A method of processing olive oil
By using cold treatment, organic solvents for cleaning, and ultra-high pressure treatment, the problem of increased fatty acid ethyl ester content during olive oil storage is solved, thus maintaining the oil quality and flavor and meeting quality standards.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ACCESS BUSINESS GROUP INTERNATIONAL LLC
- Filing Date
- 2025-06-11
- Publication Date
- 2026-05-29
AI Technical Summary
In existing technologies, the content of fatty acid ethyl esters in olive oil increases during storage, affecting oil quality and flavor, and there is a lack of effective methods to inhibit this.
A cold treatment method is used, in which olive pomace is washed with a food-grade organic solvent, crushed, added to olive oil, stirred and centrifuged, and then subjected to ultra-high pressure treatment to inhibit the formation of fatty acid ethyl esters.
During storage, the growth of fatty acid ethyl ester content is significantly inhibited, remaining at ≤35mg/kg, ensuring the quality of olive oil meets standards.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of food oils and fats, and specifically relates to a method for processing olive oil and the processed olive oil obtained by the method. Background Technology
[0002] Olive oil is rich in nutrients and has outstanding health benefits. It has functions such as preventing cardiovascular and cerebrovascular diseases, diabetes, cancer, and anti-aging. It is recognized as a green and healthy edible oil and is known as the "Queen of Edible Oils" in the West. As a result, it is becoming increasingly popular among consumers.
[0003] Extra virgin olive oil is made by directly cold-pressing fresh olives without any chemical treatment. The production process is completed within 24 hours, ensuring its pure, natural, and high-quality characteristics. Extra virgin olive oil refers to olive oil with an acidity level of no more than 0.8, and is one of the highest quality olive oils. Its production process uses a purely physical, low-temperature pressing method, without adding any preservatives or additives, ensuring that the natural nutrients and flavor of the olives are preserved to the greatest extent.
[0004] Fatty acid ethyl esters (FAEEs) in olive oil are compounds formed during the production or storage of olive oil. They are products of the esterification reaction between free fatty acids and ethanol during olive fermentation. Poor quality olives or those improperly stored may ferment to produce ethanol, which then reacts with free fatty acids to form fatty acid ethyl esters. The formation of fatty acid ethyl esters may lead to a decline in the flavor and quality of the olive oil.
[0005] The content of ethyl esters in olive oil is a crucial indicator of its quality. Lower-grade olive oils tend to have higher ethyl ester content, while extra virgin olive oils have strictly limited levels as these components can negatively impact flavor and quality. GB / T 23347-2021, "Olive Oil and Olive Pomace Oil," requires that the ethyl ester content in extra virgin olive oil be ≤35 mg / kg. However, a current industry problem is that while olive oil meets the ethyl ester content standard before bottling, the content increases with prolonged storage, affecting both flavor and quality. Currently, there are no effective methods in the technology to inhibit the formation of ethyl esters during olive oil storage. Summary of the Invention
[0006] This invention unexpectedly reveals a method for inhibiting the formation of fatty acid ethyl esters during olive oil storage through cold treatment. Specifically, this invention provides a method for treating olive oil, particularly extra virgin olive oil, such that the extra virgin olive oil treated by the method of this invention, under conditions of 30°C and sealed in a light-protected environment, maintains a fatty acid ethyl ester content of ≤35 mg / kg for at least 12 months, particularly 12-18 months, and preferably 12-24 months.
[0007] To address the issue of increased fatty acid ethyl ester content in olive oil during normal storage, this invention provides a method that inhibits the formation of fatty acid ethyl esters during storage, particularly in extra virgin olive oil, by removing the reaction substrates that generate fatty acid ethyl esters from olive oil and inhibiting the formation of these reaction substrates during storage. The storage period is at least 12 months, typically 12 to 18 months, preferably 12 to 24 months. This method does not involve high-temperature treatment and can significantly inhibit the formation of fatty acid ethyl esters during the storage of olive oil, especially extra virgin olive oil.
[0008] To obtain olive oil with a constant or minimal change in fatty acid ethyl ester content during storage, this invention first uses a food-acceptable organic solvent, preferably n-hexane or ethanol, to wash pressed olive pomace until no oil residue remains. The washed olive pomace is then dried at 50-70°C until no organic solvent remains, followed by pulverization and sieving to obtain olive pomace powder. The obtained olive pomace powder is then added to the olive oil to be processed under vacuum stirring, and the olive pomace is removed by filtration. The supernatant is collected by centrifugation to obtain the pre-treated olive oil. Finally, the pre-treated olive oil is subjected to ultra-high pressure processing to obtain the final treated olive oil.
[0009] Tests showed that the content of fatty acid ethyl esters in the treated olive oil obtained by the method described in this application did not increase significantly during storage.
[0010] The method described in this invention is particularly suitable for processing extra virgin olive oil.
[0011] Specifically, the objective of this invention is achieved through the following technical solutions:
[0012] A method for processing olive oil, the method comprising the following steps:
[0013] (1) The olive pomace after oil extraction is washed with a food-acceptable organic solvent, then dried to remove the organic solvent, then crushed and sieved to obtain olive pomace powder.
[0014] (2) Add the olive pomace powder obtained in step (1) to the olive oil and stir under vacuum. After centrifugation, the upper clear oil is taken to obtain the olive oil after preliminary treatment.
[0015] (3) The olive oil obtained in step (2) after preliminary treatment is further subjected to ultra-high pressure treatment to obtain treated olive oil.
[0016] Preferably, in step (1), the ratio of fruit pomace to organic solvent is 300g / L-500g / L.
[0017] Preferably, in step (1), the drying temperature is 50-70°C and the drying time is 5-7 hours.
[0018] Preferably, in step (1), a 40-mesh sieve is used for sieving.
[0019] Preferably, in step (2), the olive pomace powder obtained in step (1) is added to the olive oil in an amount of 0.5-5% by weight of the olive oil.
[0020] Preferably, the vacuuming conditions described in step (2) are a temperature of 30-40°C and a pressure of 0.5-1.0 Pa.
[0021] Preferably, the ultra-high pressure treatment in step (3) is carried out under conditions of 30-40℃ and 200-300MPa.
[0022] Preferably, the olive oil is extra virgin olive oil.
[0023] Furthermore, the present invention relates to a method for processing extra virgin olive oil, the method comprising the following steps:
[0024] (1) The olive pomace after oil extraction is washed with a food-acceptable organic solvent, wherein the ratio of pomace to organic solvent is 300g / L-500g / L. Then it is dried at 50-70℃ for 5-7 hours to remove the organic solvent. Then it is crushed and passed through a 40-mesh sieve to obtain olive pomace powder.
[0025] (2) Add the olive pomace powder obtained in step (1) to the extra virgin olive oil in an amount of 0.5-5% by weight, and stir for 1-5 hours under vacuum conditions of 30-40°C and 0.5-1.0 Pa. After centrifugation, the upper clear oil is taken to obtain the extra virgin olive oil after preliminary treatment.
[0026] (3) The virgin olive oil obtained in step (2) after preliminary treatment is further subjected to ultra-high pressure treatment at 30-40℃ and 200-300MPa for 5-15 minutes to obtain treated olive oil.
[0027] In step (1) of the aforementioned method, the olive pomace is washed until no oil residue remains.
[0028] In step (1) of the aforementioned method, the drying temperature is 50-70°C, more preferably 60°C; and the drying time is 5-7 hours, more preferably 6 hours.
[0029] In step (1) of the aforementioned method, the drying conditions are drying at 60°C for 6 hours.
[0030] The food-grade acceptable organic solvent used in step (1) of the aforementioned method is selected from alkane solvents or alcohol solvents, preferably n-hexane or ethanol.
[0031] In step (2) of the aforementioned method, the amount of olive pomace added is 0.5-5% by weight of extra virgin olive oil, preferably 1-3% of extra virgin olive oil, and more preferably 2% of extra virgin olive oil.
[0032] The stirring temperature in step (2) of the aforementioned method is 30-40℃.
[0033] The stirring time in step (2) of the aforementioned method is 1-5 hours, preferably 2-3 hours, and more preferably 2 hours.
[0034] In the aforementioned method, the vacuum level of step (2) is 0.5 to 1.0 Pa.
[0035] In the aforementioned method, the ultra-high pressure treatment in step (3) is carried out at 30-40℃ and 200-300MPa, preferably at 35℃ and 300MPa.
[0036] The ultra-high pressure treatment time in step (3) of the aforementioned method is 5-15 minutes, preferably 10 minutes.
[0037] The content of fatty acid ethyl esters in the extra virgin olive oil processed by the method described in this invention remains ≤35mg / kg for at least 12 months, typically 12-18 months, and preferably 12-24 months, under conditions of 30°C and light protection by packaging.
[0038] Specifically, in one embodiment, the original ethyl ester content of the extra virgin olive oil treated by the method of the present invention is 25-26 mg / kg. After 12 months of storage, the ethyl ester content of the extra virgin olive oil only increases to 27-28 mg / kg; while the ethyl ester content of the extra virgin olive oil without the method of the present invention, which originally had an original ethyl ester content of 25-26 mg / kg, increases from 25-26 mg / kg to 36-37 mg / kg after 12 months of storage. After 18 months of storage, the ethyl ester content of the extra virgin olive oil treated by the method of the present invention only increases to 29-30 mg / kg; while the ethyl ester content of the extra virgin olive oil without the method of the present invention, which originally had an original ethyl ester content of 25-26 mg / kg, increases from 25-26 mg / kg to 42-44 mg / kg. After 24 months of storage, the ethyl ester content of the extra virgin olive oil treated by the method of the present invention only increases to 31-32 mg / kg. The ethyl ester content of virgin olive oil, which was not treated by the method described in this invention and had a raw ethyl ester content of 25-26 mg / kg, increased from 25-26 mg / kg to 47-48 mg / kg.
[0039] The method of the present invention enables the content of fatty acid ethyl esters in extra virgin olive oil treated at 30°C and under sealed, light-proof conditions to remain ≤35 mg / kg for at least 12 months, typically 12-18 months, and preferably 12-24 months.
[0040] Preferably, the virgin olive oil described in this invention is extra virgin olive oil.
[0041] Unbound by any theoretical constraints, the method described in this invention employs multi-factor balance regulation to reduce the formation of ethyl fatty acid esters in olive oil. In step (2) of the method described in this invention, modified olive pomace powder is used to selectively adsorb free fatty acids and ethanol, etc.; the ultra-high pressure treatment in step (3) not only inactivates the enzymes and microorganisms that promote esterification, but also effectively slows down the esterification reaction by changing the arrangement and distribution of olive oil molecules and water. Through this multi-factor balance regulation, the purpose of reducing the formation of ethyl fatty acid esters is achieved.
[0042] The present invention also provides a treated extra virgin olive oil obtained according to the method of the present invention, characterized in that, under the conditions of 30°C and sealed in a light-proof environment, the content of fatty acid ethyl esters in the treated extra virgin olive oil can be maintained at ≤35mg / kg for at least 12 months, usually 12-18 months, and preferably 12-24 months.
[0043] Preferably, the virgin olive oil described in this invention is extra virgin olive oil.
[0044] This invention presents for the first time a method for inhibiting the formation of fatty acid ethyl esters in olive oil during storage. This method does not damage the nutritional components of olive oil and significantly inhibits the formation of fatty acid ethyl esters, solving the problem that while the fatty acid ethyl ester content of olive oil meets the standards before bottling, it exceeds the standards as storage time increases. Detailed Implementation
[0045] The present invention will be further described in detail below with reference to embodiments, but the embodiments of the present invention are not limited thereto. All raw materials involved in the present invention can be purchased directly from the market. For process parameters not specifically specified, conventional techniques can be referred to.
[0046] The terms used in this invention have the common meanings in the art, unless otherwise specified in this application.
[0047] The "virgin olive oil" described in this invention is made by directly cold pressing fresh olives without any chemical treatment; the production process of virgin olive oil is completed within 24 hours, ensuring its pure naturalness and high quality.
[0048] The "extra virgin olive oil" mentioned in this invention refers to virgin olive oil with an acidity of no more than 0.8.
[0049] The "olive pomace" mentioned in this invention refers to the olive pulp, skin, and pit remaining after pressing and extracting olive oil during the olive oil production process.
[0050] The "ultra-high pressure" mentioned in this invention refers to a pressure state with a pressure exceeding 100 MPa (megapascals).
[0051] The term "food science acceptable" as used in this invention refers to the ability of food to meet relevant regulatory requirements, technical standards, and user acceptance during the research, development, production, and use processes.
[0052] Example
[0053] The present invention will be further illustrated by the following embodiments, but the scope of protection is not limited to the scope described in the embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, after reading the contents of this invention, those skilled in the art can make various modifications to the invention, and these equivalent changes also fall within the scope defined by the appended claims.
[0054] The following examples illustrate the processing method of olive oil according to the present invention, and provide comparative data on the content of fatty acid ethyl esters in olive oil treated by the method of the present invention and in olive oil not treated by the method of the present invention in a comparative experiment.
[0055] Specifically, the experimental methods involved are as follows:
[0056] 1) Preparation of olive pomace powder:
[0057] Take the olive pomace after oil extraction into a beaker, add an organic solvent (n-hexane and / or ethanol), stir, and filter. Repeat this process three times. The ratio of pomace to organic solvent is 300 g / L-500 g / L. Then, dry the pomace in an oven at 60°C for 6 hours, pulverize it in a pulverizer for 5 minutes, and pass it through a 40-mesh sieve to obtain olive pomace powder.
[0058] 2) Preparation of extra virgin olive oil after preliminary processing:
[0059] Weigh 200g of extra virgin olive oil and add the olive pomace powder obtained in step 1) at a rate of 2wt% of the extra virgin olive oil. Stir for 2 hours at 30-40℃ and under vacuum conditions of 0.5-1.0Pa. Centrifuge to obtain the clear oil from the supernatant to obtain the pre-treated extra virgin olive oil.
[0060] 3 Ultra-high pressure treatment:
[0061] The pre-processed extra virgin olive oil obtained in step 2) is placed into a special high-pressure processing container and subjected to ultra-high pressure of 200-300 MPa at 30-40°C for 5-10 minutes. After processing, the pressure is slowly released to obtain extra virgin olive oil processed by the method described in this application.
[0062] 4) Storage conditions Place in a 35℃ constant temperature chamber.
[0063] 5) Determination of fatty acid ethyl ester content:
[0064] The content of fatty acid ethyl esters in olive oil was measured using gas chromatography-mass spectrometry (GC-MS).
[0065] The sample of extra virgin olive oil obtained in step 3) after being processed by the method described in this application was dissolved in n-hexane and purified by silica gel solid-phase extraction column. Then it was analyzed by gas chromatography-mass spectrometry, and the internal standard method was used for quantification.
[0066] When using silica gel solid phase extraction columns for purification, silica gel particles (100-200 mesh) are selected as the packing material, with a specification of 1g / 6mL (i.e., each SPE column contains 1g of silica gel and has a column volume of 6mL).
[0067] Specifically, weigh 0.05 g of olive oil sample (accurate to 0.0001 g) and add it to a 10 mL glass test tube. Add 200 μL of internal standard solution (e.g., ethyl heptadecanoate, cis-10), then add 1 mL of n-hexane. Vortex for 30 seconds to dissolve and allow to purify. Use 20 mL of n-hexane-ethyl ether mixture (80:20 v / v) to selectively elute fatty acid ethyl esters (FAEEs) to avoid interference from triglycerides and other large lipid molecules. Control the eluent flow rate to 1-2 drops per second to ensure sufficient contact between the silica gel column and the eluent, thereby improving the recovery rate of the target analyte. Concentrate the collected eluent to dryness under reduced pressure using a rotary evaporator at 40 °C, then redissolve it with 1 mL of n-hexane. Vortex and filter the solution through a 0.45 μm microporous membrane. Transfer the filtrate to a glass sample vial for analysis.
[0068] Gas chromatography conditions included the use of an electron impact ionization (EI) source, with the column temperature program set as follows: initial temperature 150 °C, ramped to 200 °C at 20 °C / min, then ramped to 240 °C at 2.5 °C / min, held for 1.5 min, and finally ramped to 310 °C at 35 °C / min, held for 2 min. The injection volume was typically 1 μL, the carrier gas flow rate was 1 mL / min, the injection port temperature was 300 °C, nitrogen was used as the carrier gas, and the total elution time was 22 min.
[0069] Mass spectrometry conditions: An electron impact ion source (EI) was used, with the ion source temperature set to 230℃ and the interface temperature set to 280℃ to ensure that the gas chromatographic effluent was fully vaporized and stably transported to the mass spectrometer detector.
[0070] The solvent delay time was set to 5 minutes to avoid interference from solvent peaks such as n-hexane with the detection signal.
[0071] Data acquisition employed Selected Ion Monitoring (SIM) mode. For target analytes such as ethyl palmitate (characteristic ions m / z 228, 256), ethyl linoleate (m / z 264, 294), ethyl oleate (m / z 264, 296), and ethyl stearate (m / z 228, 284), characteristic fragment ions were selected for monitoring, with ethyl heptadecanoate (C17:1E) serving as an internal standard (monitoring ions m / z 266, 280).
[0072] The residence time of each ion channel is typically set to 0.2 seconds to ensure sensitivity and resolution.
[0073] For chromatographic columns, it is recommended to use weakly polar columns such as DB-5MS (30m×0.25mm×0.25μm), combined with programmed temperature rise (such as gradient temperature rise from initial 150℃ to 310℃) to achieve efficient separation of target analytes.
[0074] Example 1
[0075] (1) Wash the olive pomace after oil extraction with n-hexane until there is no residual oil. The ratio of olive pomace to n-hexane is 300g / L-500g / L. Dry it at 60℃ for 6 hours, crush it and pass it through a 40-mesh sieve.
[0076] (2) Weigh 200g of extra virgin olive oil, add 2wt% olive pomace powder, and stir for 2 hours under vacuum conditions of 30-40℃ and 0.5-1.0Pa. Centrifuge at 8000rpm at room temperature for 10min and collect the supernatant oil.
[0077] (3) The supernatant oil obtained in step (2) is reacted at 35°C and 300MPa under ultra-high pressure for 10 minutes to obtain olive oil treated by the method described in this application.
[0078] The original content of fatty acid ethyl esters was detected by gas chromatography-mass spectrometry (GC-MS) as described above, and the content of fatty acid ethyl esters was monitored by periodic sampling after 1 month, 2 months, 4 months, 6 months, 8 months, 10 months, 12 months, 18 months and 24 months of sealed storage in the dark at 30℃.
[0079] According to the test results, the content of fatty acid ethyl esters in the treated extra virgin olive oil obtained in this example was 25.17 mg / kg initially, 27.41 mg / kg after 12 months of storage, 29.19 mg / kg after 18 months of storage, and 31.11 mg / kg after 24 months of storage.
[0080] Example 2
[0081] This embodiment is exactly the same as Embodiment 1, except for the following specially noted differences:
[0082] The drying temperature in step (1) is 50°C.
[0083] According to the test results, the content of fatty acid ethyl esters in the treated extra virgin olive oil obtained in this example was 25.23 mg / kg initially, 27.89 mg / kg after 12 months of storage, 29.63 mg / kg after 18 months of storage, and 31.76 mg / kg after 24 months of storage.
[0084] Example 3
[0085] This embodiment is exactly the same as Embodiment 1, except for the following specially noted differences:
[0086] Step (1) The drying temperature is 70℃.
[0087] According to the test results, the content of fatty acid ethyl esters in the treated extra virgin olive oil obtained in this example was 25.31 mg / kg initially, 28.44 mg / kg after 12 months of storage, 29.92 mg / kg after 18 months of storage, and 31.98 mg / kg after 24 months of storage.
[0088] Example 4
[0089] This embodiment is exactly the same as Embodiment 1, except for the following specially noted differences:
[0090] Step (1) Drying time: 5 hours.
[0091] According to the test results, the content of fatty acid ethyl esters in the treated extra virgin olive oil obtained in this example was 25.22 mg / kg initially, 27.16 mg / kg after 12 months of storage, 29.51 mg / kg after 18 months of storage, and 31.59 mg / kg after 24 months of storage.
[0092] Example 5
[0093] This embodiment is exactly the same as Embodiment 1, except for the following specially noted differences:
[0094] Step (1) Drying time: 7 hours.
[0095] According to the test results, the content of fatty acid ethyl esters in the treated extra virgin olive oil obtained in this example was 25.23 mg / kg initially, 27.08 mg / kg after 12 months of storage, 29.48 mg / kg after 18 months of storage, and 31.81 mg / kg after 24 months of storage.
[0096] Example 6
[0097] This embodiment is exactly the same as Embodiment 1, except for the following specially noted differences:
[0098] Step (2) The amount of olive pomace powder added is 1 wt%.
[0099] According to the test results, the content of fatty acid ethyl esters in the processed extra virgin olive oil obtained in this embodiment was 25.25 mg / kg initially, 27.29 mg / kg after 12 months of storage, 29.62 mg / kg after 18 months of storage, and 32.06 mg / kg after 24 months of storage.
[0100] Example 7
[0101] This embodiment is exactly the same as Embodiment 1, except for the following specially noted differences:
[0102] Step (2) The amount of olive pomace powder added is 3 wt%.
[0103] According to the test results, the content of fatty acid ethyl esters in the treated extra virgin olive oil obtained in this example was 25.36 mg / kg initially, 27.11 mg / kg after 12 months of storage, 29.49 mg / kg after 18 months of storage, and 31.42 mg / kg after 24 months of storage.
[0104] Example 8
[0105] This embodiment is exactly the same as Embodiment 1, except for the following specially noted differences:
[0106] The stirring time for step (2) is 1 hour.
[0107] According to the test results, the content of fatty acid ethyl esters in the treated extra virgin olive oil obtained in this example was 25.38 mg / kg initially, 27.41 mg / kg after 12 months of storage, 30.01 mg / kg after 18 months of storage, and 32.25 mg / kg after 24 months of storage.
[0108] Example 9
[0109] This embodiment is exactly the same as Embodiment 1, except for the following specially noted differences:
[0110] The stirring time for step (2) is 3 hours.
[0111] According to the test results, the content of fatty acid ethyl esters in the treated extra virgin olive oil obtained in this example was 25.37 mg / kg initially, 27.34 mg / kg after 12 months of storage, 29.64 mg / kg after 18 months of storage, and 31.35 mg / kg after 24 months of storage.
[0112] Example 10
[0113] This embodiment is exactly the same as Embodiment 1, except for the following specially noted differences:
[0114] Step (3) takes 5 minutes to process.
[0115] According to the test results, the content of fatty acid ethyl esters in the treated extra virgin olive oil obtained in this example was 25.20 mg / kg initially, 27.41 mg / kg after 12 months of storage, 29.49 mg / kg after 18 months of storage, and 31.29 mg / kg after 24 months of storage.
[0116] Example 11
[0117] This embodiment is exactly the same as Embodiment 1, except for the following specially noted differences:
[0118] Step (3) takes 15 minutes to process.
[0119] According to the test results, the content of fatty acid ethyl esters in the processed extra virgin olive oil obtained in this example was 25.16 mg / kg initially, 27.38 mg / kg after 12 months of storage, 29.22 mg / kg after 18 months of storage, and 31.18 mg / kg after 24 months of storage.
[0120] Example 12
[0121] This embodiment is exactly the same as Embodiment 1, except for the following specially noted differences:
[0122] Step (3) The pressure is 200 MPa.
[0123] According to the test results, the content of fatty acid ethyl esters in the processed extra virgin olive oil obtained in this example was 25.30 mg / kg initially, 27.81 mg / kg after 12 months of storage, 29.86 mg / kg after 18 months of storage, and 32.13 mg / kg after 24 months of storage.
[0124] Example 13
[0125] This embodiment is exactly the same as Embodiment 1, except for the following specially noted differences:
[0126] Step (3) The pressure is 250 MPa.
[0127] According to the test results, the content of fatty acid ethyl esters in the processed extra virgin olive oil obtained in this example was 25.21 mg / kg initially, 27.43 mg / kg after 12 months of storage, 29.32 mg / kg after 18 months of storage, and 32.02 mg / kg after 24 months of storage.
[0128] The experimental results of Examples 1-13 show that the extra virgin olive oil obtained by the method described in this invention has a fatty acid ethyl ester content of less than 35 mg / kg after being stored at 30°C and sealed in a light-proof environment for 12 months, 18 months, and 24 months.
[0129] To further verify the effect of each step and condition in the method of the present invention on the fatty acid ethyl ester content of the treated extra virgin olive oil during storage, the following comparative examples are provided.
[0130] Comparative Example 1
[0131] Commercially available extra virgin olive oil from the Spanish brand MUELOLIVA was stored in a 35°C constant temperature chamber. The original content of ethyl fatty acids was measured, and the ethyl fatty acid content was monitored after 0, 2, 4, 6, 8, 10, 12, 18, and 24 months of storage.
[0132] Tests showed that the ethyl ester content of fatty acids in the extra virgin olive oil in this comparative example was 25.24 mg / kg after 0 months of storage, and exceeded 35 mg / kg after 10 months of storage.
[0133] Comparative Example 2
[0134] The commercially available extra virgin olive oil described in Comparative Example 1 was processed using the same method as described in Example 1, except that:
[0135] Only step (2) is performed; step (3) is not performed.
[0136] Tests showed that the ethyl ester content of fatty acids in the extra virgin olive oil obtained in Comparative Example 2 was 25.27 mg / kg after 0 months of storage under the same storage conditions as described in Comparative Example 1, and exceeded 35 mg / kg after 10 months of storage.
[0137] Comparative Example 3
[0138] The commercially available extra virgin olive oil described in Comparative Example 1 was processed using the same method as described in Example 1, except that:
[0139] Step (3) is to process under an ultra-high pressure of 100MPa.
[0140] Tests showed that the ethyl ester content of fatty acids in the extra virgin olive oil obtained in Comparative Example 3 was 25.33 mg / kg after 0 months of storage under the same storage conditions as described in Comparative Example 1, and exceeded 35 mg / kg after 10 months of storage.
[0141] Comparative Example 4
[0142] The commercially available extra virgin olive oil described in Comparative Example 1 was processed using the same method as described in Example 1, except that:
[0143] Step (3) is processed under an ultra-high pressure of 150 MPa.
[0144] Tests showed that the ethyl ester content of fatty acids in the extra virgin olive oil obtained in Comparative Example 4 was 25.17 mg / kg after 0 months of storage under the same storage conditions as described in Comparative Example 1, and exceeded 35 mg / kg after 10 months of storage.
[0145] Comparative Example 5
[0146] The commercially available extra virgin olive oil described in Comparative Example 1 was processed using the same method as described in Example 1, except that:
[0147] Step (3) is processed under an ultra-high pressure of 350 MPa.
[0148] Tests showed that the ethyl ester content of fatty acids in the extra virgin olive oil obtained in Comparative Example 4 was 25.21 mg / kg after 0 months of storage under the same storage conditions as described in Comparative Example 1, and exceeded 35 mg / kg after 10 months of storage.
[0149] Comparative Example 6
[0150] The commercially available extra virgin olive oil described in Comparative Example 1 was processed using the same method as described in Example 1, except that:
[0151] Step (3) is processed under an ultra-high pressure of 400 MPa.
[0152] Tests showed that the ethyl ester content of fatty acids in the extra virgin olive oil obtained in Comparative Example 4 was 25.28 mg / kg after 0 months of storage under the same storage conditions as described in Comparative Example 1, and exceeded 35 mg / kg after 10 months of storage.
[0153] Comparative Example 7
[0154] The commercially available extra virgin olive oil described in Comparative Example 1 was processed using the same method as described in Example 1, except that:
[0155] Steps (1) and (2) are skipped; only before step (3), the mixture is stirred for 2 hours under vacuum conditions of 30-40°C and 0.5-1.0 Pa.
[0156] Tests showed that the ethyl ester content of fatty acids in the extra virgin olive oil obtained in Comparative Example 5 was 25.32 mg / kg after 0 months of storage under the same storage conditions as described in Comparative Example 1, and exceeded 35 mg / kg after 10 months of storage.
[0157] Comparative Example 8
[0158] The commercially available extra virgin olive oil described in Comparative Example 1 was processed using the same method as described in Example 1, except that:
[0159] Step (3) takes 3 minutes to process.
[0160] Tests showed that the ethyl ester content of fatty acids in the extra virgin olive oil obtained in Comparative Example 6 was 25.21 mg / kg after 0 months of storage under the same storage conditions as described in Comparative Example 1, and exceeded 35 mg / kg after 10 months of storage.
[0161] Comparative Example 9
[0162] The commercially available extra virgin olive oil described in Comparative Example 1 was processed using the same method as described in Example 1, except that:
[0163] Only perform step (3) ultra-high pressure treatment, without performing steps (1) and (2).
[0164] Tests showed that the ethyl ester content of fatty acids in the extra virgin olive oil obtained in Comparative Example 7 was 25.20 mg / kg after 0 months of storage under the same storage conditions as described in Comparative Example 1, and exceeded 35 mg / kg after 10 months of storage.
[0165] Comparative Example 10
[0166] The commercially available extra virgin olive oil described in Comparative Example 1 was processed using the same method as described in Example 1, except that:
[0167] The reaction in step (2) is carried out at atmospheric pressure.
[0168] Tests showed that the ethyl ester content of fatty acids in the extra virgin olive oil obtained in Comparative Example 8 was 25.26 mg / kg after 0 months of storage under the same storage conditions as described in Comparative Example 1, and exceeded 35 mg / kg after 10 months of storage.
[0169] Comparative Example 11
[0170] The commercially available extra virgin olive oil described in Comparative Example 1 was processed using the same method as described in Example 1, except that:
[0171] The olive pomace from step (1) was not washed.
[0172] Tests showed that the ethyl ester content of fatty acids in the extra virgin olive oil obtained in Comparative Example 9 was 25.22 mg / kg after 0 months of storage under the same storage conditions as described in Comparative Example 1, and exceeded 35 mg / kg after 10 months of storage.
[0173] Comparative Example 12
[0174] The commercially available extra virgin olive oil described in Comparative Example 1 was processed using the same method as described in Example 1, except that in step (1), the olive pomace powder was air-dried naturally.
[0175] Tests showed that the ethyl ester content of fatty acids in the extra virgin olive oil in this comparative example was 25.23 mg / kg initially under the same storage conditions as described in Comparative Example 1, and exceeded 35 mg / kg after 10 months of storage.
[0176] Comparative Example 13
[0177] The commercially available extra virgin olive oil described in Comparative Example 1 was processed using the same method as described in Example 1, except that: in step (1), the olive pomace powder was dried at 85°C.
[0178] Tests showed that the ethyl ester content of fatty acids in the extra virgin olive oil in this comparative example was 25.19 mg / kg initially under the same storage conditions as described in Comparative Example 1, and exceeded 35 mg / kg after 10 months of storage.
[0179] The test results of Comparative Examples 1-13 show that the content of ethyl fatty acid esters in commercially available extra virgin olive oil that has not been treated by the method described in this application or that has been treated by a method different from that described in this application, after being stored at 30°C and sealed in a light-proof environment for 10 months, did not meet the standard of ≤35mg / kg in GB / T 23347-2021 "Olive Oil and Olive Pomace Oil".
[0180] In contrast, the test results of Examples 1-13 show that the extra virgin olive oil obtained by the method described in this invention has a fatty acid ethyl ester content of less than 35 mg / kg after 12 months, 18 months and 24 months of storage at 30°C under sealed and light-proof conditions, which meets the standard of GB / T 23347-2021 "Olive Oil and Olive Pomace Oil": ≤35 mg / kg.
[0181] Table 1 below shows the changes in the content of fatty acid ethyl esters in virgin olive oil treated with the methods described in Examples 1-13 and Comparative Examples 1-13 over storage time.
[0182] Table 1
[0183]
[0184]
[0185] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.
Claims
1. A method for processing extra virgin olive oil, the method comprising the following steps: (1) The olive pomace after oil extraction is washed with a food-acceptable organic solvent, wherein the ratio of pomace to organic solvent is 300g / L-500g / L. Then it is dried at 50-70℃ for 5-7 hours to remove the organic solvent. Then it is crushed and passed through a 40-mesh sieve to obtain olive pomace powder. (2) Add the olive pomace powder obtained in step (1) to the extra virgin olive oil in an amount of 0.5-5% by weight, and stir for 1-5 hours under vacuum conditions of 30-40°C and 0.5-1.0 Pa. After centrifugation, the upper clear oil is taken to obtain the extra virgin olive oil after preliminary treatment. (3) The virgin olive oil obtained in step (2) after preliminary treatment is further subjected to ultra-high pressure treatment at 30-40℃ and 200-300MPa for 5-15 minutes to obtain treated virgin olive oil.
2. The method according to claim 1, characterized in that: The food-grade acceptable organic solvent used in step (1) is selected from alkane solvents or alcohol solvents.
3. The method according to claim 1, characterized in that: The food-grade acceptable organic solvent is selected from n-hexane or ethanol.
4. The method according to claim 1, characterized in that: The drying conditions for step (1) are drying at 60°C for 6 hours.
5. The method according to claim 1, characterized in that: In step (2), the amount of olive pomace powder added is 2% by weight of the extra virgin olive oil.
6. The method according to claim 1, characterized in that: The stirring time in step (2) is 2-3 hours.
7. The method according to claim 1, characterized in that: Step (3) React for 10 min at 35℃ and 300MPa ultra-high pressure.
8. The method according to claim 1, wherein the virgin olive oil is extra virgin olive oil.
9. A processed extra virgin olive oil obtained by the method according to any one of claims 1-8, characterized in that, The content of fatty acid ethyl esters in the treated extra virgin olive oil, under sealed and light-proof conditions at 30°C, remains ≤35 mg / kg for at least 12 months, preferably 12-18 months, and most preferably 12-24 months.
10. The processed virgin olive oil according to claim 9, wherein the virgin olive oil is extra virgin olive oil.
11. A method for processing olive oil, the method comprising the following steps: (1) The olive pomace after oil extraction is washed with a food-acceptable organic solvent, then dried to remove the organic solvent, then crushed and sieved to obtain olive pomace powder. (2) Add the olive pomace powder obtained in step (1) to the olive oil and stir under vacuum. After centrifugation, take the upper clear oil to obtain the pre-treated olive oil. (3) The olive oil obtained in step (2) is further subjected to ultra-high pressure treatment to obtain treated olive oil.
12. The method according to claim 11, characterized in that: In step (1), the ratio of fruit pomace to organic solvent is 300g / L-500g / L; the drying temperature is 50-70℃; and the drying time is 5-7 hours.
13. The method according to claim 11, characterized in that: In step (2), the olive pomace powder obtained in step (1) is added to the olive oil in an amount of 0.5-5% by weight of the olive oil.
14. The method according to claim 11, characterized in that: The vacuum conditions described in step (2) are a temperature of 30-40°C and a pressure of 0.5-1.0 Pa.
15. The method according to claim 11, characterized in that: The ultra-high pressure treatment described in step (3) is carried out under conditions of 30-40℃ and 200-300MPa.
16. The method according to any one of claims 11-15, characterized in that: The olive oil is virgin olive oil, preferably extra virgin olive oil.