Preparation method of aromatic peanut oil with benzopyrene removed

Abstract

The invention relates to the field of edible oil preparation, and particularly discloses a preparation method of benzopyrene-removed aromatic peanut oil. The invention relates to a preparation method of benzopyrene-removed aromatic peanut oil. The preparation method comprises the following steps: (1) parching; (2) squeezing: the peanuts are divided into A parts and B parts, the A parts of the peanuts are squeezed by a squeezer A to obtain crude oil A, the current proportion of the squeezer A is 45-48%, the B parts of the peanuts are squeezed by a squeezer B to obtain crude oil B, and the current proportion of the squeezer B is 52-63%; (3) mixing: mixing the crude oil A and the crude oil B; (4) degumming and crystal growing: carrying out hydration degumming on the mixed crude oil to obtain degummed oil, adding activated carbon into the degummed oil, and growing the crystal at 18-22 DEG C for 6-8 hours to obtain crystallized oil; (5) filtering: filtering the crystallized oil to prepare the aromatic peanut oil from which benzopyrene is removed; the preparation method has the advantages that benzopyrene is removed, and meanwhile the characteristic flavor of the peanut oil is reserved.

Description

Technical Field

[0001] This application relates to the field of edible oil preparation, and more specifically, it relates to a method for preparing a fragrant peanut oil with benzo[a]pyrene removed. Background Technology

[0002] The aroma of peanut oil is highly sought after in the market because it produces characteristic volatile substances such as pyrazines, furans, aldehydes and ketones during the roasting and pressing process. However, high-temperature roasting of seeds and raw materials can lead to the safety risk of excessive levels of benzo[a]pyrene (BaP). For food safety and national standards, companies need to implement a BaP removal process before bottling to reduce the benzo[a]pyrene content in the finished peanut oil.

[0003] To address the issue of excessive benzo[a]pyrene in fragrant peanut oil, several mainstream technologies exist, such as high-temperature vacuum distillation, which removes benzo[a]pyrene through high temperature and specific vacuum conditions; activated carbon-bentonite adsorption, which utilizes the adsorption properties of both to remove benzo[a]pyrene; alkali refining-adsorption coupling process, which first uses alkali refining to remove acid before adsorption; and ultraviolet / γ-irradiation degradation, which uses high-energy rays to cause ring-opening degradation of benzo[a]pyrene.

[0004] Peanut oil contains a variety of flavor compounds, which affect its flavor and taste. However, the commonly used methods mentioned above, while reducing benzo[a]pyrene, have adverse effects on these flavor compounds. For example, high-temperature vacuum distillation causes key aroma compounds in peanut oil to be distilled out simultaneously, resulting in a decrease in the "roasted aroma" and the appearance of a "burnt" off-flavor. Activated carbon-bentonite adsorption causes the loss of polar flavor compounds, resulting in significant flavor deterioration. Alkali refining-adsorption coupling processes cause the loss of neutral oil, destroy aroma precursors, produce a "soapy" aftertaste, and increase the environmental burden. Ultraviolet / γ-irradiation degradation induces oil oxidation, generating trans fatty acids and a "baked" taste, and requires high equipment investment. While removing benzo[a]pyrene, the above methods are difficult to retain flavor compounds such as pyrazines, furans, aldehydes, and ketones, failing to achieve a balance between "flavor preservation" and "low benzo[a]pyrene". Summary of the Invention

[0005] In order to remove benzo[a]pyrene while retaining the characteristic flavor of peanut oil, this application provides a method for preparing a fragrant peanut oil with benzo[a]pyrene removed.

[0006] In a first aspect, this application provides a method for preparing fragrant peanut oil free of benzo[a]pyrene, using the following technical solution: A method for preparing fragrant peanut oil after removing benzo[a]pyrene includes the following steps: (1) Roasting: Roast directly, or use crushed steamed embryos or whole kernel steaming process to obtain roasted peanuts; (2) Pressing: Peanuts are divided into A and B portions. Peanuts A are pressed by press A to obtain crude oil A. The current of press A accounts for 45-48%. Peanuts B are pressed by press B to obtain crude oil B. The current of press B accounts for 52-63%. (3) Mixing: Mix crude oil A and crude oil B to obtain mixed crude oil; (4) Degumming and crystal growth: The mixed crude oil is degummed by hydration to obtain degummed oil. Activated carbon is added to the degummed oil and crystals are grown at 18-22℃ for 6-8 hours to obtain crystallized oil. (5) Filtration: The crystallized oil is filtered to obtain a fragrant peanut oil with benzo[a]pyrene removed.

[0007] By adopting the above technical solution, peanuts are split in half and pressed using presses with different current ratios. Press A has a low current ratio, low pressing chamber pressure, and low pressing chamber temperature, resulting in crude oil A with good flavor. Press B has a high current ratio, high pressing chamber pressure, and high pressing chamber temperature, resulting in crude oil B with a high oil yield. The mixed crude oil obtained by mixing crude oil A and crude oil B has both high oil yield and high flavor content. Crude oil A can fully compensate for the flavor of peanut oil. Adding activated carbon during the crystal growth process can effectively adsorb and remove benzo[a]pyrene from peanut oil. The low crystal growth temperature allows activated carbon to selectively adsorb benzo[a]pyrene and promote crystal formation, which is beneficial to the crystal growth process. Filtration can simultaneously remove activated carbon and crystals formed during the crystal growth process, ultimately producing fragrant peanut oil with benzo[a]pyrene removed. This reduces the benzo[a]pyrene content while retaining the rich aroma of peanut oil, meeting the market demand for high-quality peanut oil.

[0008] Preferably, in the mixed crude oil, crude oil A has a mass percentage of 2-5 wt%, and the balance is crude oil B.

[0009] By adopting the above technical solution and controlling the mass ratio of crude oil A and crude oil B in the mixed crude oil, the oil yield and flavor of the mixed crude oil can be effectively adjusted. Crude oil A is obtained by low-temperature pressing and has a high content of flavor substances, while crude oil B is obtained by high-temperature pressing, has a high oil yield but contains more benzo[a]pyrene. The flavor substances adsorbed in crude oil A can enhance the flavor intensity and flavor compound content of the mixed oil, making the peanut oil have a richer aroma. If the proportion of crude oil A is too low, it cannot fully play its role in enhancing flavor. If the proportion of crude oil A is too high, the oil yield will decrease significantly. By controlling the content of crude oil A, both the oil yield and the benzo[a]pyrene removal effect can be taken into account, and high-quality preparation of fragrant peanut oil with benzo[a]pyrene removal can be achieved.

[0010] Preferably, the crude oil A is an oil-powder mixture, the powder has a mesh size of 15-35 mesh, and the mass percentage of the powder in crude oil A is 40-55 wt%.

[0011] By adopting the above technical solution, crude oil A is a mixture of oil and powder, and the content of each flavor substance in it is significantly increased compared with crude oil B. Moreover, the pyrazines, furans and other substances in crude oil A make outstanding contributions to the "typical peanut aroma" of peanut oil, thereby improving the flavor structure of the mixed crude oil, reducing the burnt taste of the mixed crude oil and the finished peanut oil, and making its aroma sweeter.

[0012] Preferably, the amount of activated carbon added is 0.05-0.2 wt% of the degumming oil.

[0013] By adopting the above technical solution and controlling the amount of activated carbon added, the activated carbon can effectively adsorb benzo[a]pyrene, reducing the content of benzo[a]pyrene in peanut oil. At the same time, it reduces the excessive non-selective adsorption of flavor substances in peanut oil by activated carbon, thus allowing most flavor substances to be retained, achieving a balance between low benzo[a]pyrene and high flavor substances.

[0014] Preferably, in step (4) hydration degumming, the amount of water added is 0.3-0.5 wt% of the mixed crude oil.

[0015] By adopting the above technical solution, controlling the amount of water added can effectively remove colloidal impurities in the mixed crude oil. An appropriate amount of water can cause colloidal substances such as phospholipids to absorb water and swell, thereby separating them from the oil phase, which facilitates subsequent crystal growth and filtration operations. This helps to further remove benzo[a]pyrene during the subsequent crystal growth and filtration process, while avoiding excessive loss of flavor substances and ensuring the quality of the final benzo[a]pyrene-free, fragrant peanut oil.

[0016] Preferably, the filtration in step (5) is a series filtration of a chamber filter and a plate and frame filter.

[0017] By adopting the above technical solution, the chamber filter and plate and frame filter are connected in series for filtration, which can effectively remove impurities and activated carbon from the crystallized oil. The chamber filter has a large filtration area and high filtration efficiency, and can first perform preliminary filtration of the crystallized oil, intercepting larger particles of impurities. The plate and frame filter can then further refine the oil after filtration by the chamber filter, removing smaller impurities and residual activated carbon, thereby ensuring the purity of the final product, which is a fragrant peanut oil with benzo[a]pyrene removed, improving product quality, and making the peanut oil meet relevant quality standards.

[0018] Secondly, this application provides a fragrant peanut oil with benzo[a]pyrene removed, using the following technical solution: A fragrant peanut oil with benzo[a]pyrene removed is prepared according to a method for preparing a fragrant peanut oil with benzo[a]pyrene removed.

[0019] Preferably, the benzo[a]pyrene-free aromatic peanut oil contains less than 0.2 ppb of benzo[a]pyrene and ≥35 ppm of flavor compounds.

[0020] By adopting the above technical solution, two types of crude oil with sufficient flavor substances and high oil yield are obtained under different pressing conditions. After mixing, the oil is degummed, crystallized, adsorbed, and filtered to obtain peanut oil with both high oil yield and high content of flavor substances, and low content of benzo[a]pyrene.

[0021] An oil composition comprising benzo[a]pyrene-free, aromatic peanut oil.

[0022] A food product comprising benzo[a]pyrene-free aromatic peanut oil, or comprising an oil composition, or made from benzo[a]pyrene-free aromatic peanut oil, or made from an oil composition.

[0023] In summary, this application has the following beneficial effects: 1. In this application, peanuts are pressed separately, and two different crude oils, crude oil A and crude oil B, are obtained by adjusting the current ratio. After being mixed according to a specific mass ratio, crude oil A supplements the flavor of crude oil B. In the subsequent crystal filtration process, it can effectively enhance the flavor of peanut oil and synergistically protect the flavor substances in crude oil B. In the end, not only is BaP undetectable, but the flavor of peanut oil is also greatly improved.

[0024] 2. Crude oil A obtained using a low current ratio is characterized by high levels of flavor compounds, with high content of furans and pyrazines, which make a significant contribution to the aroma structure of peanut oil. By enhancing the "typical peanut aroma," it effectively masks the burnt smell, resulting in a richer and sweeter aroma. Detailed Implementation

[0025] The present application will be further described in detail below with reference to the embodiments.

[0026] In this application, the ratio of the press current to the maximum current range of the press is calculated as: (actual press current / maximum press current range) × 100%. Example

[0027] Example 1 A method for preparing fragrant peanut oil after removing benzo[a]pyrene includes the following steps: (1) Roasting: Roasting directly to obtain roasted peanuts; (2) Pressing: Peanuts are divided into part A and part B. Part A peanuts are pressed by press A to obtain crude oil A. The current of press A accounts for 48%. The obtained crude oil A is an oil-powder mixture. The powder has a mesh size of 15-35 mesh and the mass percentage of powder in crude oil A is 55 wt%. Peanuts B are pressed using press B to obtain crude oil B, with press B accounting for 52% of the current. (3) Mixing: Crude oil A and crude oil B are mixed to obtain mixed crude oil. In the mixed crude oil, the mass percentage of crude oil A is 2 wt% and the mass percentage of crude oil B is 98 wt%. (4) Degumming and crystal growth: The mixed crude oil is degummed by hydration to obtain degummed oil. The amount of water added is 0.5 wt% of the mixed crude oil. Activated carbon is added to the degummed oil and crystallized at 18°C ​​for 8 hours to obtain crystallized oil. The amount of activated carbon added is 0.05 wt% of the degummed oil. (5) Filtration: The crystallized oil is filtered in series by a chamber filter and a plate and frame filter to obtain a fragrant peanut oil with benzo[a]pyrene removed.

[0028] Example 2

[0029] The difference between Example 2 and Example 1 is that in Example 2, the current of the press A accounts for 45%, the crude oil A obtained is an oil-powder mixture, the powder has a mesh size of 15-35 mesh, and the mass percentage of powder in crude oil A is 40wt%.

[0030] Example 3

[0031] The difference between Example 3 and Example 1 is that in Example 3, the current of the press B accounts for 63%.

[0032] Example 4

[0033] The difference between Example 4 and Example 1 is that in Example 4, the mass percentage of crude oil A in the mixed crude oil is 1 wt%, and the mass percentage of crude oil B is 99 wt%.

[0034] Example 5

[0035] The difference between Example 5 and Example 1 is that in Example 5, the mass percentage of crude oil A in the mixed crude oil is 5 wt%, and the mass percentage of crude oil B is 95 wt%.

[0036] Example 6

[0037] The difference between Example 6 and Example 1 is that in Example 6, the mass percentage of crude oil A in the mixed crude oil is 6 wt%, and the mass percentage of crude oil B is 94 wt%.

[0038] Example 7

[0039] The difference between Example 7 and Example 1 is that in Example 7, the amount of activated carbon added is 0.1 wt% of the degumming oil.

[0040] Example 8

[0041] The difference between Example 8 and Example 1 is that in Example 8, the amount of activated carbon added is 0.2 wt% of the degumming oil.

[0042] Example 9

[0043] The difference between Example 9 and Example 1 is that in Example 9, the amount of activated carbon added is 0.3 wt% of the degumming oil. Comparative Example

[0044] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that crude oil A was not added in Comparative Example 1.

[0045] Comparative Example 2 The difference between Comparative Example 2 and Example 2 is that no activated carbon was added in Comparative Example 2.

[0046] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that in Comparative Example 3, the current of the press A accounts for 43%, the crude oil A obtained is an oil-powder mixture, the powder has a mesh size of 15-35 mesh, and the mass percentage of powder in crude oil A is 30wt%.

[0047] Comparative Example 4 The difference between Comparative Example 4 and Example 1 is that in Comparative Example 4, the current of the press A accounts for 50%, and the crude oil A obtained does not contain powder.

[0048] Comparative Example 5 The difference between Comparative Example 5 and Example 1 is that in Comparative Example 5, the current of the press B accounts for 50%.

[0049] Comparative Example 6 The difference between Comparative Example 6 and Example 1 is that in Comparative Example 6, the current of the press B accounts for 65%. Performance testing

[0050] I. Peanut oil was prepared according to Examples 1-9 and Comparative Examples 1-6, and its benzo[a]pyrene content, peanut oil color, and total amount of flavor compounds in peanut oil were tested according to the following methods, and the results are recorded in Table 1.

[0051] 1. Flavor testing: (1) Detection equipment: 7890A-5975C gas chromatography-mass spectrometry analyzer, HP-5 column (60m×0.25mm, 0.25μm) and 25ml headspace vials with screw caps were purchased from Agilent Technologies; multi-functional injector with solid phase microextraction was purchased from Co-Chemical; extraction head: 50 / 30μm DVB / Carboxen / PDMS, purchased from Anpu Technology; Quantitative analysis was performed using the internal standard method, with 1,3-dichlorobenzene as the internal standard at a concentration of 50.0 mg / L in the internal standard solution. Sample preparation involved adding 50.0 μL of this internal standard solution to every 5.00 g of oil sample. Flavor compound testing items: pyrazines, other NS heterocycles (pyridine, pyrrole, pyran, pyrimidine), furanones, pyranones, maltol, alcohols, phenols, alcohols, phenols, aldehydes, ketones, acids, and esters.

[0052] (2) Testing conditions: ①Chromatography: Select splitless mode; Capillary column: HP-5 (60m × 0.25mm × 0.25μm); Inlet temperature: 250℃; Temperature program: Hold at 40℃ for 1 minute, then increase to 250℃ at a rate of 5℃ / min and hold for 5 minutes; ②Mass spectrometry: transfer line temperature 280℃; The ionization method is electron bombardment (EI); Ionization energy: 70 eV; Electron multiplication voltage: 1600V; Ion source temperature: 230℃. The temperature of the quadrupole is 150℃. Monitoring method: Full scan; Mass spectrometry analysis: The components were qualitatively identified based on the NIST.L mass spectrometry database, and the ratio of flavor compound content was expressed as the peak area response ratio; 2. The detection of benzo[a]pyrene was carried out in accordance with GB 5009.27-2016 "National Food Safety Standard - Determination of Benzo[a]pyrene in Food". The result ND was benzo[a]pyrene content < 0.2 μg / kg, that is, benzo[a]pyrene content < 0.2 ppb; 3. The color of peanut oil was tested using a Lovibond colorimeter; 4. Oil yield = Actual oil yield from peanuts / Oil content of peanuts × 100%; 5. The detection of aflatoxin (B1) was carried out in accordance with GB 2761-2017 "National Food Safety Standard Limits for Mycotoxins in Food", and the result (ND) was aflatoxin content <0.03 ppb; 6. Describe and record the flavor and taste of peanut oil.

[0053] Table 1. Peanut oil quality test results

[0054] Based on the analysis of Table 1 and each embodiment and comparative example, it can be seen that the peanut oils prepared in Examples 1-3, 5, and 7-9 all have high content of flavor substances and a rich peanut aroma. At the same time, benzo[a]pyrene was not detected in any of them, that is, the benzo[a]pyrene content was <0.2ppb. This indicates that the peanut oils prepared in the above embodiments have both a rich aroma and low benzo[a]pyrene content. Furthermore, the preparation method of this application is simple, the equipment cost is low, and it is suitable for large-scale production.

[0055] Compared with Examples 2 and Comparative Examples 3-4, Examples 1 and 2 yielded peanut oil with higher total flavor compounds. However, when the current ratio of press A decreased or increased, as in Comparative Examples 3-4, the flavor compound content decreased, indicating that the current ratio of press A directly affects the pressing chamber temperature and pressure. If the current ratio is too low, as in Comparative Example 3, the pressing force is insufficient. Crude oil A is an oil-powder mixture with a low powder content. The powder in the oil-powder mixture can adsorb more flavor compounds during pressing, and its content is directly related to the strength of the flavor. When the powder content is low, the peanut oil flavor decreases, resulting in insufficient release of flavor compounds from the peanuts into the crude oil, leading to insufficient flavor in the final product. If the current ratio is slightly high, as in Comparative Example 4, it may cause the pressing chamber temperature to rise. When the current ratio is within the preferred range, the pressing conditions are moderate, and the powder content in crude oil A is high. This effectively extracts flavor compounds while avoiding the formation of benzo[a]pyrene or loss of flavor compounds that may occur due to excessively high temperatures. This effectively ensures that crude oil A is rich in flavor compounds, providing a source of rich aroma for the final product. Compared to Examples 3 and Comparative Examples 5-6, Examples 1 and 3 yielded peanut oils with higher total flavor compounds and higher oil yields. However, when the current percentage of press B decreased, as in Comparative Example 5, the content of flavor compounds and the oil yield of the peanut oil decreased. This indicates that press B, bearing the primary responsibility for oil extraction, had a higher current percentage, ensuring higher pressing temperature and pressure, thus achieving a high oil yield. However, excessively high pressing temperatures may also increase the risk of benzo[a]pyrene formation or destroy some flavor components. Appropriately increasing the current percentage of press B, as in Examples 1 and 3, may have promoted the dissolution of more oil and some flavor precursors, resulting in an increase in the total detected flavor compounds. This may be due to the more complete release of certain flavor components during high-temperature pressing. However, the current percentage in Comparative Example 6 was too high. Although the oil yield further increased, a noticeable burnt flavor appeared, indicating that the pressing temperature was too high. The current percentage needs to be controlled within a reasonable upper limit to avoid the negative risks associated with excessively high temperatures. The comparison between Example 1 and Example 3, and Comparative Examples 5-6 illustrates that, within the preferred current ratio range, a balance can be struck between high oil yield and the retention of flavor compounds.

[0056] Compared with Examples 4-6 and Comparative Example 1, Examples 1 and 5 yielded peanut oils with higher total flavor compounds and higher oil yield. However, when the content of crude oil A decreased or increased, the balance between the flavor compound content and oil yield was disrupted. Example 4 showed a decrease in flavor compound content, and Example 6, while showing an increase in flavor compound content, exhibited a significant decrease in oil yield. Comparative Example 1, lacking crude oil A, had the highest oil yield but the lowest flavor compound content, indicating that crude oil A is rich in flavor compounds but contributes little to the oil yield. Crude oil B showed the opposite. If the proportion of crude oil A added is too low, as in Examples 4 and Comparative Example 1, it cannot effectively enhance the flavor. A moderate proportion of crude oil A added, as in Examples 1 and 5, can significantly increase the flavor compound content with only a slight impact on the oil yield, achieving a good balance between flavor and yield. If the proportion of crude oil A added is too high, as in Example 6, although it can further enhance the flavor, the oil yield loss is significant, reducing economic efficiency.

[0057] Compared with Examples 7-9 and Comparative Example 2, the benzo[a]pyrene content in all examples was undetectable, i.e., <0.2 ppb. The content of flavor substances decreased with the increase of activated carbon. Comparative Example 2 did not add activated carbon, and its benzo[a]pyrene content was 2.3 ppb. Both benzo[a]pyrene and aflatoxin B1 were seriously exceeded. In Examples 7-8, benzo[a]pyrene and aflatoxin B1 were undetectable or extremely low. In Example 9, although the flavor substances were not further reduced, the oil color became lighter. This indicates that activated carbon has a selective adsorption effect on harmful substances such as benzo[a]pyrene and aflatoxin during the low-temperature crystal growth process.

[0058] Without activated carbon, as in Comparative Example 2, these contaminants cannot be effectively removed. Although the most flavor substances are retained, the product safety does not meet the standards. Adding activated carbon ensures that the benzo[a]pyrene content is far below the safety limit, while aflatoxin is also effectively controlled. Controlling the activated carbon addition within the range of 0.05-0.2% allows for efficient removal of harmful substances while keeping the loss of flavor substances to a low level. However, when the addition is increased to 0.3%, as in Example 9, although the removal effect is still guaranteed, the activated carbon may over-adsorb pigments and some flavor components in the oil, leading to a lighter oil color and a risk of further loss of flavor substances. Therefore, controlling the activated carbon addition within 0.05-0.2 wt% of the degummed oil is key to achieving the best balance between efficient detoxification and flavor retention. Furthermore, in Example 1, the appropriate amount of degumming water effectively removed the gum, creating favorable conditions for subsequent activated carbon adsorption and crystal growth. Inappropriate water volume may affect the degumming effect and the overall process stability.

[0059] II. Based on Example 1, the flavor components and contents and benzo[a]pyrene contents in the following samples were detected and recorded in Tables 2 and 3: Sample 1: Crude oil A; Sample 2: Crude oil B; Sample 3: Blended crude oil 1, which is a mixture of 2wt% crude oil A and 98wt% crude oil B; Sample 4: Blended crude oil 2, which is a mixture of 1 wt% crude oil A and 99 wt% crude oil B, is peanut oil obtained by degumming, crystal growth (adding activated carbon) and filtration according to the process of Example 1 of this application. Sample 5: Peanut oil obtained by degumming, crystallization (with the addition of activated carbon), and filtration of mixed crude oil 1 according to the process of Example 1 of this application; Sample 6: Peanut oil obtained by degumming, crystal growth (without added activated carbon) and filtration of mixed crude oil 1 according to the process of Comparative Example 1 of this application; Sample 7: Peanut oil obtained by degumming, crystallization (without added activated carbon), and filtration of crude oil B according to the process of Comparative Example 1 of this application; Sample 8: Peanut oil obtained by degumming, crystallization (addition of activated carbon), and filtration of crude oil B according to the process of Example 1 of this application; Sample 9: Peanut meal obtained after pressing by press B is crushed to obtain cake powder; Sample 10: 1 wt% of the cake powder obtained from Sample 9 and 99 wt% of the peanut oil obtained from Sample 8 were mixed, and then the peanut oil was obtained by degumming, crystal growth (adding activated carbon) and filtration according to the process of Example 1 of this application.

[0060] Flavor compounds include the following: pyrazines, other NS heterocyclic compounds (pyridine, pyrrole, pyran, pyrimidine), furanones, pyranones, maltol, alcohols, phenols, aliphatic aldehydes, ketones, acids, and esters; and dihydrophenylpropanuran is detected separately.

[0061] Table 2 Flavor substance content of different samples

[0062] Table 3. Flavor compounds and benzo[a]pyrene content in different samples

[0063] Tables 2 and 3 show that, comparing samples 1 and 2, crude oil A has a total flavor content of 238.14 ppm, far exceeding crude oil B's 57.98 ppm. Particularly in key flavor compounds such as Maillard reaction products (pyrazines) and caramelization products (furanones), crude oil A's content is approximately 4-5 times that of crude oil B. This confirms that crude oil A, pressed using a low current ratio, is the main source of its rich aroma. Meanwhile, the BaP content in both samples 1 and 2 is 2.3 ppb, indicating that benzo[a]pyrene is generated in the crude oil after high-temperature pressing, regardless of the current level, and needs to be removed through subsequent processes.

[0064] Combining Samples 2 and 3, the total flavor compounds in Sample 3 were 63.21 ppm, indicating that the flavor compounds in the mixed crude oil obtained by mixing crude oil A and crude oil B are not simply additive. This suggests that the addition of crude oil A protects and synergistically enhances the flavor compounds in crude oil B. After filtration, the flavor compounds in crude oil A and crude oil B are more completely preserved, reducing their loss. Comparing Samples 4 and 5, the total flavor of the finished oil increased from 30.24 ppm to 36.09 ppm, an increase of approximately 19%. This indicates that the addition of crude oil A has a synergistic effect on the flavor of the mixed oil. This demonstrates that within a low addition range, the addition of crude oil A can significantly improve the flavor intensity of the system.

[0065] Comparing samples 1-3 and 5-6, it can be seen that "adding 0.05-0.2wt% activated carbon for crystal growth" is the key to achieving efficient removal of benzo[a]pyrene (<0.2ppb) in the process of this application. However, in this application, activated carbon is added during the crystal growth stage. Combined with sample 7, it can be seen that if crude oil A is not added, and crude oil B is treated separately according to the process of Example 1 of this application, its BaP also drops to undetectable levels, but its total flavor content drops significantly from 57.98ppm to 29.48ppm. This fully demonstrates that although adding activated carbon during the crystal growth stage can effectively remove BaP, the lack of high-flavor crude oil A for flavor compensation and synergistic protection will lead to a serious loss of flavor in crude oil B, making it impossible to remove BaP while maintaining the high flavor of peanut oil.

[0066] Comparing samples 5 and 6, the total flavor concentration of sample 5 (36.09 ppm) is lower than that of sample 6 (38.98 ppm). This indicates that while activated carbon adsorbs benzo[a]pyrene, it inevitably adsorbs a small amount of flavor substances, resulting in a loss. However, according to Table 1, the final product still has a flavor concentration of over 35 ppm and a typical peanut aroma. This shows that the integrated processing of A and B after mixing achieves a good balance between efficient BaP removal and flavor retention.

[0067] Combining Table 2-3, Samples 1-3 and 5, it can be seen that the flavor compounds of crude oil A have obvious characteristics. The content of phenolic compounds is similar, but the content of pyrazines and furans is higher. After crystal filtration, the content of pyrazines and furans still maintains a high level. Phenolic compounds are closely associated with burnt flavor compounds. After adding crude oil A, the amount of phenolic compounds does not increase or decrease significantly, but the burnt flavor is significantly reduced. This may be because the high proportion of pyrazines and furans has a significant masking effect on the burnt flavor. While improving the flavor, it also reduces the burnt flavor in the flavor, making the finished peanut oil present a prominent "typical peanut aroma".

[0068] Based on samples 5 and 7-10, this application uses crude oil A obtained from a mixture of oil and powder with a low current ratio as a flavor supplement. Compared with the cake powder obtained from pressing crude oil B as a flavor supplement, crude oil A has a significant advantage in its flavor composition. Crude oil B is pressed with a high current ratio, and its flavor substances are significantly lost during the pressing process. The cake powder obtained from crushing the peanut meal is rich in flavor substances, but these flavor substances exist in the solid phase. Using the cake powder after pressing to supplement the flavor of peanut oil, the total amount of flavor substances is still far lower than that obtained by supplementing the flavor of peanut oil with crude oil A in this application. This indicates that the flavor substances in peanut meal cannot be effectively transferred to the oil phase and are difficult to utilize. In addition, the content of important flavor substances such as furans and pyrazines is low, which cannot effectively adjust the flavor structure of peanut oil. The obtained peanut oil still has a relatively obvious burnt taste, and its "typical peanut aroma" is not prominent enough.

[0069] In summary, as shown in Tables 1-3, by adjusting the current ratio of the press, crude oil A with a high content of flavor compounds and crude oil B with a high oil yield but a low content of flavor compounds were obtained. After mixing them in a specific ratio, the resulting peanut oil, after degumming, adding activated carbon for crystal growth, and filtration, has extremely low BaP content, below 0.2 ppb, which can be considered as a removed state. The addition of activated carbon during the crystal growth stage effectively removed BaP from the finished oil. Crude oil A can supplement and synergistically protect the flavor compounds of crude oil B. In subsequent processing, it not only improves the overall flavor of peanut oil as a supplement but also synergistically protects the flavor compounds in crude oil B, thereby further increasing the total amount of flavor compounds in the finished peanut oil. It also effectively adjusts the ratio of each substance in the flavor compounds. The content of pyrazines and furans, which make outstanding contributions to the "typical peanut aroma" of peanut oil, is significantly increased, reducing the source of burnt flavor in the finished product. This achieves the dual effect of BaP removal and a rich aroma in peanut oil.

[0070] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A method for preparing a fragrant peanut oil with benzo[a]pyrene removed, characterized in that: Includes the following steps: (1) Roasting: Roast directly, or use crushed steamed embryos or whole kernel steaming process to obtain roasted peanuts; (2) Pressing: Peanuts are divided into A and B portions. Peanuts A are pressed by press A to obtain crude oil A. The current of press A accounts for 45-48%. Peanuts B are pressed by press B to obtain crude oil B. The current of press B accounts for 52-63%. (3) Mixing: Mix crude oil A and crude oil B to obtain mixed crude oil; (4) Degumming and crystal growth: The mixed crude oil is degummed by hydration to obtain degummed oil. Activated carbon is added to the degummed oil and crystals are grown at 18-22℃ for 6-8 hours to obtain crystallized oil. (5) Filtration: The crystallized oil is filtered to obtain a fragrant peanut oil with benzo[a]pyrene removed.

2. The method for preparing a fragrant peanut oil with benzo[a]pyrene removed according to claim 1, characterized in that: In the mixed crude oil, crude oil A accounts for 2-5 wt% by mass, and the balance is crude oil B.

3. The method for preparing a fragrant peanut oil with benzo[a]pyrene removed according to claim 1, characterized in that: The crude oil A is a mixture of oil and powder, with the powder having a mesh size of 15-35 and a mass percentage of 40-55 wt% in the crude oil A.

4. The method for preparing a fragrant peanut oil with benzo[a]pyrene removed according to claim 1, characterized in that: The amount of activated carbon added is 0.05-0.2 wt% of the degumming oil.

5. The method for preparing a fragrant peanut oil with benzo[a]pyrene removed according to claim 1, characterized in that: In step (4) hydration and degumming, the amount of water added is 0.3-0.5 wt% of the mixed crude oil.

6. The method for preparing a fragrant peanut oil with benzo[a]pyrene removed according to claim 1, characterized in that: The filtration in step (5) is a series filtration of a chamber filter and a plate and frame filter.

7. A fragrant peanut oil with benzo[a]pyrene removed, characterized in that: The method for preparing a fragrant peanut oil with benzo[a]pyrene removed according to any one of claims 1-6 is used.

8. The fragrant peanut oil with benzo[a]pyrene removed according to claim 7, characterized in that: The benzo[a]pyrene-free, aromatic peanut oil contains less than 0.2 ppb of benzo[a]pyrene and ≥35 ppm of flavor compounds.

9. An oil and fat composition, characterized in that: The oil composition includes the benzo[a]pyrene-free, aromatic peanut oil as described in claim 7.

10. A food product, characterized in that: The food product comprises the benzo[a]pyrene-free aromatic peanut oil as described in claim 7, or the oil composition as described in claim 9, or is made using the benzo[a]pyrene-free aromatic peanut oil as described in claim 7, or is made using the oil composition as described in claim 9.

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