阅读说明：本技术 从谷糠油、藜麦麸皮油、牡丹籽油、鱼油、磷虾油、蜂花粉油等油脂中精练脂肪酸的方法 (Method for refining fatty acid from oil and fat such as testa oryzae oil, quinoa bran oil, peony seed oil, fish oil, krill oil, bee pollen oil, etc ) 是由 侯召华 傅茂润 赵悦菡 于 2019-10-10 设计创作，主要内容包括：本发明涉及一种提取谷糠、藜麦麸皮油、牡丹籽油、鱼油、磷虾油等油脂中得到游离脂肪酸的精炼方法。其工艺流程：油脂→乙酯化或甲酯化→尿素包合→分子蒸馏精炼→成品。本发明采用先酯化、尿素包合和分子蒸馏技术结合精炼；在脂肪酸酯中添加适量甲酸、乙酸、柠檬酸,可以促进分解,该方法能节省时间,提高效率,且保持游离脂肪酸的品质。本发明高效环保、工艺简单,适宜游离脂肪酸规模化生产。(The invention relates to a refining method for extracting free fatty acid from oil such as bran coat, quinoa bran oil, peony seed oil, fish oil and krill oil. The process flow comprises the following steps: grease → ethyl esterification or methyl esterification → urea inclusion → molecular distillation refining → finished product. The invention adopts the combination of esterification, urea inclusion and molecular distillation technologies for refining; the addition of appropriate amounts of formic acid, acetic acid, and citric acid to the fatty acid ester can promote decomposition, save time, improve efficiency, and maintain the quality of free fatty acid. The method is efficient, environment-friendly and simple in process, and is suitable for large-scale production of the free fatty acid.)

1. A method for refining fatty acid from oil and fat such as bran oil, quinoa bran oil, peony seed oil, fish oil, krill oil, and the like, is characterized by comprising the following steps:

extracting oil from bran oil, quinoa bran oil, peony seed oil, fish oil or krill oil;

and (3) carrying out esterification, urea inclusion, acid treatment and molecular distillation on the grease to obtain the oil.

2. The method for refining fatty acids from oils and fats such as bran oil, quinoa bran oil, peony seed oil, fish oil, krill oil, etc. according to claim 1, wherein the method for extracting oils and fats comprises: squeezing, solvent extraction, ultrasonic assisted solvent extraction or supercritical extraction.

3. The method for refining fatty acids from oils and fats such as bran oil, quinoa bran oil, peony seed oil, fish oil, krill oil, etc. as claimed in claim 1, wherein the bran oil is obtained by subcritical extraction, and the subcritical temperature: 30-55 ℃; the extraction time is 30-80 min; the extraction times are 1-5 times; the extraction pressure is 0.4-1.0 MPa.

4. The method for refining fatty acids from oils and fats such as bran oil, quinoa bran oil, peony seed oil, fish oil, krill oil, etc. as claimed in claim 1, wherein the esterification conditions are: mixing oil and fat with KOH, ethanol or methanol uniformly, heating and refluxing under the protection of inert gas, carrying out hydrolysis reaction, and after the reaction is finished, adjusting the pH value to 2-4 to generate free fatty acid; the resulting salts, water and glycerol were removed by layer extraction.

5. The method for refining fatty acid from oil and fat such as bran oil, quinoa bran oil, peony seed oil, fish oil, krill oil and the like according to claim 1, wherein the urea inclusion comprises the following specific steps:

under the condition of heating reflux, uniformly mixing the mixed solution of methanol and urea with free fatty acid to form a fatty acid mixed solution, cooling to room temperature, standing at-15-5 ℃ for inclusion for 8-24 h, acidifying a hydration layer to acidity, placing in a separating funnel, extracting with n-hexane for three times, retaining an organic phase, washing with water for three times, removing water, and concentrating under reduced pressure to obtain unsaturated fatty acid.

6. The method of refining fatty acids from oils and fats such as bran oil, quinoa bran oil, peony seed oil, fish oil, krill oil, etc. as claimed in claim 1, wherein said acidifying conditions are: mixing unsaturated fatty acid with formic acid, acetic acid or citric acid, and acidifying.

7. The method of refining fatty acids from oils and fats such as bran oil, quinoa bran oil, peony seed oil, fish oil, krill oil, etc. as claimed in claim 1, wherein said acidifying conditions are: the temperature is 0-25 deg.C, and the time is 30-120 min.

8. The method for refining fatty acid from oil and fat such as bran oil, quinoa bran oil, peony seed oil, fish oil and krill oil according to claim 1, wherein the molecular distillation is a three-stage molecular distillation under conditions of vacuum degree of 1-5 mbar, 70-90 ℃ and rotation speed of 200-260 rpm; the vacuum degree is 0.05-0.1 mbar, the temperature is 90-180 ℃, and the rotating speed is 200-300 rpm; the vacuum degree is 0.001-0.02 mbar, the temperature is 120-200 ℃, and the rotating speed is 250-350 rpm.

9. The fatty acid produced by the method of refining fatty acid from oil and fat such as bran oil, quinoa bran oil, peony seed oil, fish oil, krill oil, etc. according to claim 1.

10. Use of the fatty acids of claim 9 in the preparation of synthetic triglycerides of caprylic/capric acid, polyol esters, and metal lubricants and personal care emollient products, herbicides, fungicides in animal feed, corrosion/rust inhibitors for antifreeze, mining flotation agents, creams and emulsions, plasticizers.

Technical Field

The invention belongs to the field of food processing, and particularly relates to a refining method for obtaining fatty acid from oil such as bran oil, quinoa bran oil, peony seed oil, fish oil and krill oil.

Background

The information in this background section is only for enhancement of understanding of the general background of the invention and is not necessarily to be construed as an admission or any form of suggestion that this information forms the prior art that is already known to a person of ordinary skill in the art.

Fatty acids are biological compounds of particular importance because they intervene in a variety of biological processes, such as the construction and maintenance of cell membranes, the synthesis of hormones (e.g., prostanoids) that act in platelet aggregation, inflammatory processes and immune responses, among others.

Fatty acids are also an important industrial raw material, and the production and separation processes of fatty acids have a long history. The medium-chain fatty acid can be used for synthesizing caprylic/capric triglyceride, polyol ester and the like, is used for metal lubricants and personal care product skin moistening, and is also used for herbicides, bactericides in animal feeds, corrosion/rust inhibitors of antifreezing agents, mining flotation agents, formulas of creams and emulsions, raw materials of plasticizers and the like.

One of the methods for producing fatty acid is to hydrolyze fatty acid methyl ester or fatty acid ethyl ester under certain conditions to obtain fatty acid. In the hydrolysis of fatty acid methyl ester or fatty acid ethyl ester, it was found that it takes a long time (24h to 72h) to completely hydrolyze fatty acid methyl ester or fatty acid ethyl ester to fatty acid, and the production efficiency was low. After hydrolysis, purification is generally carried out by recrystallization. Fatty acids are unstable, the longer they are in contact with oxygen, the more chance of oxidation increases.

Disclosure of Invention

In order to overcome the problems, the invention provides a method for preparing high-purity fatty acid from oil and fat such as bran oil, quinoa bran oil, peony seed oil, fish oil, krill oil and the like by using a refining mode of combining esterification, urea inclusion and molecular distillation.

In order to achieve the technical purpose, the technical scheme adopted by the invention is as follows:

a method for refining fatty acids from oils and fats such as bran oil, quinoa bran oil, peony seed oil, fish oil, krill oil, etc., comprising:

extracting oil from bran oil, quinoa bran oil, peony seed oil, fish oil or krill oil;

and (3) carrying out esterification, urea inclusion, acid treatment and molecular distillation on the grease to obtain the oil.

The research of the application finds that: the unsaturated fatty acid after urea inclusion is subjected to acid treatment, the formation of the fatty acid can be promoted, the proportion of the fatty acid in a finished product after molecular distillation is improved, and the method realizes the quick separation of the hydrolyzed fatty acid and obtains the high-purity fatty acid.

The method for extracting the oil is not particularly limited in this application, and in some embodiments, the method for extracting the oil is as follows: squeezing, solvent extraction, ultrasonic-assisted solvent extraction or supercritical extraction to improve the extraction efficiency and purity of the oil.

In some embodiments, the bran oil is obtained by subcritical extraction, subcritical temperature: 30-55 ℃; the extraction time is 30-80 min; the extraction times are 1-5 times; the extraction pressure is 0.4-1.0MPa, and the yield and the purity of the bran oil are improved.

In some embodiments, the esterification conditions are: mixing oil and fat with KOH, ethanol or methanol uniformly, heating and refluxing under the protection of inert gas, carrying out hydrolysis reaction, and after the reaction is finished, adjusting the pH value to 2-4 to generate free fatty acid; the resulting salt, water and glycerol were removed by layer extraction to obtain free fatty acids.

In some embodiments, the specific steps of urea inclusion are:

under the condition of heating reflux, uniformly mixing the mixed solution of methanol-urea or ethanol-urea with free fatty acid to form a fatty acid mixed solution, cooling to room temperature, standing at-15-5 ℃ for inclusion for 8-24 h, acidifying a hydration layer to acidity, placing in a separating funnel, extracting with n-hexane or petroleum ether for three times, retaining an organic phase, washing with water for three times, removing water, and concentrating under reduced pressure to obtain unsaturated fatty acid. In the solid phase of the urea inclusion compound, the purity of saturated and monounsaturated fatty acid is greatly improved, and the integral separation effect is improved.

In some embodiments, the acidification conditions are: mixing unsaturated fatty acid with formic acid, acetic acid or citric acid, and acidifying. The unsaturated fatty acid after urea inclusion is subjected to acid treatment, so that the formation of the fatty acid can be promoted, and the proportion of the fatty acid in a finished product after molecular distillation is improved.

The research finds that: as the acidification temperature is increased, the proportion of fatty acids increases, but if the temperature reaches a certain level, the increase in the temperature is not large enough to increase the proportion of fatty acids, so in some embodiments, the acidification conditions are: the temperature is 0-25 ℃, and the time is 30-120min, so that the acidification efficiency is improved, and the cost is reduced.

In some embodiments, the molecular distillation is three-stage molecular distillation under the conditions of vacuum degree of 1-5 mbar, 70-90 ℃ and rotation speed of 200-260 rpm; the vacuum degree is 0.05-0.1 mbar, the temperature is 90-180 ℃, and the rotating speed is 200-300 rpm; the vacuum degree is 0.001-0.02 mbar, the temperature is 120-200 ℃, and the rotating speed is 250-350 rpm. The molecular distillation method performs liquid phase separation under high vacuum condition according to different carbon chain lengths and saturation degrees of fatty acids in the fish oil, so that the boiling point of the substances to be separated is reduced, the separation time is greatly shortened, the extraction efficiency is high, and the environmental pollution is low.

The invention also provides the fatty acid prepared by the method for refining the fatty acid from the oil and fat such as the bran oil, the quinoa bran oil, the peony seed oil, the fish oil and the krill oil.

The invention also provides the application of the fatty acid in the preparation of synthetic caprylic/capric triglyceride, polyol ester, metal lubricant, personal care skin-moistening product, herbicide, bactericide in animal feed, corrosion/rust inhibitor of antifreezing agent, mining flotation agent, face cream and emulsion, and plasticizer.

The invention has the beneficial effects that:

(1) the invention provides a method for extracting fatty acid from oil such as bran oil, quinoa bran oil, peony seed oil, fish oil and krill oil, and refining the fatty acid in a mode of combining molecular distillation, wherein the whole process is carried out at a low temperature, and unsaturated fatty acid can be effectively maintained.

(2) Acid is added in the esterification, so that the fatty acid proportion can be effectively improved.

(3) The molecular distillation technology is a physical mode, and the processes of fatty acid generation, purification, extraction and the like are completed at one time. Compared with the traditional mode, the pretreatment in the early stage is simple, the consumed time is short, and the total time can be shortened to one third of the original time.

(4) The method is efficient, environment-friendly, simple in process, strong in practicability, suitable for large-scale production and easy to popularize.

Detailed Description

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

As introduced in the background art, the method aims at the problems of low fatty acid separation efficiency, complicated steps and low purity at present. Accordingly, the present invention provides a method for refining free fatty acids, comprising:

1) oil such as rice bran oil, quinoa bran oil, peony seed oil, fish oil, krill oil, etc.;

2) performing ethyl esterification or methyl esterification on the grease;

3) urea inclusion, namely, resolution of unsaturated fatty acid and saturated fatty acid;

4) adding appropriate amount of formic acid, acetic acid and citric acid into fatty acid methyl ester or fatty acid ethyl ester;

5) short-path molecular distillation technology, multi-stage molecular distillation treatment, and obtaining a fatty acid product with the concentration of more than or equal to 80%.

The research of the application finds that: molecular distillation refining provides fatty acids: (1) capable of hydrolyzing fatty acid ethyl esters or fatty acid methyl esters to form fatty acids; (2) meanwhile, impurities can be separated, so that the time is saved; (3) adding appropriate amount of formic acid, acetic acid, and citric acid into the esterified product to promote hydrolysis; (3) degassing, which helps to protect free fatty acids, especially unsaturated fatty acids; (4) the molecular distillation is carried out under low vacuum, and oxidation is effectively avoided.

In some embodiments, the fat may be obtained by pressing, extraction, subcritical extraction, and the like.

In some embodiments, the grease may be either ethyl esterified or methyl esterified.

In some embodiments, the molecular distillation refining is three-stage molecular distillation under the conditions of vacuum degree of 1-5 mbar, 70-90 ℃ and rotation speed of 200-260 rpm respectively; the vacuum degree is 0.05-0.1 mbar, the temperature is 90-180 ℃, and the rotating speed is 200-300 rpm; the vacuum degree is 0.001-0.02 mbar, the temperature is 120-200 ℃, and the rotating speed is 250-350 rpm.

In some embodiments, the fatty acid content may be increased by adding certain amounts of formic acid, acetic acid, citric acid, and the like during the molecular distillation.

In some embodiments, the fatty acid content of the product is no less than 80%.

The technical solution of the present application will be described below with specific examples.

The process flow of the invention is as follows: grease → ethyl esterification or methyl esterification → urea inclusion → acidification → molecular distillation and refining → finished product.

The method specifically comprises the following steps:

a method of refining fatty acids comprising: the method comprises the following steps of ethyl esterification or methyl esterification, urea inclusion and molecular distillation refining:

(1) raw materials; bran oil, quinoa bran oil, peony seed oil, fish oil, krill oil, etc.;

(2) esterification: esterification is carried out by ethyl esterification or methyl esterification, and KOH-ethanol or KOH-methanol;

(3) urea inclusion: resolving saturated fatty acid and unsaturated fatty acid;

(4) acid treatment: 0.1-5.0% formic acid, acetic acid, or citric acid;

(5) molecular distillation refining: carrying out molecular distillation refining on the fatty acid ethyl ester or the fatty acid methyl ester obtained in the step (4); three-stage molecular distillation is carried out under the conditions of vacuum degree of 1-5 mbar, temperature of 70-90 ℃ and rotation speed of 200-260 rpm respectively; the vacuum degree is 0.05-0.1 mbar, the temperature is 90-180 ℃, and the rotating speed is 200-300 rpm; the vacuum degree is 0.001-0.02 mbar, the temperature is 120-200 ℃, and the rotating speed is 250-350 rpm.

(7) Finished oil production: the fatty acid content is not less than 80%.

In order to solve the problems of long time consumption, complex steps and difficult impurity removal of the conventional fatty acid hydrolysis refining, the invention discovers the following components by a large number of experiments on the basis of systematically analyzing the composition of the raw material oil and the extraction and refining rules: the molecular distillation technology is adopted to hydrolyze the fatty acid ethyl ester or the fatty acid methyl ester, and refining and physical modes are carried out simultaneously, so that the pollution is reduced.

On the other hand, the research of the invention also finds that: the addition of a suitable amount of acid can facilitate the resolution.

The research finds that: the hydrolysis of the fatty acid ester is time-consuming, the removal of impurities is difficult, and the short-path molecular distillation refining can combine two processes into one, can effectively promote the hydrolysis and remove the impurities.

Preferably, the additive solvent is: formic acid, acetic acid and citric acid, the addition amount is 0.1-5.0%;

preferably, the molecular distillation refining conditions are as follows: three-stage molecular distillation is carried out under the conditions of vacuum degree of 1-5 mbar, temperature of 70-90 ℃ and rotation speed of 200-260 rpm respectively; the vacuum degree is 0.05-0.1 mbar, the temperature is 90-180 ℃, and the rotating speed is 200-300 rpm; the vacuum degree is 0.001-0.02 mbar, the temperature is 120-200 ℃, and the rotating speed is 250-350 rpm.