A method for efficiently removing glycidyl esters from vegetable oil

Abstract

The present application relates to a method for efficiently removing glycidyl esters (GEs) in vegetable oil, which can efficiently remove GEs in vegetable oil by treating the vegetable oil with an adsorbent with a pH < 4, an activity > 120 mol / kg, a specific surface area > 120 m 2 / g, a mesopore area > 40 m 2 / g, a mesopore volume > 0.13 m 3 / g, and the removal rate of GEs can reach 90% or even more than 95%. The method of the present application can guide the production and processing of oil and fat, and can accurately and effectively use a low dose of adsorbent to efficiently adsorb and remove GEs, and provide edible vegetable oil with low GEs content. The present application also relates to the use of the above-mentioned adsorbent in removing glycidyl esters in vegetable oil.

Description

Technical Field

[0001] This invention relates to the field of oil processing, specifically to a method for efficiently removing glycidyl esters (GEs) from vegetable oils. This method involves screening a highly efficient adsorbent for GEs. By utilizing this adsorbent, the method of this invention can achieve highly efficient and stable removal of glycidyl esters from edible vegetable oils with low-dose adsorbent. Background Technology

[0002] Glycidol has been reported by the Food and Agriculture Organization of the United Nations / World Health Organization (FAO / WHO) as a substance with nephrotoxicity, reproductive toxicity, genetic toxicity, and neurotoxicity. The International Agency for Research on Cancer (IARC) classifies it as a Group 2A carcinogen for humans, and its safety has become a focus of attention in the food industry both domestically and internationally. Glycidol mainly exists in edible vegetable oils in the form of glycidyl esters (GEs). GEs themselves are not carcinogenic, but glycidol produced in the human body through lipid metabolism is genotoxic.

[0003] Currently, the EU limits glycidyl esters (GEs) in edible vegetable oils to less than 1 mg / kg. my country also released a draft for public comment in 2021 regarding the "National Food Safety Standard for the Control of 3-Chloropropanol Ester and Glycidyl Ester Contamination in Food," and it is highly likely that significant limits will be imposed on GEs in the coming years. Currently, the levels of GE contamination in commercially available edible vegetable oils vary considerably. Palm oil has the highest GE content, often ranging from 3-12 mg / kg, followed by rapeseed oil and soybean oil, which far exceed EU limits. Therefore, controlling the GE content in edible vegetable oils is an urgent need for a healthy diet.

[0004] Currently, two main technologies are used to control the content of GEs in edible vegetable oils. One is preventative control technology: optimizing refining process parameters (deodorization temperature and time). [1,2,3] 1. Select high-quality raw materials (fresh raw materials, raw materials with low DAG content) [4] Methods such as these can effectively prevent the formation of GEs. This method is suitable for unrefined edible vegetable oils processed from the oilseed end, such as soybean oil, corn oil, and rapeseed oil processed from readily available oilseed crops (soybeans, corn germ, rapeseed, etc.). Secondly, there are removal control technologies: using adsorption removal methods (activated carbon, activated clay, etc.). [1,5,7,8] Molecular distillation [6] Methods such as these can effectively remove large amounts of GEs already present in edible vegetable oils. This method is more suitable for refined edible vegetable oils with high GE content, such as rice bran oil, rapeseed oil, peanut oil, corn oil, palm oil, soybean oil, sunflower seed oil, safflower seed oil, olive oil, walnut oil, flaxseed oil, camellia seed oil, almond oil, peony seed oil, and perilla seed oil.

[0005] Studies on the removal of GEs by adsorption methods (activated carbon, activated clay, etc.) have found that different types of adsorbents have significantly different adsorption and removal effects on GEs; even within the same type of adsorbent (e.g., activated carbon), there are significant differences in the adsorption and removal effects on GEs. This situation makes adsorption methods unsuitable for guiding actual industrial production. Choosing an unsuitable adsorbent can lead to extremely low GEs removal efficiency, resulting in a significant increase in the amount of adsorbent used and consequently, increased production costs.

[0006] Currently, there are patents and literature reports on the adsorption-removal method for removing glycidyl esters (GEs), but none of them specify clear requirements or descriptions regarding the adsorbent's parameters (such as pH, activity, specific surface area, and pore structure). In other words, not all activated clay and activated carbon can efficiently adsorb and remove GEs. Chinese patent application CN104159454A discloses a method for removing glycidyl esters from vegetable oils, claiming that acidified activated clay can effectively adsorb and remove GEs. However, in reality, acidification is a routine step in the processing of activated clay, and activated clay prepared through this step does not necessarily possess the ability to efficiently adsorb and remove GEs. Some literature also claims that acid-washed palm wood has good adsorption and removal effects, but not all activated carbon treated with acidic activators has a high efficiency in removing GEs.

[0007] In the field of oil processing, adsorbents of different properties and types may exhibit completely different or significantly different adsorption effects on different target substances, which greatly limits the development of removal processes for target substances in oils. Regarding the removal of GEs, researchers have not yet conducted in-depth research and discussion on the performance of adsorbents capable of efficiently removing GEs, and there is a lack of guiding screening methods and clear reports on effective GEs removal adsorbents.

[0008] References

[0009] [1] Ren Woxing. Study on control and removal of 3-MCPD ester and glycidyl ester in oil refining process [D]. Henan University of Technology, 2018.

[0010] [2] Wang Fengyan, Zhou Shukun, Liu Mengtao, et al. Study on the influencing factors of 3-chloropropanol fatty acid ester formation during edible oil processing [J]. Journal of Chinese Cereals and Oils. 2017, 32(10): 106-110.

[0011] [3] Li Jiaxin. Study on the formation law of 3-chloropropanol ester and glycidyl ester under deodorization conditions of corn oil [D]. Henan University of Technology, 2021.

[0012] [4] Zhu Mengyun. Study on the effects of monoglyceride, diglyceride and oil refining process on 3-MCPDEs and GEs [D]. Henan University of Technology, 2018.

[0013] [5] Cheng Weiwei. Study on the formation and adsorption-elimination mechanism of glycidyl esters in vegetable oil refining [D]. South China University of Technology, 2019.

[0014] [6] Liu Yulan, Huang Huina, Ma Yuxiang, et al. Depth removal of 3-chloropropanol esters and glycidyl esters from oils by two-stage molecular distillation [J]. China Oils and Fats. 2021, 46(06): 89-93.

[0015] [7] Liu Guoqin, Yin Shiqin, et al. A method for reducing the content of glycidyl esters in edible oils using adsorbents: CN201510448556.1.

[0016] [8] K. Baggan, Janina Louveler-Wylermann, et al. Methods for processing vegetable oils: CN201280063833.1. Summary of the Invention

[0017] As mentioned above, the existing technology has the following technical problems: not all types of adsorbents can efficiently adsorb and remove GEs. For example, attapulgite, resin, and silica gel generally have low GE removal efficiency; even adsorbents of the same type cannot necessarily efficiently adsorb and remove GEs. Taking activated carbon as an example, not all types of activated carbon have a high efficiency in adsorbing and removing GEs; improper selection of adsorbents can easily lead to difficulties in removing GEs and a low removal rate, making it difficult to achieve a removal rate of over 90% and to effectively remove GEs to below 1 mg / kg, which does not meet the EU's limit requirements for GEs.

[0018] In order to solve the above-mentioned technical problems, the inventors have conducted extensive and in-depth research and found that, unlike the target substances such as 3-monochloropropane-1,2-diol ester (3-MCPDE), aflatoxin and phthalate esters (PAEs), the following adsorbents have excellent specific adsorption effects on GEs: (1) The pH of the adsorbent (such as activated clay, activated carbon, etc.) needs to be acidic or have high activity. The stronger the acidity and the higher the activity, the more acidic active sites there are, which is more conducive to the adsorption and removal of GEs; (2) The larger the specific surface area and the richer the mesopores of the adsorbent (such as activated clay, activated carbon, etc.), the more conducive it is to the adsorption and removal of GEs.

[0019] During the research, the inventors also studied the adsorption and removal effects of the above-mentioned adsorbent on target substances such as 3-monochloropropane-1,2-diol ester (3-MCPDE), aflatoxin, and phthalic acid esters (PAEs). The experimental results showed that the above indicators of the adsorbent were not significantly related to the removal effects of 3-MCPDE, aflatoxin, and PAEs.

[0020] In a first aspect, the present invention provides a method for efficiently removing glycidyl esters from vegetable oils, wherein the method comprises the following steps: adding 0.05-2 wt% of an adsorbent to the vegetable oil based on the total weight of the vegetable oil and stirring thoroughly, wherein the adsorbent has a pH < 4, an activity > 120 mol / kg, and a specific surface area > 120 m². 2 / g, mesopore area >40m 2 / g, mesopore volume >0.13m 3 / g. Furthermore, the inventors have discovered that, in the adsorption and removal of GEs, the pH, activity, specific surface area, mesopore area, and mesopore volume of the adsorbent of this invention are mutually supportive and interactive characteristics, and must be considered holistically. If one or more of these characteristics are not met, it is difficult to achieve efficient adsorption and removal of GEs. Existing technologies have not reported the ability to achieve efficient adsorption and removal of GEs by simultaneously controlling the pH, activity, specific surface area, mesopore area, and mesopore volume of the adsorbent.

[0021] In a second aspect, the present invention provides the use of the above-mentioned adsorbent in the removal of glycidyl esters from vegetable oils.

[0022] Beneficial effects

[0023] Different types and properties of adsorbents may exhibit completely different or significantly different adsorption effects on different target substances. This invention discovers an adsorbent specifically designed for the efficient adsorption of glycidyl esters (GEs). By using this adsorbent (e.g., activated carbon or activated clay) with a low pH, high activity, and large mesopore area and volume to treat vegetable oils, this invention achieves highly efficient adsorption and removal of GEs from vegetable oils. Therefore, by using this specific adsorbent, the method of this invention can efficiently and stably remove GEs, achieving a removal rate of 90% or even 95% or higher. The glycidyl ester content in the vegetable oil treated with the adsorbent described in this invention is below 1 mg / kg (e.g., below 0.8 mg / kg, or below 0.5 mg / kg, or even below 0.3 mg / kg). This allows for guidance in oil production and processing, enabling the accurate and effective use of low-dose adsorbents for efficient adsorption and removal of GEs, providing edible vegetable oils with low GE content. Detailed Implementation

[0024] It should be understood that the following specific embodiments are only used to further explain and illustrate the present invention, and are not intended to limit the present invention.

[0025] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0026] In some embodiments, the present invention provides a method for efficiently removing glycidyl esters from vegetable oils, wherein the method includes the following steps: adding 0.05-2 wt% of an adsorbent to the vegetable oil based on its total weight and stirring thoroughly, wherein the adsorbent has a pH < 4, an activity > 120 mol / kg, and a specific surface area > 120 m². 2 / g, mesopore area >40m 2 / g, mesopore volume >0.13m 3 / g.

[0027] In some embodiments, the vegetable oil is selected from one or more of the group consisting of rice bran oil, rapeseed oil, peanut oil, corn oil, and palm oil.

[0028] In this invention, the adsorbent is characterized by low pH, high activity, high specific surface area, and abundant mesoporous structure.

[0029] In some embodiments, the adsorbent is activated carbon and / or activated clay.

[0030] In some embodiments, when the adsorbent comprises activated carbon, the amount of activated carbon added is 0.05-0.5 wt%, preferably 0.05-0.2 wt%, for example 0.05-0.1 wt%.

[0031] In some embodiments, the activated carbon satisfies one or more of the following conditions:

[0032] pH < 5, preferably pH < 4, more preferably < 3.5, for example 2 to 3;

[0033] Activity >120 mol / kg, preferably >150 mol / kg, more preferably >200 mol / kg, for example 180-190 mol / kg;

[0034] Specific surface area >1500m² 2 / g, preferably >1600m 2 / g, more preferably >1800m 2 / g, for example 1500~1940m 2 / g;

[0035] Mesopore area >150m 2 / g, preferably >180m 2 / g, more preferably >200m 2 / g, for example 170~280m 2 / g;

[0036] Mesopore volume > 0.50 m 3 / g, preferably >0.55m 3 / g, more preferably >0.60m 3 / g, for example 0.50~0.80m 3 / g.

[0037] In some embodiments, when the adsorbent comprises activated clay, the amount of activated clay added is 0.2-2 wt%, preferably 0.5-1 wt%.

[0038] In some embodiments, the activated clay satisfies one or more of the following conditions:

[0039] pH < 4, preferably < 3.5, more preferably < 3, for example 3.4 to 3.8;

[0040] Activity >100 mol / kg, preferably >120 mol / kg, more preferably >170 mol / kg, for example 200-230 mol / kg;

[0041] Specific surface area >120m² 2 / g, preferably >160m 2 / g, more preferably >200m 2 / g, for example 130~245m 2 / g;

[0042] Mesopore area > 40m 2 / g, preferably >50m 2 / g, more preferably >60m 2 / g, for example 45-75m 2 / g;

[0043] Mesopore volume > 0.13 m 3 / g, preferably >0.15m 3 / g, more preferably >0.17m 3 / g, for example 0.145~0.175m 2 / g.

[0044] In some embodiments, the adsorbent is reacted with the vegetable oil at 90-120°C under vacuum for 20-60 minutes, and the adsorbent is separated from the vegetable oil after the reaction is completed; preferably, the reaction is carried out at 20 mbar.

[0045] In some embodiments, the method includes the following steps:

[0046] (1) Add 0.05-0.1 wt% activated carbon to 1 kg of refined vegetable oil and stir thoroughly. The activated carbon has a pH of 2-3, an activity of 180-190 mol / kg, and a specific surface area of ​​1500-1940 m². 2 / g, mesopore area is 170-280m² 2 / g, mesopore volume of 0.50~0.8m 3 / g;

[0047] (2) React at 90-120℃ under vacuum for 20-60 min. After the reaction is complete, separate the adsorbent from the vegetable oil.

[0048] In a more specific embodiment, the method of the present invention includes the following steps: weighing 1 kg of refined vegetable oil rich in GEs, preferably with low pH (preferably <5, more preferably <4, more preferably <3.5) and high specific surface area (preferably >1500 m²). 2 / g, preferably >1600m 2 / g, further optimized >1800m 2 / g), high mesopore area (preferably >150m²) 2 / g, preferably >180m 2 / g, further optimized >200m 2 / g), high mesopore volume (preferably >0.50m) 3 / g, preferably >0.550m 3 / g, further optimized >0.60m 3 Take activated carbon (g), accurately weigh 0.05-0.5% of the weight of edible vegetable oil, preferably 0.05-0.2% of the recommended activated carbon, add it to the vegetable oil and stir thoroughly. React at 90-120℃ and 20mbar for 20-60 minutes. After the reaction, separate the adsorbent from the edible vegetable oil. At this time, the GEs content in the edible vegetable oil can be reduced to below 0.5mg / kg, or even below 0.2mg / kg. The GEs removal efficiency can be increased from 46% to over 90%, or even over 99%.

[0049] In other embodiments, the method includes the following steps:

[0050] (1) Add 0.5-1 wt% activated clay to 1 kg of refined vegetable oil and stir thoroughly. The activated clay has a pH of 3.4-3.8, an activity of 200-230 mol / kg, and a specific surface area of ​​130-245 m². 2 / g, mesopore area is 45-75m² 2 / g, mesopore volume is 0.145~0.175m 3 / g;

[0051] (2) React at 90-120℃ under vacuum for 20-60 min. After the reaction is complete, separate the adsorbent from the vegetable oil.

[0052] In a more specific embodiment, the method of the present invention includes the following steps: weighing 1 kg of refined vegetable oil rich in GEs, preferably with low pH (preferably <4, more preferably <3.5, even more preferably <3), high activity (preferably >100 mol / kg, more preferably >120 mol / kg, even more preferably >170 mol / kg), and high specific surface area (preferably >120 m²). 2 / g, preferably >160m 2 / g, preferably >200m 2 / g), high mesopore area (preferably >40m²) 2 / g, preferably >50m 2 / g, further optimized >60m 2 / g), high mesopore volume (preferably >0.10m). 3 / g, preferably >0.15m 3 / g, further optimized >0.17m 3 Accurately weigh 0.2-2% (preferably 0.5-1%) of activated clay (at a weight of 1 g) into the vegetable oil, stir thoroughly, and react at 90-120℃ and 20 mbar for 20-60 min. After the reaction, separate the adsorbent from the vegetable oil. At this point, the GEs content in the vegetable oil can be reduced to below 0.5 mg / kg, or even below 0.2 mg / kg, and the GEs removal efficiency can be increased from 64% to over 90%, or even over 97%.

[0053] In some embodiments, the present invention provides the use of the above-described adsorbent in the removal of glycidyl esters from vegetable oils.

[0054] Example

[0055] The present invention will be described in detail below through embodiments. It should be understood that the following embodiments are for further explanation and illustration of the present invention only, and are not intended to limit the present invention. Unless otherwise stated, all reagents, materials, and devices used in the following embodiments and comparative examples are commercially available reagents, materials, and devices known in the art. Unless otherwise stated, all operations described below are conventional operations known in the art.

[0056] In the following examples, the detection method for GEs was based on AOCS Cd 29a-13 to determine the GEs content in oils. The pH value of activated carbon was determined according to GB / T 12496.7-1999 "Test Methods for pH Value Determination of Wood-based Activated Carbon". The pH value of activated clay was determined according to GB 25571-2011 "Determination of pH Value of Activated Clay for Food Additives". The activity of activated clay was determined according to HG / T 2569-2007 "Determination of Activity of Activated Clay for Food Additives". Adsorbent characterization indicators such as specific surface area were provided by the Beijing Physical and Chemical Research Center.

[0057] Example 1

[0058] Weigh 1 kg of refined palm oil with a GE content of 11.8 mg / kg, a pH of 2.3, an activity of 180 mol / kg, and a specific surface area of ​​1939 m². 2 / g, with a mesopore area of ​​277.6m². 2 / g, mesopore volume is 0.772m 3 / g of activated carbon, accurately weigh 0.05% of the weight of edible vegetable oil of activated carbon, add it to palm oil and stir thoroughly. React at 110℃ and 20mbar for 30min. After the reaction, separate the adsorbent from the edible vegetable oil. At this time, the GEs content in the refined palm oil is reduced to 0.15mg / kg, and the GEs removal efficiency is 98.7%.

[0059] Example 2

[0060] Weigh 1 kg of refined palm oil with a GE content of 11.8 mg / kg, a pH of 2.7, an activity of 190 mol / kg, and a specific surface area of ​​1509 m². 2 / g, mesopore area is 178m² 2 / g, mesopore volume is 0.59m 3 / g of activated carbon, accurately weigh 0.1% of the weight of edible vegetable oil with activated carbon, add it to palm oil and stir thoroughly. React at 100℃ and 20mbar for 55min. After the reaction, separate the adsorbent from the edible vegetable oil. At this time, the GEs content in the refined palm oil is reduced to 0.72mg / kg, and the GEs removal efficiency is 93.9%.

[0061] Comparative Example 1

[0062] Weigh 1 kg of refined palm oil with a GE content of 11.8 mg / kg, a pH of 5.5, an activity of 113 mol / kg, and a specific surface area of ​​1587 m². 2 / g, mesopore area is 187m² 2 / g, mesopore volume is 0.58m 3 / g of activated carbon, accurately weigh 0.5% of the weight of edible vegetable oil with activated carbon, add it to palm oil and stir thoroughly. React at 115℃ and 20mbar for 25min. After the reaction, separate the adsorbent from the edible vegetable oil. At this time, the GEs content in the refined palm oil is reduced to 3.21mg / kg, and the GEs removal efficiency is 72.8%.

[0063] Comparative Example 2

[0064] Weigh 1 kg of refined palm oil, with a GE content of 9.29 mg / kg, and select a pH of 9.7, an activity of 45 mol / kg, and a specific surface area of ​​1420 m². 2 / g, mesopore area is 91m² 2 / g, mesopore volume is 0.18m 3 =1% activated carbon per gram of edible vegetable oil, and add it to palm oil and stir thoroughly. React at 120℃ and 20mbar for 35 minutes. After the reaction is complete, separate the adsorbent from the edible vegetable oil. At this time, the GEs content in the refined palm oil is reduced to 4.83mg / kg, and the GEs removal efficiency is 48.0%.

[0065] Example 3

[0066] Weigh 0.5 kg of refined palm oil with a GE content of 9.08 mg / kg, and select a pH of 3.4, an activity of 200 mol / kg, and a specific surface area of ​​241 m². 2 / g, mesopore area is 75m² 2 / g, mesopore volume is 0.16m 3 / g of activated clay, accurately weigh 0.5% of the weight of edible vegetable oil of activated clay, add it to palm oil and stir thoroughly. React at 120℃ and 20mbar for 35min. After the reaction, separate the adsorbent from the edible vegetable oil. At this time, the GEs content in the refined palm oil is reduced to 0.17mg / kg, and the GEs removal efficiency is 98.1%.

[0067] Example 4

[0068] Weigh 0.5 kg of refined palm oil with a GE content of 9.08 mg / kg, and select a pH of 3.8, an activity of 230 mol / kg, and a specific surface area of ​​131 m². 2 / g, mesopore area is 45m² 2 / g, mesopore volume is 0.14m 3 1% activated clay (by weight of edible vegetable oil) was accurately weighed and added to palm oil. The mixture was stirred thoroughly and reacted at 110℃ and 20mbar for 40 minutes. After the reaction, the adsorbent and edible vegetable oil were separated. At this point, the GEs content in the refined palm oil was reduced to 0.36 mg / kg, and the GEs removal efficiency was 96.03%.

[0069] Comparative Example 3

[0070] Weigh 0.5 kg of refined palm oil with a GE content of 9.08 mg / kg, and select a pH of 4.5, an activity of 90 mol / kg, and a specific surface area of ​​120 m². 2 / g, mesopore area is 35m² 2 / g, mesopore volume is 0.14m 3 1.5% of the activated clay (by weight of edible vegetable oil) was accurately weighed and added to palm oil. The mixture was stirred thoroughly and reacted at 110℃ and 20mbar for 40 minutes. After the reaction, the adsorbent and edible vegetable oil were separated. At this point, the GEs content in the refined palm oil was reduced to 1.95 mg / kg, and the GEs removal efficiency was 78.5%.

[0071] Comparative Example 4

[0072] Weigh 0.5 kg of refined palm oil with a GE content of 9.08 mg / kg, and select a pH of 6.5, an activity of 50 mol / kg, and a specific surface area of ​​84 m². 2 / g, mesopore area is 34m² 2 / g, mesopore volume is 0.14m 3 2% activated clay (by weight of edible vegetable oil) was accurately weighed and added to palm oil. The mixture was stirred thoroughly and reacted at 115℃ and 20mbar for 45 minutes. After the reaction, the adsorbent and edible vegetable oil were separated. At this point, the GEs content in the refined palm oil was reduced to 3.24 mg / kg, and the GEs removal efficiency was 64.2%.

[0073] Example 5

[0074] Weigh 1 kg of refined rapeseed oil, with a GE content of 5.9 mg / kg, a pH of 2.3, an activity of 175 mol / kg, and a specific surface area of ​​1587 m². 2 / g, with a mesopore area of ​​206.7m². 2 / g, mesopore volume is 0.712m 3 / g of activated carbon, accurately weigh 0.05% of the oil weight of activated carbon, add it to refined rapeseed oil and stir thoroughly. React at 120℃ and 20mbar for 40min. After the reaction, separate the adsorbent from the edible vegetable oil. At this time, the GEs content in the refined rapeseed oil is reduced to 0.33mg / kg, and the GEs removal efficiency is 94.4%.

[0075] Comparative Example 5

[0076] Weigh 1 kg of refined rapeseed oil, with a GE content of 5.9 mg / kg, a pH of 5.5, an activity of 95 mol / kg, and a specific surface area of ​​982 m². 2 / g, with a mesopore area of ​​115.2m². 2 / g, mesopore volume is 0.43m 3 / g of activated carbon, accurately weigh 0.5% of the weight of edible vegetable oil with activated carbon, add it to refined rapeseed oil and stir thoroughly. React at 110℃ and 20mbar for 35min. After the reaction, separate the adsorbent from the edible vegetable oil. At this time, the GEs content in the refined rapeseed oil is reduced to 1.90mg / kg, and the GEs removal efficiency is 67.8%.

[0077] Example 6

[0078] Weigh 1 kg of refined peanut oil, with a GE content of 4.70 mg / kg, and select a pH of 2.7, an activity of 190 mol / kg, and a specific surface area of ​​1587 m². 2 / g, mesopore area is 174m² 2 / g, mesopore volume is 0.58m 3 / g of activated carbon, accurately weigh 0.1% of the activated carbon by weight of edible vegetable oil, add it to refined peanut oil and stir thoroughly. React at 90℃ and 20mbar for 25min. After the reaction, separate the adsorbent from the edible vegetable oil. At this time, the GEs content in the refined peanut oil is reduced to 0.42mg / kg, and the GEs removal efficiency is 91.06%.

[0079] Comparative Example 6

[0080] Weigh 1 kg of refined peanut oil, with a GE content of 4.70 mg / kg, and select a pH of 8.1, an activity of 45 mol / kg, and a specific surface area of ​​557 m². 2 / g, mesopore area is 115m² 2 / g, mesopore volume is 0.24m 31% of activated carbon (by weight of oil) was accurately weighed and added to refined peanut oil. The mixture was stirred thoroughly and reacted at 90-120℃ and 20mbar for 20-60 minutes. After the reaction, the adsorbent and edible vegetable oil were separated. At this point, the GEs content in the refined peanut oil was reduced to 2.85 mg / kg, and the GEs removal efficiency was 39.4%.

[0081] Example 7

[0082] Weigh 0.5 kg of refined rice bran oil, which has an GE content of 7.63 mg / kg. Select an oil with a pH of 3.8, an activity of 230 mol / kg, and a specific surface area of ​​195 m². 2 / g, mesopore area is 55m² 2 / g, mesopore volume is 0.19m 3 / g of activated clay, accurately weigh 0.5% of the oil weight of activated clay, add it to refined rice bran oil and stir thoroughly. React at 115℃ and 20mbar for 50min. After the reaction, separate the adsorbent from the edible vegetable oil. At this time, the GEs content in the refined rice bran oil is reduced to 0.22mg / kg, and the GEs removal efficiency is 97.1%.

[0083] Comparative Example 7

[0084] Weigh 0.5 kg of refined rice bran oil, which has an GE content of 7.63 mg / kg. Select an pH of 4.5, an activity of 90 mol / kg, and a specific surface area of ​​121 m². 2 / g, mesopore area is 35m² 2 / g, mesopore volume is 0.144m 3 1.5% of the activated clay (by weight of edible vegetable oil) was accurately weighed and added to refined rice bran oil. The mixture was stirred thoroughly and reacted at 110℃ and 20mbar for 45 minutes. After the reaction, the adsorbent and edible vegetable oil were separated. At this point, the GEs content in the refined rice bran oil was reduced to 2.65 mg / kg, and the GEs removal efficiency was 65.3%.

[0085] Example 8

[0086] Weigh 0.5 kg of refined corn oil, with a GE content of 3.23 mg / kg, and select a pH of 3.8, an activity of 230 mol / kg, and a specific surface area of ​​195 m². 2 / g, mesopore area is 55m² 2 / g, mesopore volume is 0.19m 3 / g of activated clay, accurately weigh 0.5% of the oil weight of activated clay, add it to refined corn oil and stir thoroughly. React at 115℃ and 20mbar for 50min. After the reaction, separate the adsorbent from the edible vegetable oil. At this time, the GEs content in the refined corn oil is reduced to 0.00mg / kg, and the GEs removal efficiency is 100%.

[0087] Comparative Example 8

[0088] Weigh 0.5 kg of refined corn oil, with a GE content of 3.23 mg / kg, and select a pH of 4.5, an activity of 90 mol / kg, and a specific surface area of ​​121 m². 2 / g, mesopore area is 35m² 2 / g, mesopore volume is 0.144m 3 / g of activated clay, accurately weigh 1.5% of the weight of edible vegetable oil of activated clay, add it to refined corn oil and stir thoroughly. React at 110℃ and 20mbar for 45min. After the reaction, separate the adsorbent from the edible vegetable oil. At this time, the GEs content in the refined corn oil is reduced to 1.28mg / kg, and the GEs removal efficiency is 60.4%.

[0089] Example 9

[0090] Weigh 1 kg of refined sunflower seed oil, with a GE content of 1.52 mg / kg, a pH of 3.8, an activity of 230 mol / kg, and a specific surface area of ​​195 m². 2 / g, mesopore area is 55m² 2 / g, mesopore volume is 0.19m 3 / g of activated clay, accurately weigh 0.5% of the oil weight of activated clay, add it to refined sunflower seed oil and stir thoroughly. React at 115℃ and 20mbar for 50min. After the reaction, separate the adsorbent from the edible vegetable oil. At this time, the GEs content in the refined sunflower seed oil is reduced to 0.24mg / kg, and the GEs removal efficiency is 84.21%.

[0091] Comparative Example 9

[0092] Weigh 1 kg of refined sunflower seed oil, with a GE content of 1.52 mg / kg, a pH of 4.5, an activity of 90 mol / kg, and a specific surface area of ​​121 m². 2 / g, mesopore area is 35m² 2 / g, mesopore volume is 0.144m 31.5% of the activated clay (by weight of edible vegetable oil) was accurately weighed and added to refined sunflower seed oil. The mixture was stirred thoroughly and reacted at 110℃ and 20mbar for 45 minutes. After the reaction, the adsorbent and edible vegetable oil were separated. At this point, the GEs content in the refined sunflower seed oil was reduced to 0.96 mg / kg, and the GEs removal efficiency was 36.8%.

[0093] Example 10

[0094] Weigh 0.5 kg of refined soybean oil, with a GE content of 1.88 mg / kg, and select a pH of 3.8, an activity of 230 mol / kg, and a specific surface area of ​​195 m². 2 / g, mesopore area is 55m² 2 / g, mesopore volume is 0.19m 3 / g of activated clay, accurately weigh 0.5% of the oil weight of activated clay, add it to refined soybean oil and stir thoroughly. React at 115℃ and 20mbar for 50min. After the reaction, separate the adsorbent from the edible vegetable oil. At this time, the GEs content in the refined soybean oil is reduced to 0.15mg / kg, and the GEs removal efficiency is 83.0%.

[0095] Comparative Example 10

[0096] Weigh 0.5 kg of refined soybean oil, with a GE content of 1.88 mg / kg, and select a pH of 4.5, an activity of 90 mol / kg, and a specific surface area of ​​121 m². 2 / g, mesopore area is 35m² 2 / g, mesopore volume is 0.144m 3 1.5% of the activated clay (by weight of edible vegetable oil) was accurately weighed and added to refined soybean oil. The mixture was stirred thoroughly and reacted at 110℃ and 20mbar for 45 minutes. After the reaction, the adsorbent and edible vegetable oil were separated. At this point, the GEs content in the refined soybean oil was reduced to 1.12 mg / kg, and the GEs removal efficiency was 40.4%.

[0097] Example 11

[0098] Weigh 1.5 kg of refined safflower seed oil, with a GE content of 3.37 mg / kg, and select a pH of 3.8, an activity of 230 mol / kg, and a specific surface area of ​​195 m². 2 / g, mesopore area is 55m² 2 / g, mesopore volume is 0.19m 3 / g of activated clay, accurately weigh 0.5% of the oil weight of activated clay, add it to refined safflower seed oil and stir thoroughly. React at 115℃ and 20mbar for 50min. After the reaction, separate the adsorbent from the edible vegetable oil. At this time, the GEs content in the refined safflower seed oil is reduced to 0.36mg / kg, and the GEs removal efficiency is 89.3%.

[0099] Comparative Example 11

[0100] Weigh 1.5 kg of refined safflower seed oil, with a GE content of 3.37 mg / kg, and select a pH of 4.5, an activity of 75 mol / kg, and a specific surface area of ​​98 m². 2 / g, mesopore area is 30m² 2 / g, mesopore volume is 0.132m 3 1.5% of the activated clay (by weight of edible vegetable oil) was accurately weighed and added to refined safflower seed oil. The mixture was stirred thoroughly and reacted at 110℃ and 20mbar for 45 minutes. After the reaction, the adsorbent and edible vegetable oil were separated. At this point, the GEs content in the refined safflower seed oil was reduced to 2.08 mg / kg, and the GEs removal efficiency was 38.3%.

[0101] The advantages and features of this invention will become clearer as the description unfolds. However, the embodiments are merely exemplary and do not constitute any limitation on the scope of the invention. Those skilled in the art should understand that modifications or substitutions to the details and form of the technical solutions of this invention can be made without departing from the spirit and scope of the invention, but all such modifications and substitutions fall within the protection scope of this invention.

Claims

1. A method for removing glycidyl esters from vegetable oils, wherein, The method includes the following steps: adding 0.05-2 wt% of adsorbent to the vegetable oil based on its total weight and stirring thoroughly, wherein the adsorbent is activated carbon and / or activated clay. The activated carbon meets the following conditions: pH 2-3, activity 180-190 mol / kg, and specific surface area 1500-1940 m². 2 / g, mesopore area is 170~280 m² 2 / g, mesopore volume of 0.50~0.80 m 3 / g; The activated clay meets the following conditions: pH 3.4–3.8, activity 200–230 mol / kg, and specific surface area 130–245 m². 2 / g, mesopore area is 45~75 m² 2 / g, mesopore volume is 0.145~0.175 m 2 / g.

2. The method as described in claim 1, wherein, The vegetable oil is selected from one or more of the following groups: rice bran oil, rapeseed oil, peanut oil, corn oil, palm oil, soybean oil, sunflower seed oil, safflower seed oil, olive oil, walnut oil, flaxseed oil, camellia seed oil, almond oil, peony seed oil, and perilla seed oil.

3. The method as described in claim 1 or 2, wherein, The amount of activated carbon added is 0.05-0.5 wt%.

4. The method of claim 3, wherein, The amount of activated carbon added is 0.05-0.2 wt%.

5. The method as described in claim 1 or 2, wherein, The amount of activated clay added is 0.2-2 wt%.

6. The method of claim 5, wherein, The amount of activated clay added is 0.5-1 wt%.

7. The method as described in claim 1 or 2, wherein, The adsorbent and the vegetable oil are reacted at 90-120°C under vacuum for 20-60 minutes. After the reaction is completed, the adsorbent and the vegetable oil are separated.

8. The method of claim 7, wherein, The reaction was carried out at 20 mbar.

9. The method as claimed in claim 1 or 2, wherein, The method includes the following steps: (1) Add 0.05-0.1 wt% activated carbon to 1 kg of refined vegetable oil and stir thoroughly, wherein the activated carbon has a pH of 2-3, an activity of 180-190 mol / kg, and a specific surface area of ​​1500-1940 m². 2 / g, mesopore area is 170~280m 2 / g, mesopore volume of 0.50~0.80 m 3 / g; (2) React at 90-120℃ under vacuum for 20-60 min. After the reaction is completed, separate the adsorbent from the vegetable oil.

10. The method as claimed in claim 1 or 2, wherein, The method includes the following steps: (1) Add 0.5-1 wt% activated clay to 1 kg of refined vegetable oil and stir thoroughly. The activated clay has a pH of 3.4-3.8, an activity of 200-230 mol / kg, and a specific surface area of ​​130-245 m². 2 / g, mesopore area is 45~75m 2 / g, mesopore volume is 0.145~0.175 m 2 / g; (2) React at 90-120℃ under vacuum for 20-60 min. After the reaction is complete, separate the adsorbent from the vegetable oil.