A method for producing a triglyceride-type fish oil and a triglyceride-type fish oil

Abstract

The present application relates to the field of fish oil purification, and particularly to a method for producing triglyceride fish oil and the triglyceride fish oil, the method comprising the following steps: inputting raw fish oil with a ratio of 1:(8-15) and supercritical CO2 into a crystallization reactor at 20-35 MPa and 28-38 DEG C, with a density of 0.7-0.9 g / cm 3 After the raw fish oil with a ratio of 1:(8-15) and supercritical CO2 are input into the crystallization reactor for 40-90 min, separation is performed by using a tray separation device, the separation device includes at least 6 layers of trays with a pore size of 1-2 mm, an opening rate of 10%-20%, and supercritical CO2 is input from the bottom end of the separation device and the crystallization mixed phase is input from the top end, slurry of at least one layer of the lowermost tray is collected, and after desolventization and inert filtration, the fish oil product is obtained. The present application realizes the production of high-purity triglyceride fish oil product by performing multi-stage separation after inducing selective crystallization of triglyceride fish oil in the raw material, and the purity of the product can reach 99%.

Description

Technical Field

[0001] This invention relates to the field of fish oil purification, and in particular to a method for producing triglyceride-type fish oil and the triglyceride-type fish oil thereof. Background Technology

[0002] Fish oil, as the most important dietary source of Omega-3 polyunsaturated fatty acids (mainly eicosapentaenoic acid EPA and docosahexaenoic acid DHA), has had its health benefits widely confirmed. However, the efficacy of fish oil products is highly dependent on their purity, chemical form (triglyceride type TG, ethyl ester type EE, re-esterified triglyceride type rTG), and safety.

[0003] Numerous clinical studies have confirmed that the bioavailability of ethyl ester-type fish oil is significantly lower than that of triglyceride-type fish oil. Furthermore, rTG-type fish oil, obtained through chemical re-esterification, has a different fatty acid distribution than natural TG, and its bioavailability is still lower than that of natural TG. Therefore, fish oil product production usually uses natural fish oil as raw material. However, the Omega-3 content in natural fish oil is typically less than 30%, and it coexists with a large amount of saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), and other lipids.

[0004] Traditional fish oil purification technologies mainly include molecular distillation, urea inclusion complexation, liquid-phase preparation, and heavy metal complexation. Molecular distillation typically operates at temperatures between 180-250℃, allowing only semi-continuous production. It also easily generates trans fatty acids and undergoes thermal oxidation, resulting in fish oil with a TG content typically of 85-92% and an Omega-3 content of 70-90%. Urea inclusion complexation typically operates at temperatures between 60-80℃, which is too high and only allows for batch production. The resulting fish oil typically has a TG content of 88-95% and an Omega-3 content of 75-85%. Due to the need to add urea / ethanol, the product is prone to urethane residue. Liquid-phase preparation typically operates at temperatures between 40-60℃, which is too high and only allows for batch production. It is also extremely costly and cannot be scaled up. Due to the need to add methanol / acetonitrile, organic solvent residue is also prone to occur. While heavy metal complexation can be carried out at room temperature, the addition of Ag during the production process... + / Cu 2+ There is a high risk of heavy metal contamination; moreover, these traditional fish oil purification technologies are difficult to improve the purity of Omega-3 to over 90% while preserving the natural TG form.

[0005] Supercritical carbon dioxide (SC-CO2) fluid technology is widely used in the field of natural product extraction due to its green and mild characteristics. However, existing supercritical extraction technologies mainly rely on the differences in solubility of different components in SC-CO2 for separation. For triglyceride homologues with similar molecular weights and structures (such as saturated fatty acid triglycerides Sat-TG, monounsaturated fatty acid triglycerides MUFA-TG, and polyunsaturated fatty acid triglycerides PUFA-TG), their solubility differences are limited, resulting in low separation efficiency and the inability to directly obtain Omega-3 TG products with a purity >99%. Summary of the Invention

[0006] Based on this, the purpose of the present invention is to provide a method for producing triglyceride-type fish oil and the triglyceride-type fish oil thereof. By limiting the pressure, temperature and supercritical CO2 density, the triglyceride-type fish oil in the raw fish oil is induced to undergo selective crystallization. Through multi-stage separation by a tray-type separation device, a triglyceride-type fish oil product with high total Omega-3 fatty acid content and high triglyceride content is produced.

[0007] The technical solution of the present invention is achieved in the following ways:

[0008] A method for producing triglyceride-type fish oil includes the following steps: At 20–35 MPa and 28–38 °C, the density of supercritical CO2 is 0.7–0.9 g / cm³. 3 Under the following conditions: raw fish oil and supercritical CO2 are fed into the crystallization reactor at a mass ratio of 1:(8~15) and maintained for 40~90 minutes. The resulting crystalline mixed phase is separated by a tray separator. The tray separator is equipped with at least 6 trays. The trays are provided with sieve holes with a pore size of 1~2 mm and a single tray opening rate of 10%~20%. Supercritical CO2 is conveyed to the bottom tray and the crystalline mixed phase is conveyed to the top tray. The slurry on at least one tray closest to the bottom of the tray separator is collected. The slurry collected from the trays was subjected to solvent removal and inert filtration to obtain the triglyceride-type fish oil.

[0009] Supercritical crystallization is a novel separation technique that utilizes the unique physicochemical properties of supercritical fluids to induce solute crystallization. Its basic principle is that, near the critical point, the density of a supercritical fluid approaches that of a liquid, while its viscosity and diffusion coefficient approach those of a gas. These unique properties endow it with distinctive solvation capabilities and mass transfer characteristics.

[0010] Through extensive practical experience, the inventors discovered that in a specific supercritical environment, triglyceride molecules with different structures exhibit distinctly different phase behaviors: saturated and monounsaturated triglycerides have relatively regular molecular structures and weak intermolecular forces, and tend to dissolve in supercritical CO2; while long-chain polyunsaturated triglycerides (such as EPA / DHA-TG) have multiple double bonds in their molecular chains and curved molecular configurations, and tend to form ordered aggregates through π-π stacking and van der Waals forces.

[0011] The inventors discovered through experimentation that at around 30°C, when the pressure increases from 20 MPa to 30 MPa, the density of SC-CO2 decreases from approximately 0.70 g / cm³. 3 Increased to approximately 0.85 g / cm³ 3 During this process, the dissolution free energy of low double bond Sat / MUFA-TG continuously decreases with increasing density. Due to conformational bending, higher polarizability, and the presence of a solvation shell, high double bond PUFA-TG is prone to rearrangement, resulting in a local increase in dissolution free energy or a decrease in dissolution driving force. As a result, it preferentially reaches supersaturation conditions and exhibits phenomena such as nucleation and crystal growth, forming a gas-liquid-solid three-phase crystalline mixed phase.

[0012] The above mechanism can be explained by ΔG i (ρ)=ΔH i -TΔS i +PΔV i +ΔGsolv,i(ρ) represents the density-dependent solvation free energy term, where ρ is the supercritical CO2 density. For TG with different numbers of double bonds, ΔGsolv,i(ρ) responds differently to ρ, therefore the critical point for supersaturation differs for different molecular species. This difference is due to phase behavior threshold separation, rather than simple solubility differential separation.

[0013] The inventors explored the window of the above phenomenon by adjusting pressure and temperature, and found that the pressure and temperature were not arbitrarily chosen, but rather set around the density of SC-CO2: at 20~35MPa, 28~38℃, and an SC-CO2 density of 0.7~0.9g / cm³. 3 Under these conditions, it is possible to ensure that high double bond PUFA-TG is preferentially precipitated, and low double bond Sat / MUFA-TG can dissolve in SC-CO2 to obtain a gas-liquid-solid three-phase crystalline mixed phase, so as to achieve the enrichment of high double bond PUFA-TG without changing the molecular skeleton.

[0014] Specifically, at 20 MPa and 30 °C, the density of SC-CO2 is approximately 0.7 g / cm³. 3At this point, the solubility of low-double-bond Sat / MUFA-TG in SC-CO2 is already relatively high, and high-double-bond PUFA-TG has also reached supersaturation and shown a small amount of nucleation, thus achieving the purpose of enrichment; after pressurization, at 25 MPa and 30℃, the density of SC-CO2 is approximately 0.78~0.82 g / cm³. 3 At this point, the solubility of low-double-bond Sat / MUFA-TG in SC-CO2 further increases, while high-double-bond PUFA-TG exhibits the highest nucleation rate and the best enrichment effect. When pressurized to 30 MPa and heated to 30–35 °C, the density of SC-CO2 is approximately 0.83–0.86 g / cm³. 3 Within this range, the solubility of low-double-bond Sat / MUFA-TG in SC-CO2 further increases, while the crystals of high-double-bond PUFA-TG become larger; if the pressure is increased to above 38 MPa, the density of SC-CO2 exceeds 0.9 g / cm³. 3 Although the solubility of low double bond Sat / MUFA-TG in SC-CO2 increases further, high double bond PUFA-TG crystals also dissolve, increasing energy consumption and cost while deteriorating the enrichment effect.

[0015] Based on this, the present invention limits the mass ratio of raw fish oil to supercritical CO2 to 1:(8~15), which is beneficial to reduce the loss of Omega-3. The present invention also limits the holding time of raw fish oil and supercritical CO2 in the recrystallization reactor to 40~90min, which is beneficial to ensure that the crystal completes the nucleation, growth and maturation process.

[0016] Based on this, the present invention employs a tray-type separation device to separate the high double bond PUFA-TG and low double bond Sat / MUFA-TG in the aforementioned gas-liquid-solid three-phase crystalline mixture. In the tray-type separation device, the gas-liquid-solid three-phase crystalline mixture is fed from the top to the uppermost tray and, under gravity, flows through the sieve holes on the tray layer by layer to the next tray. SC-CO2 enters the separation device from below the lowermost tray and flows through the sieve holes on the tray to the uppermost tray and exits the separation device. Within the separation device, the SC-CO2 flowing upwards from the bottom reacts with the SC-CO2 flowing upwards from the top… When the SC-CO2 comes into contact with the mixed phase, on the one hand, the SC-CO2 washes the mixed phase. Based on the principle of diffusion from high concentration to low concentration, the low double bond Sat / MUFA-TG and other impurities dissolved in the SC-CO2 in the mixed phase diffuse into the pure / low-loaded SC-CO2 from bottom to top, thereby diluting the concentration of low double bond Sat / MUFA-TG and other impurities in the mixed phase. On the other hand, the pure / low-loaded SC-CO2 from bottom to top also dissolves the low double bond Sat / MUFA-TG entrained on the crystal surface, in pores, and in the liquid film, thereby achieving further purification of the crystal.

[0017] Since the above process occurs in each tray and between every two trays, under the tray parameters defined by this invention, such as a sieve aperture of 1-2 mm, a single-plate opening rate of 10%-20%, and at least 6 trays, high-purity enrichment of high double-bonded PUFA-TG can be achieved, resulting in triglyceride-type fish oil products with high total Omega-3 fatty acid content and high triglyceride content.

[0018] In addition, since the production method of the present invention is carried out at a temperature below 45°C throughout, the destruction of heat-sensitive components is effectively avoided, which is beneficial to maintaining the natural TG molecular structure.

[0019] Furthermore, the spacing between the trays in the tray separator is 150~250mm. Within this limited spacing range, it is beneficial to ensure that the tray separator has appropriate throughput, separation efficiency, mass transfer efficiency, and separation accuracy.

[0020] Furthermore, the method includes the following step: adding an entrainer with a volume fraction of 0.05-0.5% to the supercritical CO2 input to the crystallization reactor; the entrainer is one or more of ethyl acetate and acetone. Adding an entrainer with a volume fraction of 0.05-0.5% can moderately adjust the polarity of SC-CO2, selectively reducing the solubilization ability of supercritical CO2 on PUFA-TG, thereby further improving crystallization selectivity.

[0021] Furthermore, at 20–30 MPa and 28–35 °C, the density of supercritical CO2 is 0.75–0.85 g / cm³. 3 Crystallization and separation are carried out under specific conditions, with the raw fish oil and supercritical CO2 maintained in the crystallization reactor for 60-90 minutes. Controlling the pressure at 20-30 MPa ensures that the CO2 is in a supercritical state with adjustable density, enhancing the crystallization driving force of PUFA-TG while reducing equipment load. Controlling the temperature at 28-35℃ ensures the system has suitable viscosity, which is beneficial for crystal growth and oxidation resistance. Controlling the crystallization time at 60-90 minutes helps to ensure the completion of crystal nucleation, growth, and maturation while balancing crystal purity and throughput.

[0022] Further, crystallization was carried out at 25 MPa and 30-35 °C, and separation was carried out at 30 MPa and 30-35 °C.

[0023] Furthermore, the method includes the following step: applying a pulsating flow field with a frequency of 1~10Hz and an amplitude of 0.1~0.5MPa at the inlet of the crystallization reactor via a high-pressure pulsating pump or an electrically controlled back pressure valve. By applying low-frequency pulsation, the stagnant boundary layer on the surface of the crystal particles is disrupted, which can significantly enhance the mass transfer rate and shorten the crystallization time.

[0024] Furthermore, the crystallization reactor includes a static mixer connected in series and at least two crystallization vessels. The crystallization vessels are filled with nucleation-inducing packing material, which is surface-modified with silanization. The specific surface area of ​​the nucleation-inducing packing material is 500~1500 m². 2 / m 3 The porosity is 40-70%. The specific surface area of ​​the nucleation-induced filler is 500-1500 m². 2 / m 3 The porosity is 40-70%.

[0025] The system employs a series design of a static mixer and at least two crystallization reactors. The static mixer ensures rapid and uniform mixing of fish oil and SC-CO2 at the micron scale, initiating initial supersaturation. The first-stage crystallization reactor is primarily used to induce nucleation and form fine crystal nuclei, while subsequent crystallization reactors are mainly used for crystal growth, maturation, and slurry stabilization. The crystallization reactors are filled with surface-silanized nucleation-inducing fillers, whose high specific surface area and specific surface properties provide a large number of low-energy-barrier heterogeneous nucleation sites for PUFA-TG, promoting regular and rapid crystal growth and avoiding the randomness and lag of homogeneous nucleation.

[0026] In homogeneous systems without fillers, the nucleation of high-double-bond PUFA-TG exhibits randomness and hysteresis, easily leading to batch-to-batch fluctuations. By introducing nucleation-inducing fillers with surface-silanized modification into the crystallization vessel, hydrophobic microregions and curved interfaces are formed on the filler surface, which lowers the heterogeneous nucleation energy barrier. According to classical nucleation theory, the homogeneous nucleation energy barrier ΔG... With (lnS) 2 The energy barrier is inversely proportional to the supersaturation; the higher the supersaturation, the lower the nucleation energy barrier. During heterogeneous nucleation, the energy barrier becomes ΔG. het=f(θ)ΔG In the case of hom, the nucleation-inducing filler modified with surface silanization has a nucleation potential of f(θ) < 1, thus requiring less energy for heterogeneous nucleation than for homogeneous nucleation. Therefore, when the supersaturation S is the same, the nucleation-inducing filler modified with surface silanization can significantly increase the effective nucleation sites, enabling PUFA-TG to form crystals with more uniform particle size, and is more conducive to ensuring the settling and washability of the formed microcrystalline slurry.

[0027] Furthermore, the crystallization vessel is provided with two porous partitions, which divide the inner cavity of the crystallization vessel into a fluid distribution zone, a packing crystallization zone, and a crystal slurry buffer zone along the material flow direction. The volume of the packing crystallization zone accounts for 60-85% of the volume of the crystallization vessel, and the nucleus-induced packing is filled in the packing crystallization zone.

[0028] Furthermore, the production method for triglyceride-type fish oil is carried out under an inert atmosphere with an oxygen concentration of <30 ppm. This helps ensure that the oxidation index of the fish oil does not increase additionally throughout the entire production process.

[0029] The present invention also provides a triglyceride-type fish oil, which is prepared according to any of the above-described methods for producing triglyceride-type fish oil.

[0030] To better understand and implement this invention, the following detailed description is provided in conjunction with the accompanying drawings. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the separation process of the tray-type separation device according to an embodiment of the present invention; Figure 2 This is a schematic diagram illustrating the connection relationship between the tray, the shut-off valve, and the back pressure regulator according to an embodiment of the present invention. Figure 3 This is a schematic diagram of the process flow for producing triglyceride-type fish oil according to an embodiment of the present invention. Detailed Implementation

[0032] It should be understood that the described embodiments are merely some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of the embodiments of this application.

[0033] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the embodiments of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0034] In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims. In the description of this application, it should be understood that the terms "first," "second," "third," etc., are used only to distinguish similar objects and are not necessarily used to describe a specific order or sequence, nor should they be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0035] Furthermore, in the description of this application, unless otherwise stated, "multiple" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0036] It should be understood that the embodiments of this application are not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from their scope. The scope of the embodiments of this application is limited only by the appended claims.

[0037] The equivalent particle size mentioned in this invention refers to the particle size of non-spherical particles or ring packings determined by the nominal outer diameter of the sieve, the maximum external dimension, or the diameter of an equal-volume sphere.

[0038] The packing material described in this invention refers to a packing material with a fixed geometric structure and stacked in an orderly manner according to modules, such as stainless steel corrugated wire mesh packing, corrugated plate packing, or honeycomb ceramic structured packing; granular or ring-shaped ceramic packing should generally be called random packing and does not belong to structured packing.

[0039] This invention provides a method for producing triglyceride-type fish oil, comprising the following steps: At 20–35 MPa and 28–38 °C, the density of supercritical CO2 is 0.7–0.9 g / cm³. 3 Under the following conditions: raw fish oil and supercritical CO2 are fed into the crystallization reactor at a mass ratio of 1:(8~15) and maintained for 40~90 minutes. The resulting crystalline mixed phase is separated by a tray separator. The tray separator is equipped with at least 6 trays. The trays are provided with sieve holes with a pore size of 1~2 mm and a single tray opening rate of 10%~20%. Supercritical CO2 is conveyed to the bottom tray and the crystalline mixed phase is conveyed to the top tray. The slurry on at least one tray closest to the bottom of the tray separator is collected. The slurry collected from the trays was subjected to solvent removal and inert filtration to obtain the triglyceride-type fish oil.

[0040] Furthermore, the spacing between each tray in the tray-type separation device is 150~250mm.

[0041] Furthermore, the method also includes the following steps: adding an entrainer with a volume fraction of 0.05-0.5% to the supercritical CO2 input to the crystallization reactor; the entrainer is one or more of ethyl acetate and acetone.

[0042] Furthermore, at 20–30 MPa and 28–35 °C, the density of supercritical CO2 is 0.75–0.85 g / cm³. 3 Crystallization and separation are carried out under specific conditions, with the raw fish oil and supercritical CO2 maintained in the crystallization reactor for 60-90 minutes.

[0043] Further, crystallization was carried out at 25 MPa and 30-35 °C, and separation was carried out at 30 MPa and 30-35 °C.

[0044] Furthermore, the method also includes the following steps: applying a pulsating flow field with a frequency of 1~10Hz and an amplitude of 0.1~0.5MPa at the inlet of the crystallization reactor by means of a high-pressure pulsating pump or an electrically controlled back pressure valve.

[0045] Furthermore, the crystallization reactor includes a static mixer connected in series and at least two crystallization vessels. The crystallization vessels are filled with nucleation-inducing packing material, which is surface-modified with silanization. The specific surface area of ​​the nucleation-inducing packing material is 500~1500 m². 2 / m 3 The porosity is 40-70%. The specific surface area of ​​the nucleation-induced filler is 500-1500 m². 2 / m 3 The porosity is 40-70%. The nucleation-inducing packing can be a porous ceramic packing or a stainless steel packing modified with surface silanization. When using granular or cyclic ceramic packing, its equivalent particle size is 3-10 mm. Too small a particle size will lead to increased pressure drop and increased risk of blockage, while too large a particle size will reduce the effective nucleation area. Preferably, it is 4-8 mm. When using structured packing, such as stainless steel corrugated wire mesh packing, corrugated plate packing, or honeycomb ceramic structured packing, the single-layer height of the structured packing module is 20-80 mm and it is layered and pressed along the axial direction of the crystallizer. The nucleation-inducing packing can provide low-energy-barrier heterogeneous nucleation sites for PUFA-TG crystal formation in the supercritical CO2-fish oil system. After the nucleation-inducing packing is filled, the operating pressure drop does not exceed 0.8 MPa, and the crystal slurry can be stably discharged.

[0046] Furthermore, along the material flow direction, the volume of the subsequent crystallizer is greater than that of the preceding crystallizer. This allows for a longer residence time for crystal growth and sedimentation pretreatment.

[0047] Furthermore, the crystallization reactor includes two-stage crystallization vessels with a volume ratio of 1:(1.0~2.0).

[0048] Furthermore, the crystallization reactor includes a three-stage crystallization vessel with a volume ratio of 1:(1.0~1.5):(1.2~2.0).

[0049] Furthermore, the pressure drop of the crystallization reactor is between 0.1 and 0.8 MPa.

[0050] Furthermore, the crystallization vessel is provided with two porous partitions, which divide the inner cavity of the crystallization vessel into a fluid distribution zone, a packing crystallization zone, and a crystal slurry buffer zone along the material flow direction. The volume of the packing crystallization zone accounts for 60-85% of the volume of the crystallization vessel, and the nucleus-induced packing is filled in the packing crystallization zone.

[0051] The porous ceramic filler modified with surface silanization in this invention can be either commercially available surface-modified filler or prepared by the following steps: First, ultrasonically clean the ordinary porous ceramic filler with ethanol and deionized water, and dry it at 110°C for 2 hours; then, impregnate it with an ethanol solution of 0.5-2.0% (v / v) octyltriethoxysilane or methyltrimethoxysilane for 1-3 hours; subsequently, wash away the free silane with ethanol, and cure it at 80-120°C for 2-4 hours to obtain the porous ceramic filler modified with surface silanization.

[0052] Furthermore, the production method of triglyceride-type fish oil is carried out under an inert atmosphere with an oxygen concentration of <30ppm.

[0053] Furthermore, the solvent removal process includes two reduced-pressure flash evaporation treatments. The pressure of the first flash evaporation treatment is 5~8MPa, and the pressure of the second flash evaporation treatment is 0.1~0.5MPa. The treatment temperature is maintained at 30~38℃.

[0054] Furthermore, the inert filtration process includes the following steps: passing the fish oil through a filter under an inert atmosphere, wherein the filter has a filtration accuracy of 0.1~0.5μm.

[0055] The present invention also provides a triglyceride-type fish oil, which is prepared according to any of the above-mentioned methods for producing triglyceride-type fish oil.

[0056] The physical properties and testing methods of the embodiments or comparative examples of the present invention are as follows: Triglyceride content (TG content): determined by high performance liquid chromatography-evaporative light scattering detector method according to GB5009.168-2016.

[0057] Total Omega-3 fatty acid content (total Omega-3 content): determined by gas chromatography according to GB5009.168-2016.

[0058] Fatty acid composition, including EPA content, DHA content, other Omega-3 (such as DPA) content, total saturated fatty acid (SFA) content, and total monounsaturated fatty acid (MUFA) content: determined by gas chromatography after methylation, in accordance with GB 5009.168-2016.

[0059] Peroxide value (PV): Determined according to GB 5009.227-2023.

[0060] Anisidine value (AV): determined according to GB / T 24304 or ISO 6885.

[0061] Total oxidation state TOTOX = 2PV + AV.

[0062] Trans fatty acid content: measured with reference to GB5009.257-2016.

[0063] α-Tocopherol content: measured according to reference gB 5009.82.

[0064] Squalene content: Measured according to GB / T 43732-2024.

[0065] Astaxanthin content: measured according to SC / T 3053-2019.

[0066] Moisture content: determined using the Karl Fischer method.

[0067] Color: Determined using the Lovibond colorimetric method.

[0068] Heavy metals: After microwave digestion, ICP-MS was used for determination, and the results were determined in accordance with the current national food safety standards.

[0069] Solvent residue: Detected by headspace gas chromatography.

[0070] The raw material fish oil used in this embodiment of the invention is wild anchovy oil from the South Pacific (purchased from a well-known supplier in Peru, batch number: FO-20231025A). Although the supplier has already performed preliminary refining on the raw material fish oil (including degumming, deacidification, decolorization, and deodorization), to ensure the consistency of the raw material and the production process and to facilitate comparison between subsequent embodiments, this invention performs standard pretreatment on the raw material fish oil to make the triglyceride (TG) content, total Omega-3 fatty acid content, and peroxide value of the pretreated raw material fish oil similar. It should be noted that the pretreated raw material fish oil is also applicable to the production method of the triglyceride-type fish oil of this invention.

[0071] The pretreatment of raw fish oil in this embodiment of the invention includes dehydration and denitrification treatment and precision filtration treatment. The pretreated raw fish oil is immediately transferred to an intermediate storage tank with nitrogen protection (oxygen concentration <15ppm).

[0072] The dehydration and denitrification treatment in this embodiment of the invention includes the following steps: Raw fish oil is placed in a pretreatment tank equipped with a stirring and heating jacket, and stirred, dehydrated, and degassed for 2 hours at 75°C and a vacuum of -0.095 MPa until no more bubbles are generated. This step prevents moisture and oxygen from causing blockage or oxidation in the ultra-high pressure system.

[0073] The precision filtration process in this embodiment of the invention includes the following steps: using nitrogen pressurization, the dehydrated and denitrified raw fish oil is passed through a series of 1μm and 0.5μm sintered titanium metal filters (Pall Corporation) to remove any trace solid impurities that may be present.

[0074] The CO2 used in the embodiments of this invention is food-grade CO2 with a purity > 99.995%.

[0075] Example 1 (with entrainment but no pulsation) This embodiment provides a method for producing triglyceride-type fish oil. The production method of this embodiment is based on a laboratory-grade supercritical crystallization-separation linkage system, which includes the following equipment: a nitrogen protection cabinet and a CO2 supply and pressurization unit located in the nitrogen protection cabinet, a fish oil raw material supply unit, a crystallization reactor, a tray-type separation device, a pressure and temperature control system, a product collection and post-processing unit, and an online analysis system.

[0076] CO2 supply and pressurization unit: two food-grade liquid CO2 storage tanks, two high-pressure plunger pumps (Maximator GmbH, maximum working pressure 50MPa, flow range 0-50L / h, equipped with cooling jackets to ensure pump head temperature is maintained at 2-4℃ to prevent cavitation, and connected to the two CO2 storage tanks respectively); CO2 is pressurized to supercritical CO2 (SC-CO2) by the high-pressure plunger pumps and then transported.

[0077] Fish oil raw material supply unit: raw material storage tank (5L volume, with magnetic stirring and cooling water jacket, maintained at 10℃) and hydraulic diaphragm metering pump (Lewa GmbH, maximum pressure 40MPa, flow accuracy ±0.5%); the raw material storage tank stores pre-treated raw fish oil, which is then quantitatively delivered by the hydraulic diaphragm metering pump.

[0078] Crystallization reactor: Static mixer (Sulzer SMX type, 316L stainless steel, inner diameter 10mm, length 200mm), primary crystallizer (volume 2L, design pressure 40MPa, with viewing window and temperature control system, temperature control accuracy ±0.3℃; the inside of the reactor has two porous partitions, namely a 40-mesh sintered metal mesh and a porous limiting plate. The 40-mesh sintered metal mesh is located above the porous limiting plate, dividing the inner cavity of the reactor from top to bottom into a fluid distribution zone, a packing crystallization zone, and a crystal slurry buffer zone. The volume of the packing crystallization zone accounts for 70% of the reactor volume; only the packing crystallization zone is filled with nucleation-induced packing: silanized θ-ring ceramic random packing, with a specific surface area of ​​approximately 800m²). 2 / m 3 The reactor has a porosity of approximately 55% and an equivalent particle size of approximately 5mm. It also has a secondary crystallizer (volume 3L, design pressure 40MPa, with a viewing window and temperature control system, temperature control accuracy ±0.3℃, internal structure, proportion of the packing crystallization zone, and the nucleus-inducing packing are the same as the primary crystallizer, so they will not be described in detail), and a back pressure valve (connected to the outlet of the secondary crystallizer). Raw fish oil and SC-CO2 are rapidly homogenized at a microscale in a static mixer, and then sequentially conveyed to a primary crystallizer and a secondary crystallizer. The primary crystallizer is mainly used to induce nucleation and form fine crystal nuclei, while the secondary crystallizer is mainly used for crystal growth and crystal slurry maturation. Its effective volume is larger than that of the primary crystallizer to extend the crystal growth residence time. A pressure-resistant short pipe, online temperature and pressure measuring points, and a detachable filter protection screen are provided between the two stages. After passing through the crystallization reactor, the raw fish oil and SC-CO2 output a gas-liquid-solid three-phase crystallized mixed phase.

[0079] Tray-type separator: Main body (pressure-resistant alloy steel, inner diameter 50mm, design pressure 40MPa, equipped with a slurry inlet for conveying the gas-liquid-solid three-phase crystallization mixture to the uppermost tray, a CO2 inlet for conveying SC-CO2 to the bottom tray, and a CO2 outlet for discharging CO2 from the uppermost tray to the outside of the main body), 8 trays (sieve aperture 1.5mm, opening rate 15%, tray spacing 200mm, the uppermost tray is the 1st tray, arranged from top to bottom, the bottom tray is the 8th tray), jacket (set on the main body, connected to an external circulating bath for temperature control, temperature control accuracy ±0.5℃), 8 shut-off valves (connected to the discharge ports of the 8 trays respectively), and 8 back pressure regulators (connected to the 8 shut-off valves respectively). Please see Figure 1 and Figure 2SC-CO2 enters the main body from below the 8th tray, with a tendency to flow from bottom to top, pass through the sieve holes on the tray, pass through the 8 trays, and exit from the CO2 outlet above the 1st tray; after the gas-liquid-solid three-phase crystalline mixed phase enters the main body, it first reaches the 1st tray, and has a tendency to fall from top to bottom onto each tray and finally fall onto the 8th tray.

[0080] Pressure and temperature control system: High-precision pressure sensors (accuracy ±0.1MPa, installed after each pump such as the high-pressure plunger pump and the hydraulic diaphragm metering pump, as well as at the inlet and outlet of each crystallizer and on each tray), Pt100 platinum resistance thermometers (accuracy ±0.1℃, installed after each pump such as the high-pressure plunger pump and the hydraulic diaphragm metering pump, as well as at the inlet and outlet of each crystallizer and on each tray), PLC system (electrically connected to each pressure sensor and each thermometer to obtain pressure, temperature and other information; also electrically connected to the control terminals of each pump such as the high-pressure plunger pump and the hydraulic diaphragm metering pump to realize pump control; also electrically connected to each temperature control system, each heating component and each cooling component to realize temperature regulation).

[0081] Product collection and post-processing unit: Please refer to Figure 1 and Figure 2 The system includes 6 collection tanks (2L capacity, with cooling jackets, divided into three groups, each group connected to the discharge ports of the 2nd-3rd, 4th-5th, and 6th-8th trays respectively; each group of collection tanks alternately collects the mixed phase discharged from the tray outlet; when one collection tank reaches the set liquid level / capacity, it switches to another collection tank, working alternately), a first flash tank (operating pressure 6MPa, temperature 35℃), a second flash tank (operating pressure 0.3MPa, temperature 35℃), and a terminal filter (0.2μmPTFE membrane filter). The collection tank connected to the discharge port of the 2nd and 3rd trays can collect light components rich in Sat / MUFA-TG. The collection tank connected to the discharge port of the 4th and 5th trays can collect intermediate transition components for reflux to the raw material storage tank. The collection tank connected to the discharge port of the 6th to 8th trays can collect target heavy components for feeding into a two-stage vacuum flash evaporation system consisting of a first flash tank and a second flash tank for solvent removal. The liquid after solvent removal will be sent to the terminal filter for inert filtration under nitrogen protection.

[0082] Online analysis system: Online near-infrared (NIR) spectral probes (BüchiNIRFlexN-500, installed at the discharge ports of the 3rd, 5th, and 7th trays respectively) are used to monitor the fatty acid composition trend of the fluid in real time.

[0083] Based on the above-described equipment, the production method of triglyceride-type fish oil in this embodiment (Example 1) includes the following steps: Leak detection and pretreatment: Purge the nitrogen protection cabinet and the equipment inside the nitrogen protection cabinet with high-purity nitrogen to ensure that the oxygen concentration at the outlet of the nitrogen protection cabinet and the equipment inside the cabinet is <20ppm; then use SC-CO2 to circulate and flush the equipment inside the cabinet at 25MPa and 35℃ for 30 minutes to remove any possible contaminants; then increase the pressure and conduct a pressure test to ensure that there are no leaks at all connections at 35MPa before restoring to normal pressure.

[0084] The raw fish oil was pretreated, and the pretreated raw material was then transported to a raw material storage tank for storage, where the temperature was controlled at 30℃. The pretreated raw fish oil was analyzed and tested, and the results are as follows: The TG content is 94.7%; the total Omega-3 fatty acid content is 40.8%. The EPA (C20:5n-3) content is 18.2%, the DHA (C22:6n-3) content is 11.9%, and the content of other Omega-3s (such as DPA) is 10.7%. The total saturated fatty acids (SFA) are approximately 35.2%, and the total monounsaturated fatty acids (MUFA) are approximately 22.1%. The peroxide value is 2.3 meq / kg, the anisidine value is 4.1, and the total oxidation value is 8.7; the trans fatty acid content is 0.08%; the α-tocopherol content is 185 mg / kg, the squalene content is 62 mg / kg, the astaxanthin content is 3.2 mg / kg, and the moisture content is <0.05%; the color is Lovibond color 1.5R5.0Y0.3N.

[0085] Pressurization and stabilization: Restart the high-pressure plunger pump and slowly increase the pressure of the crystallization reactor to 25 MPa and the pressure of the tray separator to 30 MPa at a rate of 5 MPa / min; and start heating to stabilize the temperature of the primary crystallizer at 30℃, the secondary crystallizer at 31℃, and the temperature of each tray at 35℃. After all equipment has reached the predetermined temperature and pressure, continue to run for 15 minutes.

[0086] Feeding and Crystallization Reaction: The CO2 flow rate to the crystallization reactor is adjusted to 5.0 kg / h. Fish oil from the raw material storage tank is pumped to the crystallization reactor at a flow rate of 0.5 kg / h using a hydraulic diaphragm metering pump, maintaining a fish oil:CO2 mass ratio of 1:10. In this embodiment, the total feed amount of fish oil is 4 kg. Simultaneously, 0.1% (v / v) of food-grade ethyl acetate (entrainer) is continuously injected before the static mixer inlet using a micro-injection pump (ISCO100DX). Fish oil and CO2... After being thoroughly mixed with the entrainer in a static mixer, the mixture is sequentially processed into a primary crystallizer and a secondary crystallizer. Through the viewing window, it can be observed that microcrystals appear in the latter part of the primary crystallizer, indicating that the crystals in the reactor have completed the initial nucleation. In the secondary crystallizer, the crystals gradually increase in size with the direction of material flow and eventually become a slurry, indicating that the crystals have completed crystal growth and maturation in the reactor, resulting in a gas-liquid-solid three-phase crystalline mixed phase. The total residence time of fish oil, CO2 and entrainer in the crystallization reactor is 75 min (calculated based on the volume and total flow rate of the two-stage crystallizer).

[0087] Multi-stage tray separation: The gas-liquid-solid three-phase crystallization mixture output from the bottom of the secondary crystallizer is transported to the first tray through the crystal slurry inlet of the main body of the tray-type separator. Before the operation is stable, the crystal slurry dripping to the bottom of the separator is transported to an external transition tank. In a preferred embodiment, the crystal slurry in the transition tank can be directly transported to the first tray. After about 90 minutes, the operation is stable (judged by the monitoring results of the online near-infrared spectroscopy probe, the NIR signal fluctuates for 15 minutes continuously <±5%). Then, the crystal slurry (light component, rich in Sat / MUFA-TG) of the second and third trays is output to the first set of collection tanks by adjusting the shut-off valve. The crystal slurry (intermediate transition component) of the fourth and fifth trays is output to the second set of collection tanks. The crystal slurry (target heavy component, rich in PUFA-TG) of the sixth to eighth trays and the crystal slurry at the bottom of the separator are output to the third set of collection tanks.

[0088] Desolventizing treatment: The crystal slurry in the third collection tank is transferred to the first flash tank (6MPa, 35℃). In the first flash tank, the pressure of the crystal slurry drops instantly from 30MPa to 6MPa, causing most of the CO2 to vaporize and separate. Then, the material output from the first flash tank is transferred to the second flash tank (0.3MPa, 35℃). In the second flash tank, the pressure is further reduced from 6MPa to 0.3MPa, and most of the remaining CO2 is removed in this process.

[0089] Inert filtration: Under nitrogen positive pressure protection, the slightly turbid oil output from the second flash tank (slightly turbid due to trace amounts of crystals and misty CO2) is passed through a 0.2μm PTFE membrane filter to obtain 0.68kg of clear and transparent triglyceride-type fish oil product. The product is then packaged in a brown glass bottle under nitrogen and stored at -20℃ in the dark.

[0090] The triglyceride-type fish oil of this embodiment (Example 1) was analyzed and tested, and the results are as follows: The TG content is 99.4%, which indicates that the process successfully removed about 5% of non-triglyceride impurities (such as phospholipids, sterols, and some oxidation products) from the raw materials without damaging the TG molecules themselves. The total Omega-3 content was 99.3%, which indicates that almost all saturated fatty acids and monounsaturated fatty acids were effectively separated. The EPA content is 40.1%, and the DHA content is 49.4%, accounting for as much as 90.1% of the total Omega-3, indicating that the production method of the present invention has excellent selectivity for long-chain PUFA-TG; The peroxide value was 0.6 meq / kg, which was not only not higher than that of the pretreated fish oil raw material (2.3 meq / kg), but was significantly lower. This indicates that the low temperature and oxygen-free process conditions of the production method of the present invention can effectively prevent the oxidation process and even remove some primary oxidation products during the purification process. The anisidine value was 2.8, which was lower than that of the pretreated fish oil raw material (4.1), indicating that some secondary oxidation products (aldehydes and ketones) were also removed during crystallization or separation. The trans fatty acid content is 0.05%, lower than that of pretreated fish oil (0.08%) and far lower than that of molecular distillation products (typically >1.5%), confirming the absolute advantage of low-temperature processing in avoiding isomerization. The α-tocopherol content was 178 mg / kg, with a retention rate of 96.2%; the squalene content was 59 mg / kg, with a retention rate of 95.2%; and the astaxanthin content was 3.1 mg / kg, with a retention rate of 96.9%. Heavy metals: Lead, cadmium, mercury, and arsenic were not detected (below the detection limit of ICP-MS); Solvent residue: No ethyl acetate residue detected (<1 ppm); Color: Ghana color code <1G, almost colorless, with excellent sensory quality; Odor: The characteristic odor of pure fish oil, without any off-odors or rancid smell; (Total Omega-3) Yield: (0.68kg / 2.0kg) (99.3% / 40.8%)≈41.2%.

[0091] Throughout the entire operation, the pressure fluctuation was <±0.3MPa, the temperature fluctuation was <±0.5℃, and the raw material / CO2 ratio remained stable, demonstrating the good controllability of the production process.

[0092] Example 2 (No entrainment, no pulsation) This embodiment provides a method for producing triglyceride-type fish oil, which is the same as that in Example 1, so it will not be described in detail. The difference is that no entrainer is added in this application. The total Omega-3 content of the triglyceride-type fish oil in this embodiment is 98.62%, the triglyceride (TG) content is 99.21%, and the product yield is 37.8%. It is evident that even without the addition of an entrainer, the triglyceride-type fish oil produced using the production method of this invention can achieve a high purity.

[0093] Example 3 (without entrainment and pulsation) This embodiment provides a method for producing triglyceride-type fish oil. The production method is the same as that in Example 1, so it will not be described in detail. The difference is that no entrainer is added in this application, and a pressure pulsating flow field with a frequency of 3Hz and an amplitude of 0.2MPa is applied at the inlet of the static mixer through an electronically controlled back pressure valve. In this embodiment, the total Omega-3 content of the triglyceride-type fish oil is 99.05%, the triglyceride (TG) content is 99.30%, and the product yield is 40.1%. It can be seen that, without adding an entrainer, the total Omega-3 content of the produced triglyceride-type fish oil can be increased by applying a pulsating flow field, resulting in triglyceride-type fish oil with both total Omega-3 content and triglyceride (TG) content > 99%.

[0094] Example 4 (with pulsation) This embodiment provides a method for producing triglyceride-type fish oil. The production method is the same as that in Example 1, so it will not be described in detail. The difference is that this application also applies a pressure pulsating flow field with a frequency of 3Hz and an amplitude of 0.2MPa at the inlet of the static mixer through an electronically controlled back pressure valve. In this embodiment, the total Omega-3 content of the triglyceride-type fish oil was 99.42%, the triglyceride (TG) content was 99.45%, and the product yield was 42.6%. It is evident that by adding an entrainer and further applying a pulsating flow field, the total Omega-3 content, triglyceride (TG) content, and yield of the produced triglyceride-type fish oil can be further improved.

[0095] Example 5 (100 tons) This embodiment provides a method for producing triglyceride-type fish oil. The production method in this embodiment is based on the laboratory-grade supercritical crystallization-separation linkage system of Example 1, scaled up. Apart from the increase in equipment volume, the key changes are as follows: CO2 supply and pressurization unit: large CO2 storage tank, oil-free hydraulically driven compressor unit (displacement of 500L / h), CO2 purification and recovery system; pressurizes and controls the flow of CO2 through the compressor unit.

[0096] The crystallization reactor consists of a static mixer and a three-stage crystallizer (316L pressure-resistant lined vessel, designed pressure 40MPa, packing crystallization zone volume ratio 70%, packing material is industrial-grade silanized ceramic rectangular saddle ring packing, equivalent particle size approximately 6mm) connected in series along the material direction. The first-stage crystallizer has a volume of 0.7m³. 3 The volume of the secondary crystallization vessel is 0.8 m³. 3 The volume of the three-stage crystallization reactor is 1.0 m³. 3 Total volume 2.5m³ 3 The primary crystallizer is responsible for initial supersaturation and nucleation, the secondary crystallizer is responsible for crystal growth, and the tertiary crystallizer is responsible for slurry maturation and particle size uniformization.

[0097] Tray-type separation device: overall height is 4.5m, main body inner diameter is 300mm, tray spacing is 250mm, opening rate is 15%, and screen aperture is 2.0mm.

[0098] Product collection and post-processing unit: First flash evaporator (effective volume 0.8m³) 3 Operating pressure 6MPa), second flash tower (effective volume 1m³) 3 Operating pressure 0.3MPa), backwash filter (using 0.2μm sintered metal filter element).

[0099] Flow sensor: detects the flow rate of CO2 and fish oil raw materials.

[0100] The source of the raw fish oil processed in this embodiment is the same as that in Example 1 (20 tons / batch). The production method of the triglyceride-type fish oil in this embodiment is the same as that in Example 1, so it will not be described again. The difference is: In this embodiment, after pretreatment, the raw fish oil is mainly evaluated for TG content, total Omega-3 content, and PV. Specifically, the required TG content is 94±0.5%, the total Omega-3 content is 40.5±1.0%, and the PV is <3.0 meq / kg.

[0101] Feeding and crystallization reaction: The pressure in the crystallizer is controlled at 25 MPa. With a raw material fish oil:CO2 mass ratio of 1:10, 0.1% (v / v) of food-grade ethyl acetate (entrainer) is continuously injected before the inlet of the static mixer. A pressure pulsating flow field with a frequency of 3 Hz and an amplitude of 0.2 MPa is applied at the inlet of the static mixer via an electrically controlled back pressure valve. The temperature of the first-stage crystallizer is controlled at 30℃, the temperature of the second-stage crystallizer at 31℃, and the temperature of the third-stage crystallizer at 32℃. The total residence time of fish oil, CO2, and entrainer in the crystallization reactor is 75 min (calculated based on the volume and total flow rate of the third-stage crystallizer).

[0102] Multi-stage tray separation: The pressure of the tray separation unit is controlled at 30MPa and the temperature is controlled at 35℃.

[0103] The production method for triglyceride-type fish oil in this embodiment was continuously operated for 720 hours (including the time spent on initial heating, waiting for system stabilization, and final shutdown, therefore not 720 hours of full-load operation), processing a total of 85.6 tons of raw fish oil and obtaining 28.1 tons of triglyceride-type fish oil product that meets the standards (total Omega-3 content >99%, TG content >99%). Samples were taken from the final product line every 8 hours for testing. The average total Omega-3 content was 99.25% with a standard deviation of 0.15%, the average TG content was 99.38% with a standard deviation of 0.12%, the average peroxide value was 0.72 meq / kg with a standard deviation of 0.18 meq / kg, the average trans fatty acid content was 0.06% with a standard deviation of 0.01%, and the average yield was approximately 40%. The product quality and yield are highly consistent with those of Example 1, proving the success of the scale-up. The extremely small standard deviations of all quality indicators indicate that the production method of this invention has excellent production stability and product consistency even after scale-up.

[0104] After 30 days of operation, the production method of triglyceride-type fish oil in this embodiment has a comprehensive energy consumption (electricity, cooling water, nitrogen) of approximately 5800 kWh per ton of triglyceride-type fish oil product that meets the standards (total Omega-3 content >99%, TG content >99%). In addition, the CO2 recycling recovery rate remains above 95%, the pressure drop in the packing crystallization zone remains between 0.25-0.55 MPa, the main equipment (compressor, high-pressure pump) operates stably without major failures, and there are no phenomena such as crystallization kettle blockage, tray flooding, or crystallization blockage in the collection pipeline. This indicates that the packing particle size, packing height, and pulsating flow field parameters are suitable for industrial continuous operation.

[0105] The continuous operation data for 30 days proves that the production method of this invention can stably and reliably achieve large-scale continuous production, with stable product quality and key technical and economic indicators reaching or even exceeding laboratory expectations. It has fully met the technical maturity for large-scale commercial promotion.

[0106] Based on the following products produced in Example 5 (total Omega-3 content >99%, TG content >99%), in vitro digestion experiments, in vivo pharmacokinetic experiments, and long-term feeding experiments were conducted on the following products: triglyceride-type fish oil (product of this invention) that meets the standards (total Omega-3 content >99%, TG content >99%), commercially available re-esterified triglyceride-type fish oil (reference a, nominal total Omega-3 content 70%), commercially available high-purity ethyl ester-type fish oil (reference 2, nominal total Omega-3 content 90%), and commercially available ordinary natural triglyceride-type fish oil (reference c, nominal total Omega-3 content 30%). The relevant steps and results are as follows.

[0107] In vitro digestion experiment: Experimental animals: Healthy adult male SPF rats, weighing 180-220g, were randomly assigned to 4 groups.

[0108] Experimental Procedure: In vitro digestion model (INFOGEST): Strictly following international standard procedures, the digestive stages of the stomach and intestines were simulated. The release rate of free fatty acids (FFA) in intestinal fluid was measured at different time points (0, 30, 60, 120 min) to characterize digestion efficiency.

[0109] Experimental results: After 120 minutes of digestion, the FFA release rate of the product of this invention reached as high as 92%, significantly higher than that of control a (FFA release rate of 68%), control b (FFA release rate of 43%), and control c (FFA release rate of 58%). Compared with control a, control b, and control c, the product of this invention, due to its high purity and intact natural TG structure, is most easily hydrolyzed by pancreatic lipase and has the highest absorption potential.

[0110] In vivo pharmacokinetic experiments: Experimental animals: Healthy adult male SPF rats, weighing 180-220g, were randomly assigned to 4 groups of 8 rats each.

[0111] Experimental Procedure: After fasting, a single gavage administration of a dose equivalent to 500 mg Omega-3 was administered. Blood samples were collected from the tail vein before administration and at 0.5, 1, 2, 4, 6, 8, 12, and 24 hours after administration. Plasma was processed, and the concentrations of EPA and DHA were accurately determined by LC-MS / MS. Pharmacokinetic parameters were calculated: peak concentration (Cmax), time to peak concentration (Tmax), and area under the curve (AUC0-24h).

[0112] The results of the in vivo pharmacokinetic experiments are shown in Table 1.

[0113] Table 1. Pharmacokinetic parameters of total EPA+DHA in plasma of rats after oral administration of different fish oils.

[0114] The product of this invention has the shortest Tmax (4.0h), indicating that it has the fastest absorption rate; and the Cmax and AUC of the product of this invention are significantly higher than those of all other groups; compared with control b, the relative bioavailability of the product of this invention is as high as 167%, which not only far exceeds control b, but is also significantly better than control a (101%) and control c (122%).

[0115] Long-term feeding experiment: Experimental animals: Healthy adult male SPF rats, weighing 180-220g, were randomly assigned to two groups and induced into metabolic syndrome model rats by a high-fat diet.

[0116] Experimental procedure: Two groups of rats were supplemented with the product of this invention and control product b respectively for 8 weeks, and changes in blood lipids, inflammatory factors, etc. were detected.

[0117] Experimental results: Compared with rats supplemented with control b, rats supplemented with the product of this invention showed a more significant decrease in serum triglycerides (TG), higher levels of high-density lipoprotein cholesterol (HDL-C), and lower levels of inflammatory markers (such as TNF-α) after 8 weeks. This suggests that the product of this invention may have superior health effects in improving blood lipids and reducing inflammation.

[0118] Based on the above three experiments (including in vivo and in vitro biological evaluations), it can be seen that the triglyceride-type fish oil produced by this invention has high bioavailability, and its absorption rate and total absorption are significantly better than various commercially available products; thus, the product of this invention can be used as a top-grade dietary supplement.

[0119] As an optional implementation, please refer to Figure 3 The tray-type separator has 9 trays. Three sets of collection tanks are connected to the discharge ports of the 2nd to 3rd trays, the 4th to 6th trays, and the 7th to 9th trays, respectively. The intermediate transition components collected from the discharge ports of the 4th to 6th trays are returned to the raw material storage tank.

[0120] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and the present invention also intends to include these modifications and variations.

Claims

1. A method for producing triglyceride-type fish oil, characterized in that, Includes the following steps: At 20–35 MPa and 28–38 °C, the density of supercritical CO2 is 0.7–0.9 g / cm³. 3 Under the following conditions: raw fish oil and supercritical CO2 are fed into the crystallization reactor at a mass ratio of 1:(8~15) and maintained for 40~90 minutes. The resulting crystalline mixed phase is separated by a tray separator. The tray separator is equipped with at least 6 trays. The trays are provided with sieve holes with a pore size of 1~2 mm and a single tray opening rate of 10%~20%. Supercritical CO2 is conveyed to the bottom tray and the crystalline mixed phase is conveyed to the top tray. The slurry on at least one tray closest to the bottom of the tray separator is collected. The slurry collected from the trays was subjected to solvent removal and inert filtration to obtain the triglyceride-type fish oil.

2. The method for producing triglyceride-type fish oil according to claim 1, characterized in that, The spacing between the trays in the tray-type separation device is 150~250mm.

3. The method for producing triglyceride-type fish oil according to claim 1, characterized in that, It also includes the following steps: An entrainer with a volume fraction of 0.05-0.5% is added to the supercritical CO2 input to the crystallization reactor; the entrainer is one or more of ethyl acetate and acetone.

4. The method for producing triglyceride-type fish oil according to claim 1, characterized in that, At 20–30 MPa and 28–35 °C, the density of supercritical CO2 is 0.75–0.85 g / cm³. 3 Crystallization and separation are carried out under specific conditions, with the raw fish oil and supercritical CO2 maintained in the crystallization reactor for 60-90 minutes.

5. The method for producing triglyceride-type fish oil according to claim 4, characterized in that, Crystallization was carried out at 25 MPa and 30-35 °C, and separation was carried out at 30 MPa and 30-35 °C.

6. The method for producing triglyceride-type fish oil according to claim 1, characterized in that, It also includes the following steps: A pulsating flow field with a frequency of 1~10Hz and an amplitude of 0.1~0.5MPa is applied at the inlet of the crystallization reactor by a high-pressure pulsating pump or an electrically controlled back pressure valve.

7. The method for producing triglyceride-type fish oil according to claim 1, characterized in that, The crystallization reactor comprises a static mixer connected in series and at least two crystallization vessels. The crystallization vessels are filled with nucleation-inducing packing material, which is surface-modified with silanization. The specific surface area of ​​the nucleation-inducing packing material is 500–1500 m². 2 / m 3 The porosity is 40-70%.

8. The method for producing triglyceride-type fish oil according to claim 7, characterized in that, The crystallization vessel is provided with two porous partitions, which divide the inner cavity of the crystallization vessel into a fluid distribution zone, a packing crystallization zone, and a crystal slurry buffer zone along the material flow direction. The volume of the packing crystallization zone accounts for 60-85% of the volume of the crystallization vessel, and the nucleus-inducing packing is filled in the packing crystallization zone. The nucleus-inducing packing is a porous ceramic packing modified with surface silanization or a stainless steel packing modified with surface silanization.

9. The method for producing triglyceride-type fish oil according to claim 1, characterized in that, The production method of triglyceride-type fish oil is carried out in an inert atmosphere with an oxygen concentration of <30ppm.

10. A triglyceride-type fish oil, characterized in that, The triglyceride-type fish oil is prepared according to any one of claims 1 to 9.

Images