A water enzymatic extraction process of flaxseed oil based on an abrasive disc-shaped solid phase force chemistry-super gravity field strengthening

Abstract

The application belongs to the technical field of plant oil extraction, and more particularly relates to a water enzymatic extraction process of flaxseed oil based on a grinding disc-shaped solid phase chemical-ultra high gravity field strengthening. The flaxseed is ground and crushed by a grinding disc-shaped solid phase chemical reactor, the initial cell wall structure of the flaxseed is destroyed, and the oil is further released by combining with complex enzymolysis, and then the mass transfer separation process is strengthened by using an ultra high gravity field, so that the technical bottleneck of low efficiency of traditional static stratification and serious emulsification phenomenon is effectively broken. The application improves the oil extraction rate, shortens the separation time, and does not need to add chemical solvents in the whole process, and completely meets the green production requirements of food-grade oil.

Description

Technical Field

[0001] This application belongs to the field of vegetable oil extraction technology, and more specifically, relates to a water-enzymatic extraction process for flaxseed oil based on a millstone-shaped solid-phase mechanochemistry-hypergravity field enhanced by gravity. Background Technology

[0002] Flaxseed oil (also known as linseed oil or sesame oil) is a high-value-added vegetable oil. It is rich in alpha-linolenic acid, an essential fatty acid that the human body cannot synthesize on its own. It participates in the construction of human brain and body tissues and also has multiple physiological functions such as regulating blood lipids, protecting eyesight, and anti-oxidation. It has broad application prospects in the health food industry.

[0003] Currently, industrial flaxseed oil extraction involves various technologies, including solvent extraction, mechanical pressing, and hydro-enzymatic extraction. Solvent extraction offers excellent oil yield, but the finished oil may contain solvent residues, and the high-temperature desolventizing process can easily cause oxidation and deterioration of unsaturated nutrients. Physical pressing is simple, but mechanical extrusion alone cannot fully remove intracellular oils, resulting in low raw material utilization. Hydro-enzymatic extraction uses water as the extraction medium and enzymes to catalyze the decomposition of oilseed structures, avoiding the problems of organic solvent residues and oil deterioration caused by high temperatures. With its green and safe characteristics, it is gradually becoming a research hotspot in the field of vegetable oil extraction.

[0004] In practical applications, conventional aqueous enzymatic methods cannot achieve complete cell wall disruption of oilseeds. A large amount of intracellular oil is trapped and bound by the cell wall and colloidal structure, making it difficult to release fully and resulting in a low oil extraction rate. Furthermore, the mixture after enzymatic hydrolysis relies on natural sedimentation to achieve oil-water separation, which is time-consuming. Endogenous proteins and pectin in the oilseeds easily form stable emulsions at the oil-water interface, trapping a large amount of oil and causing extraction losses, thus reducing oil yield. The inability to simultaneously achieve high extraction rates, low emulsion layers, and high retention of active ingredients is a pressing problem that needs to be solved in the current aqueous enzymatic method for producing high-quality food-grade flaxseed oil. Summary of the Invention

[0005] To address the issues of low retention and low extraction rates of active oil components in the aqueous enzymatic extraction of flaxseed oil, this application provides an aqueous enzymatic extraction process for flaxseed oil based on a millstone-shaped solid-phase mechanochemistry-supergravity field enhanced process.

[0006] In a first aspect, this application provides a water-enzymatic extraction process for flaxseed oil based on a millstone-shaped solid-phase mechanochemical-hypergravity field enhanced by a millstone, employing the following technical solution: A water-enzymatic extraction process for flaxseed oil based on a millstone-shaped solid-phase mechanochemical-hypergravity field enhanced process includes the following steps: (1) Raw material pretreatment: Flaxseed is washed, dried, and ground into powder by solid-phase mechanochemical processing; (2) Compound enzymatic hydrolysis: It is mixed with water at a material-liquid ratio of 1:5-1:8 (w / v), the pH is adjusted to 4.5-6.0, enzymatic hydrolysis components are added, and enzymatic hydrolysis is carried out at 45-60℃ for 2-4 hours to obtain enzymatic hydrolysate; (3) Hypergravity field separation: The enzymatic hydrolysate is introduced into a hypergravity rotating packed bed reactor and dynamically separated for 10-30 minutes at a temperature of 40-50℃ and a centrifugal acceleration of 200-800g; (4) Oil phase purification: The upper oil phase is collected, purified and refined to obtain high-purity flaxseed oil.

[0007] This application presents a water-enzymatic extraction process for flaxseed oil that combines millstone-shaped solid-phase mechanochemistry with hypergravity field enhancement. Through steps including raw material pretreatment, compound enzymatic hydrolysis, hypergravity field separation, and oil phase purification, the solid-phase mechanochemical reactor employs a three-stage system of grinding and pulverizing pretreatment, compound enzymatic hydrolysis, and hypergravity separation. The solid-phase mechanochemical grinding process pre-disrupts cell wall structures, enhancing enzymatic hydrolysis efficiency and achieving highly efficient flaxseed oil extraction. In the hypergravity field separation step, the enzymatic hydrolysate is centrifuged in the hypergravity rotating packed bed reactor of this application. Under high-intensity shear force, the emulsion stability is disrupted, balancing separation efficiency with reduced energy consumption. Utilizing the density differences between the oil, water, and residue phases, the three-phase stratification is completed rapidly and efficiently. Simultaneously, the shear force generated by the centrifugal acceleration breaks down residual weak emulsion structures, allowing previously difficult-to-separate trace amounts of encapsulated oil to be completely released and incorporated into the clear oil phase, thereby reducing oil loss and improving the final extraction rate and oil phase purity. The oil phase purification step refines the upper oil phase, ultimately yielding high-purity flaxseed oil. This process effectively reduces oil loss, increases extraction rate and product purity, while protecting active ingredients such as α-linolenic acid.

[0008] Preferably, the solid-state mechanical chemical processing grinding and pulverization in step (1) includes: solid-state mechanical chemical processing grinding after atmospheric pressure low-temperature plasma treatment, wherein the grinding disc temperature is 20-35℃, the pressure is 8-20MPa, and the rotation speed is 50-120r / min.

[0009] More preferably, atmospheric pressure low-temperature plasma treatment uses an air / argon mixed atmosphere, a power of 20-80W, an electrode spacing of 3-10mm, and a treatment time of 30-120s.

[0010] Atmospheric pressure low-temperature plasma treatment, under low-temperature and heat-damage-free conditions, utilizes the generated high-energy electrons and oxygen-containing free radicals to perform nanoscale physical etching on the flaxseed epidermis and cell walls, generating numerous microscopic pores and cracks on the cell wall surface. Simultaneously, oxidative modification introduces hydroxyl, carboxyl, and carbonyl hydrophilic groups onto the cellulose, hemicellulose, and lignin molecular chains. This enhances the hydrophilicity of the cell wall, facilitating the infiltration of subsequent aqueous systems and enzyme components, thereby increasing the oil release rate. Furthermore, it breaks the hydrogen bonds between polysaccharide molecules and the ether and ester bonds connecting lignin and polysaccharides, relaxing the dense cross-linked structure of the cell wall and reducing its mechanical strength. The entire modification process is conducted at temperatures below 40℃, preventing thermal oxidation of intracellular unsaturated oils and effectively preserving the intact structure of α-linolenic acid. Plasma pre-relaxation modification significantly improves the brittleness of flaxseed cell walls. The high pressure and circumferential shear force applied during subsequent solid-phase mechanical chemical processing and milling can extend into the seed interior along the microscopic gaps formed by plasma etching. This avoids the loss of α-linolenic acid due to local overheating and gelatinization of the material during the grinding process. At the same time, it greatly reduces mechanical energy consumption and improves cell wall breaking efficiency, allowing the oil body that was originally buried deep inside the cell wall to be fully exposed. This significantly increases the probability of contact between subsequent enzyme molecules and oil bodies, reducing the loss of oil that cannot be dissolved due to solid phase encapsulation from the source of raw material pretreatment. Simultaneously, it reduces the large amount of soluble protein and pectin entering the liquid phase to form emulsion precursors due to insufficient crushing, thus reducing the large amount of emulsion layer generated from the source.

[0011] Preferably, the enzymatic hydrolysis components in step (2) include a hydrolysis aid component and a complex enzyme in a mass ratio of (0.3-0.5):1.

[0012] Preferably, the complex enzyme is one or more of cellulase, pectinase, and protease.

[0013] More preferably, the complex enzyme is cellulase, pectinase and protease in a mass ratio of 1:1:1.

[0014] Preferably, the decomposition aids include cellulose nanofibers, lipopeptides, and sophorolipids in a mass ratio of (7-10):(0.5-1):(0.5-1).

[0015] The enzyme-assisted decomposition component helps the complex enzyme to specifically degrade cell walls and oil-encapsulating structures. The two components work synergistically to improve the problems of insufficient enzymatic hydrolysis, limited oil release, significant emulsification side reactions, and easy loss of active components in traditional aqueous enzymatic methods, thereby increasing oil extraction rate and maintaining the integrity and stability of α-linolenic acid. The cellulose nanofibers in the enzyme-assisted component possess a high specific surface area and abundant surface hydroxyl structures. They can bind to cellulase, pectinase, and protease molecules in the complex enzyme through hydrogen bonds and other interactions, effectively buffering the disturbances to the spatial conformation of enzyme proteins caused by stirring, shearing, and temperature fluctuations during enzymatic hydrolysis, reducing the rate of enzyme activity decay, and maintaining the continuous and stable catalytic ability of the complex enzyme. Simultaneously, its nanofiber structure can create a micro-shearing effect in the liquid-phase stirred system, further fragmenting and dissociating the dense cell wall fragments and incompletely dissociated polysaccharide cross-linked structures remaining after pretreatment. This increases substrate exposure sites and creates more sufficient contact conditions for the complex enzyme to hydrolyze cellulose glycosidic bonds, pectin glycosidic bonds, and oil-encapsulating protein peptide bonds, effectively improving cell wall degradation. The degree of dissociation from intracellular lipids reduces the residue of bound lipids, thus improving the lipid extraction rate. Lipopeptides and sophorolipids are amphiphilic bio-based components; their hydrophilic ends can form hydrogen bonds with the hydroxyl groups on the surface of cellulose nanofibers. Lipopeptides preferentially adsorb hydrophobic emulsifying proteins in the system, and their steric hindrance prevents protein molecules from arranging themselves in an orderly manner at the oil-water interface to form a film. Sophorolipids complex polar pectin polysaccharides in the system, thereby capturing free pectin, soluble proteins, and other emulsifying precursors, weakening the film-forming stability at the oil-water interface. Furthermore, the long-chain sophorolipid hydrophobic segments penetrate deep into the phospholipid membrane, disrupting the hydrophobic association between phospholipids and oils. The short-chain lipopeptide hydrophobic segments intersect in the gaps on the surface of the phospholipid membrane, gradually expanding the oil's membrane structure. This helps to alleviate the degree of emulsification in the system, reduce the loss caused by oil encapsulation in the emulsion layer, improve the purity of oil recovery, optimize the efficiency of enzymatic hydrolysis, improve emulsification, and enhance the utilization rate of raw material oil and the purity of oil products. At the same time, it ensures the unsaturated α-linolenic acid structure, effectively preserving the heat-sensitive active nutrients in the oil.

[0016] The complex enzyme contains cellulase, which hydrolyzes β-1,4-glycosidic bonds in cellulose; pectinase, which hydrolyzes α-1,4-glycosidic bonds in pectin; and protease, which hydrolyzes peptide bonds in oil body membrane proteins. Under the stabilizing and dispersing effect of cellulose nanofibers, these three components simultaneously and efficiently degrade the cell wall skeleton and the protective structure of oil bodies. Lipopeptides and sophorolipids work together to achieve deep oil disintegration and interfacial modification. The synergistic effect of these components and the complex enzyme leads to more thorough oil release and easier system separation, further enhancing cell wall disruption, maintaining high enzyme activity, promoting oil body dissociation, and reducing oil encapsulation loss. This, in turn, improves oil extraction rate and product purity while protecting active ingredients such as α-linolenic acid. Therefore, if the amount of cellulose nanofibers added is too low, the enzyme adsorption sites and stable micro-shearing are weakened, reducing the enzyme stabilization and activation effect of the complex enzyme, accelerating enzyme activity loss, and weakening the adsorption and emulsification of impurities and optimization of system dispersion by lipopeptides and sophorolipids. This can easily lead to insufficient cell wall disruption and a decrease in oil release rate.

[0017] Preferably, in step (3), the supergravity rotating packed bed reactor includes an outer shell, a hollow rotor is installed inside the outer shell, a packing layer is provided on the outer wall of the hollow rotor, an inlet for liquid inlet is provided at one end of the outer shell, a liquid distributor is installed at the position of the inlet on the outer shell, an aqueous phase outlet, a slag phase outlet and an oil phase outlet are provided at the end of the outer shell away from the inlet, and a slag phase collection tank for collecting slag phase deposits is provided at the position of the slag phase outlet.

[0018] Preferably, the filler layer is made of stainless steel wire mesh or ceramic corrugated plate, and its filling density is 80-95%.

[0019] After the enzymatic hydrolysate enters through the inlet of the high-gravity rotating packed bed reactor, it is evenly sprayed into the hollow chamber of the hollow rotor through a liquid distributor. The high-speed rotation of the rotor generates a high-gravity field, and the liquid is thrown towards the packing layer. Under the action of shear force and centrifugal force, the low-density oil phase moves towards the inner wall of the outer shell and is discharged through the oil phase outlet; the aqueous phase flows along the inner side of the packing layer and is discharged through the aqueous phase outlet; the slag phase is deposited at the bottom of the packing layer and is periodically discharged through the slag phase outlet to the slag phase collection tank, thereby achieving efficient and continuous separation of the oil-water-slag three phases. The density difference of the oil, water and slag three phases is used to achieve efficient stratification. Combined with the strong shear force of the high-gravity field, the residual weak emulsion structure is further broken down, so that the originally difficult-to-separate trace amounts of encapsulated oil are completely released and merged into the clear oil phase, minimizing oil loss and improving the final extraction rate and oil phase purity.

[0020] The packing layer of stainless steel wire mesh or ceramic corrugated plate with high packing density allows the enzymatic hydrolysate to be dispersed into fine liquid films and droplets under centrifugal force and packing shear after entering the centrifugal rotating packed bed. It also allows lipopeptides, sophorolipids and CNF to interact and, together with the emulsified impurities such as proteins and pectin adsorbed by CNF, to be enriched at the bottom of the packing under centrifugal force and included in the slag phase. The slag phase is then periodically discharged from the slag phase outlet to remove the impurities, thus avoiding separation loss caused by oil droplets being encapsulated by the emulsion film.

[0021] Preferably, step (4) purification includes one or both of centrifugation at 3000-6000 rpm for 5-10 min or microfiltration membrane purification with a pore size of 0.1-0.5 μm.

[0022] By further purifying and refining, trace amounts of water and solid impurities in the upper oil phase are removed, thereby obtaining high-purity flaxseed oil.

[0023] In summary, this application has the following beneficial effects: 1. This application utilizes a three-stage system of solid-phase mechanochemical reactor grinding and pulverization pretreatment, compound enzymatic hydrolysis, and high-gravity separation to improve extraction rate and product purity while protecting active ingredients such as α-linolenic acid. Specifically, the disc-shaped solid-phase mechanochemical pretreatment disrupts the cell wall structure of flaxseed in advance, improving the accessibility of the enzymatic hydrolysis substrate and thus increasing the hydrolysis efficiency. High-gravity separation utilizes droplet shearing and collision to achieve rapid stratification of the oil, water, and residue phases, with the oil phase purity reaching food-grade standards. The entire process is solvent-free, resulting in high retention of active oil components, improved extraction rate, and both environmental and economic benefits.

[0024] 2. In the separation under a supergravity field, the supergravity rotating packed bed reactor dynamically separates under specific temperature and centrifugal acceleration conditions. It can utilize the density difference of the three phases to achieve rapid stratification, reduce oil loss, and improve the final extraction yield. At the same time, it reduces the probability of α-linolenic acid oxidizing and deteriorating due to prolonged exposure to air, reduces energy consumption, reduces the oxidation and deterioration of α-linolenic acid, and improves the retention rate of α-linolenic acid. Attached Figure Description

[0025] Figure 1 This application presents a schematic diagram of a supergravity rotating packed bed reaction device in Embodiment 1.

[0026] Explanation of reference numerals in the attached drawings: 1. Liquid inlet; 11. Outer shell; 2. Liquid distributor; 3. Packing layer; 4. Hollow rotor; 5. Aqueous phase outlet; 6. Oil phase outlet; 7. Slag phase outlet; 8. Slag phase collection tank. Detailed Implementation

[0027] The present application will be further described in detail below with reference to the embodiments.

[0028] Some of the raw materials used in the preparation examples and embodiments: Flaxseed (non-roasted native seeds): Hohhot Mengguxiang Biotechnology Co., Ltd.; Cellulase (10,000 u / g): Henan Laimiyuan Biotechnology Co., Ltd.; Protease (100,000 u / g): Jiangxi Huihai Biotechnology Co., Ltd.; Pectinase (food grade 30,000 U / g): Maoming Chuizi New Materials Co., Ltd.; Lipopeptide: Bacillus subtilis lipopeptide: Shaanxi Shengyuan Biotechnology Co., Ltd.; Sophorolipid: Yinjie Chemical; Cellulose nanofiber model CNF-CD1; Unless otherwise specified, all raw materials used in the embodiments and comparative examples are conventional products that can be purchased commercially. Example 1

[0029] This embodiment provides a high-gravity rotating packed bed reaction device.

[0030] like Figure 1 As shown, the high-gravity rotating packed bed reactor includes a cylindrical outer shell 11. A hollow rotor 4 is vertically arranged inside the outer shell 11. A packing layer 3 is fixed around the outer periphery of the hollow rotor 4. The packing layer 3 is made of stainless steel wire mesh, and the overall filling density is controlled at 85%. A liquid inlet 1 is provided at the top of the outer shell 11. A liquid distributor 2 is connected to the lower end of the liquid inlet 1. The liquid distributor 2 is suspended directly above the hollow cavity at the upper end of the hollow rotor 4. Three discharge ports are opened at the bottom of the outer shell 11: an aqueous phase discharge port 5, an oil phase discharge port 6, and a slag phase discharge port 7. The slag phase discharge port 7 is connected to a slag phase collection tank 8.

[0031] The working principle of this embodiment is as follows: The enzymatic hydrolysate to be separated is sent into the equipment through the top inlet 1. After being evenly distributed by the liquid distributor 2, it is evenly dripped into the hollow cavity of the hollow rotor 4. The high-speed rotation of the rotor forms a centrifugal force field. Under the centrifugal traction, the liquid in the cavity continuously impacts the outer packing layer 3. The packing brings mechanical shearing combined with centrifugal classification. Based on the density difference of oil, water and solid residue, phase differentiation occurs. The light oil component gathers along the inner wall of the shell and is drawn out from the oil phase outlet 6. The medium-density water phase adheres to the inner side of the packing and gathers and is discharged from the water phase outlet 5. The high-density solid residue continues to settle at the bottom of the packing. After accumulation, it is discharged into the slag phase collection tank 8 through the slag phase outlet 7. At the same time, the shearing action of the packing breaks the remaining emulsion film. The trace amount of oil wrapped in emulsion is released and enters the oil phase, and finally the continuous and efficient separation of oil, water and slag is completed.

[0032] Example 2 (Basic Example) A process for enzymatic extraction of flaxseed oil based on a millstone-shaped solid-phase mechanochemical-hypergravity field enhanced by the following steps: (1) Raw material pretreatment: After washing, flaxseeds are dried at 65°C to a moisture content of 7%, and milled using a millstone-shaped solid-phase mechanochemical milling method. The temperature of the millstone surface is controlled at 25°C, the pressure at 10MPa, and the rotation speed is set at 60r / min to mill until the particle size is 3mm; (2) Compound enzymatic hydrolysis: Flaxseeds are mixed with water at a material-liquid ratio of 1:6 (w / v), the pH is adjusted to 5.6 with a citrate-sodium citrate buffer solution, and a compound enzyme (cellulase) accounting for 1.5% of the flaxseed mass is added to the material solution. Pectinase:protease = 1:1:1), placed in a constant temperature enzymatic hydrolysis reactor at 55℃, stirred at 100 rpm for 3 hours, and then subjected to intermittent low-frequency ultrasound (40 kHz, 50 W / L, 5 min every 30 min) to obtain the hydrolysate; (3) separation under hypergravity: the hydrolysate was pumped to the hypergravity rotating packed bed reaction device of Example 1 and the reaction device speed was adjusted to 4000 rpm (corresponding to centrifugal acceleration of 400 g) for dynamic separation for 20 min; (4) oil phase purification: the upper oil phase was collected and centrifuged at 3000 rpm for 8 min to obtain high-purity flaxseed oil.

[0033] Orthogonal experiment: The following discusses the effects of single factors such as particle size, enzymatic hydrolysis temperature, and hypergravity acceleration on separation efficiency based on the basic example. a. Extraction rate: According to GB5009.6-2016 "National Food Safety Standard - Determination of Fat in Food" (Soxhlet extraction method), the oil extraction rate = Mactual oil / Mtotal oil × 100%; where Mtotal oil: dried and impurity-removed flaxseed raw material, pulverized and sieved, extracted by Soxhlet extraction and reflux extraction with anhydrous ether, and the solvent was removed by rotary evaporation and constant weight; Mactual oil: collected clear flaxseed oil, dried at constant temperature to remove trace moisture, and weighed at constant weight; b. Emulsion layer percentage: Take 100 mL of the enzymatic hydrolysate and transfer it into a stoppered graduated cylinder. After sealing, let it stand at 45℃ for 12 h. The system will separate into three layers from top to bottom: an upper free clear oil layer, a middle turbid emulsion layer, and a lower water-sludge mixed layer. Read the volume of each layer. Emulsion layer percentage = V emulsion layer / V total sample liquid × 100%; c. α-Linolenic acid retention rate, refer to GB28404-2012; α-linolenic acid retention rate = C sample / C original × 100%; where, C sample: measured α-linolenic acid content in finished oil (g / 100g); C original: α-linolenic acid content in low-temperature cold-pressed benchmark oil of the same batch of flaxseed (g / 100g). Table 1. Effect of particle size on extraction rate (other conditions are fixed as in Example 2)

[0034] As shown in Table 1 above, excessively fine particle size (<0.1 mm) can easily lead to gelatinization and blockage of the filler, while excessively coarse particle size (>0.5 mm) results in insufficient cell disruption; 0.3 mm is the optimal particle size for grinding.

[0035] Table 2. Effects of enzymatic hydrolysis temperature and time (other conditions are fixed as in Example 2)

[0036] As shown in Table 2 above, at a lower temperature (45℃), the overall catalytic activity of the compound enzyme is insufficient. Even with an extended enzymatic hydrolysis time of 4 hours, the oil extraction rate remains significantly lower than under the 55℃ condition. Shortening the reaction time further reduces the enzymatic hydrolysis and decreases the oil yield. At a higher temperature (60℃), prolonged high temperatures can gradually damage the spatial conformation of cellulase, pectinase, and protease, leading to enzyme activity degradation. As the hydrolysis time increases from 2 hours to 4 hours, the extraction rate slightly decreases from 87.5% to 88.0%. Excessive heat preservation accelerates enzyme inactivation and inhibits oil release. Under the same temperature conditions, within a reasonable range, enzymatic hydrolysis gradually becomes more complete and the extraction rate increases with time. After 3 hours, the increase in extraction rate becomes less significant. Therefore, considering both extraction rate and cost, 55℃ and 3 hours are the optimal choices.

[0037] Table 3. Effect of CGI Acceleration on Separation Efficiency (Other conditions are fixed as in Example 2)

[0038] As shown in Table 3 above, in the 100g-800g range: with increasing acceleration due to gravity, the shearing effect of the filler and centrifugal separation are enhanced, resulting in more thorough demulsification, increased release of encapsulated oil, and a continuous increase in extraction rate; the separation shearing of the equipment becomes stronger, and the extraction time is continuously shortened. When the acceleration reaches 1200g, the strong mechanical shearing intensifies oil oxidation, significantly reducing the α-linolenic acid retention rate, which does not meet food-grade requirements. A large amount of α-linolenic acid is destroyed, and the retention rate drops sharply to 95.6%, resulting in a decrease in extraction rate. For α-linolenic acid retention exceeding 800g, strong shearing destroys the structure of unsaturated fatty acids, significantly reducing the retention rate. To balance high extraction rate and α-linolenic acid retention, the optimal extraction rate is 400g for 20 minutes. Example 3

[0039] A process for enzymatic extraction of flaxseed oil based on a millstone-shaped solid-phase mechanochemical-hypergravity field enhanced by water: (1) Raw material pretreatment: After washing, flaxseeds are dried at 65°C to a moisture content of 7%. After drying, the flaxseeds are spread on the plasma reactor tray, and the thickness of the material layer is controlled to be 5 mm. An air / argon (v:v=1) mixed atmosphere is selected, the electrode spacing is 5 mm, the output power is 30 W, the processing time is 50 s, and the system temperature is ≤40°C. After completing the atmospheric pressure low-temperature plasma treatment, the flaxseeds are then ground by millstone-shaped solid-phase mechanochemical grinding. The temperature of the millstone surface is controlled at 25°C, the pressure is 10 MPa, and the rotation speed is set to 60 r / min to grind until the particle size is 3 mm. (2) Compound enzymatic hydrolysis: Flaxseeds are mixed with water at a material-liquid ratio of 1:6 (w / v). The pH is adjusted to 5.6 with citric acid-sodium citrate buffer. A hydrolysis aid and flaxseed are added to the material solution. 1.5% of a compound enzyme (the mass ratio of the decomposition aid to the compound enzyme is 0.4:1; wherein, the decomposition aid consists of cellulose nanofibers, lipopeptides, and sophorolipids in a mass ratio of 8:0.5:0.5; the compound enzyme is cellulase: pectinase: protease = 1:1:1) was placed in a 55℃ constant temperature enzymatic hydrolysis reactor, stirred at 100 rpm for 3 hours, and then subjected to intermittent low-frequency ultrasound (40 kHz, 50 W / L, 5 min every 30 min) to obtain the enzymatic hydrolysate; (3) Hypergravity field separation: the enzymatic hydrolysate was pumped to the hypergravity rotating packed bed reaction device of Example 1, and the reaction device speed was adjusted to 4000 rpm (corresponding to a centrifugal acceleration of 400 g), and dynamic separation was performed for 20 min; (4) Oil phase purification: the upper oil phase was collected and centrifuged at 3000 rpm for 8 min to obtain high-purity flaxseed oil. The oil extraction rate was 92.7%, the emulsion layer accounted for 3.1%, and the α-linolenic acid retention rate was 99.2%. Example 4

[0040] The difference between this embodiment and Embodiment 3 lies only in: (1) Raw material pretreatment: Flaxseeds were washed and dried at 65°C to a moisture content of 7%, then ground using a disc-type solid-phase chemical grinding method. The disc surface temperature was controlled at 25°C, the pressure at 10 MPa, and the rotation speed at 60 r / min until the particle size was 3 mm. The oil extraction rate was 91.9%, the emulsion layer accounted for 3.3%, and the α-linolenic acid retention rate was 99.0%. Example 5

[0041] The difference between this embodiment and Example 3 is only in the following: (2) Compound enzymatic hydrolysis: Flaxseed is mixed with water at a material-liquid ratio of 1:6 (w / v), and the pH is adjusted to 5.6 with citrate-sodium citrate buffer. A hydrolysis aid and a compound enzyme accounting for 1.5% of the flaxseed mass (mass ratio of hydrolysis aid to compound enzyme is 0.2:1; wherein, the hydrolysis aid is cellulose nanofibers, lipopeptides and sophorolipids in a mass ratio of 8:0.5:0.5; the compound enzyme is cellulase: pectinase: protease = 1:1:1) are added to the material solution and placed in a constant temperature enzymatic hydrolysis reactor at 55℃. The reactor is stirred and hydrolyzed for 3 hours at 100 rpm, and intermittent low-frequency ultrasound (40 kHz, 50 W / L, 5 min every 30 min) is used to obtain the hydrolysate. The oil extraction rate is 90.8%, the emulsion layer accounts for 5.6%, and the α-linolenic acid retention rate is 98.7%. Example 6

[0042] The difference between this embodiment and Example 3 is only in the following: (2) Compound enzymatic hydrolysis: Flaxseed is mixed with water at a material-liquid ratio of 1:6 (w / v), and the pH is adjusted to 5.6 with citrate-sodium citrate buffer. A hydrolysis aid and a compound enzyme accounting for 1.5% of the flaxseed mass (mass ratio of hydrolysis aid to compound enzyme is 0.4:1; wherein, the hydrolysis aid is cellulose nanofibers, lipopeptides and sophorolipids in a mass ratio of 6:1.5:1.5; the compound enzyme is cellulase: pectinase: protease = 1:1:1) are added to the material solution and placed in a constant temperature enzymatic hydrolysis reactor at 55℃. The reactor is stirred and hydrolyzed for 3 hours at 100 rpm, and intermittent low-frequency ultrasound (40 kHz, 50 W / L, 5 min every 30 min) is used to obtain the hydrolysate. The oil extraction rate is 92.1%, the emulsion layer accounts for 5.2%, and the α-linolenic acid retention rate is 98.9%. Example 7

[0043] The difference between this embodiment and Example 3 is only in the following: (2) Compound enzymatic hydrolysis: Flaxseed is mixed with water at a material-to-liquid ratio of 1:6 (w / v), and the pH is adjusted to 5.6 with citrate-sodium citrate buffer. A hydrolysis aid and a compound enzyme accounting for 1.5% of the flaxseed mass (mass ratio of hydrolysis aid to compound enzyme is 0.4:1; wherein, the hydrolysis aid is cellulose nanofibers and lipopeptides with a mass ratio of 8:1; the compound enzyme is cellulase: pectinase: protease = 1:1:1) are added to the material solution and placed in a constant temperature enzymatic hydrolysis reactor at 55℃. The reactor is stirred and hydrolyzed for 3 hours at 100 rpm, and intermittent low-frequency ultrasound (40 kHz, 50 W / L, 5 min every 30 min) is used to obtain the hydrolysate. The oil extraction rate is 92.0%, the emulsion layer accounts for 7.6%, and the α-linolenic acid retention rate is 98.7%. Example 8

[0044] The difference between this embodiment and Example 3 is only in the following: (2) Compound enzymatic hydrolysis: Flaxseed is mixed with water at a material-to-liquid ratio of 1:6 (w / v), and the pH is adjusted to 5.6 with citrate-sodium citrate buffer. A hydrolysis aid and a compound enzyme accounting for 1.5% of the flaxseed mass (mass ratio of hydrolysis aid to compound enzyme is 0.4:1; wherein, the hydrolysis aid is cellulose nanofibers and sophorolipids at a mass ratio of 8:1; the compound enzyme is cellulase: pectinase: protease = 1:1:1) are added to the material solution and placed in a 55℃ constant temperature enzymatic hydrolysis reactor. The mixture is stirred and hydrolyzed for 3 hours at 100 rpm, and then subjected to intermittent low-frequency ultrasound (40 kHz, 50 W / L, 5 min every 30 min) to obtain the hydrolysate. The oil extraction rate is 91.9%, the emulsion layer accounts for 8.6%, and the α-linolenic acid retention rate is 98.6%. Example 9

[0045] The difference between this embodiment and Example 3 is only in the following: (2) Compound enzymatic hydrolysis: Flaxseed is mixed with water at a material-to-liquid ratio of 1:6 (w / v), and the pH is adjusted to 5.6 with citrate-sodium citrate buffer. A hydrolysis aid and a compound enzyme accounting for 1.5% of the flaxseed mass (mass ratio of hydrolysis aid to compound enzyme is 0.4:1; wherein, the hydrolysis aid is cellulose nanofiber; the compound enzyme is cellulase: pectinase: protease = 1:1:1) are added to the material solution. The mixture is placed in a constant temperature enzymatic hydrolysis reactor at 55℃, and the rotation speed is 100 rpm. The mixture is stirred and hydrolyzed for 3 hours, supplemented by intermittent low-frequency ultrasound (40 kHz, 50 W / L, 5 min every 30 min) to obtain the hydrolysate. The oil extraction rate is 91.4%, the emulsion layer accounts for 10.2%, and the α-linolenic acid retention rate is 98.5%. Comparing Examples 3-9, it can be seen that the decomposition aid component assists the complex enzyme in the targeted degradation of cell walls and oil body encapsulation structures. The two work together to improve the problems of insufficient enzymatic hydrolysis, limited oil release, obvious emulsification side reactions, and easy loss of active components in the traditional water enzymatic method, thereby improving the oil extraction rate and maintaining the integrity and stability of α-linolenic acid.

[0046] Comparative Example 1 The only difference between Comparative Example 1 and Example 2 is: (1) Raw material pretreatment: Flaxseed was washed and dried at 65°C to a moisture content of 7%, then pulverized to a particle size of 0.3 mm using a hammer mill. The oil extraction rate was 79.4%, the emulsion layer accounted for 9.2%, and the α-linolenic acid retention rate was 97.1%. Compared to Example 2 (extraction rate 89.7%), the extraction rate decreased simply by changing the millstone-shaped solid-phase mechanochemical pretreatment method, indicating that grinding and pulverizing pretreatment in the millstone-shaped solid-phase mechanochemical reactor is a key prerequisite for improving overall efficiency. This pretreatment, along with subsequent enzymatic hydrolysis and high-gravity separation, forms a positive cycle of structural destruction, efficient release, and rapid separation, thereby improving enzymatic hydrolysis efficiency and achieving efficient extraction of flaxseed oil.

[0047] Comparative Example 2 The only difference between Comparative Example 2 and Example 2 is that (3) separation under hypergravity: the enzymatic hydrolysate was pumped to the hypergravity rotating packed bed reactor of Example 1 and the reactor speed was adjusted to 4000 rpm (corresponding to a centrifugal acceleration of 400 g) for dynamic separation for 20 min; this was replaced by natural standing for 12 h. The extraction rate was 82.6% and the emulsion layer accounted for 16.5%.

[0048] Compared to Example 2, even with pretreatment and enzymatic hydrolysis optimization, the emulsification problem still cannot be solved without enhanced separation by a hypergravity field, resulting in losses caused by the oil encapsulated in the emulsion layer.

[0049] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made to the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A water-enzymatic extraction process for flaxseed oil based on a millstone-shaped solid-phase mechanochemical-hypergravity field enhanced by gravity, characterized in that: The process includes the following steps: (1) Raw material pretreatment: Flaxseed is washed, dried, and ground into powder by solid-phase chemical processing; (2) Compound enzymatic hydrolysis: It is mixed with water at a ratio of 1:5-1:8 (w / v), the pH is adjusted to 4.5-6.0, enzymatic hydrolysis components are added, and it is enzymatically hydrolyzed at 45-60℃ for 2-4 hours to obtain enzymatic hydrolysate; (3) Hypergravity field separation: The enzymatic hydrolysate is introduced into a hypergravity rotating packed bed reactor and dynamically separated for 10-30 minutes at a temperature of 40-50℃ and a centrifugal acceleration of 200-800g; (4) Oil phase purification: The upper oil phase is collected, purified and refined to obtain high-purity flaxseed oil.

2. The aqueous enzymatic extraction process for flaxseed oil based on a millstone-shaped solid-phase mechanochemical-hypergravity field enhancement as described in claim 1, characterized in that: The solid-state mechanochemical grinding and pulverization in step (1) includes: after atmospheric pressure low-temperature plasma treatment, solid-state mechanochemical grinding is performed, wherein the grinding disc temperature is 20-35℃, the pressure is 8-20MPa, and the rotation speed is 50-120r / min.

3. The aqueous enzymatic extraction process for flaxseed oil based on a millstone-shaped solid-phase mechanochemical-hypergravity field enhancement as described in claim 1, characterized in that: The enzymatic hydrolysis components in step (2) include a hydrolysis aid component and a complex enzyme in a mass ratio of (0.3-0.5):

1.

4. The aqueous enzymatic extraction process for flaxseed oil based on a millstone-shaped solid-phase mechanochemical-hypergravity field enhancement according to claim 3, characterized in that: The complex enzyme is one or more of cellulase, pectinase, and protease.

5. The aqueous enzymatic extraction process for flaxseed oil based on a millstone-shaped solid-phase mechanochemical-hypergravity field enhancement according to claim 3, characterized in that: The decomposition aids consist of cellulose nanofibers, lipopeptides, and sophorolipids in a mass ratio of (7-10):(0.5-1):(0.5-1).

6. The aqueous enzymatic extraction process for flaxseed oil based on a millstone-shaped solid-phase mechanochemical-hypergravity field enhancement according to claim 1, characterized in that: The supergravity rotating packed bed reactor in step (3) includes a shell (11), a hollow rotor (4) is installed inside the shell (11), a packing layer (3) is provided on the outer wall of the hollow rotor (4), a liquid inlet (1) is provided at one end of the shell (11), a liquid distributor (2) is installed at the liquid inlet (1) of the shell (11), an aqueous phase outlet (5), a slag phase outlet (7) and an oil phase outlet (6) are provided at the end of the shell (11) away from the liquid inlet (1), and a slag phase collection tank (8) is provided at the slag phase outlet (7) for collecting slag phase sediments.

7. The aqueous enzymatic extraction process for flaxseed oil based on a millstone-shaped solid-phase mechanochemical-hypergravity field enhancement according to claim 6, characterized in that: The filler layer (3) is made of stainless steel wire mesh or ceramic corrugated plate, and its filling density is 80-95%.

8. The aqueous enzymatic extraction process for flaxseed oil based on a millstone-shaped solid-phase mechanochemical-hypergravity field enhancement according to claim 1, characterized in that: The purification step (4) includes one or both of the following: centrifugation at 3000-6000 rpm for 5-10 min or microfiltration membrane purification with a pore size of 0.1-0.5 μm.

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