阅读说明：本技术 一种脂肪酸的酶法提取工艺 (Enzymatic extraction process of fatty acid ) 是由 周建根 刘飞 刘成林 范军伟 王媚艳 于 2019-08-30 设计创作，主要内容包括：本发明公开了一种脂肪酸的酶法提取工艺,包括以下步骤：1)将皂脚或油脚加入容器内,并加入水搅拌均匀,得到第一混合物；2)采用酸溶液对第一混合物调节PH至4～6；3)向第一混合物中加入复合酶,控制温度,搅拌24～72h进行酶解反应,得到第二混合物；4)将步骤3)酶解反应后的第二混合物升温至80～90℃,保温一定时间；5)经步骤4)处理的第二混合物中加入沉降剂,自然降温沉降；6)经沉降后的第二混合物进行油水分离,得到脂肪酸。本发明的脂肪酸的酶法提取工艺,向皂脚或油脚中加入复合酶进行酶解反应,使用复合酶制剂可加快反应快速,反应温和,提高中性油和脂肪酸的收率。(The invention discloses an enzymatic extraction process of fatty acid, which comprises the following steps: 1) adding soapstock or oil residue into a container, adding water, and stirring uniformly to obtain a first mixture; 2) adjusting the pH of the first mixture to 4-6 by using an acid solution; 3) adding a complex enzyme into the first mixture, controlling the temperature, and stirring for 24-72 hours to perform an enzymolysis reaction to obtain a second mixture; 4) heating the second mixture obtained after the enzymolysis reaction in the step 3) to 80-90 ℃, and preserving heat for a certain time; 5) adding a settling agent into the second mixture treated in the step 4), and naturally cooling and settling; 6) and carrying out oil-water separation on the settled second mixture to obtain the fatty acid. According to the enzymatic extraction process of fatty acid, the complex enzyme is added into the soapstock or the oil residue for enzymolysis reaction, the reaction can be accelerated rapidly by using the complex enzyme preparation, the reaction is mild, and the yield of neutral oil and fatty acid is improved.)

1. An enzymatic extraction process of fatty acid is characterized by comprising the following steps:

1) adding soapstock or oil residue into a container, adding water, and stirring uniformly to obtain a first mixture;

2) adjusting the pH of the first mixture to 4-6 by using an acid solution;

3) adding a complex enzyme into the first mixture, controlling the temperature, and stirring for 24-72 hours to perform an enzymolysis reaction to obtain a second mixture;

4) heating the second mixture obtained after the enzymolysis reaction in the step 3) to 80-90 ℃, and preserving heat for a certain time;

5) adding a settling agent into the second mixture treated in the step 4), and naturally cooling and settling;

6) and carrying out oil-water separation on the settled second mixture to obtain the fatty acid.

2. The enzymatic extraction process of fatty acids according to claim 1, wherein the mass ratio of the soapstock or oil residue and water in step 1) is 1: 2-5.

3. The enzymatic extraction process of fatty acids according to claim 1, wherein the acid solution in step 2) is citric acid or acetic acid with a mass concentration of 10-20%.

4. The enzymatic extraction process of fatty acids according to claim 1, wherein the enzymolysis temperature in step 3) is 40-60 ℃.

5. The enzymatic extraction process of fatty acids according to claim 1, wherein the amount of the complex enzyme in step 3) is 0.05-0.5% of the mass of the soapstock or the oil residue in step 1).

6. The enzymatic extraction process of fatty acids according to claim 1, wherein the heat preservation time in step 4) is 30-60 min.

7. The enzymatic extraction process of fatty acid according to claim 1, wherein the sedimentation agent in step 5) is NaCl with a mass concentration of 5-20%, and the sedimentation time is 24-72 h.

8. The enzymatic extraction process of fatty acids according to claim 1, wherein the complex enzyme comprises 40-50 wt% of acid lipase, 30-40 wt% of neutral lipase and 10-20 wt% of phospholipase A2.

Technical Field

The invention relates to the technical field of food processing, in particular to an enzymatic extraction process of fatty acid.

Background

The vegetable oil is mainly eaten by people in China, and most edible oil needs to be refined. The refining of the crude oil is not questionable depending on the variety, impurity content and grade of the edible oil, but is mainly divided into two main types of alkali refining and hydration, the sediment obtained by the alkali refining is called soapstock, and the sediment obtained by the hydration is called oil stock, except that the former adopts liquid alkali to neutralize free fatty acid in the crude oil into fatty acid sodium salt and form soap colloid in which impurities such as neutral oil and pigment are entrained, and the latter adopts water to make phospholipid in the crude oil absorb water and swell to form colloid in which neutral oil and other impurities are entrained, wherein the amount of the entrained neutral oil is generally related to the impurity content of the crude oil, the refining method, the operation technology and the like.

Cottonseed oil, rice bran oil and other vegetable oils with acid values not reaching the quality of edible oil all need alkali refining, domestic soapstock mainly comprises cotton oil soapstock, and is mainly concentrated in the areas for producing dregs, such as Shandong, Jiangsu, Hebei, Henan, Anhui, and the like.

Rapeseed oil, soybean oil, peanut meal and vegetable oil containing phospholipid all need hydration to remove phospholipid, and rapeseed oil residues are mainly concentrated in southern provinces, are quite large in number, and are fully developed and utilized at present. Secondly, the soybean oil residue is mainly saved in northeast; the main industrial use of acidified oils is the manufacture of fatty acid methyl esters (biodiesel). Also for the production of oleic acid; the fatty acid content of the soapstock comprises two parts of soap and neutral oil, wherein the soap content is about 25-30%, the neutral oil content is 12-25%, and the total fatty acid content is about 40-50%; the fatty matter in the oil residue comprises two parts, namely phospholipid and neutral oil, and the total content of the fatty matter is about 20-40%; the crude oil obtained by oil seeds all contain phospholipid, and the content of the phospholipid is different according to the variety and the preparation method of the oil seeds. The soybean oil and corn oil obtained by the leaching method contain 1-3% of phospholipid. Because the phospholipid is similar to a grease structure, only two fatty acids are combined with two hydroxyl groups, and the other phosphorus-containing compound is combined with the hydroxyl groups, after hydrolysis, one less fatty acid molecule exists; the fatty acid component of the phospholipid after hydrolysis is substantially similar to the fatty acid component of the lipid after hydrolysis.

Soapstock is the most valuable of the oil and fat refining by-products in terms of quantity and content. The soapstock contains all the fatty acids of the starting fats and oils and is present in the form of soap. Adding excessive alkali in the alkali refining process to saponify part of the neutral oil and transfer the saponified oil into soapstock; meanwhile, the soapstock inevitably carries a part of neutral oil, and in addition, alkali, glycerol, protein, pigment and the like; gossypol in the cotton oil is also brought into the soapstock, and the gossypol is unstable in an alkaline medium and is quickly converted into various dark compounds which enable the soapstock to have dark brown to black colors.

Disclosure of Invention

In view of the above disadvantages, the present invention aims to provide an enzymatic extraction process for fatty acids, which has the advantage of high yield of extracted fatty acids.

The technical scheme of the invention is summarized as follows:

an enzymatic extraction process of fatty acid, which comprises the following steps:

1) adding soapstock or oil residue into a container, adding water, and stirring uniformly to obtain a first mixture;

2) adjusting the pH of the first mixture to 4-6 by using an acid solution;

3) adding a complex enzyme into the first mixture, controlling the temperature, and stirring for 24-72 hours to perform an enzymolysis reaction to obtain a second mixture;

4) heating the second mixture obtained after the enzymolysis reaction in the step 3) to 80-90 ℃, and preserving heat for a certain time;

5) adding a settling agent into the second mixture treated in the step 4), and naturally cooling and settling;

6) and carrying out oil-water separation on the settled second mixture to obtain the fatty acid.

Preferably, the fatty acid enzymatic extraction process comprises the step 1) of mixing soapstock or oil residue with water in a mass ratio of 1: 2-5.

Preferably, in the enzymatic extraction process of fatty acid, the acid solution in the step 2) is citric acid with the mass concentration of 10-20% or acetic acid with the mass concentration of 10-20%.

Preferably, the fatty acid enzymatic extraction process is carried out at a temperature of 40-60 ℃ in the step 3).

Preferably, the process for extracting the fatty acid by the enzyme method comprises the step 3) of adding the complex enzyme in an amount of 0.05-0.5% of the mass of the soapstock or the oil residue in the step 1).

Preferably, the fatty acid enzymatic extraction process is characterized in that the heat preservation time in the step 4) is 30-60 min.

Preferably, in the enzymatic extraction process of fatty acid, the sedimentation agent in the step 5) is 5-20% of NaCl, and the sedimentation time is 24-72 h.

Preferably, the process for extracting the fatty acid by the enzyme method comprises the steps of mixing 40-50 wt% of acid lipase, 30-40 wt% of neutral lipase and 10-20 wt% of phospholipase A2.

The invention has the beneficial effects that:

(1) according to the enzymatic extraction process of fatty acid, the complex enzyme is added into the soapstock or the oil residue for enzymolysis reaction, the reaction can be accelerated rapidly by using the complex enzyme preparation, the reaction is mild, and the yield of neutral oil and fatty acid is improved.

(2) The compound enzyme preparation used in the invention comprises acid lipase, neutral lipase and phospholipase A2 which are compounded in a certain proportion, so that the neutral oil in soapstock and oil residue can be quickly and effectively separated from soap and hydrolyzed, the conversion rate and yield of fatty acid extracted from the soapstock and the oil residue are optimal, and the yield of the fatty acid is improved by 15-26%.

Detailed Description

The present invention is further described in detail below with reference to examples so that those skilled in the art can practice the invention with reference to the description.

The invention provides an enzymatic extraction process of fatty acid, which comprises the following steps:

1) adding soapstock or oil residue into a container, adding water, and stirring uniformly to obtain a first mixture;

2) adjusting the pH of the first mixture to 4-6 by using an acid solution;

3) adding a complex enzyme into the first mixture, controlling the temperature, and stirring for 24-72 hours to perform an enzymolysis reaction to obtain a second mixture;

4) heating the second mixture obtained after the enzymolysis reaction in the step 3) to 80-90 ℃, and preserving heat for a certain time;

5) adding a settling agent into the second mixture treated in the step 4), and naturally cooling and settling;

6) and carrying out oil-water separation on the settled second mixture to obtain the fatty acid.

The soapstock is a by-product in the process of refining animal and vegetable oil by alkali, is a product in a deacidification section, mainly contains fatty acid salt, namely sodium fatty acid generated by the reaction of free fatty acid in the oil and sodium hydroxide, and contains less neutral oil and more pigments and electrolytes; the neutral oil comprises glyceride and cholesterol, the oil foot is the by-product of hydration degumming in the oil refining process, the professional name is wet glue, a certain amount of hot water or diluted acid, alkali, salt and other electrolyte aqueous solution are added into the oil by utilizing hydrophilic groups contained in lipoid molecules such as phospholipid and the like, colloid impurities in the oil are expanded and coagulated by absorbing water, finally, the settled colloid is called the oil foot, the main components are phospholipid, neutral oil, moisture and other lipoid, and a small amount of protein, sugar, wax and pigment, as well as organic impurities and inorganic impurities.

As another embodiment of the scheme, the mass ratio of the soapstock or the oil residue in the step 1) to the water is 1: 2-5.

As another embodiment of the present disclosure, the acid solution in step 2) is citric acid with a mass concentration of 10-20% or acetic acid with a mass concentration of 10-20%.

As another embodiment of the present application, the temperature in step 3) is 40-60 ℃.

As another embodiment of the scheme, the adding amount of the complex enzyme in the step 3) is 0.05-0.5% of the mass of the soapstock or the oil residue in the step 1).

As another embodiment of the scheme, the heat preservation time in the step 4) is 30-60 min.

As another embodiment of the present application, in the step 5), the sedimentation agent is 5-20% NaCl, and the sedimentation time is 24-72 h.

As another embodiment of the present invention, the complex enzyme comprises 40 to 50 wt% of acid lipase, 30 to 40 wt% of neutral lipase and 10 to 20 wt% of phospholipase A2. The acid lipase can hydrolyze glyceride and cholesterol, the neutral lipase can catalyze and hydrolyze triacylglycerols to generate diglyceride, monoglyceride, glycerol and free fatty acid, and the acidic lipase has high stability, selectivity and substrate specificity; the phospholipase is a hydrolase which can catalyze the two-position acyl on the phospholipid glycerol molecule, and the acid lipase, the neutral lipase and the phospholipase A2 have synergistic effect, so that the conversion rate and the yield of fatty acid extracted from the soapstock and the oil residue are optimal.

Specific examples and comparative examples are listed below:

example 1:

an enzymatic extraction process of fatty acid comprises the following steps:

1) adding 300g of soapstock into a container, adding 600g of water, and uniformly stirring to obtain a first mixture;

2) adjusting the pH of the first mixture to 4 with 10% acetic acid solution;

3) adding 0.15g of complex enzyme into the first mixture, wherein the complex enzyme comprises 40 wt% of acid lipase, 40 wt% of neutral lipase and 20 wt% of phospholipase A2, controlling the temperature to be 40 ℃, and stirring for 24 hours to perform enzymolysis reaction to obtain a second mixture;

4) heating the second mixture obtained after the enzymolysis reaction in the step 3) to 80 ℃, and preserving the temperature for 30 min;

5) adding NaCl with 5% of settling agent into the second mixture treated in the step 4), and naturally cooling and settling for 24 hours;

6) and carrying out oil-water separation on the settled second mixture to obtain the fatty acid.

Example 2:

an enzymatic extraction process of fatty acid comprises the following steps:

1) adding 400g of soapstock into a container, adding 1200g of water, and uniformly stirring to obtain a first mixture;

2) adjusting the pH of the first mixture to 5 with a 20% citric acid solution;

3) adding 0.4g of complex enzyme into the first mixture, wherein the complex enzyme comprises 45 wt% of acid lipase, 36 wt% of neutral lipase and 19 wt% of phospholipase A2, controlling the temperature to be 50 ℃, and stirring for 50 hours to perform enzymolysis reaction to obtain a second mixture;

4) heating the second mixture obtained after the enzymolysis reaction in the step 3) to 85 ℃, and preserving the temperature for 40 min;

5) adding 10% NaCl of a settling agent into the second mixture treated in the step 4), and naturally cooling and settling for 48 h;

6) and carrying out oil-water separation on the settled second mixture to obtain the fatty acid.

Example 3:

an enzymatic extraction process of fatty acid comprises the following steps:

1) adding 500g of oil residue into a container, adding 2500g of water, and uniformly stirring to obtain a first mixture;

2) adjusting the pH of the first mixture to 6 with a 20% citric acid solution;

3) adding 2.5g of complex enzyme into the first mixture, wherein the complex enzyme comprises 50 wt% of acid lipase, 40 wt% of neutral lipase and 10 wt% of phospholipase A2, controlling the temperature to be 60 ℃, and stirring for 72 hours to perform enzymolysis reaction to obtain a second mixture;

4) heating the second mixture obtained after the enzymolysis reaction in the step 3) to 90 ℃, and preserving the temperature for 60 min;

5) adding 20% NaCl of a settling agent into the second mixture treated in the step 4), and naturally cooling and settling for 72 h;

6) and carrying out oil-water separation on the settled second mixture to obtain the fatty acid.

Comparative example 1:

an enzymatic extraction process of fatty acid comprises the following steps:

1) adding 300g of soapstock into a container, adding 600g of water, and uniformly stirring to obtain a first mixture;

2) adjusting the pH of the first mixture to 4 with 10% acetic acid solution;

3) adding 0.15g of complex enzyme into the first mixture, wherein the complex enzyme comprises 60 wt% of acid lipase and 40 wt% of neutral lipase, controlling the temperature to be 40 ℃, and stirring for 24 hours to perform enzymolysis reaction to obtain a second mixture;

4) heating the second mixture obtained after the enzymolysis reaction in the step 3) to 80 ℃, and preserving the temperature for 30 min;

5) adding NaCl with 5% of settling agent into the second mixture treated in the step 4), and naturally cooling and settling for 24 hours;

6) and carrying out oil-water separation on the settled second mixture to obtain the fatty acid.

Comparative example 2:

an enzymatic extraction process of fatty acid comprises the following steps:

1) adding 300g of soapstock into a container, adding 600g of water, and uniformly stirring to obtain a first mixture;

2) adjusting the pH of the first mixture to 4 with 10% acetic acid solution;

3) adding 0.15g of complex enzyme into the first mixture, wherein the complex enzyme is acid lipase, controlling the temperature to be 40 ℃, and stirring for 24 hours to perform enzymolysis reaction to obtain a second mixture;

4) heating the second mixture obtained after the enzymolysis reaction in the step 3) to 80 ℃, and preserving the temperature for 30 min;

5) adding NaCl with 5% of settling agent into the second mixture treated in the step 4), and naturally cooling and settling for 24 hours;

6) and carrying out oil-water separation on the settled second mixture to obtain the fatty acid.

Comparative example 3:

an enzymatic extraction process of fatty acid comprises the following steps:

1) adding 400g of soapstock into a container, adding 1200g of water, and uniformly stirring to obtain a first mixture;

2) adjusting the pH of the first mixture to 5 with a 20% citric acid solution;

3) adding 0.4g of complex enzyme into the first mixture, wherein the complex enzyme comprises 45 wt% of acid lipase and 55 wt% of phospholipase A2, controlling the temperature at 50 ℃, and stirring for 50 hours to perform enzymolysis reaction to obtain a second mixture;

4) heating the second mixture obtained after the enzymolysis reaction in the step 3) to 85 ℃, and preserving the temperature for 40 min;

5) adding 10% NaCl of a settling agent into the second mixture treated in the step 4), and naturally cooling and settling for 48 h;

6) and carrying out oil-water separation on the settled second mixture to obtain the fatty acid.

Comparative example 4:

an enzymatic extraction process of fatty acid comprises the following steps:

1) adding 400g of soapstock into a container, adding 1200g of water, and uniformly stirring to obtain a first mixture;

2) adjusting the pH of the first mixture to 5 with a 20% citric acid solution;

3) adding 0.4g of complex enzyme into the first mixture, wherein the complex enzyme is neutral lipase, controlling the temperature at 50 ℃, and stirring for 50 hours to perform enzymolysis reaction to obtain a second mixture;

4) heating the second mixture obtained after the enzymolysis reaction in the step 3) to 85 ℃, and preserving the temperature for 40 min;

5) adding 10% NaCl of a settling agent into the second mixture treated in the step 4), and naturally cooling and settling for 48 h;

6) and carrying out oil-water separation on the settled second mixture to obtain the fatty acid.

Comparative example 5:

an enzymatic extraction process of fatty acid comprises the following steps:

1) adding 500g of oil residue into a container, adding 2500g of water, and uniformly stirring to obtain a first mixture;

2) adjusting the pH of the first mixture to 6 with a 20% citric acid solution;

3) adding 2.5g of complex enzyme into the first mixture, wherein the complex enzyme comprises 40 wt% of neutral lipase and 60 wt% of phospholipase A2, controlling the temperature at 60 ℃, and stirring for 72 hours to perform enzymolysis reaction to obtain a second mixture;

4) heating the second mixture obtained after the enzymolysis reaction in the step 3) to 90 ℃, and preserving the temperature for 60 min;

5) adding 20% NaCl of a settling agent into the second mixture treated in the step 4), and naturally cooling and settling for 72 h;

6) and carrying out oil-water separation on the settled second mixture to obtain the fatty acid.

Comparative example 6:

an enzymatic extraction process of fatty acid comprises the following steps:

1) adding 500g of oil residue into a container, adding 2500g of water, and uniformly stirring to obtain a first mixture;

2) adjusting the pH of the first mixture to 6 with a 20% citric acid solution;

3) adding 2.5g of complex enzyme which is phospholipase A2 into the first mixture, controlling the temperature at 60 ℃, and stirring for 72 hours to perform enzymolysis reaction to obtain a second mixture;

4) heating the second mixture obtained after the enzymolysis reaction in the step 3) to 90 ℃, and preserving the temperature for 60 min;

5) adding 20% NaCl of a settling agent into the second mixture treated in the step 4), and naturally cooling and settling for 72 h;

6) and carrying out oil-water separation on the settled second mixture to obtain the fatty acid.

Comparative example 7:

an enzymatic extraction process of fatty acid comprises the following steps:

1) adding 500g of oil residue into a container, adding 2500g of water, and uniformly stirring to obtain a first mixture;

2) adjusting the pH of the first mixture to 6 with a 20% citric acid solution;

3) adding 2.5g of HCl into the first mixture, controlling the temperature at 60 ℃, and stirring for 72 hours to perform an enzymolysis reaction to obtain a second mixture;

4) heating the second mixture obtained after the enzymolysis reaction in the step 3) to 90 ℃, and preserving the temperature for 60 min;

5) adding 20% NaCl of a settling agent into the second mixture treated in the step 4), and naturally cooling and settling for 72 h;

6) and carrying out oil-water separation on the settled second mixture to obtain the fatty acid.

The results of the performance tests of the examples and comparative examples are shown in table 1:

TABLE 1

As can be seen from the data in Table 1, the fatty acid yield test is carried out on the enzymatic extraction process of the fatty acid, the yield of the fatty acid is obviously different from that of comparative example 7 (no complex enzyme preparation is added) by adding the complex enzyme preparation of the invention, the fatty acid yield can be improved by 15-26% in examples 1-3 with the complex enzyme preparation, compared with comparative example 7 (no complex enzyme preparation), the fatty acid yield is improved by 4-15% by adding one or two of acid lipase, neutral lipase and phospholipase A2 in the complex enzyme in comparative examples 1-6, and the fatty acid yield is lower than that in examples 1-3 in comparative examples 1-6.

While embodiments of the invention have been disclosed above, it is not limited to the applications listed in the description and the embodiments, which are fully applicable in all kinds of fields of application of the invention, and further modifications may readily be effected by those skilled in the art, so that the invention is not limited to the specific details without departing from the general concept defined by the claims and the scope of equivalents.