for 16-20 hours, grinding, and passing through a 100-mesh sieve to obtain high-pressure porous starch; (c) Deionized water is added to the high-pressure porous starch to prepare a starch milk, sodium hydroxide and sodium chloride are added, and the mixture is stirred with a magnetic stirrer until dissolved. The mixture is heated in a water bath at 35-45°C for 1-2 hours, and then sodium trimetaphosphate is added. The mixture is placed in a constant temperature oscillator and reacted at a speed of 140 r / min for 3 hours. The pH is then adjusted to neutral with hydrochloric acid, the mixture is filtered, washed three times, and then dried in a constant temperature drying oven for 16-20 hours. The mixture is ground and passed through a 100-mesh sieve to obtain a high-pressure cross-linked porous starch.
5. The process for removing di(2-ethyl)hexyl phthalate from fragrant peanut oil according to claim 4, wherein: In step (a), the pressure of the high static pressure pretreatment is 180-220 MPa.
6. The process for removing di(2-ethyl)hexyl phthalate from fragrant peanut oil according to any one of claims 1 to 5, characterized in that: In step (3), the discharge temperature of the continuous seed roasting furnace is 145-155°C.
7. The process for removing di(2-ethyl)hexyl phthalate from rich-flavor peanut oil according to claim 6, wherein: In step (4), the residual oil content in the peanut cake is 5-7%.
8. The process for removing di(2-ethyl)hexyl phthalate from rich-flavor peanut oil according to claim 7, wherein: In step (5), the specific operation of cooling and filtering is: cooling the pressed crude oil to 20-25°C with cold water once, filtering it once with a plate and frame filter, cooling it to 18-20°C a second time, and then pumping it into the plate and frame filter for secondary filtration.