CN110760376B - Novel algae oil purification method - Google Patents
Novel algae oil purification method Download PDFInfo
- Publication number
- CN110760376B CN110760376B CN201810837473.5A CN201810837473A CN110760376B CN 110760376 B CN110760376 B CN 110760376B CN 201810837473 A CN201810837473 A CN 201810837473A CN 110760376 B CN110760376 B CN 110760376B
- Authority
- CN
- China
- Prior art keywords
- alcohol
- oil
- water solution
- water
- algae
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
- C11B—PRODUCING, e.g. BY PRESSING RAW MATERIALS OR BY EXTRACTION FROM WASTE MATERIALS, REFINING OR PRESERVING FATS, FATTY SUBSTANCES, e.g. LANOLIN, FATTY OILS OR WAXES; ESSENTIAL OILS; PERFUMES
- C11B3/00—Refining fats or fatty oils
- C11B3/10—Refining fats or fatty oils by adsorption
-
- C—CHEMISTRY; METALLURGY
- C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
- C11B—PRODUCING, e.g. BY PRESSING RAW MATERIALS OR BY EXTRACTION FROM WASTE MATERIALS, REFINING OR PRESERVING FATS, FATTY SUBSTANCES, e.g. LANOLIN, FATTY OILS OR WAXES; ESSENTIAL OILS; PERFUMES
- C11B3/00—Refining fats or fatty oils
- C11B3/001—Refining fats or fatty oils by a combination of two or more of the means hereafter
-
- C—CHEMISTRY; METALLURGY
- C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
- C11B—PRODUCING, e.g. BY PRESSING RAW MATERIALS OR BY EXTRACTION FROM WASTE MATERIALS, REFINING OR PRESERVING FATS, FATTY SUBSTANCES, e.g. LANOLIN, FATTY OILS OR WAXES; ESSENTIAL OILS; PERFUMES
- C11B3/00—Refining fats or fatty oils
- C11B3/008—Refining fats or fatty oils by filtration, e.g. including ultra filtration, dialysis
-
- C—CHEMISTRY; METALLURGY
- C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
- C11B—PRODUCING, e.g. BY PRESSING RAW MATERIALS OR BY EXTRACTION FROM WASTE MATERIALS, REFINING OR PRESERVING FATS, FATTY SUBSTANCES, e.g. LANOLIN, FATTY OILS OR WAXES; ESSENTIAL OILS; PERFUMES
- C11B3/00—Refining fats or fatty oils
- C11B3/02—Refining fats or fatty oils by chemical reaction
- C11B3/04—Refining fats or fatty oils by chemical reaction with acids
-
- C—CHEMISTRY; METALLURGY
- C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
- C11B—PRODUCING, e.g. BY PRESSING RAW MATERIALS OR BY EXTRACTION FROM WASTE MATERIALS, REFINING OR PRESERVING FATS, FATTY SUBSTANCES, e.g. LANOLIN, FATTY OILS OR WAXES; ESSENTIAL OILS; PERFUMES
- C11B3/00—Refining fats or fatty oils
- C11B3/02—Refining fats or fatty oils by chemical reaction
- C11B3/06—Refining fats or fatty oils by chemical reaction with bases
-
- C—CHEMISTRY; METALLURGY
- C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
- C11B—PRODUCING, e.g. BY PRESSING RAW MATERIALS OR BY EXTRACTION FROM WASTE MATERIALS, REFINING OR PRESERVING FATS, FATTY SUBSTANCES, e.g. LANOLIN, FATTY OILS OR WAXES; ESSENTIAL OILS; PERFUMES
- C11B3/00—Refining fats or fatty oils
- C11B3/16—Refining fats or fatty oils by mechanical means
Landscapes
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Microbiology (AREA)
- Engineering & Computer Science (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Wood Science & Technology (AREA)
- Organic Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Mechanical Engineering (AREA)
- Fats And Perfumes (AREA)
Abstract
The invention relates to a method for purifying algae oil, which contains polyunsaturated fatty acid in the form of triglyceride, glycolipid and phospholipid or esterified polyunsaturated fatty acid after transesterification with lower alcohol, and comprises the following steps: 1) optionally, contacting the algae oil with a dilute acid and adding calcium carbonate to neutralize the acid, the precipitate being removed by filtration or centrifugation; 2) contacting algae oil with an alcohol-water solution in the presence of a lipid adsorbent, wherein the volume ratio of alcohol to water in the alcohol-water solution is below 1: 1; 3) separating the oil adsorbent from the alcohol-water solution; 4) optionally washing the grease adsorbent with water; and 5) separating the algae oil from the oil adsorbent.
Description
Technical Field
The invention relates to a method for purifying algae oil, which comprises the steps of contacting the algae oil with an alcohol-water solution with the volume ratio of alcohol to water being less than 1:1, and separating the algae oil from the alcohol-water solution through a grease adsorbent to achieve the effect of removing water-soluble impurities in the algae oil.
Background
Polyunsaturated fatty acids (PUFA), such as omega-3 fatty acids, are of great interest for human health. Omega-3 fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), can reduce the amount of triglycerides in the blood. These polyunsaturated fatty acids also have cardiovascular protective functions, and can prevent and treat inflammation, neurodegenerative diseases, promote cognitive functions, etc. (Sugano, Michihiro, Balanced intake of secreted fatty acids for health benefits. J. Oleo Sci.2001,50(5): 305-. More studies have shown that EPA, but not DHA, is the main component for the above-mentioned effects (Martins JG. EPA but not DHA appeares to be responsive for the effect of omega-3long chain unskilled fatty acid deletion in expression: observation from a method-analysis of random controlled metals. J Am Cold nutrient. 2009 Oct; 28(5): 525-42.; Eclov J et al, EPA, not DHA, present fibers in compression-induced fatty acid: positional roll of free fatty acid 4. Lipid. Dec; 56-12. i. 2297. 10.1194. M034. J. 034. for the purpose of improving blood circulation in expression of fatty acid).
Omega-3 fatty acids are typically derived from marine fish. However, with the decrease of fish resources, the enrichment of fish body pollutants caused by the environment and the like, and more people devote vegetarian diet, the demand for omega-3 fatty acids from plants is increasing. Algal polyunsaturated fatty acids show great potential in plant resources, whether as dietary supplements or as pharmaceuticals. The algae has the advantages that the area occupied by algae cultivation is smaller than that of common land crops, and seawater or fresh water resources can be widely applied.
However, algal oil extracted from algae using ethanol contains a large amount of impurities including salts, carbohydrates, proteins, pigments, etc. due to low selectivity of ethanol. The presence of these impurities, coupled with the presence of omega-3 fatty acids in the algae oil, mainly in the form of triglycerides, glycolipids and phospholipids, makes the algae oil very viscous, which poses a significant obstacle to subsequent purification and concentration, and makes the appearance of the algae oil poor. In large-scale industrial production, the triglycerides, glycolipids and phospholipids are generally converted into a more fluid ethyl ester form by transesterification, followed by subsequent purification and concentration. If desired, the purified and concentrated ethylated omega-3 fatty acids are converted back to their native form, e.g., triglycerides, by transesterification.
Disclosure of Invention
The present invention provides a method for purifying a natural algal oil containing polyunsaturated fatty acids in the form of triglycerides, glycolipids and phospholipids, comprising contacting the algal oil with an alcohol-water solution and separating from the alcohol-water solution by adsorption on a lipid adsorbent, wherein the volume ratio of alcohol to water in the alcohol-water solution is 1:1 or less. The algae oil is in the form of liquid drops in the alcohol-water solution with the alcohol-water ratio, the working fluidity is improved, and the algae oil can be fully contacted with the alcohol-water solution, so that water-soluble impurities can be better removed. After the algae oil is purified by the method, the physical and chemical properties, particularly the fluidity, of the algae oil are greatly improved, the purity of the contained polyunsaturated fatty acid is improved, and the algae oil product with good appearance and quality is obtained.
The invention is also suitable for purifying the algae oil containing methyl ester or ethylated polyunsaturated fatty acid, can improve the physicochemical property of the algae oil, and can improve the purity of the methyl ester or ethylated polyunsaturated fatty acid in the algae oil.
Specifically, the present invention provides a method for purifying algal oil, comprising:
1) contacting algae oil with an alcohol-water solution in the presence of a lipid adsorbent;
2) separating the oil adsorbent from the alcohol-water solution; and
3) separating algae oil from the oil adsorbent.
The contacting of the algal oil of step 1) with the alcohol-water solution can be carried out, for example, for 2 hours with stirring.
The alcohol-water solution may be selected from lower alcohol-water solutions, such as methanol-water solution, ethanol-water solution, propanol-water solution, or combinations thereof. In some embodiments, the alcohol-water solution is an ethanol-water solution. In the alcohol-water solution, the volume ratio of alcohol to water is 1:1 or less. In some embodiments, the volume ratio of alcohol to water in the alcohol-water solution can be 1:1 or less, 2:3 or less, or 1:2 or less, and 1:5 or more, 1:4 or more, or 1:3 or more. In some embodiments, the alcohol-water solution has a volume ratio of alcohol to water of 1:1, 1:2, 1:3, 1:4, or 1: 5. In one embodiment, the alcohol-water solution has a volume ratio of alcohol to water of 1: 1.
The algae oil in the step 1) can be crude algae oil extracted by treating natural dry algae with ethanol, or esterified algae oil obtained by transesterification with lower alcohol after ethanol extraction. The lower alcohol for transesterification of algae oil can be methanol, ethanol or propanol. In some embodiments, the lower alcohol used for transesterification is ethanol, particularly absolute ethanol. The weight to volume ratio of algal oil in step 1) to alcohol in the above alcohol-water solution may be in the range of 0.2 to 0.4g/mL, for example, 0.225 to 0.354g/mL, based on the crude algal oil extracted with ethanol.
The grease adsorbent in the step 1) can be selected from cellulose products, activated carbon and the like. The cellulosic product may be a shredded tissue. In an embodiment of the tissue, the weight ratio of the algae oil to the tissue in step 1) may be in the range of 1:1-10:1, in the above range.
Step 2) the fat adsorbent may be collected by filtration, for example, filtration under reduced pressure, or centrifugation.
Step 3) may be achieved by dissolving the algal oil with a suitable solvent and removing the oil adsorbent by filtration or centrifugation or the like. A suitable solvent may be absolute ethanol, which may be removed by evaporation or the like. After the grease adsorbent is collected, the grease adsorbent may be washed with water to further remove water-soluble impurities.
The process of the present invention may further comprise, prior to step 1), contacting the algal oil with a dilute acid. The algal oil may be contacted with the dilute acid in the presence of an alcohol, which may be a lower alcohol, such as ethanol and the like. The dilute acid may be selected from dilute sulfuric acid, dilute hydrochloric acid, and dilute nitric acid, preferably dilute sulfuric acid. The working concentration of dilute sulfuric acid may be 0.01-0.1mol/L, for example 0.036-0.048 mol/L. Calcium carbonate, calcium hydroxide, and/or sodium hydroxide may be added to neutralize the sulfuric acid after the algae oil has been contacted with the dilute acid for a period of time. The precipitate resulting from the neutralization can be removed by filtration, for example, filtration under reduced pressure, or can be removed by centrifugation.
According to the method, the algae oil is placed in the alcohol-water solution with a specific proportion, so that the algae oil is distributed in an oil drop shape, the working fluidity of the algae oil is increased, the contact area of the algae oil and the alcohol-water solution is increased, and water-soluble impurities are better dissolved in the alcohol-water solution; then the algae oil is absorbed in the oil adsorbent, and the oil adsorbent is separated from the alcohol-water solution by filtration or centrifugation, so as to achieve the effect of fully removing water-soluble impurities in the algae oil. The method is not only suitable for natural algae oil with polyunsaturated fatty acid in the form of triglyceride, glycolipid and phospholipid, but also suitable for esterified algae oil obtained by transesterification of lower alcohol such as methanol or ethanol. After treatment by the method of the present invention, the algae oil has an increased total fatty acid content, particularly useful polyunsaturated fatty acids such as EPA, and the algae oil has a greatly improved fluidity.
Detailed Description
The algal oil extracted from microalgae by ethanol contains a large amount of impurities including salts, carbohydrates, proteins, pigments, etc., and fatty acids in algal oil mainly exist in three forms of triglyceride, glycolipid and phospholipid. The superposition of the two factors causes the algae oil to be viscous and nearly solid, which causes certain difficulty in subsequent purification, concentration and the like.
The inventors of the present invention have found that when algal oil is placed in an alcohol-water solution having a volume ratio of alcohol to water of 1:1 or less, the algal oil in a near-solid state is in the form of oil droplets, and fluidity during handling is improved, and the contact area between the algal oil and the alcohol-water solution is increased, so that water-soluble impurities in the algal oil can be more easily dissolved in the alcohol-water solution. This makes it possible to purify algal oil directly and efficiently without transesterification, greatly reducing the flow and cost of the purification process.
By adding an oil adsorbent, for example, a cellulose product such as a paper towel, activated carbon or the like to the alcohol-water solution, fatty acids such as EPA in algal oil are adsorbed on the oil adsorbent. The oil adsorbent is collected by filtration or centrifugation, so that the separation of the effective components of the algae oil, such as polyunsaturated fatty acid, from the alcohol-water solution and the water-soluble impurities contained in the alcohol-water solution is realized. After removing a large amount of impurities, the fluidity of algal oil is improved and the purity of polyunsaturated fatty acids is increased. The better fluidity means that the purity of the grease in the algae oil is high, and the algae oil product is provided with better appearance feeling.
The method of the invention is also suitable for the esterified algae oil after the transesterification treatment of lower alcohol such as methanol or ethanol. The esterified algae oil is also in an oil drop shape in an alcohol-water solution with the volume ratio of alcohol to water being less than 1:1, so that the working fluidity of the algae oil can be further increased, the contact surface of the algae oil and the alcohol-water solution is increased, and water-soluble impurities are better removed.
The algae oil can be extracted by treating the dry algae with ethanol, and the extraction parameters can be adjusted by those skilled in the art according to the needs. In one embodiment, dried algae having a water content of less than 5 wt% is placed in absolute ethanol in a water bath at 80 ℃ and at 20rpm for 2 hours, wherein the ratio of dried algae to absolute ethanol may be 1:20 g/mL.
The ethanol extracted algal oil can be purified by the following process steps:
1) optionally, the algae oil is contacted with dilute acid, calcium carbonate or the like is added to neutralize the acid, and the precipitate is removed by filtration or centrifugation or the like;
2) contacting algae oil with an alcohol-water solution in the presence of a lipid adsorbent;
3) separating the oil adsorbent from the alcohol-water solution;
4) optionally washing the grease adsorbent with water; and
5) separating algae oil from the oil adsorbent.
In the ethanol-extracted algal oil, impurities such as salts, carbohydrates, proteins, and pigments are present. The addition of low concentrations of acid to the algae oil allows certain classes of impurities to be separated from the active ingredients in the algae oil, such as fatty acids, allowing for better removal of impurities. The low concentration acid may be dilute sulfuric acid, dilute hydrochloric acid, dilute nitric acid, and the like. Hydrochloric acid and nitric acid are volatile, hydrochloric acid is too weak in acidity, and nitric acid remains to cause nitrogen compounds in the final product. Therefore, dilute sulfuric acid is the best choice. In order to use a sufficient amount of sulphuric acid while avoiding the occurrence of excessively high concentrations, the algal oil may be contacted with sulphuric acid in the presence of a lower alcohol, such as ethanol, the working concentration of sulphuric acid may be in the range of 0.01-0.1mol/L, for example in the range of 0.036-0.048 mol/L. Due to the low concentration of sulfuric acid, coupled with the temperature control, transesterification of polyunsaturated fatty acids with lower alcohols does not occur even in the presence of alcohols. The original concentration of the added dilute sulfuric acid is not too low, so that more water is brought, and the formulation of the ratio of alcohol-water solution in the subsequent step is difficult. In one embodiment, 45ml of dilute sulfuric acid with a concentration of 3.6mol/L is added to 4.5L of ethanol solution containing about 100g of algal oil, and the mixture is treated at room temperature at 20rpm for 2 hours. After the dilute acid treatment, excessive calcium carbonate, calcium hydroxide and the like are added to neutralize the dilute acid and stop the action of the acid. Insoluble matter can be removed by filtration or centrifugation.
After dilute acid treatment, the algae oil is contacted with an alcohol-water solution in the presence of a grease adsorbent, and the volume ratio of alcohol to water in the alcohol-water solution can be below 1: 1. When the algae oil is placed in the alcohol-water solution with the alcohol-water volume ratio, the algae oil is distributed in an oil drop shape, so that the contact area of the algae oil and the alcohol-water solution is increased, water-soluble impurities contained in the algae oil can better enter the alcohol-water solution, the oil drops are gradually adsorbed in the oil adsorbent, and then the adsorbent is separated from the alcohol-water solution through a physical method, so that the effect of removing the water-soluble impurities contained in the algae oil is realized.
The contacting of the algal oil of step 2) with the alcohol-water solution can be carried out, for example, for 2 hours with stirring. The alcohol-water solution may be selected from a methanol-water solution and an ethanol-water solution. In the alcohol-water solution, the volume ratio of alcohol to water is 1:1 or less. In some embodiments, the volume ratio of alcohol to water in the alcohol-water solution can be 1:1 or less, 2:3 or less, or 1:2 or less, and 1:5 or more, 1:4 or more, or 1:3 or more. In some embodiments, the alcohol-water solution has a volume ratio of alcohol to water of 1:1, 1:2, 1:3, 1:4, or 1: 5. The volume ratio of alcohol to water in the alcohol-water solution is not suitable to be too low, otherwise the recycling of ethanol is not facilitated. Therefore, in practical operation, the volume ratio of alcohol to water can be set in the range of 1:1 to 1: 2.
The ratio of algal oil to alcohol-water solution should be in a proper range. When this ratio is too high, the alcohol-water solution may be caused to be insufficient to dissolve all the water-soluble impurities; when the ratio is too low, the amount of alcohol and water used is too large, and the cost is increased. The weight to volume ratio of algal oil to alcohol in step 2) may be in the range of 0.2-0.4g/mL, for example 0.225-0.354g/mL, based on the crude algal oil extracted with ethanol. Since algal oil is extracted by ethanol, if the extraction step is directly carried out to the purification step of the present invention without removal of ethanol, there may be a problem that the ratio of algal oil to alcohol-water solution is too low, the volume of ethanol may be compressed by distillation or the like, and then water may be added according to the amount of ethanol after compression.
The grease adsorbent can be cellulose products, or activated carbon, and the like, and the type and the dosage of the grease adsorbent can be determined by those skilled in the art according to actual needs. In the present invention, the cellulosic product may be a shredded tissue, such as any common household tissue. Cellulose products such as paper towels contain a large amount of cellulose, and the cellulose can adsorb grease and is not dissolved in water and common organic solvents, so that the separation of algae oil and alcohol-water solution is facilitated. In one embodiment, the weight ratio of algae oil to paper towel may be in the range of 1:1-10:1, or a salt thereof.
The oil-and-fat adsorbent having adsorbed algal oil can be separated from the alcohol-water solution by filtration such as filtration under reduced pressure or centrifugation. The oil adsorbent may be washed with water to further remove water-soluble impurities. The oil adsorbed in the oil adsorbent can be dissolved in absolute ethanol, the adsorbent is removed by filtration or centrifugation, and the absolute ethanol is removed by distillation, so as to obtain purified algae oil.
As described above, the method of the present invention is also applicable to esterified algal oils subjected to transesterification with lower alcohols such as methanol or ethanol. The algae oil extracted by processing dry algae with ethanol can be transesterified with lower alcohol under the catalysis of concentrated sulfuric acid at 70 ℃. The transesterification conditions can be set by the person skilled in the art as a function of the circumstances. The lower alcohol can be methanol, ethanol, etc., and is typically ethanol. The esterification reaction can be stopped by adding an excess of calcium carbonate or the like to neutralize the sulfuric acid.
The transesterified algal oil can be purified by the following process steps:
1) contacting the transesterified algal oil with an alcohol-water solution in the presence of a lipid adsorbent;
2) separating the oil adsorbent from the alcohol-water solution;
3) optionally washing the grease adsorbent with water; and
4) the grease is separated from the grease adsorbent.
In step 1), the transesterified algal oil is contacted with an alcohol-water solution in the presence of a lipid adsorbent, and the volume ratio of alcohol to water in the alcohol-water solution can be 1:1 or less. When the transesterified algae oil is placed in the alcohol-water solution with the alcohol-water volume ratio, the transesterified algae oil is distributed in an oil drop shape, so that the contact area of the algae oil and the alcohol-water solution is increased, water-soluble impurities contained in the algae oil better enter the alcohol-water solution, the oil drops are gradually adsorbed in the oil adsorbent, and then the adsorbent is separated from the alcohol-water solution by a physical method, so that the effect of removing the water-soluble impurities contained in the transesterified algae oil is realized. This step can be carried out with stirring for, for example, 2 hours. The alcohol-water solution may be selected from water solutions of lower alcohols such as methanol or ethanol, etc. In the alcohol-water solution, the volume ratio of alcohol to water is 1:1 or less. In some embodiments, the volume ratio of alcohol to water in the alcohol-water solution can be 1:1 or less, 2:3 or less, or 1:2 or less, and 1:5 or more, 1:4 or more, or 1:3 or more. In some embodiments, the alcohol-water solution has a volume ratio of alcohol to water of 1:1, 1:2, 1:3, 1:4, or 1: 5. The volume ratio of alcohol to water may be set in the range of 1:1 to 1:2 in view of the recovery of ethanol.
The ratio of transesterified algal oil to alcohol-water solution should be within a suitable range. When this ratio is too high, the alcohol-water solution may be caused to be insufficient to dissolve all the water-soluble impurities; when the ratio is too low, the amount of alcohol and water used is too large, and the cost is increased. The weight to volume ratio of algal oil to alcohol in step 2) may be in the range of 0.2-0.4g/mL, for example 0.225-0.354g/mL, based on the crude algal oil extracted with ethanol. Since algal oil is extracted by ethanol, if the extraction step directly enters the purification step of the present invention without ethanol removal, there may be a problem that the ratio of algal oil to alcohol-water solution is too low, the volume of ethanol may be compressed by distillation or the like, and then water may be added according to the amount of ethanol after compression.
The grease adsorbent can be cellulose products such as paper towels, activated carbon and the like, and the type and the dosage of the grease adsorbent can be determined by those skilled in the art according to actual needs. In one embodiment, the grease sorbent is a cellulosic product, such as a paper towel, and the weight ratio of algae oil to paper towel can be in the range of 1:1 to 10: 1.
In step 2), the oil-and-fat adsorbent having the transesterified algal oil adsorbed thereon can be separated from the alcohol-water solution by filtration such as filtration under reduced pressure or centrifugation.
In step 3), the fat adsorbent may be washed with water to further remove water-soluble impurities.
In step 4), the transesterified algae oil adsorbed in the oil adsorbent can be dissolved in absolute ethyl alcohol, the adsorbent is removed by filtration or centrifugation, and the absolute ethyl alcohol is removed by distillation, so that purified transesterified algae oil can be obtained.
Example 1 Dry algae preparation
Nannochloropsis salina is grown in artificial seawater containing 22g/L NaCl and 2.44g/L MgSO for 7 days4·7H2O, 0.6g/L KCl, 0.25g/L urea, 0.3g/LCaCl2·2H2O、4.4mg/L NaH2PO4·2H2O、0.1g/L NaHCO3、0.75mg/L Na2EDTA·2H2O、0.097mg/L FeCl3·6H2O、0.5mg/L H3BO3、1mg/L MnSO4、0.05mg/L ZnSO4、0.02mg/L CoCl2·6H2O, and 0.1mg/L Na2MoO4·2H2O。
1 ton of algae solution was taken and added with 6M NaOH solution to adjust the pH to 10.5 at which the algae began to settle. After three hours, the aqueous layer was discarded, and the residue was filtered through a Miracloth filter having a pore size of 25 μm to obtain about 1kg of algal mud having a water content of about 80 wt%. The algal mud was treated with ZPG-G spray dryer for 2 hours to obtain 146G of dried algae having a water content of 5 wt% or less.
The method for measuring the water content is as follows: baking the algae mud or algae powder in an oven at 80 ℃ for more than 2 hours until constant weight is achieved; the weight before placing in the oven was compared to the final constant weight and the water content was calculated as (weight before baking-constant weight)/weight before baking 100%.
Example 2 extraction of algal oil
250g of the dried alga prepared in example 1 (containing 6.86% by weight of eicosapentaenoic acid (EPA) and 18.50% of Total Fatty Acids (TFA)) was taken, placed in 2.5L of 94% ethanol, treated in a water bath at 80 ℃ for 2h, and a magnetic stirrer was set at 20 rpm. Thereafter, filtration was performed under reduced pressure (-0.1MPA) using a cloth funnel connected to a suction pump with filter paper (pore size 15-20 μm, Xinxing, qualitative filter paper). The filtered algal bodies were added to 2.5L of 94% ethanol and the above procedure was repeated. The two filtrates were combined to a total volume of about 4.5L and contained about 106.2g of crude algal oil.
1.5L of the filtrate was taken and treated in a rotary evaporator at 70 ℃ until no liquid appeared in the condenser. 35.4g of crude algal oil, having almost no fluidity, containing 14.74 wt% EPA and 33.63 wt% TFA was obtained.
Example 3 purification of algal oil
1.5L of the filtrate from example 2 was taken, 15mL of 3.6mol/L dilute sulfuric acid was added, and the mixture was stirred at room temperature for 2 hours with a magnetic stirrer set at 20 rpm. 10g of CaCO are added3To neutralize the sulfuric acid and stir for an additional 2 h. Filtration was carried out with filter paper (pore size 15-20 μm, Xinxing, qualitative filter paper) to obtain about 1.5L of filtrate. The filtrate was concentrated to 100mL by rotary evaporation (70 ℃, -0.1 MPA). To the resulting suspension was added 5g of shredded paper towels (Vida, each strip of paper towels was approximately 2cm long and 1cm wide). 300mL of water was added with stirring by a magnetic stirrer at 20rpm, and stirring was continued for 2 h. The resulting tissue was collected by filtration through a filter paper (the same as above) under reduced pressure (-0.1MPA), and the tissue was rinsed with 200mL of water to remove water-soluble components from the algal oil. The washed paper towel was placed in 200mL of 100% ethanol, and then filtered with filter paper (same as above) under reduced pressure (-0.1MPA) to obtain a filtrate. The filtered tissue was rinsed with 100mL of 100% ethanol and filtered again. The two filtrates were combined and rotary evaporated at 70 ℃ to give 15.3g of a purified crude oil, better in flowability, containing 31.50 wt% EPA and 64.52 wt% TFA.
The fluidity of the algal oil in this example was greatly improved and the purity of the polyunsaturated fatty acids was improved compared to the unpurified algal oil.
Example 4 transesterification and purification of algal oil
1.5L of the filtrate from example 2 was taken and ethanol was removed by rotary evaporation at 70 ℃ to give 35.4g of crude algal oil. To the crude algal oil were added 70mL of 100% ethanol and 5mL of 98% concentrated sulfuric acid. The magnetic stirrer is set to rotate at 20rpm and the transesterification reaction is carried out for 2h at 70 ℃.20 g of CaCO was added to the reaction3To neutralize the sulfuric acid and stir for an additional 2 h.
Ethanol was added to the reaction solution to a total volume of 500mL for convenient subsequent filtration. Filtration through filter paper (pore size 15-20 μm, Xinxing, qualitative filter paper) gave about 500mL of filtrate. The filtrate was concentrated to 100mL by rotary evaporation (70 ℃, -0.1 MPA). To the resulting suspension was added 5g of paper towels (Vida, each strip of paper towels was approximately 2cm long and 1cm wide). 300mL of water was added with stirring by a magnetic stirrer at 20rpm, and stirring was continued for 2 h. The paper towel was collected by filtration through filter paper (same as above) under reduced pressure (-0.1MPA), and the paper towel was washed with 200mL of water to remove water-soluble components. The washed paper towel was placed in 200mL of 100% ethanol, and filtered with filter paper (same as above) under reduced pressure (-0.1MPA) to obtain a filtrate. The filtered tissue was rinsed with 100mL of 100% ethanol and filtered again. The two filtrates were combined and rotary evaporated at 70 ℃ to give 12.5g of purified fatty acid ethyl ester, better in flowability, containing 38.65 wt% ethylated EPA and 83.45 wt% ethylated TFA.
The purity of the polyunsaturated fatty acids of the algae oil in this example was increased compared to unpurified algae oil.
Example 5 Dry algae preparation
Nannochloropsis oculata was cultured as described in example 1, and dried algae was prepared.
The quality of microalgae varies greatly due to the variation of growth conditions such as illumination. Specifically, the amounts of EPA and TFA contained in the dried algae obtained by the preparation are shown in table 1.
TABLE 1 amount of EPA and TFA contained in dried algae
| EPA wt％ | TFA wt％ | |
| Algae 1 | 6.86 | 18.50 |
| Algae 2 | 3.70 | 16.87 |
| Algae 3 | 4.20 | 16.87 |
| Algae 4 | 3.40 | 21.99 |
Example 6 extraction of algal oil
250g of each of the dried algae 1 to 3 prepared in example 5 was taken, 5L of absolute ethanol was added, and the mixture was treated in a water bath at 80 ℃ for 2 hours with a magnetic stirrer set at 20 rpm. Thereafter, the mixture was filtered through a filter paper (pore size: 15 to 20 μm, Xinxing, qualitative filter paper) under reduced pressure (-0.1MPA) using a Buchner funnel connected to a suction pump to obtain filtrates of about 4.5L each containing 98.9g, 78g and 67.6g of crude algal oil containing EPA and TFA as shown in Table 2.
TABLE 2 amount of EPA and TFA contained in unpurified crude algal oil
| EPA wt％ | TFA wt％ | |
| Algae 1 | 13.67 | 35.68 |
| Algae 2 | 6.51 | 41.40 |
| Algae 3 | 12.01 | 60.20 |
Example 7 purification of algal oil
4.5L of the filtrate obtained in example 6, two parts of algae 1, and one part of each of algae 2 and algae 3 were taken. 60mL, 45mL and 45mL of 3.6mol/L dilute sulfuric acid were added to each filtrate, and the mixture was stirred at room temperature for 2 hours with a magnetic stirrer set at 20 rpm. 30g of CaCO were added separately3To neutralize the sulfuric acid and stir for an additional 2 h. Filtration was carried out with filter paper (pore size 15-20 μm, Xinxing, qualitative filter paper) to obtain filtrates of about 4.5L each. The filtrate was concentrated to 300mL by rotary evaporation (70 ℃, -0.1 MPA). To each suspension obtained, 50g, 20g and 15g of paper towels (Vida, each strip of paper towels is approximately 2cm long and 1cm wide) were added, respectively. 900mL, 600mL, 1500mL, and 300mL of water were added with stirring at 20rpm of a magnetic stirrer. The paper towel was collected by filtration through filter paper (same as above) under reduced pressure (-0.1 MPA). The paper towel was rinsed with 900mL of water to remove water soluble components. The washed paper towel was placed in 600mL of 100% ethanol, and then filtered with filter paper (same as above) under reduced pressure (-0.1MPA) to obtain a filtrate. The filtered tissue was rinsed with 600mL of 100% ethanol and filtered. The two filtrates were combined and rotary evaporated (70 ℃ C., -0.1MPA) to give 45.9g, 40.60g, 39.0g and 59.4g of purified crude oil with better flowability, which contained EPA and TFA as shown in Table 3.
TABLE 3 amount of EPA and TFA contained in purified algal oil
The fluidity of the algal oil in this example was greatly improved and the purity of the polyunsaturated fatty acids was improved compared to the unpurified algal oil.
Example 8 esterification and purification of algal oil
4.5L of the filtrate obtained in example 6, two parts of algae 1, one part of algae 2 and one part of algae 3 were taken, rotary evaporation was carried out at 70 ℃ and concentrated to 500mL, 14mL of 98% concentrated sulfuric acid was added, and a magnetic stirrer was set at 20rpm and subjected to transesterification reaction at 70 ℃ for 3 hours. 40g of CaCO was added to the reaction3To neutralize the sulfuric acid and stir for an additional 2 h.
Filtration through filter paper (pore size 15-20 μm, Xinxing, qualitative filter paper) gave about 500mL of filtrate. The filtrate was concentrated to 300mL by rotary evaporation (70 ℃, -0.1 MPA). To the resulting suspension were added 10g, 15g, 25g and 15g of paper towels (Vida, each strip of paper towels was approximately 2cm long and 1cm wide), respectively. 900mL, 1500mL, 1200mL, and 300mL of water were added with stirring at 20rpm of a magnetic stirrer. The paper towel was collected by filtration through filter paper (same as above) under reduced pressure (-0.1 MPA). The paper towel was rinsed with 900mL of water to remove water soluble components. The washed paper towel was placed in 600mL of 100% ethanol, and then filtered with filter paper (same as above) under reduced pressure (-0.1MPA) to obtain a filtrate. The filtered tissue was rinsed with 600mL of 100% ethanol and filtered. The two filtrates were combined and rotary evaporated at 70 ℃ to give 37.5g, 34.4g, 50.4g and 50.4g of purified fatty acid ethyl esters with good flowability, which contained EPA ethyl ester and TFA ethyl ester as shown in Table 4.
TABLE 4 amount of EPA and TFA Ethyl esters contained in purified ethylated algae oils
The purity of the polyunsaturated fatty acids of the algae oil in this example was increased compared to unpurified algae oil.
Example 9 extraction of algal oil
3000g of the dried alga 4 prepared in example 5 were taken, added with 24L of absolute ethanol, treated in a water bath at 80 ℃ for 2 hours, and a magnetic stirrer was set at a rotation speed of 20 rpm. Thereafter, filtration through filter paper (pore size 15-20 μm, New Star, qualitative filter paper) under reduced pressure (-0.1MPA) using a Buchner funnel connected to a suction pump gave about 20L of filtrate containing 930g of crude algal oil containing 10.67 wt% EPA and 60.37 wt% TFA.
Example 10 purification of algal oil
20L of the filtrate obtained in example 9 was taken, 200mL of 3.6mol/L dilute sulfuric acid was added to the filtrate, and the mixture was stirred at room temperature for 2 hours with a magnetic stirrer set at 20 rpm. 100g of CaCO are added3To neutralize the sulfuric acid and stir for an additional 2 h. Filtration was performed with filter paper (pore size 15-20 μm, Xinxing, qualitative filter paper) to obtain about 20L volume of filtrate. The filtrate was concentrated to 4mL by rotary evaporation (70 ℃, -0.1 MPA). To the resulting suspension was added 250g of paper towels (Vida, each strip of paper towels was approximately 2cm long and 1cm wide). 4L of water was added with stirring by a magnetic stirrer at 20 rpm. The paper towel was collected by filtration through filter paper (same as above) under reduced pressure (-0.1 MPA). The paper towel was rinsed with 4L of water to remove water-soluble components. The washed paper towel was placed in 4L of 100% ethanol, and then filtered with filter paper (same as above) under reduced pressure (-0.1MPA) to obtain a filtrate. The filtered tissue was rinsed with 4L of 100% ethanol and filtered. The two filtrates were combined and rotary evaporated (70 ℃ C., -0.1MPA) to give 900g of a purified crude oil, better in flowability, containing 12.83 wt% EPA and 67.11 wt% TFA.
The fluidity of the algal oil in this example was greatly improved and the purity of the polyunsaturated fatty acids was improved compared to the unpurified algal oil.
Determination of fatty acid composition in dried algae
0.100g of the dried algae of example 1 or 5 was weighed into a 50mL glass hydrolysis tube (with a lid), 21mL of chloroform-methanol mixture (2:1, v/v) was added, and the mixture was shaken for 12 hours at 200r/min in a shaker. The hydrolysis tube was removed from the shaker, placed in a water bath at 60 ℃ and blown dry with nitrogen, then 10mL of 5% methanolic sulfate solution (95mL methanol +5mL sulfuric acid) was added and placed in a water bath at 100 ℃ for 1 h. The hydrolysis tube was removed from the water bath, cooled, then 2mL n-hexane was added, mixed well, and an appropriate amount of deionized water was added to stratify the solution. The upper organic phase was passed through a 0.22 μm organic membrane (nylon, brand: agilent) and loaded into a sample bottle, which was placed on a GC sample tray, and was ready for testing.
The GC detection instrument is Agilent 7890B, an FID detector, a chromatographic column: agilent 19091J-413HP-530m 0.32mm 0.25 μm. Sample introduction volume: 1 μ L, injection port temperature: at 250 ℃ without splitting. Temperature programming: 60 deg.C (0min) -270 deg.C (31.25min) @8 deg.C/min, 5min, 270 deg.C (31.25min) -280 deg.C (38.25min) @2 deg.C/min, 2 min. The detector temperature is 280 ℃, the air flow is 400mL/min, the hydrogen gas flow is 30mL/min, and the tail gas blowing flow is 31.5 mL/min.
Determination of fatty acid composition in non-transesterified algal oil
After distilling off any ethanol present, 0.05g of the algal oil of example 2, 3, 6, 7, 9 or 10 was weighed out, and then 10mL of 5% methanol sulfate solution was added thereto in a water bath at 100 ℃ for 1 hour. Taking out the hydrolysis tube, cooling, adding 5mL of n-hexane, mixing, adding a proper amount of deionized water for layering, putting the upper organic phase into a sample bottle after passing through a 0.22 mu m organic film, putting the bottle on a GC sample tray, and waiting for detection.
The compositional measurements were performed using the same instruments and parameters described above.
Determination of fatty acid composition in transesterified algal oil
After distilling off the ethanol which may be present, 0.05g of the algal oil of example 4 or 8 was weighed out, and then dissolved in n-hexane to a volume of 10 mL. After passing through a 0.22 μm organic film, the mixture was put into a sample bottle and put on a GC sample plate to wait for detection.
The compositional measurements were performed using the same instruments and parameters described above.
The present invention has been described with reference to the above specific embodiments, but these embodiments do not limit the scope of the present invention. The scope of protection of the invention is defined by the appended claims.
Claims (7)
1. A method for purifying algal oil containing polyunsaturated fatty acids in the form of triglycerides, glycolipids and phospholipids, or esterified polyunsaturated fatty acids after transesterification with lower alcohols, comprising:
1) contacting the algae oil with dilute acid at room temperature, adding calcium carbonate to neutralize the acid, and removing precipitates by filtering or centrifuging, wherein the working concentration of the dilute acid is 0.01-0.1 mol/L;
2) contacting the algae oil with an alcohol-water solution in the presence of a lipid adsorbent, wherein the volume ratio of alcohol to water in the alcohol-water solution is below 1:1, the weight-to-volume ratio of the algae oil to alcohol in the alcohol-water solution is 0.2-0.4g/mL, and the lipid adsorbent is selected from paper towels and activated carbon;
3) separating the oil adsorbent from the alcohol-water solution;
4) optionally, washing the grease sorbent with water; and
5) separating the algae oil from the lipid adsorbent.
2. The method of claim 1, wherein the alcohol-water solution is selected from a methanol-water solution, an ethanol-water solution, a propanol-water solution, or a combination thereof.
3. The method of claim 1, wherein the algal oil is contacted with the alcohol-water solution with stirring for 2 hours.
4. The process of claim 1, wherein the dilute acid is selected from dilute sulfuric acid, dilute hydrochloric acid, and dilute nitric acid.
5. The method of claim 1, wherein step 5) is accomplished by dissolving the algal oil with a suitable solvent and removing the lipid adsorbent by filtration or centrifugation.
6. The method of claim 5, wherein the suitable solvent is absolute ethanol.
7. The method of claim 1, wherein the lower alcohol with which the algal oil is subjected to transesterification reaction is selected from the group consisting of methanol, ethanol, and propanol.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810837473.5A CN110760376B (en) | 2018-07-26 | 2018-07-26 | Novel algae oil purification method |
| CN202011126530.2A CN112210437B (en) | 2018-07-26 | 2018-07-26 | Method for purifying algae oil |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810837473.5A CN110760376B (en) | 2018-07-26 | 2018-07-26 | Novel algae oil purification method |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011126530.2A Division CN112210437B (en) | 2018-07-26 | 2018-07-26 | Method for purifying algae oil |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110760376A CN110760376A (en) | 2020-02-07 |
| CN110760376B true CN110760376B (en) | 2020-11-13 |
Family
ID=69327295
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810837473.5A Active CN110760376B (en) | 2018-07-26 | 2018-07-26 | Novel algae oil purification method |
| CN202011126530.2A Active CN112210437B (en) | 2018-07-26 | 2018-07-26 | Method for purifying algae oil |
Family Applications After (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011126530.2A Active CN112210437B (en) | 2018-07-26 | 2018-07-26 | Method for purifying algae oil |
Country Status (1)
| Country | Link |
|---|---|
| CN (2) | CN110760376B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11401540B2 (en) * | 2017-11-17 | 2022-08-02 | Guangxi Xiaozao Agriculture Technology Co., Ltd. | Production of algae-derived polyunsaturated fatty acids |
| CN117343792A (en) * | 2023-10-30 | 2024-01-05 | 临沂友康生物科技有限公司 | Algae oil purification equipment and purification method thereof |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102746947B (en) * | 2012-07-18 | 2013-10-02 | 福建华尔康生物科技有限公司 | Method for separating and purifying DHA (docosahexaenoic acid) and saturated fatty acid from schizochytrium limacinum oil |
| CN103937604B (en) * | 2014-04-08 | 2016-07-06 | 北京化工大学 | A kind of extract the method for oils and fats in microalgae |
| CN104059773A (en) * | 2014-07-02 | 2014-09-24 | 华南理工大学 | Method for wet extraction of purified microalgae oil |
| CN107760440A (en) * | 2017-12-07 | 2018-03-06 | 河西学院 | A kind of method of purification of microalgae grease |
-
2018
- 2018-07-26 CN CN201810837473.5A patent/CN110760376B/en active Active
- 2018-07-26 CN CN202011126530.2A patent/CN112210437B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN112210437A (en) | 2021-01-12 |
| CN112210437B (en) | 2023-10-13 |
| CN110760376A (en) | 2020-02-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| WO1994024984A2 (en) | Anti-inflammatory compositions containing eicosapentaenoic acid bearing monogalactosyldiacylglycerol and methods relating thereto | |
| Cartens et al. | Eicosapentaenoic acid (20∶ 5n-3) from the marine microalga Phaeodactylum tricornutum | |
| CA1273640A (en) | Method for obtaining lipids from fungus bodies | |
| US11401540B2 (en) | Production of algae-derived polyunsaturated fatty acids | |
| CN105601666B (en) | Method of phosphatide and products thereof is extracted in a kind of fish head from silver carp | |
| CN106794394A (en) | Method and apparatus for being demulsified and be combined organic compound in emulsion | |
| CN110760376B (en) | Novel algae oil purification method | |
| JPH0225447A (en) | Production of highly unsaturated fatty acids | |
| WO2002012159A1 (en) | Process for producing oleanolic acid and/or maslinic acid | |
| CN111187660B (en) | Method for extracting high-quality krill oil from krill | |
| US11180445B2 (en) | Method for recycling urea in urea adduct process | |
| ES2937926T3 (en) | Cholesterol in fish oil | |
| AU2023208144A1 (en) | Process for producing antarctic krill oil | |
| CN101584366A (en) | Be rich in the preparation method of the Chinese gooseberry seed oil of alpha-linolenic acid | |
| CN109988670B (en) | Decolorization of algal polyunsaturated fatty acids | |
| CN110004190A (en) | A method of preparing lecithin epoxy-type polyunsaturated fatty acid | |
| US20230271930A1 (en) | Process for isolation and purification of thca from cannabis | |
| RU2698720C1 (en) | Method of producing docosahexaenoic acid | |
| CN111979051A (en) | Method for extracting polyunsaturated fatty acid from microalgae algal oil | |
| CN108157970A (en) | The preparation method of the compound grease microcapsule of silkworm chrysalis | |
| CN109894075A (en) | The preparation method of one vegetable oil deacidification agent | |
| RU2404786C2 (en) | METHOD FOR PRODUCTION OF EXTRACT FROM CYSTS OR NAUPLII, OR ADULT MAXILLOPOD Artemia salina FOR EXTERNAL OR INTERNAL USE | |
| JPH01207258A (en) | Method for removing acid | |
| CN109081850A (en) | A method of high bioactivity phosphatide is prepared from tuna eye | |
| CN107573303B (en) | Novel fatty acid compound and separation preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| TA01 | Transfer of patent application right |
Effective date of registration: 20200729 Address after: Room 404, 4 / F, unit 2, building 3, Hengda yujingwan, No. 99, Beibu Wan Avenue, Port District, Fangchenggang City, Guangxi Zhuang Autonomous Region Applicant after: Fangchenggang microalgae Medicine Technology Co., Ltd Address before: 518057 North Block 301, Yuanxing Science and Technology Building, No. 1 Songpingshan Road, Nanshan District, Shenzhen City, Guangdong Province Applicant before: SHENZHEN QIANHAI XIAOZAO TECH Co.,Ltd. |
|
| TA01 | Transfer of patent application right | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |