Glyceryl diester compound edible oil for assisting reduction of uric acid and preparation method thereof

Abstract

This invention discloses a diglyceride-based edible oil for assisting in lowering uric acid and its preparation method, relating to the field of edible oil technology. This diglyceride-based edible oil for assisting in lowering uric acid comprises the following ingredients in parts by weight: 42-50 parts modified high-oleic sunflower seed oil, 8-12 parts food-grade glycerol, 1.5-2.5 parts immobilized Rhizopus oryzae lipase, 0.3-0.8 parts modified apigenin, 0.2-0.4 parts vitamin E, 0.3-0.5 parts monoglyceride citrate, and 1.0-1.5 parts hydroxytyrosol. This composite edible oil combines the health benefits of diglycerides with the function of assisting in lowering uric acid. It exhibits good compatibility and stability of active ingredients, high bioavailability, excellent physicochemical properties, suitability for various cooking methods, and easy storage.

Description

Technical Field

[0001] This invention relates to the field of edible oil technology, specifically to a glycerol diglyceride compound edible oil that helps lower uric acid and its preparation method. Background Technology

[0002] With changes in residents' dietary structure and increased intake of high-purine and high-fat foods, the incidence of hyperuricemia is showing a year-on-year upward trend and is affecting younger people. Long-term high uric acid not only easily leads to gout, but also affects multiple organs such as the kidneys and cardiovascular system, becoming a significant metabolic problem threatening human health. Currently, most uric acid-lowering methods on the market are drug-based, but long-term use can easily cause side effects such as gastrointestinal discomfort and burden on liver and kidney function. Therefore, developing foods that combine daily consumption and auxiliary uric acid-lowering functions has become a research hotspot.

[0003] Diglyceride-based edible oils have become an important category of healthy edible oils due to their physiological functions of lowering blood lipids and reducing fat accumulation. However, as a single type, they lack the effect of assisting in lowering uric acid and cannot meet the dietary needs of people with high uric acid. Although natural active ingredients such as apigenin and hydroxytyrosol have been proven to inhibit uric acid production and promote uric acid excretion, these ingredients are poorly water-soluble or fat-soluble, and their direct addition to edible oils can easily lead to uneven dispersion, poor stability, and low bioavailability.

[0004] Meanwhile, traditional edible oil modification processes mostly focus on improving oxidative stability, without incorporating compounding and encapsulation technologies for uric acid-lowering active ingredients. This leads to defects in compound oils, such as loss of active ingredients, deterioration in flavor, and short shelf life. Therefore, there is an urgent need to develop a compound edible oil that combines the physiological advantages of diglycerides with natural uric acid-lowering active ingredients, improves component compatibility and stability through modification processes, and possesses both edibility and auxiliary uric acid-lowering functions. This would solve the technical problems of existing products having single functions and low utilization efficiency of active ingredients. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a diglyceride-based edible oil that helps lower uric acid and its preparation method, solving the problems of limited functionality, poor component compatibility, and easy loss of activity in existing edible oils.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A compound edible oil containing diglycerides that helps lower uric acid contains the following ingredients in parts by weight: 42-50 parts modified high-oleic sunflower seed oil, 8-12 parts food-grade glycerol, 1.5-2.5 parts immobilized Rhizopus oryzae lipase, 0.3-0.8 parts modified apigenin, 0.2-0.4 parts vitamin E, 0.3-0.5 parts monoglyceride citrate, and 1.0-1.5 parts hydroxytyrosol.

[0007] Furthermore, the modified high-oleic sunflower seed oil is prepared using the following specific steps: A1. In a jacketed reactor, high-oleic sunflower seed oil is first added, stirring is started and the temperature is raised to 40-42℃, then food-grade glycerol and immobilized Rhizopus oryzae lipase are added sequentially. The stirring speed is 200-300 r / min, and the reaction is kept at this temperature for 4-6 h. Nitrogen gas is bubbled through the reaction system to continuously remove water, thus obtaining the first modified high-oleic sunflower seed oil. The immobilized Rhizopus oryzae lipase (1,3-specific) catalyzes the acyl transfer between the sn-1,3 position acyl group of triglyceride and glycerol, directionally generating 1,3-diglyceride, increasing the content and providing a substrate for subsequent structural recombination. Nitrogen gas bubbling removes by-product water, driving the equilibrium to the positive direction.

[0008] A2. The temperature of the above reaction vessel was controlled at 42-44℃, and a vacuum of -0.08 MPa was applied. Medium-chain fatty acid methyl esters were slowly added, followed by immobilized Rhizopus oryzae lipase. The reaction was carried out at 42-45℃ under a vacuum of -0.08 MPa for 3-4 hours. Methanol generated during the reaction was continuously removed to obtain modified high-oleic sunflower seed oil. Medium-chain fatty acids are enriched at the sn-1,3 positions, providing rapid energy during metabolism, reducing fat accumulation, and improving postprandial blood lipids.

[0009] Furthermore, the ratio of high oleic sunflower seed oil, food-grade glycerol, and immobilized Rhizopus oryzae lipase in A1 is 500g: 45-55g: 10-15g.

[0010] Furthermore, the ratio of medium-chain fatty acid methyl ester to immobilized Rhizopus miltiorrhiza lipase in A2 is 40-70g:8-12g; wherein the ratio of medium-chain fatty acid methyl ester C8:C10 is 6:4.

[0011] Furthermore, the activity of the immobilized Rhizopus oryzae lipase is ≥10000 PLU / g.

[0012] Furthermore, the modified apigenin is prepared using the following specific steps: B1. Add apigenin powder and 75% ethanol (by volume) to a stirred extraction tank, start stirring, heat to 50℃ and extract for 30 minutes. After extraction, transfer the liquid to a crystallization tank, cool to 10℃ for crystallization, filter, and dry the filter cake under reduced pressure to obtain high-purity microcrystalline apigenin. Selectively dissolve apigenin with 75% ethanol (by volume), and remove impurities such as polysaccharides and pigments by low-temperature crystallization.

[0013] B2. In a dry, anhydrous jacketed reactor, microcrystalline apigenin, vinyl octanoate, and 4Å molecular sieve are added. Stirring is started and the temperature is raised to 50-55℃. Immobilized Candida antarcticis lipase B is then added. The pressure is evacuated to -0.08MPa, and the reaction is maintained at this temperature for 24-36 hours. Acetaldehyde generated during the reaction is continuously removed. After the reaction is completed, the enzyme and molecular sieve are removed by filtration to obtain the first modified apigenin. Immobilized Candida antarcticis lipase B preferentially recognizes apigenin 7-OH, catalyzing the regioselective acylation of vinyl octanoate. Vacuum removal of acetaldehyde drives the equilibrium. Apigenin-7-O-octanoate is generated, with improved oil solubility, regioselectivity ≥80%, and retention of uric acid-lowering active sites.

[0014] B3. In a high-shear dispersion vessel, deionized water and fish collagen peptides are first added and stirred to dissolve. The temperature is then raised to 50-55℃. The first-modified apigenin is dissolved in modified high-oleic sunflower seed oil and slowly added dropwise to the above aqueous phase. High-speed shearing is applied for 20-30 minutes to form an oil-in-water emulsion. This emulsion is then freeze-dried at -50℃ and 10 Pa for 24-48 hours to obtain modified apigenin. The peptides on the surface of the oil droplets in the emulsion bind to apigenin caprylate through hydrophobic interactions. After freeze-drying, a peptide-encapsulated solid dispersion system is formed. This complex can be redispersed in the oil phase to form stable nanoparticles.

[0015] Furthermore, the ratio of apigenin powder to ethanol in B1 is 50g:40-60ml.

[0016] Furthermore, the ratio of microcrystalline apigenin, vinyl octanoate, 4Å molecular sieve, and immobilized Candida antarcticis lipase B in B2 is 35g:30-45g:2.0-3.5g:1.5-2.5g; and the activity of the immobilized Candida antarcticis lipase B is ≥10000U / g.

[0017] Furthermore, the ratio of deionized water, fish collagen peptide, first-modified apigenin, and modified high-oleic sunflower seed oil in B3 is 80-120mL: 10-20g: 30g: 40-60g.

[0018] A method for preparing a glycerol-based edible oil that helps lower uric acid specifically includes the following steps: S1. Mix 42-50 parts of modified high-oleic sunflower seed oil, 8-12 parts of food-grade glycerol, and 1.5-2.5 parts of immobilized Rhizopus oryzae lipase, and react at 40-42℃ and -0.08MPa vacuum for 12-14 hours, stirring at 80-120r / min and bubbling with nitrogen to remove water. S2. The above reaction solution is first filtered through a 200-mesh plate and frame filter to recover the immobilized lipase. The filtrate is then transferred to a centrifuge and centrifuged at 4000 r / min and 50℃ for 15 min to separate and remove the glycerol phase and free fatty acids. The solution is then purified by two-stage molecular distillation: the first stage removes free fatty acids and residual glycerol at 180℃ and 0.5 mbar, and the second stage enriches the solution at 200℃ and 0.1 mbar to obtain the base oil. S3. Heat the base oil to 45℃, add 0.3-0.8 parts modified apigenin, 1.0-1.5 parts hydroxytyrosol, 0.2-0.4 parts vitamin E, and 0.3-0.5 parts glyceryl citrate. First, pre-disperse at 7000r / min for 10min using high-speed shearing, then homogenize and cycle at 40-60MPa for 3 times, controlling the particle size D50 of the dispersion to ≤200nm, to obtain the composite oil. S4. The compound oil is filtered through a 0.5μm nylon microporous membrane to remove trace impurities. The filtrate is transferred to a degassing and filling system, where it is degassed with nitrogen until the residual oxygen content is ≤3%. The finished product is then refrigerated or stored in a cool, dry place.

[0019] This invention provides a diglyceride compound edible oil that helps lower uric acid and its preparation method, which has the following beneficial effects: 1. The compound edible oil for lowering uric acid diglycerides prepared by this invention achieves efficient fusion of diglyceride base and natural uric acid-lowering active ingredients. Through a two-step enzymatic modification of high-oleic sunflower seed oil and a directional modification and encapsulation process of apigenin, the industry problem of uneven dispersion and poor compatibility of active ingredients in the oil system is solved. This allows modified apigenin, hydroxytyrosol and other components to exist stably in the oil, which not only retains the healthy eating characteristics of diglycerides themselves, but also gives the product the function of lowering uric acid. This breaks through the limitation of the single function of traditional diglyceride edible oils and meets the daily cooking and health conditioning needs of people with high uric acid.

[0020] 2. This invention significantly improves the bioavailability of active ingredients in the product through precise process parameter control and compound formula design. The modified apigenin, after lipase catalytic modification and freeze-drying encapsulation, overcomes the defects of poor fat solubility and easy oxidation and decomposition of the original powder. Hydroxytyrosol, vitamin E, and glyceryl citrate form a synergistic antioxidant system, which not only protects the active ingredients from loss and inactivation during storage and cooking, but also significantly improves the absorption efficiency of uric acid-lowering active ingredients by the human body, so that the product's auxiliary uric acid-lowering effect can be stably exerted. At the same time, it also improves the product's food safety, with no additional chemical additives, and meets food-grade safety standards.

[0021] 3. The preparation process of this invention is both efficient and practical. It adopts an immobilized enzyme catalytic reaction, realizing the recovery and reuse of lipase, reducing raw material loss and cost input in the production process. Moreover, the process steps such as secondary molecular distillation purification, high-pressure homogenization, and nitrogen degassing precisely control the physicochemical indicators of the product, making the particle size D50 of the compound oil ≤200nm, with uniform and stable texture. Under normal temperature and cool storage conditions, there is no stratification or crystallization phenomenon, and the oxidation stability is greatly improved. At the same time, the acid value and peroxide value of the product are controlled within the standard range of high-quality edible oil, retaining the normal flavor of edible oil, without any off-flavors or impurities, and suitable for various cooking methods such as frying, stir-frying, cooking, and deep-frying, making it highly practical.

[0022] 4. The compound edible oil of this invention achieves a dual improvement in functionality and stability. The components in the formula work synergistically. Citric acid monoglyceride, as an emulsifying stabilizer, combined with high-speed shearing and high-pressure homogenization processes, allows the oil phase system to form a stable dispersion system, avoiding the separation of active ingredients from oils. Vitamin E not only has antioxidant properties but also works synergistically with diglycerides and hydroxytyrosol to protect the cardiovascular system. This gives the product the dual health benefits of assisting in lowering uric acid and maintaining lipid metabolism. Furthermore, the finished product is degassed with nitrogen to a residual oxygen content of ≤3%, which significantly extends the product's shelf life. It can be stored under refrigeration or in a cool, dry place without special storage conditions, making it more suitable for industrial mass production and market promotion, and easily accepted and used by consumers. Detailed Implementation

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Example 1: Preparation of a diglyceride-based edible oil that helps lower uric acid. The specific preparation steps are as follows: S1. Mix 42 parts of modified high oleic sunflower seed oil, 8 parts of food-grade glycerol, and 1.5 parts of immobilized Rhizopus oryzae lipase, and react at 40℃ and -0.08MPa vacuum for 12h, stirring at 80r / min and bubbling with nitrogen to remove water. S2. The above reaction solution is first filtered through a 200-mesh plate and frame filter to recover the immobilized lipase. The filtrate is then transferred to a centrifuge and centrifuged at 4000 r / min and 50℃ for 15 min to separate and remove the glycerol phase and free fatty acids. The solution is then purified by two-stage molecular distillation: the first stage removes free fatty acids and residual glycerol at 180℃ and 0.5 mbar, and the second stage enriches the solution at 200℃ and 0.1 mbar to obtain the base oil. S3. Heat the base oil to 45℃, add 0.3 parts modified apigenin, 1.0 part hydroxytyrosol, 0.2 parts vitamin E, and 0.3 parts glyceryl citrate. First, pre-disperse at 7000r / min for 10min, then homogenize and cycle at 40MPa for 3 times. Control the particle size of the dispersion D50≤200nm to obtain the composite oil. S4. The compound oil is filtered through a 0.5μm nylon microporous membrane to remove trace impurities. The filtrate is transferred to a degassing and filling system, where it is degassed with nitrogen until the residual oxygen content is ≤3%. The finished product is then refrigerated or stored in a cool, dry place.

[0025] Example 2: Preparation of a diglyceride-based edible oil that helps lower uric acid. The specific preparation steps are as follows: S1. Mix 50 parts of modified high oleic sunflower seed oil, 12 parts of food-grade glycerol, and 2.5 parts of immobilized Rhizopus oryzae lipase, and react at 42℃ and -0.08MPa vacuum for 14h, stirring at 120r / min and bubbling with nitrogen to remove water. S2. The above reaction solution is first filtered through a 200-mesh plate and frame filter to recover the immobilized lipase. The filtrate is then transferred to a centrifuge and centrifuged at 4000 r / min and 50℃ for 15 min to separate and remove the glycerol phase and free fatty acids. The solution is then purified by two-stage molecular distillation: the first stage removes free fatty acids and residual glycerol at 180℃ and 0.5 mbar, and the second stage enriches the solution at 200℃ and 0.1 mbar to obtain the base oil. S3. Heat the base oil to 45℃, add 0.8 parts modified apigenin, 1.5 parts hydroxytyrosol, 0.4 parts vitamin E, and 0.5 parts glyceryl citrate. First, pre-disperse at 7000r / min for 10min, then homogenize and cycle at 60MPa for 3 times. Control the particle size of the dispersion D50≤200nm to obtain the composite oil. S4. The compound oil is filtered through a 0.5μm nylon microporous membrane to remove trace impurities. The filtrate is transferred to a degassing and filling system, where it is degassed with nitrogen until the residual oxygen content is ≤3%. The finished product is then refrigerated or stored in a cool, dry place.

[0026] Example 3: Preparation of a diglyceride-based edible oil that helps lower uric acid. The specific preparation steps are as follows: S1. Mix 46 parts of modified high oleic sunflower seed oil, 10 parts of food-grade glycerol, and 2 parts of immobilized Rhizopus oryzae lipase, and react at 41℃ and -0.08MPa vacuum for 13h, stirring at 100r / min and bubbling with nitrogen to remove water. S2. The above reaction solution is first filtered through a 200-mesh plate and frame filter to recover the immobilized lipase. The filtrate is then transferred to a centrifuge and centrifuged at 4000 r / min and 50℃ for 15 min to separate and remove the glycerol phase and free fatty acids. The solution is then purified by two-stage molecular distillation: the first stage removes free fatty acids and residual glycerol at 180℃ and 0.5 mbar, and the second stage enriches the solution at 200℃ and 0.1 mbar to obtain the base oil. S3. Heat the base oil to 45℃, add 0.5 parts modified apigenin, 1.2 parts hydroxytyrosol, 0.3 parts vitamin E, and 0.4 parts glyceryl citrate. First, pre-disperse at 7000r / min for 10min, then homogenize and cycle at 50MPa for 3 times. Control the particle size of the dispersion D50≤200nm to obtain the composite oil. S4. The compound oil is filtered through a 0.5μm nylon microporous membrane to remove trace impurities. The filtrate is transferred to a degassing and filling system, where it is degassed with nitrogen until the residual oxygen content is ≤3%. The finished product is then refrigerated or stored in a cool, dry place.

[0027] Example 4: Preparation of modified high-oleic sunflower seed oil. The specific preparation steps are as follows: A1. In a jacketed reactor, first add 500g of high oleic sunflower seed oil, start stirring and heat to 40℃, then add 45g of food-grade glycerol and 10g of immobilized Rhizopus oryzae lipase in sequence, stir at 200r / min, keep the reaction at the temperature for 4h, and continuously remove water by bubbling nitrogen gas through the reaction system to obtain the first modified high oleic sunflower seed oil. A2. The temperature of the above reaction vessel is controlled at 42℃, and the vacuum is drawn to -0.08MPa. 40g of medium-chain fatty acid methyl ester is slowly added, followed by 8g of immobilized Rhizopus oryzae lipase. The reaction is carried out at 42℃ and under vacuum of -0.08MPa for 3 hours. The methanol generated in the reaction is continuously removed to obtain modified high oleic acid sunflower seed oil.

[0028] Example 5: Preparation of modified high-oleic sunflower seed oil. The specific preparation steps are as follows: A1. In a jacketed reactor, first add 500g of high oleic sunflower seed oil, start stirring and heat to 42℃, then add 55g of food-grade glycerol and 15g of immobilized Rhizopus oryzae lipase in sequence, stir at 300r / min, keep the reaction at the temperature for 6h, and continuously remove water by bubbling nitrogen gas through the reaction system to obtain the first modified high oleic sunflower seed oil. A2. The temperature of the above reaction vessel was controlled at 44℃, and the vacuum was drawn to -0.08MPa. 70g of medium-chain fatty acid methyl ester was slowly added, followed by 12g of immobilized Rhizopus oryzae lipase. The reaction was carried out at 45℃ and under vacuum of -0.08MPa for 4 hours. The methanol generated in the reaction was continuously removed to obtain modified high oleic acid sunflower seed oil.

[0029] Example 6: Preparation of modified apigenin. The specific preparation steps are as follows: B1. Add 50g of apigenin raw powder and 40ml of 75% ethanol to a stirred extraction tank, start stirring, heat to 50℃ and extract for 30min. After extraction, transfer the liquid to a crystallization tank, cool to 10℃ for crystallization, filter, and dry the filter cake under reduced pressure to obtain high-purity microcrystalline apigenin. B2. In a dry, anhydrous jacketed reactor, add 35g of microcrystalline apigenin, 30g of vinyl octanoate, and 2.0g of 4Å molecular sieve. Start stirring and heat to 50℃. Then add 1.5g of immobilized Candida antarctica lipase B. Vacuum the reactor to -0.08MPa and keep it at this temperature for 24h. Continuously remove the acetaldehyde generated during the reaction. After the reaction is complete, filter to remove the enzyme and molecular sieve to obtain the first modified apigenin. B3. In a high-shear dispersion vessel, first add 80 mL of deionized water and 10 g of fish collagen peptide, stir to dissolve, and heat to 50 °C; then dissolve 30 g of the first modified apigenin in 40 g of the modified high-oleic sunflower seed oil prepared in Example 4, and slowly add it dropwise to the above aqueous phase, and shear at high speed for 20 min to form an oil-in-water emulsion. After freeze-drying at -50 °C and 10 Pa for 24 h, the modified apigenin is obtained.

[0030] Example 7: Preparation of modified apigenin. The specific preparation steps are as follows: B1. Add 50g of apigenin raw powder and 60ml of 75% ethanol to a stirred extraction tank, start stirring, heat to 50℃ and extract for 30min. After extraction, transfer the liquid to a crystallization tank, cool to 10℃ for crystallization, filter, and dry the filter cake under reduced pressure to obtain high-purity microcrystalline apigenin. B2. In a dry, anhydrous jacketed reactor, add 35g of microcrystalline apigenin, 45g of vinyl octanoate, and 3.5g of 4Å molecular sieve. Start stirring and heat to 55℃. Then add 2.5g of immobilized Candida antarcticis lipase B. Vacuum the reactor to -0.08MPa and keep it at this temperature for 36h. Continuously remove the acetaldehyde generated during the reaction. After the reaction is complete, filter to remove the enzyme and molecular sieve to obtain the first modified apigenin. B3. In a high-shear dispersion vessel, first add 120 mL of deionized water and 20 g of fish collagen peptide, stir to dissolve, and heat to 55 °C; then dissolve 30 g of the first modified apigenin in 60 g of the modified high-oleic sunflower seed oil prepared in Example 5, and slowly add it dropwise to the above aqueous phase, and shear at high speed for 30 min to form an oil-in-water emulsion. After freeze-drying at -50 °C and 10 Pa for 48 h, the modified apigenin is obtained.

[0031] Comparative Example 1: A diglyceride complex edible oil was prepared to help lower uric acid. The specific preparation steps are as follows: The remaining steps remain the same, except that the modified high-oleic sunflower seed oil prepared in Example 4 used in Example 3 is replaced with unmodified high-oleic sunflower seed oil to prepare a glycerol diglyceride complex edible oil that helps lower uric acid.

[0032] Comparative Example 2: A diglyceride complex edible oil was prepared to help lower uric acid. The specific preparation steps are as follows: The remaining steps remain unchanged, except that the modified apigenin prepared in Example 7 and used in Example 3 are replaced with unmodified apigenin to prepare a glycerol diglyceride compound edible oil that helps lower uric acid.

[0033] Comparative Example 3: A diglyceride complex edible oil was prepared to help lower uric acid. The specific preparation steps are as follows: The remaining steps remain unchanged, except that the modified high-oleic sunflower seed oil prepared in Example 4 used in Example 3 is replaced with unmodified high-oleic sunflower seed oil, and the modified apigenin prepared in Example 7 is replaced with unmodified apigenin, so as to prepare a glycerol diglyceride compound edible oil that helps lower uric acid.

[0034] Performance testing Test Project Test standards / methods Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Uric acid inhibition rate (%) In vitro xanthine oxidase inhibition assay 45.3 46.7 47.6 35.1 36.5 31.4 Acid value (mgKOH / g) GB5009.229-2025 0.32 0.28 0.24 0.45 0.41 0.51 Peroxide value (meq / kg) GB5009.227-2023 3.5 3.1 2.8 4.8 4.5 5.3 The performance test results of the glycerol-based edible oil for assisting in lowering uric acid showed that the products of Examples 1-3, prepared using modified high-oleic sunflower seed oil and modified apigenin, exhibited superior uric acid inhibition rates. Among them, Example 3 achieved the highest uric acid inhibition rate of 47.6%, which was significantly higher than that of Comparative Examples 1-3 using unmodified raw materials. At the same time, the acid value (0.24-0.32 mgKOH / g) and peroxide value (2.8-3.5 meq / kg) of Examples 1-3 were significantly lower than those of Comparative Examples 1-3. Furthermore, the acid value and peroxide value of all examples met the standards for high-quality edible oils. In contrast, the physicochemical indicators and uric acid inhibition effects of the comparative examples that replaced the unmodified raw materials were significantly worse. This fully demonstrates that the raw material modification process plays a crucial role in improving the product's uric acid-lowering effect and physicochemical stability.

[0035] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A compound edible oil containing diglycerides that helps lower uric acid, characterized in that: It contains the following ingredients by weight: 42-50 parts modified high-oleic sunflower seed oil, 8-12 parts food-grade glycerin, 1.5-2.5 parts immobilized Rhizopus oryzae lipase, 0.3-0.8 parts modified apigenin, 0.2-0.4 parts vitamin E, 0.3-0.5 parts monoglyceride citrate, and 1.0-1.5 parts hydroxytyrosol.

2. The glycerol-containing edible oil for assisting in lowering uric acid according to claim 1, characterized in that: The modified high-oleic sunflower seed oil is prepared using the following specific steps: A1. In a jacketed reactor, first add high-oleic sunflower seed oil, start stirring and heat to 40-42℃, then add food-grade glycerol and immobilized Rhizopus oryzae lipase in sequence, stir at 200-300 r / min, keep the reaction at the temperature for 4-6 h, and continuously remove water by bubbling nitrogen gas through the reaction system to obtain the first modified high-oleic sunflower seed oil. A2. Control the temperature of the above reaction vessel at 42-44℃, evacuate to -0.08MPa, slowly add medium-chain fatty acid methyl ester, then add immobilized Rhizopus oryzae lipase, and react at 42-45℃ and -0.08MPa vacuum for 3-4 hours. Continuously remove the methanol generated in the reaction to obtain modified high oleic sunflower seed oil.

3. The glycerol-containing edible oil for assisting in lowering uric acid as described in claim 2, characterized in that: The ratio of high oleic sunflower seed oil, food-grade glycerol, and immobilized Rhizopus oryzae lipase in A1 is 500g: 45-55g: 10-15g. The ratio of medium-chain fatty acid methyl ester to immobilized Rhizopus oryzae lipase in A2 is 40-70g: 8-12g; The ratio of C8 to C10 in medium-chain fatty acid methyl esters is 6:

4.

4. The glycerol-containing edible oil for assisting in lowering uric acid according to claim 2, characterized in that: The activity of the immobilized Rhizopus niger lipase is ≥10000 PLU / g.

5. The glycerol-containing edible oil for assisting in lowering uric acid according to claim 1, characterized in that: The modified apigenin is prepared using the following specific steps: B1. Add apigenin powder and 75% ethanol by volume to a stirred extraction tank, start stirring, heat to 50℃ and extract for 30 minutes. After extraction, transfer the liquid to a crystallization tank, cool to 10℃ to crystallize, filter, and dry the filter cake under reduced pressure to obtain high-purity microcrystalline apigenin. B2. In a dry, anhydrous jacketed reactor, add microcrystalline apigenin, vinyl octanoate, and 4Å molecular sieve. Start stirring and heat to 50-55℃. Then add immobilized Candida antarcticis lipase B. Vacuum the reactor to -0.08MPa and keep it at this temperature for 24-36 hours. Continuously remove the acetaldehyde generated during the reaction. After the reaction is complete, filter to remove the enzyme and molecular sieve to obtain the first modified apigenin. B3. In a high-shear dispersion vessel, first add deionized water and fish collagen peptides, stir to dissolve, and heat to 50-55℃; dissolve the first modified apigenin in modified high-oleic sunflower seed oil, and slowly add it dropwise to the above aqueous phase, and shear at high speed for 20-30 min to form an oil-in-water emulsion, and freeze-dry at -50℃ and 10Pa for 24-48 h to obtain modified apigenin.

6. The glycerol-containing edible oil for assisting in lowering uric acid according to claim 5, characterized in that: The ratio of apigenin raw powder to ethanol in B1 is 50g:40-60ml; The ratio of microcrystalline apigenin, vinyl octanoate, 4Å molecular sieve, and immobilized Candida antarcticis lipase B in B2 is 35g:30-45g:2.0-3.5g:1.5-2.5g; the activity of the immobilized Candida antarcticis lipase B is ≥10000U / g. The ratio of deionized water, fish collagen peptide, first-modified apigenin, and modified high-oleic sunflower seed oil in B3 is 80-120mL: 10-20g: 30g: 40-60g.

7. A method for preparing a diglyceride-based edible oil that helps lower uric acid, characterized in that: Specifically, it includes the following steps: S1. Mix 42-50 parts of modified high-oleic sunflower seed oil, 8-12 parts of food-grade glycerol, and 1.5-2.5 parts of immobilized Rhizopus oryzae lipase, and react at 40-42℃ and -0.08MPa vacuum for 12-14 hours, stirring at 80-120r / min and bubbling with nitrogen to remove water. S2. The above reaction solution is first filtered through a 200-mesh plate and frame filter to recover the immobilized lipase. The filtrate is then transferred to a centrifuge and centrifuged at 4000 r / min and 50℃ for 15 min to separate and remove the glycerol phase and free fatty acids. Further purification by two-stage molecular distillation: the first stage at 180℃ and 0.5mbar removes free fatty acids and residual glycerol, and the second stage at 200℃ and 0.1mbar enriches the base oil. S3. Heat the base oil to 45℃, add 0.3-0.8 parts modified apigenin, 1.0-1.5 parts hydroxytyrosol, 0.2-0.4 parts vitamin E, and 0.3-0.5 parts glyceryl citrate. First, pre-disperse at 7000r / min for 10min using high-speed shearing, then homogenize and cycle at 40-60MPa for 3 times, controlling the particle size D50 of the dispersion to ≤200nm, to obtain the composite oil. S4. The compound oil is filtered through a 0.5μm nylon microporous membrane to remove trace impurities. The filtrate is transferred to a degassing and filling system, where it is degassed with nitrogen until the residual oxygen content is ≤3%. The finished product is then refrigerated or stored in a cool, dry place.