A method for extracting functional fatty acids

Abstract

The application discloses an extraction method of functional fatty acid, which comprises the following steps: dissolving lanolin in an alcohol aqueous solution, adding an excess of strong alkali, and heating to perform saponification to obtain a saponification solution; adjusting the pH of the saponification solution to neutral or weak alkaline by using a strong acid aqueous solution; adding a calcium chloride alcohol aqueous solution to the saponification solution to obtain a calcium fatty acid precipitate, and washing the precipitate with an alcohol aqueous solution; taking the calcium fatty acid precipitate, adding water, and adjusting the pH to strong acidity, and performing acidification under the condition of ultrasonic heating; adding an extraction solvent to perform extraction and separation, removing the water phase, reserving the organic phase, removing the extraction solvent by rotary evaporation, and obtaining the functional fatty acid. The application uses an ultrasonic acidification method to improve the technology of extracting functional fatty acid in lanolin by calcium precipitation, significantly solves the problem of calcium fatty acid acidification difficulty in lanolin, greatly improves the yield and purity of the functional fatty acid, and shortens the production time of the functional fatty acid.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of oil processing, and particularly relates to a functional fatty acid extraction method. BACKGROUND

[0002] The branched-chain fatty acid is a kind of saturated fatty acid with a methyl branched structure, and exists in human sebum, dairy products, meat products and microorganisms. The monomethyl branched-chain fatty acid has multiple important physiological functions and is an important functional fatty acid. A large number of studies have shown that the branched-chain fatty acid can reduce the incidence of infant necrotizing enterocolitis, has a significant anti-inflammatory effect, and is an important component of infant formula milk powder. In addition, the branched-chain fatty acid can induce programmed apoptosis of cancer cells and has a significant anti-cancer effect in in vivo and in vitro experiments. Studies have also found that the branched-chain fatty acid level in human blood is negatively correlated with obesity, indicating that the branched-chain fatty acid may have a certain lipid-lowering effect. In summary, the development and preparation of branched-chain fatty acid are of great significance to human health.

[0003] The branched-chain fatty acid is generally low in content in nature, and the content of the branched-chain fatty acid in lanolin fatty acid, a byproduct of the livestock industry, is more than 45%, which is a rich natural source of branched-chain fatty acid. Therefore, research on the extraction and enrichment of the branched-chain fatty acid in lanolin has gradually been carried out in recent years.

[0004] The currently reported fatty acid extraction methods include solvent extraction, molecular distillation and calcium precipitation. The solvent extraction method is simple in process and high in production efficiency, but consumes a large amount of organic solvent, is complex in recovery, and pollutes the environment. The molecular distillation method can remove part of the alcohol, but is high in cost and complicated in operation, and is not conducive to large-scale promotion. The calcium precipitation method is low in cost and less polluting, and is an ideal method for large-scale industrial production. However, due to the emulsification phenomenon, the fatty acid calcium is difficult to be acidified and dissolved, and the acidification time is long, which seriously hinders its application in lanolin separation. Therefore, the acidification problem of the calcium salt still needs to be further solved. SUMMARY

[0005] This section aims to summarize some aspects of the embodiments of the application and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of the specification to avoid obscuring the purpose of this section, the abstract and the title, and such simplifications or omissions cannot be used to limit the scope of the application.

[0006] In view of the above and / or problems existing in the prior art, the present application is proposed.

[0007] One of the purposes of the present application is to provide a preparation method of functional fatty acid.

[0008] To solve the above technical problems, the present application provides the following technical scheme: comprising,

[0009] The lanolin is dissolved in the alcohol aqueous solution to obtain a lanolin alcohol aqueous solution, a strong base is added to perform saponification under heating to obtain a saponification solution, and a strong acid aqueous solution is used to adjust the pH of the saponification solution to neutral or weak alkaline;

[0010] The calcium chloride is dissolved in the alcohol aqueous solution to obtain a calcium chloride alcohol aqueous solution, which is added to the saponification solution to obtain a reaction solution I, the reaction solution I is heated and left to stand to precipitate, and the precipitate is filtered to obtain a calcium fatty acid precipitate;

[0011] The calcium fatty acid precipitate is washed with the alcohol aqueous solution, and after drying, solvent water is added, a strong acid solution is used to adjust the system to strong acidity, and an acidification reaction is performed under ultrasonic heating to obtain a reaction solution II;

[0012] The reaction solution II is extracted by adding an extraction solvent, washed with water to neutral, and the upper organic phase is reserved, and the solvent is removed by rotary evaporation to obtain the functional fatty acid.

[0013] As a preferred scheme of the method for extracting the functional fatty acid, the strong base comprises one of sodium hydroxide or potassium hydroxide, and the addition amount is 10% to 20% of the mass of the lanolin.

[0014] As a preferred scheme of the method for extracting the functional fatty acid, the saponification is performed by adding the strong base under heating, wherein the heating temperature is 45 to 75°C, and the saponification time is 1 to 8 hours.

[0015] As a preferred scheme of the method for extracting the functional fatty acid, the content of the calcium chloride in the reaction solution I is 3% to 50% of the mass of the saponification solution, the reaction solution I is left to stand to precipitate for 1 to 4 hours at a temperature of 30 to 80°C.

[0016] As a preferred scheme of the method for extracting the functional fatty acid, the mass ratio of the lanolin to the alcohol aqueous solution in the lanolin alcohol aqueous solution is 1:1 to 5, and the mass ratio of the calcium chloride to the alcohol aqueous solution in the calcium chloride alcohol aqueous solution is 1:1 to 10.

[0017] As a preferred scheme of the method for extracting the functional fatty acid, the alcohol aqueous solution comprises one of a methanol aqueous solution, an ethanol aqueous solution or a propanol aqueous solution, and the mass fraction is 60% to 100%.

[0018] As a preferred scheme of the method for extracting the functional fatty acid, the calcium fatty acid precipitate is washed with the alcohol aqueous solution for 1 to 5 times.

[0019] As a preferred scheme of the method for extracting the functional fatty acid, in the reaction solution II, the solvent water is 5 to 20 times of the mass of the calcium fatty acid.

[0020] As a preferred scheme of the method for extracting the functional fatty acid, the ultrasonic frequency for the ultrasonic heating for the acidification reaction is 300-600 W, the heating temperature is 30-70 DEG C, and the reaction time is 1-9 h.

[0021] As a preferred scheme of the method for extracting the functional fatty acid, the extraction solvent comprises one of benzene, toluene, n-hexane, n-heptane, n-octane, petroleum ether or tert-butyl alcohol.

[0022] Compared with the prior art, the method has the following beneficial effects:

[0023] The method for preparing the branched fatty acid enriched in lanolin by using the ultrasonic acidification method can significantly solve the problem of acidification difficulty of the calcium salt of the branched fatty acid prepared by using the calcium precipitation method, greatly improves the yield and purity of the branched fatty acid, greatly shortens the acidification time, and improves the acidification efficiency. DETAILED DESCRIPTION

[0024] In order to make the above objectives, characteristics and advantages of the present application more apparent and comprehensible, the specific embodiments of the present application will be described in detail below with reference to the description and examples.

[0025] In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present application, but the present application can also be implemented in other manners different from those described herein, and those skilled in the art can make similar generalizations without departing from the connotation of the present application, so the present application is not limited to the specific embodiments disclosed below.

[0026] Secondly, the "one embodiment" or "embodiment" referred to herein means that the specific features, structures or characteristics can be included in at least one implementation of the present application. The "in one embodiment" appearing in different places in the specification does not mean the same embodiment, nor is the embodiment independent or alternative to other embodiments.

[0027] Unless otherwise specified, the raw materials used in the embodiments are commercially purchased.

[0028] The method for detecting the relative content of the fatty acid is as follows:

[0029] The triple quadrupole gas chromatography-mass spectrometer is used to test the content of the branched fatty acid in the obtained product, and the test conditions are as follows:

[0030] The chromatographic column is DB-5 (30 m x 0.25 mm x 0.25 µm);

[0031] Temperature program: initial 60℃, hold for 2 min, increase to 180℃ at 6℃ / min, hold for 1 min, increase to 220℃ at 2℃ / min, hold for 5 min, increase to 280℃ at 2℃ / min, finally hold at 280℃ for 10 min;

[0032] Injection port temperature: 280℃; split ratio: 1:100; carrier gas: He; flow rate: 0.8 mL / min.

[0033] Mass spectrometry conditions: transfer line temperature 240℃, ion source temperature 230℃, electron energy 70eV, molecular ion fragment scan range m / z 50-500, solvent delay 5 min.

[0034] Spectral analysis was performed by searching the NIST spectral library through a chemical workstation data processing system to confirm the chemical structure of each fatty acid, and the relative content of the fatty acid was detected by area normalization method

[0035] Example 1

[0036] The present example provides a functional fatty acid extraction method, in particular:

[0037] 1) Lanolin was dissolved in 80% ethanol aqueous solution, 15% sodium hydroxide was added, and the mixture was heated and stirred at 65℃ for 4h to saponify, obtaining a saponification solution, and the pH of the saponification solution was adjusted to neutral or weak alkaline by using 15% hydrochloric acid aqueous solution;

[0038] 2) 20% calcium chloride was taken from the saponification solution, dissolved in 80% ethanol aqueous solution to prepare calcium chloride alcohol aqueous solution, and the mass ratio of calcium chloride to alcohol aqueous solution was 1:5, then added to the saponification solution to obtain reaction solution I, and the reaction solution I was heated at 70℃ and statically precipitated for 2h, then filtered to obtain calcium fatty acid precipitate;

[0039] 3) The calcium fatty acid precipitate was washed with 80% ethanol aqueous solution for 4 times, then dried and weighed, 5 times mass of water was added to the calcium fatty acid precipitate, and the pH was adjusted to strong acid by using 15% hydrochloric acid, then the mixture was subjected to acidification reaction at 65℃ and 600W ultrasonic for 3h to obtain reaction solution II

[0040] 4) One volume of n-heptane was added to the reaction solution II, washed with water until neutral, and the upper organic phase was reserved, then the solvent was removed by rotary evaporation to obtain the functional fatty acid.

[0041] The content of branched-chain fatty acid in the product of the present example was 50.8%.

[0042] Example 2

[0043] The difference between this embodiment and embodiment 1 is that the number of times of washing the calcium fatty acid precipitate with 80% ethanol aqueous solution in step 3) is adjusted to 1-5 times, the influence of different washing times on the content of branched chain fatty acids in the product is compared, and the content of branched chain fatty acids in the obtained product is tested, and the test results are shown in Table 1.

[0044] Table 1

[0045] Precipitation washing number (%) 1 2 3 4 5 Branched fatty acid content (%) 34.8 41.7 48.3 50.8 49.8

[0046] It can be seen that with the increase of the number of times of washing the calcium fatty acid precipitate, the content of branched chain fatty acids obtained first increases and then decreases, and when the washing times is 4 times, the content of branched chain fatty acids is the highest, because within a certain number of washing times, impurities and residues in the precipitate can be effectively removed, and multiple washing can improve the extraction effect of fatty acids, while too many washing times can wash away the target product in the subsequent washing process, thereby reducing the yield.

[0047] Example 3

[0048] The difference between this embodiment and embodiment 1 is that in step 3), after drying and weighing, 5-20 times mass of water is added to the calcium fatty acid precipitate, the influence of different water addition amounts on the content of branched chain fatty acids in the product is compared, and the content of branched chain fatty acids in the obtained product is tested, and the test results are shown in Table 2.

[0049] Table 2

[0050] Calcium fatty acid precipitate water addition amount (times) 5 10 15 20 Branched fatty acid content (%) 50.8 48.1 47.2 46.9

[0051] It can be seen that with the increase of the amount of water, the content of branched chain fatty acids obtained decreases continuously, and when the amount of water is 5 times, the content of branched chain fatty acids is the highest, and when the amount of water is <5 times, the calcium fatty acid precipitate is not obviously layered and is not easy to separate, therefore, the amount of water is preferably 5 times.

[0052] Example 4

[0053] The difference between this embodiment and embodiment 1 is that the ultrasonic time in step 3) is adjusted to 1-9 h, the content of branched chain fatty acids in the obtained product is tested, the influence of different ultrasonic times on the content of branched chain fatty acids in the product is compared, and the test results are shown in Table 3.

[0054] Table 3

[0055] Ultrasonic time (h) 1 2 3 6 9 Branched fatty acid content (%) 47.2 50.0 50.8 50.9 51.1

[0056] It can be seen that with the increase of the ultrasonic time, the content of branched chain fatty acids obtained increases continuously, and when the ultrasonic time is more than 3 h, the trend of the increase of the content of branched chain fatty acids slows down, therefore, the ultrasonic time is preferably 3 h.

[0057] Example 5

[0058] The difference between this example and Example 1 is that the ultrasonic temperature in step 3) is adjusted to 45-75°C, and the branched fatty acid content of the obtained product is tested to compare the influence of different ultrasonic temperatures on the branched fatty acid content of the product, and the test results are shown in Table 4.

[0059] Table 4

[0060] Ultrasonic temperature (°C) 45 55 65 75 Branched fatty acid content (%) 46.6 49.7 50.8 50.9

[0061] It can be seen that as the ultrasonic temperature increases, the branched fatty acid content of the obtained product gradually increases, and when the ultrasonic temperature increases from 65°C to 75°C, the trend of increase in branched fatty acid content slows down, and therefore the ultrasonic temperature is preferably 65°C.

[0062] Example 6

[0063] The difference between this example and Example 1 is that the ultrasonic frequency in step (5) is adjusted to 0-900W, and the branched fatty acid content of the obtained product is tested to compare the influence of different ultrasonic frequencies on the branched fatty acid content of the product, and the test results are shown in Table 5.

[0064] Table 5

[0065] Ultrasonic frequency (W) 0 300 600 900 Branched fatty acid content (%) 13.8 35.2 50.9 47.4

[0066] It can be seen that as the ultrasonic frequency increases, the branched fatty acid content of the obtained product first increases and then decreases, and when the frequency is low, the effect is not good, which is because ultrasonic treatment can accelerate the mass transfer speed and reaction efficiency of calcium fatty acid salt and hydrogen ions, and when the frequency is too low, it cannot release enough energy to promote the diffusion of substances and the increase of reaction rate, and when the frequency is too high, it can cause the generated bubbles to be too large and difficult to uniformly distribute in the reaction system, which can cause local overheating and rate increase of the reaction, while the reaction rate and temperature in other areas are still low, resulting in uneven reaction and affecting the extraction effect of fatty acids, and therefore the ultrasonic frequency is preferably 600W.

[0067] Example 7

[0068] The difference between this example and Example 1 is that the extraction solvent in step 4) is respectively benzene, toluene, n-hexane, n-heptane, n-octane, petroleum ether and tert-butanol, and the branched fatty acid content of the obtained product is tested to compare the influence of different extraction solvents on the branched fatty acid content of the product, and the test results are shown in Table 6.

[0069] Table 6

[0070] Extraction solvent type Benzene Toluene n-Hexane n-Heptane n-Octane Petroleum ether Tert-butanol Branched fatty acid content (%) 36.2 39.6 45.7 50.8 50.2 47.6 24.8

[0071] It can be seen that under the same reaction conditions, changing the extraction solvent has a greater impact on the content of branched-chain fatty acids. When the extraction solvent is n-heptane, the content of branched-chain fatty acids is the highest, and this trend is different from the previous study, which is due to the presence of calcium chloride in reaction solution II, which can change the ionic strength and polarity of the solution, thereby affecting the solubility and affinity of fatty acids. Under this condition, the affinity of n-heptane may be better than that of fatty acids in the solution, thereby improving the extraction effect.

[0072] Example 8

[0073] The difference between this example and Example 1 is that the amount of calcium chloride added in step 2) is adjusted to be 5-30% of the mass of the saponification solution. The content of branched-chain fatty acids in the obtained product is tested to compare the effect of different amounts of calcium chloride on the content of branched-chain fatty acids in the product. The test results are shown in Table 7.

[0074] Table 7

[0075] Calcium chloride addition amount (%) 5 10 15 20 25 30 Branched fatty acid content (%) 12.7 24.8 34.5 50.8 45.6 39.4

[0076] It can be seen that with the increase of the amount of calcium chloride, the content of branched-chain fatty acids first increases and then decreases. When the amount of calcium chloride is 20% of the mass of the saponification solution, the content of branched-chain fatty acids is the highest. In the present scheme, on the one hand, calcium ions can form insoluble calcium compounds with fatty acids, achieving separation and extraction of fatty acids, and on the other hand, the presence of calcium salt can change the ionic strength and polarity of the solution, thereby further affecting the solubility and affinity of fatty acids in the subsequent extraction and separation process. Too high or too low content will significantly affect the extraction effect.

[0077] Example 9

[0078] The difference between this example and Example 1 is that the calcium chloride in step 2) is replaced by calcium nitrate and calcium acetate. The content of branched-chain fatty acids in the obtained product is tested to compare the effect of different extraction solvents on the content of branched-chain fatty acids in the product. The test results are shown in Table 8.

[0079] Table 8

[0080] Calcium salt type (%) Calcium nitrate Calcium chloride Calcium acetate Branched fatty acid content (%) 37.2 50.8 43.5

[0081] It can be seen that different types of calcium salts have a significant impact on the extraction effect, which is due to the solubility, reactivity and stability of different calcium salts, thereby affecting their effect in the ultrasonic acidification and subsequent extraction steps, and affecting the extraction efficiency.

[0082] Comparative Example 1

[0083] The difference between the present comparative example and example 1 is that the calcium fatty acid precipitate is not washed with 80% ethanol aqueous solution in step (4), and the branched fatty acid content of the obtained product is tested. The result is that the non-precipitation leads to too much impurities, and the branched fatty acid content of the final product is only 9.4%.

[0084] Comparative Example 2

[0085] The difference between the present comparative example and example 1 is that the ultrasonic temperature in step (5) is 35℃, at which the system is viscous and difficult to extract and separate, and the functional fatty acids cannot be obtained.

[0086] Comparative Example 3

[0087] The difference between the present comparative example and example 1 is that the acidification time in step (3) is 24h, and no ultrasonic treatment is used, and the branched fatty acid content of the obtained product is tested. The result is that the non-ultrasonic treatment leads to difficult acidification, and the branched fatty acid content of the final product is only 14.0%.

[0088] In summary, the present application uses ultrasonic acidification method to improve the problem of difficult acidification of calcium salt precipitate in the preparation of functional fatty acids in lanolin by calcium precipitation method, greatly improves the yield of branched fatty acids, greatly shortens the acidification time of fatty acid calcium, and is a major breakthrough in solving the extraction of branched fatty acids in lanolin by calcium precipitation method.

[0089] The ultrasonic acidification method not only reduces the amount of extraction solvent by ultrasonic demulsification, but also effectively reduces the acidification temperature, saves the production energy consumption of functional fatty acids in lanolin by calcium precipitation method, reduces the damage to functional substances, saves the production cost, reduces the environmental pollution, reduces the foam and colloidal particles in the system, avoids the blockage of equipment in the subsequent process, and simplifies the subsequent process.

[0090] It should be noted that the above examples are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application, and they should be covered in the scope of the claims of the present application.

Claims

1. A method for extracting functional fatty acids, characterized by: The lanolin is dissolved in an alcohol aqueous solution to obtain a lanolin alcohol aqueous solution, a strong base is added to saponify the lanolin alcohol aqueous solution to obtain a saponification solution, and a strong acid aqueous solution is used to adjust the pH of the saponification solution to neutral or weak alkaline; Calcium chloride is dissolved in an alcohol aqueous solution to obtain a calcium chloride alcohol aqueous solution, which is added to the saponification solution to obtain a reaction solution I, the reaction solution I is heated and left to precipitate, and the precipitate of calcium fatty acid is obtained by filtration, wherein the content of calcium chloride is 20% of the mass of the saponification solution; The precipitate of calcium fatty acid is washed with an alcohol aqueous solution, and after drying, solvent water is added, a strong acid solution is used to adjust the system to strong acidity, and an acidification reaction is performed by ultrasonic heating to obtain a reaction solution II; The ultrasonic frequency for the acidification reaction by ultrasonic heating is 600 W, the heating temperature is 45-70℃, and the reaction time is 1-9 h. An extraction solvent is added to the reaction solution II for extraction, washed with water to neutral, and the upper organic phase is reserved, and the solvent is removed by rotary evaporation to obtain the functional fatty acid; The extraction solvent includes one of n-heptane and n-octane. The strong base includes one of sodium hydroxide and potassium hydroxide, and the addition amount is 10%-20% of the mass of the lanolin.

2. The method of extracting functional fatty acids according to claim 1, wherein: The saponification is performed by heating, wherein the heating temperature is 45-75℃, and the saponification time is 1-8 h.

3. The method for extracting functional fatty acids as described in claim 1, characterized in that: The reaction solution I is heated and left to precipitate for 1-4 h at a temperature of 30-80℃.

4. The method of extracting functional fatty acids as claimed in claim 1, characterized by: The mass ratio of lanolin to alcohol aqueous solution in the lanolin alcohol aqueous solution is 1:1-5, and the mass ratio of calcium chloride to alcohol aqueous solution in the calcium chloride alcohol aqueous solution is 1:1-10.

5. The method of claim 1, wherein the functional fatty acid is extracted from the oil. The alcohol aqueous solution includes one of a methanol aqueous solution, an ethanol aqueous solution, or a propanol aqueous solution, and the mass fraction is 60-100%.

6. The method of extracting functional fatty acids according to any one of claims 1 or 5, wherein: The number of times of washing the calcium fatty acid with the alcohol aqueous solution is 1-5 times.

7. The method of extracting functional fatty acids as claimed in claim 1, wherein: In the reaction solution II, the solvent water is 5-20 times the mass of the calcium fatty acid.

8. The method of extracting functional fatty acids as claimed in claim 1, wherein: ​