A method for simultaneous production of five components in flax seed

Abstract

The application discloses a method for simultaneously producing five components in flaxseed, comprising the following steps: (1) preliminarily extracting flaxseed gum and lignan from flaxseed; (2) preparing flaxseed oil by cold pressing of degummed flaxseed through a hydraulic oil press; (3) performing skin kernel separation on the degummed and defatted flaxseed; (4) crushing the flaxseed skin after the skin kernel separation to extract flaxseed gum and flax lignan again; (5) preparing flaxseed oil again from the flaxseed kernel after the skin kernel separation; (6) extracting flaxseed protein from the defatted flaxseed kernel; (7) separating flax cyclic peptide from the flaxseed oil prepared twice; and (8) extracting flax cyclic peptide again from the defatted and deproteinized flaxseed kernel. The method is interlocked, the preliminary extraction or preparation of partial components provides favorable conditions for the flaxseed skin kernel separation, and after the flaxseed skin kernel separation, the extraction or preparation rate of the components and other components is improved, the components are complementary, the method has low cost, simple and easy-to-operate process, is green and environment-friendly, can be produced on a large scale, and in addition, the five components are simultaneously produced, so that the added value of the flaxseed is greatly improved.

Description

Technical Field

[0001] This invention relates to a method for simultaneously producing several components from flaxseed, and more particularly to a method for simultaneously producing five components, namely flaxseed oil, flaxseed gum, flax lignans, flaxseed protein, and flaxseed cyclic peptides. Background Technology

[0002] Flax (Linum usitatissimum L.), also known as sesame, is one of the world's seven major oilseed crops. my country's flaxseed production ranks second in the world, after Canada. Flaxseed contains many valuable components, such as flaxseed gum, lignans, flaxseed oil, linolenic acid, and flaxseed protein. Flaxseed gum and lignans are mainly found in the flaxseed husk, while flaxseed oil, linolenic acid, and flaxseed protein are mainly found in the flaxseed kernel. Directly extracting flaxseed gum and lignans from unhulled flaxseed results in low extraction rates and high residues due to the unbroken flaxseed husk. This also affects the extraction rates of flaxseed protein and linolenic acid from the flaxseed kernel. Separating the flaxseed husk from the kernel reduces interference during extraction, making the extraction of these components easier and achieving higher extraction rates.

[0003] However, flaxseed not only has a tight bond between the husk and kernel, but the kernel also contains a high flaxseed oil content of 55-70%. This very high oil content causes the husk and kernel to stick together, making them difficult to separate and a major factor contributing to the difficulty in separating them. Even after the husk and kernel of an individual flaxseed are removed, the small amount of oil released during the husk-kernel separation process further increases the kernel's stickiness, making it even more difficult to separate the kernel from the husk mixture.

[0004] Traditionally, due to the difficulty of hulling flaxseed, it is generally used to directly press flaxseed for oil, and then the byproducts are used to extract the useful components. With societal development, some flaxseed hull-kernel separation technologies have been developed in recent years. However, due to the high oil content in flaxseed kernels, some of these technologies remain only in the laboratory research stage and cannot be industrialized. A few have been applied to actual production, but their high cost and low separation efficiency significantly restrict large-scale application. Patent CN108686736B discloses "a method for separating flaxseed hulls and kernels based on ethanol wet filtration." While it is true that the hulls are generally larger than the kernels when flaxseeds are crushed, a considerable portion of the hulls are still crushed into powder. Additionally, some flaxseed kernels are not finely crushed and cannot pass through the sieve. Therefore, in practical operation, this method is difficult to completely separate the hulls and kernels. Furthermore, flaxseed oil is only slightly soluble in ethanol, not readily soluble, resulting in a huge ethanol consumption and rendering the method impractical and unable to obtain relatively intact flaxseed kernels. Summary of the Invention

[0005] This invention provides a method for simultaneously and effectively producing flaxseed oil, flaxseed gum, flax lignans, flaxseed protein, and flax cyclic peptides from flaxseed, involving the separation of flaxseed husk and kernel, specifically including the following steps:

[0006] (1) Select flax seeds and mix them with water at 20-95℃ in a ratio of 1:(2-20) and stir for 1-5 hours. After extraction, squeeze and filter with gauze to obtain filtrate and filtered flax seeds. Filter the flax seeds and extract them again in the above way 3-8 times. Combine the extracts to obtain degummed flax seeds and filtrate A.

[0007] (2) In the above steps, the degummed flaxseeds are dried or roasted (at a temperature not exceeding 60°C) to remove water until the moisture content is less than 1.8%. Then, the oil is extracted by a hydraulic oil press at a temperature of 10-60°C and a pressure of 25-40 MPa to obtain flaxseed oil A and defatted flaxseeds. The flaxseeds that have been extracted by the hydraulic oil press not only have a lower oil content in the kernel, but also have a looser bond between the skin and kernel due to the squeezing and sliding. Therefore, it is easier to separate the flax skin from the kernel. The defatted flaxseeds are then dehulled by a dehulling machine to obtain flax skin and flax kernel A.

[0008] (3) The flax bark obtained in step (2) above is crushed and then mixed with alkaline water in a ratio of 1: (3-10). It is stirred and extracted at 60-90℃ for 1-3 hours, filtered, extracted 3-8 times, and the extracts are combined. The pH is adjusted to neutral to obtain filtrate B and filter residue.

[0009] (4) Combine filtrate A and filtrate B to obtain filtrate C. Concentrate filtrate C under reduced pressure. Gradually add 95% ethanol to the concentrate to precipitate until the precipitation no longer increases. Filter and collect the filtrate and filter residue. Wash the filter residue with anhydrous ethanol or 95% ethanol and dry it under reduced pressure or by spray drying. After pulverizing the dried material, flaxseed gum is obtained. Combine the washing liquid and filtrate to obtain filtrate D.

[0010] (5) Filtrate D was concentrated under reduced pressure, passed through macroporous resin, and eluted with water, 10% ethanol and 40-60% ethanol respectively. The 40-60% ethanol eluent was collected, concentrated under reduced pressure, and then redissolved with ethanol. After filtration, the filtrate was dried under reduced pressure to obtain linseed phenol.

[0011] (6) The flaxseed A obtained in step (2) above is pressed again by a hydraulic oil press or a screw oil press to obtain residual flaxseed oil B and flaxseed B or flaxseed cake;

[0012] (7) Pulverize the flaxseed B or flaxseed cake obtained in step (6), add 3-10 times the volume of alkaline water solution with pH 8-12, extract with ultrasound for 0.5-2 hours, filter, repeat the extraction 3-8 times, combine the filtrates to obtain the residue and filtrate, adjust the pH of the filtrate with hydrochloric acid until no more precipitation occurs, filter again, retain the filter cake, wash with water to remove salt, then detoxify with microwave, and dry to obtain flaxseed protein;

[0013] (8) After flaxseed oil A and flaxseed oil B obtained in the above steps are combined, they are winterized at -5-10℃ for 3-24h, filtered, and filtered oil is obtained. The filtered oil is heated to 20-50℃ and separated by a tangential flow inorganic ceramic membrane with a pore size of 200-1000nm under a pressure of 0.05-1MPa to obtain permeate oil. Column chromatography is performed with permeate oil as the mobile phase and food-grade beer silica gel with a particle size of 40-800 mesh as the stationary phase. The amount of permeate oil is 1-20 times the volume of beer silica gel. Finally, a vacuum pump is used to evacuate the air or an air compressor is used to ventilate until no oil flows out. The flowing oil is collected in a container to obtain dewaxed and debittered flaxseed oil.

[0014] (9) Elute the chromatographic column containing 1-8 column volumes of the oil collected in step (8) with anhydrous ethanol or 95% ethanol, collect the desorbed portion, and distill under reduced pressure to obtain linolenic acid cyclic peptide I; add 3-10 volumes of 80-100% ethanol (or anhydrous ethanol) to the filter residue in step (7), stir and extract at 20-80℃ for 0.5-3 hours, filter, repeat the extraction 3-5 times, combine the filtrates and concentrate under reduced pressure to obtain linolenic acid cyclic peptide II; combine linolenic acid cyclic peptide I and linolenic acid cyclic peptide II to obtain total linolenic acid cyclic peptide.

[0015] The present invention enables low-cost separation of flaxseed husk and kernel through the above method. After separation, it is more conducive to the extraction of various components. Ultimately, the extraction rate of flaxseed gum can reach more than 95%, the extraction rate of flax lignans is greater than 90%, the extraction rate of flaxseed oil is greater than 95%, the extraction rate of flaxseed protein is greater than 80%, and the extraction rate of flax cyclic peptides is greater than 90%, which greatly improves the added value of flaxseed.

[0016] A hydraulic oil press is a device that uses pressure to squeeze oilseeds to extract oil. Compared to a screw press, its advantages include the ability to press without adding water or residue, resulting in clear, transparent oil with good quality and long shelf life. Additionally, it operates at a lower pressing temperature and allows the raw material to retain its original shape while being flattened. The disadvantage is a lower oil yield, which is highly dependent on the properties of the raw material. The harder and denser the outer shell, the lower the oil yield, and vice versa. Flaxseed gum is present in flax husks, and both flaxseed gum and flax husks affect the oil yield from flaxseed. Flaxseed gum easily clogs the oil passages, while flax husks easily absorb flaxseed oil. Therefore, degumming flaxseeds facilitates the extraction of flaxseed oil using a hydraulic press, while defatted flaxseeds facilitate the separation of flaxseed husk and kernel. This separation further facilitates the extraction of residual flaxseed oil from the kernel, thereby increasing the flaxseed oil yield. Simultaneously, the separation of husk and kernel can improve the extraction rate of residual flaxseed gum and flax lignans from the flaxseed husk, as well as the extraction rate of flaxseed protein and flax cyclic peptides from defatted flaxseed.

[0017] The advantage of this invention lies in the preliminary degumming of flaxseed, which facilitates the extraction of flaxseed oil containing some flaxseed cyclic peptides using a hydraulic oil press. In contrast, the defatted flaxseed after oil extraction by the hydraulic oil press is merely flattened vertically, with little change in other aspects of its shape. Because the oil content of the flaxseed kernel is reduced after defatting but before peeling, the flaxseed kernel is less likely to stick together, thus making separation of the flaxseed and kernel easier. The separated flaxseed hull is then pulverized and used to extract flaxseed gum and flax lignans again. Combined with the extraction before peeling, the total extraction rate of these two components is significantly increased.

[0018] Furthermore, the defatted and degreased flaxseeds obtained can be used again to extract flaxseed oil using a hydraulic oil press or a screw press. This compensates for the low oil yield when using a hydraulic oil press for the first extraction, and combining the two flaxseed oil extractions further improves the overall flaxseed oil yield. Simultaneously, using degummed, degreased, and defatted flaxseeds to extract flaxseed protein significantly reduces interfering substances, resulting in a higher extraction rate and easier acquisition of high-purity flaxseed protein. After flaxseed protein extraction, the further reduction of interfering substances makes it easier to obtain residual flaxseed cyclic peptides from the flaxseeds. Combining these with the flaxseed cyclic peptides obtained from the flaxseed oil further significantly improves the extraction rate of flaxseed cyclic peptides.

[0019] This invention is progressive and interconnected. The preliminary extraction or preparation of some components provides favorable conditions for the separation of flaxseed and flax bark. After the separation of flaxseed and flax bark, it is beneficial to improve the extraction or preparation rate of these components and other components. They influence and complement each other, so that the five components in flaxseed can be cleverly separated at the same time. Moreover, the cost is low, the process is simple and easy to operate, and it can be produced on a large scale. The simultaneous acquisition of the five components also reduces the production cost and greatly increases the added value of flaxseed.

[0020] Furthermore, this invention does not use any toxic or harmful solvents throughout the entire process, making it green, environmentally friendly, and safe. The entire process is also conducted at low temperatures, so the nutrients are less likely to deteriorate or be lost. Detailed Implementation

[0021] Example 1

[0022] (1) Mix 50 kg of flaxseed with hot water at 60 °C at a ratio of 1:8 and extract for 1 hour. Squeeze and filter with gauze to obtain filtrate and filtered flaxseed. Extract the filtered flaxseed five times using the above method. Combine the extracts to obtain degummed flaxseed and filtrate A.

[0023] (2) In step (1) above, the degummed flaxseeds are roasted at 60°C to remove water until the moisture content is less than 1.8%. Then, the oil is extracted by a hydraulic oil press at 25°C and 30MPa to obtain flaxseed oil A and defatted flaxseeds. The defatted flaxseeds are then dehulled by a dehulling machine to obtain flax hulls and flax kernels A.

[0024] (3) The flax bark obtained in step (2) above is pulverized and then mixed with sodium hydroxide solution at a ratio of 1:5. The mixture is stirred and extracted at 80°C for 2 hours, filtered, and extracted 5 times. The extracts are combined and the pH is adjusted to neutral to obtain filtrate B and filter residue.

[0025] (4) Combine filtrate A and filtrate B to obtain filtrate C. Concentrate filtrate C under reduced pressure. Gradually add 95% ethanol to the concentrate to precipitate until the precipitation no longer increases. Filter and collect the filtrate and filter residue. Wash the filter residue with anhydrous ethanol and dry it under reduced pressure or by spray drying. After pulverizing the dried material, 2 kg of flaxseed gum is obtained. Combine the washing liquid and filtrate as filtrate D.

[0026] (5) Filtrate D was concentrated under reduced pressure, passed through macroporous resin, eluted with water, 10% ethanol and 50% ethanol, the 50% ethanol eluent was collected, concentrated under reduced pressure, then redissolved with ethanol, filtered, and the filtrate was concentrated under reduced pressure and dried to obtain 0.5 kg of linseed lignans.

[0027] (6) The flaxseed A obtained in step (2) above is pressed again using a screw press to obtain residual flaxseed oil B and flaxseed cake;

[0028] (7) The flaxseed cake obtained in step (6) was crushed, and 6 times the volume of sodium hydroxide alkaline solution with pH 9 was added. The mixture was ultrasonically extracted for 1 hour, filtered, and the extraction was repeated 5 times. The filtrates were combined to obtain the residue and filtrate. The pH of the filtrate was adjusted with hydrochloric acid until no more precipitation was produced. The mixture was filtered again, and the filter cake was washed with water to remove the salt. The residue was then detoxified by microwave and dried to obtain 8 kg of flaxseed protein.

[0029] (8) After flaxseed oil A and flaxseed oil B obtained in the above steps are combined, they are winterized at 4°C for 10 hours, filtered, and filtered oil is obtained. The filtered flaxseed oil is heated to 40°C and separated by a tangential flow inorganic ceramic membrane with a pore size of 300 nm at a pressure of 0.08 MPa to obtain permeate oil. Column chromatography is performed with permeate oil as the mobile phase and 600-mesh beer silica gel as the stationary phase. The amount of permeate oil is 8 times the volume of the beer silica gel. Finally, the vacuum pump is used to evacuate the gas until no oil flows out. The flowing oil is collected in a container to obtain 17 kg of dewaxed and debittered flaxseed oil.

[0030] (9) Elute the column with 95% ethanol for 5 times the column volume of the oil collected in step (8), collect the desorbed part, and distill under reduced pressure to obtain 18g of linolenic acid cyclic peptide I; add 6 times the volume of anhydrous ethanol to the filter residue in step (7), stir and extract at 50°C for 1 hour, filter, repeat the extraction 4 times, combine the filtrates and concentrate under reduced pressure to obtain 9.5g of linolenic acid cyclic peptide II; combine linolenic acid cyclic peptide I and linolenic acid cyclic peptide II to obtain a total of 27.5g of linolenic acid cyclic peptide.

[0031] Example 2

[0032] (1) Select 200kg of flax seeds and mix them with water at 20℃ at a ratio of 1:15 and stir for 5 hours. After extraction, squeeze and filter with gauze to obtain filtrate and filtered flax seeds. Filter the flax seeds and extract them 3 times in the same way as above. Combine the extracts to obtain degummed flax seeds and filtrate A.

[0033] (2) The above degummed flaxseeds were sun-dried outdoors until the moisture content was less than 1.8%, and then the oil was extracted by a hydraulic oil press at a temperature of 10°C and a pressure of 40MPa to obtain flaxseed oil A and defatted flaxseeds; the defatted flaxseeds were then dehulled by a dehulling machine to obtain flax hulls and flax kernels A.

[0034] (3) The flax bark obtained in step (2) above is pulverized and then mixed with potassium hydroxide solution at a ratio of 1:10. It is stirred and extracted at 60°C for 3 hours, filtered, extracted 3 times, and the extracts are combined. The pH is adjusted to neutral to obtain filtrate B and filter residue.

[0035] (4) Combine filtrate A and filtrate B to obtain filtrate C. Concentrate filtrate C under reduced pressure. Gradually add 95% ethanol to the concentrate to precipitate until the precipitation no longer increases. Filter and collect the filtrate and filter residue. Wash the filter residue with 95% ethanol and dry it under reduced pressure or by spray drying. After pulverizing the dried material, 7.5 kg of flaxseed gum is obtained. Combine the washing liquid and filtrate as filtrate D.

[0036] (5) Filtrate D was concentrated under reduced pressure, passed through macroporous resin, and eluted with water, 10% ethanol and 40% ethanol respectively. The 40% ethanol eluent was collected, concentrated under reduced pressure, and then redissolved with ethanol. After filtration, the filtrate was dried under reduced pressure to obtain 1.9 kg of linseed lignans.

[0037] (6) The flaxseed A obtained in step (2) above is then pressed with a hydraulic oil press to obtain residual flaxseed oil B and flaxseed B;

[0038] (7) The flaxseed B obtained in step (6) was crushed and added to a 10-fold volume of potassium hydroxide alkaline solution with pH 8. The mixture was ultrasonically extracted for 2 hours, filtered, and the extraction was repeated 8 times. The filtrates were combined to obtain the residue and filtrate. The pH of the filtrate was adjusted with hydrochloric acid until no more precipitation was produced. The mixture was filtered again, and the filter cake was washed with water to remove the salt. The residue was then detoxified by microwave and dried to obtain 38.6 kg of flaxseed protein.

[0039] (8) After flaxseed oil A and flaxseed oil B obtained in the above steps are combined, they are winterized at 10℃ for 24 hours, filtered, and filtered oil is obtained. The filtered oil is heated to 50℃ and separated by a tangential flow inorganic ceramic membrane with a pore size of 200nm under a pressure of 0.05MPa to obtain permeate oil. Column chromatography is performed with permeate oil as the mobile phase and food-grade beer silica gel with a particle size of 300 mesh as the stationary phase. The amount of permeate oil is 15 times the volume of beer silica gel. Finally, the air compressor is purged until no oil flows out. The outflowing oil is collected in a container to obtain 63kg of dewaxed and debittered flaxseed oil.

[0040] (9) Elute the column with anhydrous ethanol for 3 times the column volume of the oil collected in step (8), collect the desorbed portion, and distill under reduced pressure to obtain 65g of linolenic acid cyclic peptide I; add 10 times the volume of 95% ethanol to the filter residue in step (7), stir and extract at 20°C for 3 hours, filter, repeat the extraction 5 times, combine the filtrates and concentrate under reduced pressure to obtain 33g of linolenic acid cyclic peptide II; combine linolenic acid cyclic peptide I and linolenic acid cyclic peptide II to obtain 98g of total linolenic acid cyclic peptide.

[0041] Example 3

[0042] (1) Select 500 kg of flax seeds and mix them with water at 95℃ in a 1:3 ratio and stir for 2 hours. After extraction, squeeze and filter with gauze to obtain filtrate and residue. Extract the residue 8 times in the same way as above, combine the extracts to obtain degummed flax seeds and filtrate A.

[0043] (2) In step (1) above, the degummed flaxseeds are roasted at 50°C to remove water until the moisture content is less than 1.8%, and then the oil is extracted by a hydraulic oil press at 60°C and 25MPa to obtain flaxseed oil A and defatted flaxseeds; the defatted flaxseeds are then dehulled by a dehulling machine to obtain flax hulls and flax kernels A.

[0044] (3) The flax bark obtained in step (2) above is pulverized and then mixed with sodium hydroxide solution in a 1:3 ratio. It is stirred and extracted at 90°C for 1 hour, filtered, extracted 8 times, and the extracts are combined. The pH is adjusted to neutral to obtain filtrate B and filter residue.

[0045] (4) Combine filtrate A and filtrate B to obtain filtrate C. Concentrate filtrate C under reduced pressure. Gradually add 95% ethanol to the concentrate to precipitate until the precipitation no longer increases. Filter and collect the filtrate and filter residue. Wash the filter residue with 95% ethanol and dry it under reduced pressure or by spray drying. After pulverizing the dried material, 19 kg of flaxseed gum is obtained. Combine the washing liquid and filtrate as filtrate D.

[0046] (5) Filtrate D was concentrated under reduced pressure, passed through macroporous resin, and eluted with water, 10% ethanol and 60% ethanol respectively. The 40-60% ethanol eluent was collected, concentrated under reduced pressure, and then redissolved with ethanol. After filtration, the filtrate was dried under reduced pressure to obtain 4.8 kg of linseed lignans.

[0047] (6) The flaxseed A obtained in step (2) above is pressed again using a screw press to obtain residual flaxseed oil B and flaxseed cake;

[0048] (7) The flaxseed cake obtained in step (6) was crushed, and 3 times the volume of sodium hydroxide alkaline solution with pH 12 was added. The mixture was ultrasonically extracted for 0.5 hours, filtered, and the extraction was repeated 3 times. The filtrates were combined to obtain the residue and filtrate. The pH of the filtrate was adjusted with hydrochloric acid until no more precipitation was produced. The mixture was filtered again, and the filter cake was washed with water to remove the salt. The residue was then detoxified by microwave and dried to obtain 92 kg of flaxseed protein.

[0049] (8) After flaxseed oil A and flaxseed oil B obtained in the above steps are combined, they are winterized at -5℃ for 3 hours, filtered, and filtered oil is obtained. The filtered oil is heated to 20℃ and separated by a tangential flow inorganic ceramic membrane with a pore size of 600nm under a pressure of 1MPa to obtain permeate oil. Column chromatography is performed with permeate oil as the mobile phase and food-grade beer silica gel with a particle size of 100 mesh as the stationary phase. The amount of permeate oil is 6 times the volume of beer silica gel. Finally, the vacuum pump is used to evacuate the gas until no oil flows out. The flowing oil is collected in a container to obtain 164kg of dewaxed and debittered flaxseed oil.

[0050] (9) Elute the chromatographic column with 8 times the column volume of the oil collected in step (8) with anhydrous ethanol or 95% ethanol, collect the desorbed part, and distill under reduced pressure to obtain 169g of linolenic acid cyclic peptide I; add 3 times the volume of anhydrous ethanol to the filter residue in step (7), stir and extract at 80°C for 0.5 hours, filter, repeat the extraction 3 times, combine the filtrates and concentrate under reduced pressure to obtain 86g of linolenic acid cyclic peptide II; combine linolenic acid cyclic peptide I and linolenic acid cyclic peptide II to obtain a total of 255g of linolenic acid cyclic peptide.

Claims

1. A method for simultaneously producing five components in flaxseed, comprising the following steps: (1) The flaxseed is mixed with water at 20-95℃ at a mass ratio of 1:(2-20) and stirred for 1-5 hours, and then filtered with gauze after squeezing, to obtain filtrate and filtered flaxseed; the filtered flaxseed is extracted again 3-8 times by the above method, and the extract is combined to obtain degummed flaxseed and filtrate A; (2) The degummed flaxseed in the above step is dried by airing or low-pressure baking at a temperature not higher than 60℃ until the moisture content is less than 1.8%, and then the oil is pressed out under a temperature of 10-60℃ and a pressure of 25-40 MPa by a hydraulic oil press to obtain flaxseed oil A and defatted flaxseed; the defatted flaxseed is shelled by a huller to obtain flaxseed coat and flaxseed kernel A; (3) The flaxseed coat obtained in the above step (2) is crushed and mixed with lye at a ratio of 1:(3-10), stirred at 60-90℃ for 1-3 hours, filtered, and extracted 3-8 times, and the extract is combined and adjusted to neutral pH to obtain filtrate B and residue; (4) The filtrate A and the filtrate B are combined to obtain filtrate C, which is concentrated under reduced pressure, and 95% ethanol is gradually added to the concentrated solution for precipitation until no more precipitate is formed, and then filtered to collect the filtrate and residue; the residue is washed with anhydrous ethanol or 95% ethanol and then dried under reduced pressure or by spray drying, and the dried product is crushed to obtain flaxseed gum; the washing liquid and the filtrate are combined as filtrate D; (5) The filtrate D is concentrated under reduced pressure, and then passed through a macroporous resin, and eluted with water, 10% ethanol and 40-60% ethanol, respectively; the eluate of 40-60% ethanol is collected, concentrated under reduced pressure, redissolved with ethanol, filtered, and dried under reduced pressure to obtain flax lignan; (6) The flaxseed kernel A obtained in the above step (2) is pressed by a hydraulic oil press or a screw oil press to obtain residual flaxseed oil B and flaxseed kernel B or flaxseed kernel cake; (7) The flaxseed kernel B or flaxseed kernel cake obtained in step (6) is crushed, and 3-10 times the volume of an alkaline aqueous solution with a pH of 8-12 is added, and ultrasonic extraction is performed for 0.5-2 hours; the mixture is filtered, and the extraction is repeated 3-8 times; the filtrate is combined to obtain residue and filtrate, and the filtrate is adjusted to a pH at which no more precipitate is formed with hydrochloric acid, and then filtered again; the filter cake is washed with water to remove salt, and then subjected to microwave detoxification treatment, and dried to obtain flaxseed protein; (8) The flaxseed oil A and the flaxseed oil B obtained in the above steps are combined, and winterized at-5-10℃ for 3-24 hours, and then filtered to obtain filtered oil; the filtered oil is heated to 20-50℃, and separated by a tangential flow inorganic ceramic membrane with a pore size of 200-1000 nm under a pressure of 0.05-1 MPa to obtain membrane permeated oil; column chromatography is performed with the membrane permeated oil as mobile phase and food-grade beer silica gel with a particle size of 40-800 mesh as stationary phase, and the amount of the membrane permeated oil is 1-20 times the volume of the beer silica gel; finally, a vacuum pump or an air compressor is used until no oil flows out; the flowing oil is collected to obtain dewaxed and debittered flaxseed oil. (9) The column 1-8 times the column volume of step (8) collected oil liquid elution with anhydrous ethanol or 95% ethanol, desorption site collection, reduced pressure distillation obtained flax cyclic peptide I; step (7) in the filter residue is added to 3-10 times the volume of 80-100% ethanol or anhydrous ethanol, 20-80 ℃ stirring extraction 0.5-3 hours, filtration, repeated extraction 3-5 times, combined filtrate concentrated under reduced pressure, flax cyclic peptide II was obtained; flax cyclic peptide I and flax cyclic peptide II were combined to obtain total flax cyclic peptide.