Method for separating lauric acid from coconut oil and application
By combining a single microdistillation, room temperature crystallization, and a second microdistillation, the problems of low separation efficiency and low purity of lauric acid in coconut oil have been solved, achieving the preparation of high-purity, high-yield, and low-energy-consumption lauric acid, which is suitable for food additives and nutritional health fields.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- INNER MONGOLIA MENGNIU DAIRY IND (GROUP) CO LTD
- Filing Date
- 2026-01-30
- Publication Date
- 2026-05-08
AI Technical Summary
Existing technologies for separating lauric acid from coconut oil suffer from problems such as low separation efficiency, low purity, long processing time, and off-odors caused by high-temperature treatment.
Specific operating procedures and parameters are employed, including primary microdistillation, room temperature crystallization, and secondary microdistillation, combined with specific vacuum levels, heating rates, and reflux conditions. Separation is achieved through miniaturized equipment, avoiding high-temperature processing and the use of chemical reagents.
It achieves high-purity and high-yield separation of lauric acid, reduces temperature control energy consumption, avoids odor generation, and is suitable for industrial production.
Smart Images
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Abstract
Description
Technical Field
[0001] This invention relates to the field of material extraction technology, and more specifically, to a method and application for separating lauric acid from coconut oil. Background Technology
[0002] Coconut oil is made from coconut meat through processes such as pressing or extraction. It retains its natural coconut aroma, has a saturated fatty acid content of approximately 90%, and possesses a unique taste. It is widely used in food processing, including ice cream, baking, plant-based products, and beverages. Furthermore, coconut oil contains about 50% lauric acid, as well as linoleic acid, phenols, and fat-soluble byproducts, playing an important role in nutritional health.
[0003] Lauric acid, the main saturated fatty acid in coconut oil, accounts for approximately 50% of the total fatty acid content. As a food additive, lauric acid can act as an emulsifier and stabilizer, and some studies have also reported its antibacterial and preservative effects. In short, this natural component has significant application value.
[0004] Currently, lauric acid is mainly obtained by enzymatically hydrolyzing coconut oil or other vegetable oils to obtain mixed fatty acids, and then using molecular distillation technology to distill out the lauric acid from the mixed fatty acids to achieve the separation effect.
[0005] Enzymatic hydrolysis is a bioprocessing technique that breaks down complex macromolecules into smaller molecules under mild conditions. Molecular distillation, being a short-path distillation method, produces products with low purity after a single distillation, requiring the design of multi-step molecular distillation to improve the purity of lauric acid. The entire separation process is time-consuming, and prolonged exposure to high temperatures can introduce unpleasant odors into the experimental environment and cause high-temperature degradation of other long-chain fatty acids, affecting resource reuse. Therefore, further research on the separation and extraction technology of lauric acid is necessary. Summary of the Invention
[0006] One of the objectives of this invention is to provide a method for efficiently separating and obtaining high-purity lauric acid products with lower temperature control energy consumption.
[0007] This invention provides a method for separating lauric acid from coconut oil. After hydrolyzing the coconut oil and separating the free fatty acids, the following steps are performed sequentially: (1) Single micro-distillation: The free fatty acids in the coconut oil are subjected to a single micro-distillation. The conditions for the first micro-distillation are as follows: under a vacuum of 14-17 mbar and a heating rate of 5-10℃ / 10min, the temperature at the top of the distillation column reaches 143-156℃. Then, at 143-156℃, intermittent reflux-collection is performed at a rate of 0.75ml-1.25ml after each 0.5ml reflux for 20-60min. (2) Crystallization and centrifugation: After step (1) is completed, the residue in the distillation column is cooled and crystallized, then centrifuged to collect the liquid components. The cooling crystallization method is as follows: the temperature of the residue is reduced to 24-26℃ under the conditions of stirring speed of 250-350r / min and cooling rate of 1-5℃ / 30min, and then the crystallization is carried out by heat preservation. (3) Secondary micro-distillation: The liquid component obtained in step (2) is subjected to secondary micro-distillation; The conditions for the secondary micro-distillation are as follows: under a vacuum of 2-5 mbar and a heating rate of 1-5℃ / 10min, the temperature at the top of the distillation column is brought to 148-183℃. Then, at 148-183℃, intermittent reflux-collection is performed at a rate of 0.75ml-1.25ml after each 0.5ml reflux for 20-60min.
[0008] This invention provides a method for separating lauric acid from coconut oil. The method involves sequentially performing specific microdistillation, crystallization, centrifugation, and secondary microdistillation operations on hydrolyzed coconut oil (hydrolysis converts triglycerides in coconut oil into free fatty acids). First, the primary microdistillation effectively removes fatty acid components with a carbon chain length of less than 12. Then, room temperature crystallization and centrifugation preliminarily remove high-melting-point long-chain fatty acid components (carbon number 14-24) (achieving coarse separation of impurities based on melting point differences). Finally, secondary microdistillation yields high-purity and high-yield lauric acid.
[0009] Specifically, the method of the present invention, through the overall coordination of specific process conditions in each step, enables the efficient and complete separation of fatty acids with different carbon chain lengths without the use of any chemical reagents. It features short continuous high-temperature processing time, fewer purification steps, no odor generated during production, and both the target product and by-products are safe and environmentally friendly.
[0010] This invention specifically reveals that in the production process of this invention, if the heating rate is too fast during microdistillation, the components cannot be effectively separated, affecting the yield of lauric acid. If the time for collecting the distilled components during intermittent reflux-collection of microdistillation is too long (i.e., too many distilled components are collected each time), it will simultaneously affect the yield and purity of lauric acid. When the reflux conditions of this invention are adopted, both product quality and production efficiency can be balanced. If the vacuum degree and column top temperature are not properly matched during microdistillation, it will also simultaneously affect the yield and purity of lauric acid. If the cooling rate in the crystallization stage is too fast, or the temperature in the heat preservation crystallization stage is too low, it will also simultaneously affect the yield and purity of lauric acid. Furthermore, an improper stirring rate during crystallization will also affect the crystallization rate. Only when the operating conditions of each step of this invention are coordinated as a whole can the final preparation of lauric acid with high purity and high yield be guaranteed.
[0011] Furthermore, the method of this invention, through specific settings of the processing sequence of each specific operation, enables the crystallization step to be achieved at room temperature, eliminating the need to further cool the feed liquid below room temperature to achieve the generation and separation of crystalline impurities (high-melting-point long-chain fatty acid components). This reduces the energy consumption for temperature control during preparation and helps ensure yield. Moreover, setting a room-temperature crystallization step between the two-step microdistillation operations avoids the thermal decomposition of the distillation residue due to continuous high temperatures and prevents the generation of off-odors during production.
[0012] In this invention, microdistillation refers to a continuous or intermittent distillation separation process using miniaturized equipment (with a throughput as low as 1 mL and a working flow rate as low as 0.1 mL / min).
[0013] Preferably, in step (1) of the method for separating lauric acid from coconut oil of the present invention, the conditions for the first micro-distillation are as follows: under a vacuum of 14-15 mbar and a heating rate of 5-9℃ / 10min, the temperature at the top of the distillation column is brought to 154-155℃, and then intermittent reflux-collection is performed at 154-155℃ in a manner that 0.9ml-1ml of distillate is collected after each reflux of 0.5ml for 30-50min. In step (2), the cooling crystallization method is as follows: the temperature of the residue is reduced to 25-26℃ under the conditions of stirring speed of 300r / min and cooling rate of 1-2℃ / 30min, and then the crystallization is carried out by heat preservation. In step (3), the conditions for the secondary micro-distillation are as follows: under a vacuum of 4 mbar and a heating rate of 2-3℃ / 10min, the temperature at the top of the distillation column is brought to 180-181℃. Then, at 180-181℃, the distillation component is collected in 1ml after each 0.5ml reflux for 30-50min.
[0014] More preferably, in step (1) of the method for separating lauric acid from coconut oil of the present invention, the conditions for the first micro-distillation are as follows: under the conditions of a vacuum degree of 15 mbar and a heating rate of 5 °C / 10 min, the temperature at the top of the distillation column is brought to 155 °C, and then intermittent reflux-collection is performed at 155 °C in a manner of collecting 1 ml of distillate after each reflux of 0.5 ml; In step (2), the cooling crystallization method is as follows: the temperature of the residue is reduced to 25°C under the conditions of stirring speed of 300 r / min and cooling rate of 2°C / 30 min, and then the crystallization is carried out by heat preservation. In step (3), the conditions for the secondary micro-distillation are as follows: under the conditions of a vacuum of 4 mbar and a heating rate of 2℃ / 10min, the temperature at the top of the distillation column is made to reach 180℃, and then at 180℃, the distillation component is collected in 1ml after each 0.5ml reflux for 30min.
[0015] In step (2) of the method for separating lauric acid from coconut oil of the present invention, the time for heat preservation and crystallization is 1-2 hours; And / or, in step (2), the centrifugation conditions are: 24-26℃, 10000-15000r / min, 20-50min.
[0016] In the method for separating lauric acid from coconut oil of the present invention, the hydrolysis rate of the coconut oil is 90-95%.
[0017] In this invention, coconut oil hydrolysis can be carried out using methods known in the art. In one specific embodiment, the method for separating lauric acid from coconut oil uses lipase enzymatic hydrolysis to obtain free fatty acids from coconut oil. The specific method includes: 1) Hydrolysis: After mixing coconut oil, water and lipase evenly, dynamically hydrolyze for 8-12 hours at 55-65℃ and 160-200r / min. Preferably, hydrolysis is performed using coconut oil, water, and an aqueous lipase solution, wherein the mass ratio of coconut oil, water, and the aqueous lipase solution is (1-1.5):1:(0.003-0.009), and the mass concentration of lipase in the aqueous lipase solution is 2-5%. 2) Inactivate enzymes; 3) Centrifuge and collect the upper layer to obtain free fatty acids from coconut oil.
[0018] In step 2) of the enzymatic hydrolysis method for separating lauric acid from coconut oil in this invention, the enzyme inactivation method is boiling in water for 10-20 minutes. And / or, in step 3), the centrifugation conditions are: 5000-10000 r / min, 10-20 min.
[0019] In step 3), the centrifugation temperature is room temperature. In this invention, room temperature generally refers to 24-26℃.
[0020] In the method for separating lauric acid from coconut oil of the present invention, the coconut oil is refined coconut oil that has undergone degumming, deacidification, decolorization and deodorization processes.
[0021] The refined coconut oil in this invention is preferably an edible oil made from crude coconut oil through processes such as degumming, deacidification, decolorization, and deodorization, and it meets the specifications for refined coconut oil in the agricultural standard "NY / T230 2006 Coconut Oil".
[0022] In the method for separating lauric acid from coconut oil of the present invention, the theoretical plate number in the distillation column is 80-90, which is more conducive to obtaining the ideal product by matching the microdistillation operating parameters of the present invention.
[0023] The present invention also provides the application of the above-described method for separating lauric acid from coconut oil in reducing the energy consumption of temperature control during the separation and extraction of lauric acid.
[0024] The beneficial effects of this invention are at least as follows: This invention achieves efficient and complete separation of fatty acids with different carbon chain lengths in coconut oil by combining room-temperature crystallization and two-stage microdistillation, and through effective coordination of the sequence of steps and specific operating parameters, without the use of any chemical reagents. This results in high-purity and high-yield lauric acid. Furthermore, this method features short continuous high-temperature processing time, low energy consumption for temperature control, fewer purification steps, and no off-odors generated during production, making it suitable for industrial production. Attached Figure Description
[0025] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0026] Figure 1 A schematic diagram of the process flow for separating lauric acid. Detailed Implementation
[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.
[0028] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the materials and reagents used in the following examples are commercially available or prepared according to conventional methods in the art.
[0029] The microdistillation equipment used in the specific embodiments of this invention is a concentric tube precision fractionation column equipped with 90 theoretical plates, manufactured by PILODIST, Germany, model HRS500C.
[0030] This invention provides a method for separating lauric acid from coconut oil, as detailed below: 1. Lipase hydrolysis: Using refined coconut oil as raw material, mix refined coconut oil and purified water at a mass ratio of 1-1.5:1. After mixing evenly, add lipase solution (lipase concentration of 2-5% and enzyme activity greater than 5000 U / g) at a mass of 0.3-0.6% of the refined coconut oil mass and mix evenly. Then place in a constant temperature shaking incubator at 160-200 r / min and 55-65℃ for dynamic hydrolysis for 8-12 hours. After hydrolysis, boil in water to inactivate the enzyme for 10-20 minutes, and centrifuge at room temperature at 5000-10000 r / min for 10-20 minutes. Collect the supernatant to obtain a coconut oil hydrolysate mixture (coconut oil free fatty acids) with a hydrolysis rate of 90.0-95.0%.
[0031] 2. The coconut oil hydrolysate mixture was processed using a combination of single-stage microdistillation, room temperature crystallization, room temperature centrifugation, and double-stage microdistillation to separate the lauric acid contained therein. The specific process parameters are as follows: (1) Single micro-distillation: The vacuum degree is 14-17 mbar, the sample heating rate is 5-10℃ / 10min, and the top temperature of the distillation column reaches 143-156℃. Then, reflux at this temperature for 20-60min, and set the reflux ratio to 10s / 15s-10s / 25s (flow rate is 0.05ml / s) to collect the distillation components until no fraction flows out. This step can completely remove fatty acid components with carbon chain length less than 12 by distillation.
[0032] (2) Room temperature crystallization: The residue in the column of the first micro-distillation is cooled to 24-26℃ under the conditions of stirring speed of 250-350r / min and cooling rate of 1-5℃ / 30min, and kept at the temperature for 1-2h. This step can allow the high melting point long chain fatty acid components to crystallize naturally to obtain a solid-liquid mixture.
[0033] (3) Room temperature centrifugation: The solid-liquid mixture obtained by room temperature crystallization is centrifuged for 20-50 minutes at a crystallization temperature of 24-26℃ and a rotation speed of 10000-15000r / min to obtain two components, precipitate and liquid, thus achieving coarse separation.
[0034] (4) Secondary microdistillation: The liquid obtained by centrifugation is separated by secondary microdistillation. The vacuum degree is 2-5 mbar and the sample heating rate is 1-5℃ / 10min. After the temperature at the top of the distillation column reaches 148-183℃, it is refluxed at this temperature for 20-60min. The reflux ratio is set to 10s / 15s-10s / 25s (flow rate is 0.05ml / s). The distillation component (top effluent) is collected to obtain C12 (lauric acid) component with a purity of 95.0-99.0% and a yield of 65.0-80.0%. No off-odor is generated during the separation process.
[0035] A schematic diagram of the process for separating lauric acid using refined coconut oil is shown below. Figure 1 .
[0036] Examples 1-8 In Examples 1-8 of this invention, lauric acid was separated using the above method. The experimental conditions and results of each example are shown in Table 1.
[0037] Table 1
[0038] Comparative Examples 1-5 The comparative examples 1-5 of this invention use the above method to separate lauric acid. The experimental conditions for the lipase hydrolysis stage in each comparative example are the same as those in Example 8. The experimental conditions and results for other steps are shown in Table 2.
[0039] Table 2
[0040] Comparative Example 6 This comparative example provides a method for separating lauric acid from coconut oil, as follows: Lipase hydrolysis: Refined coconut oil was used as raw material and mixed with purified water at a mass ratio of 1.25:1. After mixing evenly, lipase solution was added at 0.5% of the refined coconut oil and mixed evenly. Then, it was placed in a constant temperature shaking incubator at 180 r / min and 60℃ for dynamic hydrolysis for 10 h. After hydrolysis, the enzyme was inactivated by boiling in water for 10 min and centrifuged at room temperature at 8000 r / min for 10 min to obtain a coconut oil hydrolysate mixture with a hydrolysis rate of 95%.
[0041] The coconut oil hydrolysate mixture was processed using a combination of crystallization-centrifugation-single micro-distillation-double micro-distillation to separate the lauric acid contained therein. The specific process parameters are as follows: Crystallization: The coconut oil hydrolysis mixture was cooled to 24°C at a rate of 2°C / 30min under 300r / min conditions and kept at that temperature for 1h.
[0042] The experimental results showed that the hydrolysis mixture did not crystallize at 24°C and remained a clear liquid, making solid-liquid separation impossible and coarse separation unattainable. Further experiments revealed that the hydrolysis mixture required crystallization at 20°C, which increased the energy consumption for temperature control. Furthermore, after performing the subsequent crystallization steps as described in Example 8 of this invention, the final lauric acid obtained had a purity of 96.3% and a yield of 47.5%.
[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A method for separating lauric acid from coconut oil, characterized in that, After hydrolyzing coconut oil and separating the free fatty acids, the following steps are performed sequentially: (1) Single micro-distillation: The free fatty acids in the coconut oil are subjected to a single micro-distillation. The conditions for the first micro-distillation are as follows: under a vacuum of 14-17 mbar and a heating rate of 5-10℃ / 10min, the temperature at the top of the distillation column reaches 143-156℃. Then, at 143-156℃, intermittent reflux-collection is performed at a rate of 0.75ml-1.25ml after each 0.5ml reflux for 20-60min. (2) Crystallization and centrifugation: After step (1) is completed, the residue in the distillation column is cooled and crystallized, then centrifuged to collect the liquid components. The cooling crystallization method is as follows: under the conditions of stirring speed of 250-350 r / min and cooling rate of 1-5℃ / 30min, the temperature of the residue is reduced to 24-26℃, and then the crystallization is carried out by heat preservation. (3) Secondary micro-distillation: The liquid component obtained in step (2) is subjected to secondary micro-distillation; The conditions for the secondary micro-distillation are as follows: under a vacuum of 2-5 mbar and a heating rate of 1-5℃ / 10min, the temperature at the top of the distillation column is brought to 148-183℃. Then, at 148-183℃, intermittent reflux-collection is performed at a rate of 0.75ml-1.25ml after each 0.5ml reflux for 20-60min.
2. The method for separating lauric acid from coconut oil according to claim 1, characterized in that, In step (1), the conditions for the first micro-distillation are as follows: under a vacuum of 14-15 mbar and a heating rate of 5-9℃ / 10min, the temperature at the top of the distillation column is brought to 154-155℃, and then intermittent reflux-collection is performed at 154-155℃ in a manner that 0.9ml-1ml of distillate is collected after each reflux of 0.5ml for 30-50min. In step (2), the cooling crystallization method is as follows: the temperature of the residue is reduced to 25-26℃ under the conditions of stirring speed of 300r / min and cooling rate of 1-2℃ / 30min, and then the crystallization is carried out by heat preservation. In step (3), the conditions for the secondary micro-distillation are as follows: under a vacuum of 4 mbar and a heating rate of 2-3℃ / 10min, the temperature at the top of the distillation column is brought to 180-181℃. Then, at 180-181℃, the distillation component is collected in 1ml after each 0.5ml reflux for 30-50min.
3. The method for separating lauric acid from coconut oil according to claim 2, characterized in that, In step (1), the conditions for the first micro-distillation are: under a vacuum of 15 mbar and a heating rate of 5℃ / 10min, the temperature at the top of the distillation column is brought to 155℃, and then intermittent reflux-collection is carried out at 155℃ in the manner of collecting 1 ml of distilled component after each reflux of 0.5 ml; In step (2), the cooling crystallization method is as follows: the temperature of the residue is reduced to 25°C under the conditions of stirring speed of 300 r / min and cooling rate of 2°C / 30 min, and then the crystallization is carried out by heat preservation. In step (3), the conditions for the secondary micro-distillation are as follows: under the conditions of a vacuum of 4 mbar and a heating rate of 2℃ / 10min, the temperature at the top of the distillation column is made to reach 180℃, and then at 180℃, the distillation component is collected in 1ml after each 0.5ml reflux for 30min.
4. The method for separating lauric acid from coconut oil according to any one of claims 1-3, characterized in that, In step (2), the time for heat preservation and crystallization is 1-2 hours; And / or, in step (2), the centrifugation conditions are: 24-26℃, 10000-15000r / min, 20-50min.
5. The method for separating lauric acid from coconut oil according to any one of claims 1-4, characterized in that, The hydrolysis rate of the coconut oil is 90.0-95.0%.
6. The method for separating lauric acid from coconut oil according to claim 5, characterized in that, Coconut oil is hydrolyzed using lipase to obtain free fatty acids. Specific methods include: 1) Hydrolysis: After mixing coconut oil, water and lipase evenly, dynamically hydrolyze for 8-12 hours at 55-65℃ and 160-200r / min. Preferably, hydrolysis is performed using coconut oil, water, and an aqueous lipase solution, wherein the mass ratio of coconut oil, water, and the aqueous lipase solution is (1-1.5):1:(0.003-0.009), and the mass concentration of lipase in the aqueous lipase solution is 2-5%. 2) Inactivate enzymes; 3) Centrifuge and collect the upper layer to obtain free fatty acids from coconut oil.
7. The method for separating lauric acid from coconut oil according to claim 6, characterized in that, In step 2), the enzyme is inactivated by boiling in a water bath for 10-20 minutes; And / or, in step 3), the centrifugation conditions are: 5000-10000 r / min, 10-20 min.
8. The method for separating lauric acid from coconut oil according to any one of claims 1-7, characterized in that, The coconut oil is refined coconut oil that has undergone degumming, deacidification, decolorization, and deodorization processes.
9. The method for separating lauric acid from coconut oil according to any one of claims 1-8, characterized in that, The theoretical plate number in the distillation column is 80-90.
10. The application of the method for separating lauric acid from coconut oil according to any one of claims 1-9 in reducing the energy consumption for temperature control during the separation and extraction of lauric acid.