Foam SiO2 enzyme array and application thereof in preparation of diglyceride edible oil

Abstract

The invention discloses a foam SiO2 enzyme array and application thereof in preparation of diglyceride edible oil, and belongs to the technical field of grease chemistry. A hydrophobic foam SiO2 carrier (MCF-C8) is prepared, lipase ANL, lipase NE and lipase CALB are loaded through a physical adsorption method, three functional specific enzyme arrays are prepared, then a hydrolysis-esterification and glycerolysis-esterification double-coupling reaction strategy is constructed, proper hydrolysis of vegetable oil is catalyzed through ANL (at) MCF-C8 or glycerolysis of the vegetable oil is catalyzed through NE (at) MCF-C8, and therefore the functional specific enzyme arrays are obtained. A primary diglyceride mixture is obtained; and recovering a byproduct fatty acid generated in the reaction, and carrying out esterification reaction on the byproduct fatty acid and glycerol under the catalysis of CALB (at) MCF-C8 to obtain a secondary diglyceride mixture. And purifying to obtain an edible oil product in which the content of diglyceride is 40-82% and the proportion of 1, 3-diglyceride is 90%. According to the method, efficient recycling of the by-product fatty acid is achieved, the product yield is increased, the enzyme array is high in stability, easy to separate and recycle and capable of being repeatedly used, and the production cost is effectively reduced.

Description

Technical Field

[0001] This invention belongs to the field of oleochemical technology, and more specifically relates to a foamed SiO2 enzyme array and its application in the preparation of diglyceride edible oil. Background Technology

[0002] Diacylglycerol (DAG) is a functional lipid with multiple physiological activities, such as preventing obesity and improving cardiovascular health, and has broad application prospects in the fields of food, health products and medicine.

[0003] Currently, the core technology for industrial preparation of diglycerides mainly relies on free enzyme preparations, achieved through single linear synthetic routes such as hydrolysis, glycerol hydrolysis, and esterification. However, these traditional technical routes have many insurmountable bottlenecks. At the catalyst level, free lipases are easily deactivated by factors such as temperature, pH, and substrate concentration in the reaction system, and are difficult to recover after the reaction, resulting in the inability to reuse enzyme preparations and significantly increasing enzyme consumption costs in the production process. At the same time, free enzymes have insufficient catalytic specificity, easily triggering side reactions and affecting product purity. To alleviate this problem, some existing technologies attempt to use commercially available immobilized enzymes (such as Lipozyme TL IM and Novozyme 435). However, the carrier materials of these commercial enzymes have structural defects: Lipozyme TL IM uses inorganic silica gel as a carrier, which has a simple pore structure and strong surface hydrophilicity. In the oil-water two-phase reaction system, the interaction between enzyme molecules and the carrier is weak, and it is easy to detach and lose, resulting in a continuous decline in catalytic efficiency. Novozyme 435 uses organic resin as a carrier, which has a large particle size and poor mechanical stability. During the stirring reaction, the carrier is prone to breakage, which not only affects the recovery and reuse of enzymes, but may also cause carrier impurities to be mixed into the product, increasing the difficulty of subsequent separation. At the synthetic route level, the limitations of single linear processes further exacerbate the technical pain points: the hydrolysis method directly hydrolyzes vegetable oil to prepare diglycerides, but the degree of hydrolysis is difficult to control precisely during the reaction, and over-hydrolysis is very likely to occur, resulting in a low diglyceride content in the product. At the same time, a large amount of free fatty acids and monoglycerides are generated, causing a serious waste of high-quality fatty acids in the raw materials. Moreover, the excessive by-products require additional deacidification, purification and other processes, which significantly increases the production cost; the glycerol hydrolysis method uses vegetable oil and glycerol as substrates for transesterification reaction, but its reaction system has extremely high viscosity and low substrate mass transfer efficiency, which not only leads to low catalytic conversion rate and long reaction cycle, but also easily generates by-products such as triglycerides and monoglycerides, affecting product quality; the esterification method directly synthesizes diglycerides by esterification of free fatty acids and glycerol, but free fatty acids need to be prepared by multiple steps such as pre-hydrolysis of vegetable oil, separation and purification, etc. The substrate source route is long and the preparation cost is high, resulting in poor economic efficiency of the entire process, which is difficult to meet the needs of large-scale industrial production. A patent report (CN105400837A) attempted a two-step process of "esterification of vegetable oil hydrolysis products," which, while alleviating the problem of over-hydrolysis to some extent, still has significant shortcomings: the diglyceride content in the final product is only 60%-65%, far from meeting the current market demand for high-purity diglycerides (usually requiring a purity of ≥80%, and ≥90% for high-end applications); moreover, this process relies on the aforementioned traditional commercial immobilized enzymes, failing to solve core problems such as poor compatibility between the carrier and the enzyme and limited catalytic efficiency; the proportion of the 1,3-diglyceride isomer with the best functionality in the product is not effectively controlled, further limiting its application in high-end health products.

[0004] Therefore, developing a foamed SiO2 enzyme array and its application in the preparation of diglyceride edible oil has become an urgent technical problem to be solved in this field. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a foamed SiO2 enzyme array and its application in the preparation of diglyceride edible oil, which has the advantages of high catalytic efficiency, environmental friendliness, and easy product separation.

[0006] To achieve the above objectives, the present invention first provides a foam SiO2 enzyme array, the preparation method of which includes the following steps.

[0007] S1, using tetraethyl orthosilicate and 1,2-bis(triethoxysilyl)ethane as a composite silicon source, was co-condensed to construct a framework. The framework was then extracted, washed, and dried using a mixed solution of hydrochloric acid and ethanol to obtain a foamed SiO2 carrier MCF with a hierarchical pore structure; the MCF had a specific surface area of ​​800~952 m². 2 / g, with mesopore size of 11~14nm and contact angle of 27°~30°.

[0008] S2, MCF is dispersed in a hexane solution containing n-octyltrichlorosilane, ultrasonically treated, oscillated, and surface-hydrophobicated. After filtration, washing, and drying, hydrophobic foam SiO2 carrier MCF-C8 with a hierarchical pore structure is obtained; the specific surface area of ​​MCF-C8 is 432~500 m². 2 / g, with mesopore size of 11~13nm and contact angle of 99°~103°.

[0009] S3, using MCF-C8 as a carrier, was prepared by loading Aspergillus niger lipase, Thermophilus spp. lipase, and Candida antarcticis lipase B onto the carrier via physical adsorption. This resulted in the preparation of foam SiO2 enzyme arrays ANL@MCF-C8 (highly efficient hydrolytic activity), NE@MCF-C8 (highly efficient glycerolysis activity), and CALB@MCF-C8 (highly efficient esterification activity). The loading capacities of ANL@MCF-C8, NE@MCF-C8, and CALB@MCF-C8 were 132–142 mg / g, 100–156 mg / g, and 130–150 mg / g, respectively.

[0010] Preferably, the co-condensation construction of the framework in step S1 specifically involves: stirring polyether P123, 1,3,5-trimethylbenzene, ammonium fluoride, and hydrochloric acid at 37°C for 1 hour; sequentially adding tetraethyl orthosilicate and 1,2-bis(triethoxysilyl)ethane, continuing stirring for 12 hours, then transferring to an autoclave for static hydrothermal aging for 24 hours, cooling, washing with anhydrous ethanol, and drying; the mass ratio of polyether P123 to the volume ratio of 1,3,5-trimethylbenzene is 3~4 g:3.4 g. 5~4.6 mL; the mass ratio of polyether P123 to ammonium fluoride is 3~4:0.035~0.046; the volume ratio of 1,3,5-trimethylbenzene to hydrochloric acid is 3.45~4.6:15~20, and the concentration of hydrochloric acid is 1.6 mol / L; the mass ratio of tetraethyl orthosilicate to 1,2-bis(triethoxysilyl)ethane is 3~1:1~3; the mass ratio of polyether P123 to tetraethyl orthosilicate is 3~4:2.2~6.6; the static hydrothermal aging temperature is 100℃, the drying temperature is 60℃, and the time is 12h.

[0011] Preferably, in step S1, the volume fraction of hydrochloric acid in the hydrochloric acid and ethanol mixed solution is 1-2%, and the concentration of hydrochloric acid used is 12 mol / L; the extraction time is 6 h, repeated three times; the washing is done with ethanol; and the drying temperature is 60 °C for 12 h.

[0012] Preferably, in step S2, the volume ratio of n-octyltrichlorosilane to n-hexane in the n-octyltrichlorosilane solution is 0.46:20; the mass ratio of MCF to n-octyltrichlorosilane is 1g:0.46~1.30mL; the ultrasonic treatment time is 10min, the oscillation speed is 250rpm, the temperature is 25℃, and the time is 2h; the washing is done with ethanol; and the drying temperature is 60℃ and the time is 12h.

[0013] Preferably, the physical adsorption method in step S3 specifically involves: preparing enzyme solutions of *Aspergillus niger* lipase, *Thermophilus spp.* lipase, and *Candida antarcticis* lipase B using phosphate buffer, respectively; then mixing the ethanol-soaked MCF-C8 with the enzyme solutions, sonicating, evacuating to remove gas from the pores, incubating on a shaker, centrifuging, collecting the precipitate, and freeze-drying to obtain a foamed SiO2 enzyme array; the concentration of the *Aspergillus niger* lipase solution is 125-150 mg / mL, the phosphate buffer concentration during preparation is 50 mM / L, and the pH is 5; the concentration of the *Thermophilus spp.* lipase solution is 20-50 mg / mL, the phosphate buffer concentration during preparation is 50 mM / L, and the pH is 7; the concentration of the *Candida antarcticis* lipase B solution is 40-60 mg / mL. The concentration of the phosphate buffer in the solution is 50 mM / L and the pH is 7. The ratio of MCF-C8 to enzyme solution is 1 g: 100 mL. The sonication time is 5 min, the vacuuming time is 5 min, the shaking incubation temperature is 30℃, the rotation speed is 220 rpm, and the time is 40 min. The centrifugation speed is 8000 rpm and the time is 10 min.

[0014] The beneficial effects of the preparation method of the foamed SiO2 enzyme array of this invention are as follows: It develops a novel organic-inorganic hybrid mesoporous foamed SiO2 support material. This material not only inherits the inherent high specific surface area, ordered and tunable pore structure, and excellent chemical and mechanical stability of mesoporous foamed SiO2, but also covalently integrates organic bridging groups into the inorganic pore walls at the molecular level. This creates a hydrophobic microenvironment on the inner surface of the mesoporous channels, which is difficult to reach by conventional modification methods, thereby enhancing its ability to immobilize lipases. This unique structure can induce lipases to form a highly active conformation during loading, while simultaneously enhancing the interaction between the enzyme and the support, effectively preventing enzyme molecule detachment, significantly improving the enzyme's catalytic activity, stability, and reusability. Furthermore, it is adaptable to various catalytic reaction types such as hydrolysis, esterification, and glycerolization, meeting the needs of diverse application scenarios.

[0015] Secondly, the present invention also provides a method for preparing diglyceride edible oil using foam SiO2 enzyme arrays. The foam SiO2 enzyme arrays ANL@MCF-C8 and CALB@MCF-C8 prepared by the above method include the following steps.

[0016] S1, Hydrolysis reaction: Vegetable oil, water, and ANL@MCF-C8 are mixed evenly and subjected to hydrolysis reaction. After the reaction is completed, the primary diglyceride mixture is obtained by centrifugation and ANL@MCF-C8 is recovered. The primary diglyceride mixture is purified by molecular distillation to obtain edible oil rich in diglycerides and free fatty acids are recovered.

[0017] S2, Esterification reaction: The recovered free fatty acids, glycerol, and CALB@MCF-C8 are mixed evenly and subjected to esterification reaction. After the reaction is completed, the secondary diglyceride mixture is obtained by centrifugation. After molecular distillation purification, edible oil rich in diglycerides is obtained.

[0018] Preferably, the vegetable oil mentioned in step S1 is selected from any one of peanut oil, soybean oil, rice bran oil, sunflower seed oil, perilla seed oil, rapeseed oil, pecan oil, and flaxseed oil.

[0019] Preferably, in step S1, the amount of ANL@MCF-C8 added is 0.5-3% of the mass of the vegetable oil, the mass ratio of vegetable oil to water is 1:0.4-1:1, the hydrolysis reaction temperature is 25-45℃, and the time is 1-8h; the diglyceride content in the initial diglyceride mixture is 25%-29%. The molecular distillation purification conditions are: heating temperature 170-190℃, feed rate 10-15kg / h, vacuum degree 0.1-10Pa, and scraper rotation speed 200-300r / min.

[0020] Preferably, in step S2, the amount of CALB@MCF-C8 added is 1-5% of the total mass of free fatty acids and glycerol, and the molar ratio of free fatty acids to glycerol is 1:1-1:3; the esterification reaction temperature is 40-80℃, and the time is 2-12h; the diglyceride content in the secondary diglyceride mixture is 41%-62%. The molecular distillation purification conditions are: heating temperature 170-190℃, feed rate 10-15kg / h, vacuum degree 0.1-10Pa, and scraper rotation speed 200-300r / min.

[0021] In addition, the present invention also provides another method for preparing diglyceride edible oil using foam SiO2 enzyme arrays. The foam SiO2 enzyme arrays NE@MCF-C8 and CALB@MCF-C8 prepared by the above method include the following steps.

[0022] S1, Glycerolysis reaction: Vegetable oil, glycerol, water, and NE@MCF-C8 are mixed evenly and stirred to react. After the reaction is completed, the primary diglyceride mixture is obtained by centrifugation, and NE@MCF-C8 is recovered. The primary diglyceride mixture is purified by molecular distillation to obtain edible oil rich in diglycerides, and free fatty acids are recovered.

[0023] S2, Esterification reaction: The recovered free fatty acids, glycerol, and CALB@MCF-C8 are mixed evenly and subjected to esterification reaction. After the reaction is completed, the secondary diglyceride mixture is obtained by centrifugation. After molecular distillation purification, edible oil rich in diglycerides is obtained.

[0024] Preferably, the vegetable oil mentioned in step S1 is selected from any one of peanut oil, soybean oil, rice bran oil, sunflower seed oil, perilla seed oil, rapeseed oil, pecan oil, and flaxseed oil.

[0025] Preferably, in step S1, the amount of NE@MCF-C8 added is 1-3% of the mass of the vegetable oil, the amount of water added is 1-2% of the mass of the vegetable oil, the molar ratio of vegetable oil to glycerol is 1:1-1:4, the stirring reaction temperature is 45-65℃, and the reaction time is 6-12h; the diglyceride content in the initial diglyceride mixture is 40%-49%. The molecular distillation purification conditions are: heating temperature 170-190℃, feed rate 10-15kg / h, vacuum degree 0.1-10Pa, and scraper rotation speed 200-300r / min.

[0026] Preferably, in step S2, the amount of CALB@MCF-C8 added is 1-5% of the total mass of free fatty acids and glycerol, and the molar ratio of free fatty acids to glycerol is 1:1-1:3; the esterification reaction temperature is 40-80℃, and the time is 2-12h; the diglyceride content in the secondary diglyceride mixture is 42%-56%. The molecular distillation purification conditions are: heating temperature 170-190℃, feed rate 10-15kg / h, vacuum degree 0.1-10Pa, and scraper rotation speed 200-300r / min.

[0027] Both methods described above can yield products with diglyceride content ranging from 40% to 82% after purification. The proportion of 1,3-diglycerides is 90% in both cases.

[0028] The beneficial effects of the method for preparing diglyceride edible oil using foamed SiO2 enzyme array of this invention are as follows: It innovatively develops a new strategy of "hydrolysis-esterification dual-reaction coupling" and "glycerolysis-esterification dual-reaction coupling." Through the synergistic linkage of the two-step reaction, it not only solves the problems of low substrate utilization and numerous byproducts in a single linear route, but also precisely controls the reaction process. While significantly improving product purity, it flexibly prepares products of different specifications with diglyceride content ranging from 40% to 82%, and the key active ingredient, 1,3-diglyceride, accounts for 90%. This fully meets the differentiated needs of different application scenarios for product purity and functional activity, providing a new technical path for the high-value and large-scale production of diglycerides.

[0029] In summary, the present invention provides a foamed SiO2 enzyme array and its application in the preparation of diglyceride edible oil, which has the following beneficial effects compared with the prior art.

[0030] (1) The present invention uses foam SiO2 enzyme array ANL@MCF-C8 as a catalyst. In the process of preparing diglycerides by hydrolysis, ANL@MCF-C8 can be enriched at the oil-water interface, increasing the contact area between the enzyme and the substrate, enabling rapid hydrolysis of natural oils under mild reaction conditions.

[0031] (2) The present invention uses a foam SiO2 enzyme array NE@MCF-C8 to catalyze the glycerolization reaction of vegetable oil and glycerol. Its catalytic efficiency and operational stability are significantly better than those of free lipase. At the same time, the selected lipase NE is inexpensive, and after immobilization, the diglyceride content is greater than 40% under the condition of repeated use 6 times, which further reduces the application cost.

[0032] (3) The present invention further uses the foam SiO2 enzyme array CALB@MCF-C8 with esterification activity to efficiently convert the by-product free fatty acids, so as to maximize the utilization rate of raw materials and increase the content of diglycerides by controlling the esterification reaction conditions. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0034] Figure 1 The images show SEM (a) and TEM (b) images of the carrier material obtained in Example 2 of this invention.

[0035] Figure 2 This is the Fourier transform infrared spectrum of the carrier material obtained in Example 2 of the present invention.

[0036] Figure 3 This is a diagram illustrating the reusability of the ANL@MCF-C8 catalytic synthesis of perilla seed oil diglyceride in Example 4 of this invention.

[0037] Figure 4 This is a diagram illustrating the reusability of the NE@MCF-C8 catalytic synthesis of rapeseed oil diglycerides in Example 13 of this invention. Detailed Implementation

[0038] The present invention will now be described in detail with reference to specific embodiments. These embodiments are merely illustrative of the technical solutions of the present invention and are not intended to limit the present invention, unless otherwise specified. Experimental methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions unless otherwise specified.

[0039] In addition, the raw materials used in the following examples, such as Aspergillus niger lipase (ANL), Candida antarcticis lipase B (CALB), Thermophilus nephrolepis lipase (NE), and reagents, are all commercially available unless otherwise specified.

[0040] It should be noted that the DAG products generated by the foam SiO2 enzyme array in the dual coupling strategy of catalytic hydrolysis-esterification and glycerol hydrolysis-esterification were all detected by high-temperature gas chromatography. The gas chromatography (GC2030, Shimazu, Japan) detection conditions are as follows.

[0041] The chromatographic column was a fused silica capillary column (DB-5HT, 15m × 320µm × 0.25µm, Agilent Technologies, Santa Clara, CA, USA), with an injection volume of 1 μL and a split ratio of 50:1. The carrier gas was high-purity nitrogen at a total flow rate of 2 mL / min, with hydrogen at 32 mL / min and air at 200 mL / min. The detector was a flame ionization detector (FID), and both the detector and injection port temperatures were set to 380 °C. The column oven program started at 170 °C and held for 2 min, then increased to 380 °C at a rate of 5 °C / min and held for 6 min.

[0042] Example 1

[0043] A foamed SiO2 enzyme array is prepared by the following steps.

[0044] S1. 4 g of polyether P123, 4.6 mL of 1,3,5-trimethylbenzene, 46 mg of ammonium fluoride, and 20 mL of hydrochloric acid (1.6 mol / L) were stirred at 37 °C for 1 h. Then, 2.35 mL (2.2 g) of tetraethyl orthosilicate and 6.89 mL (6.6 g) of 1,2-bis(triethoxysilyl)ethane were added sequentially, and stirring continued for 12 h. The mixture was then transferred to an autoclave and statically hydrothermally aged at 100 °C for 24 h. After cooling, the mixture was washed at least three times with anhydrous ethanol and dried at 60 °C for 12 h. The solid particles were extracted for 6 h with a mixed solution of hydrochloric acid and ethanol (1% hydrochloric acid, 12 mol / L concentration). The extraction was repeated three times with ethanol washing and drying at 60 °C for 12 h to obtain a foamed SiO2 support (MCF) with a hierarchical pore structure and a specific surface area of ​​800 m². 2 / g, pore size 11nm, contact angle 30°.

[0045] S2, 1g of MCF was dispersed in a hexane solution containing n-octyltrichlorosilane (0.46mL n-octyltrichlorosilane, 20mL n-hexane), sonicated for 10min, and then shaken at 25℃ and 250rpm for 2h to perform surface hydrophobic modification. The solid was collected by filtration, washed with ethanol, and dried at 60℃ for 12h to obtain a hydrophobic foam SiO2 support (MCF-C8) with a hierarchical pore structure and a specific surface area of ​​432m². 2 / g, pore size of 11nm, contact angle of 103°.

[0046] S3, 12.5g of Aspergillus niger lipase (ANL) was weighed and dissolved in 100mL of 50mM / L, pH=5.0 phosphate buffer to obtain enzyme solution; MCF-C8 was pre-soaked with anhydrous ethanol, dispensed into conical flasks, enzyme solution was added, and the mixture was sonicated and vacuumed for 5min to remove gas from the pores; the system was incubated in a shaker at 30℃ and 220rpm for 40min; centrifuged at 8000rpm for 10min, the precipitate was collected, and freeze-dried to obtain foam SiO2 enzyme array ANL@MCF-C8 with a loading of 132mg / g and an enzyme activity of 18U / g.

[0047] 6g of *Thermophilus nephrolepis* lipase (NE) and 4g of *Candida antarcticis* lipase B (CALB) were weighed and dissolved in 100mL of 50mM phosphate buffer (pH 7.0) to obtain enzyme solutions. MCF-C8 enzyme arrays were pre-soaked in anhydrous ethanol, dispensed into conical flasks, and the enzyme solutions were added. The flasks were then subjected to sonication and vacuum treatment for 5min to remove gas from the pores. The system was incubated at 30℃ and 220rpm for 40min. After centrifugation at 8000rpm for 10min, the precipitate was collected, freeze-dried, and foam SiO2 enzyme arrays NE@MCF-C8 and CALB@MCF-C8 were obtained. The immobilization capacity of NE@MCF-C8 was 100mg / g, and the enzyme activity was 190U / g. The immobilization capacity of CALB@MCF-C8 was 130mg / g, and the enzyme activity was 14U / g.

[0048] Example 2 A foamed SiO2 enzyme array, the preparation method of which includes the following steps.

[0049] S1. 4g of polyether P123, 4.6mL of 1,3,5-trimethylbenzene, 46mg of ammonium fluoride, and 20mL of hydrochloric acid (1.6mol / L) were stirred at 37℃ for 1h. Then, 7.06mL (6.6g) of tetraethyl orthosilicate and 2.29mL (2.2g) of 1,2-bis(triethoxysilyl)ethane were added sequentially, and stirring was continued for 12h. The mixture was then transferred to an autoclave and statically hydrothermally aged at 100℃ for 24h. After cooling, the mixture was washed at least 3 times with anhydrous ethanol and dried at 60℃ for 12h. The solid particles were extracted with a mixed solution of hydrochloric acid and ethanol (hydrochloric acid volume fraction of 2% and concentration of 12mol / L) for 6h. The mixture was washed with ethanol, and the extraction was repeated 3 times. The mixture was dried at 60℃ for 12h to obtain a foamed SiO2 support (MCF) with a hierarchical pore structure, a specific surface area of ​​952m² / g, a pore size of 14nm, and a contact angle of 27°.

[0050] S2, 3g of MCF was dispersed in a hexane solution containing n-octyltrichlorosilane (1.30mL n-octyltrichlorosilane, 30mL n-hexane), sonicated for 10min, and then oscillated at 25℃ and 250rpm for 2h to perform surface hydrophobic modification. The solid was collected by filtration, washed with ethanol, and dried at 60℃ for 12h to obtain a hydrophobic foam SiO2 support (MCF-C8) with a hierarchical pore structure. Its specific surface area was 500m² / g, the pore size was 13nm, and the contact angle was 99°.

[0051] S3, 15g of Aspergillus niger lipase (ANL) was weighed and dissolved in 100mL of 50mM / L, pH=5.0 phosphate buffer to obtain enzyme solution; MCF-C8 was pre-soaked with anhydrous ethanol, dispensed into conical flasks, enzyme solution was added, and the mixture was sonicated and vacuumed for 5min in sequence to remove gas from the pores; the system was incubated in a shaker at 30℃ and 220rpm for 40min; centrifuged at 8000rpm for 10min, the precipitate was collected, and freeze-dried to obtain foam SiO2 enzyme array ANL@MCF-C8 with a loading of 142mg / g and an enzyme activity of 25U / g.

[0052] 2g of *Thermophilus nephrolepis* lipase (NE) and 6g of *Candida antarcticis* lipase B (CALB) were weighed and dissolved in 100mL of 50mM, pH 7.0 phosphate buffer to obtain enzyme solutions. MCF-C8 enzyme arrays were pre-wetted with anhydrous ethanol, dispensed into conical flasks, and the enzyme solutions were added. The flasks were then sonicated and vacuum-treated to remove gas from the pores. The system was incubated at 30℃ and 220rpm for 40min. After centrifugation at 8000rpm for 10min, the precipitate was collected, freeze-dried, and foam SiO2 enzyme arrays NE@MCF-C8 and CALB@MCF-C8 were obtained. The immobilization capacity of NE@MCF-C8 was 156mg / g and the enzyme activity was 212U / g. The immobilization capacity of CALB@MCF-C8 was 150mg / g and the enzyme activity was 20U / g.

[0053] The materials prepared in Example 2 were characterized and analyzed. Figure 1 The images show SEM (a) and TEM (b) images of MCF-C8. MCF-C8 exhibits a relatively regular cluster shape, resembling foam. Figure 2 The Fourier transform infrared spectra of MCF and MCF-C8 are shown. The spectrum of MCF-C8 shows an appearance at 2855 cm⁻¹. -1 and 2929cm -1 The characteristic peaks at the positions correspond to the asymmetric and symmetric stretching vibrations of CH, respectively, indicating that the alkyl chain was successfully grafted onto the MCF.

[0054] Example 3 A method for preparing diglyceride edible oil using foam SiO2 enzyme arrays, employing the foam SiO2 enzyme arrays ANL@MCF-C8 and CALB@MCF-C8 prepared in Example 1, includes the following steps.

[0055] S1, Hydrolysis reaction: Mix 100g soybean oil, 40g water, and 0.5g ANL@MCF-C8 evenly and hydrolyze at 25℃ for 1h. After the reaction, centrifuge to obtain a primary diglyceride mixture, with a diglyceride content of 25% and a fatty acid content of 27%. ANL@MCF-C8 is also recovered. The primary diglyceride mixture is purified by molecular distillation (process conditions: heating temperature 170℃, feed rate 10kg / h, vacuum degree 0.1Pa, scraper speed 200r / min) to obtain soybean oil rich in diglycerides, with a diglyceride content of 40%, and about 24g of free fatty acids are recovered.

[0056] S2, Esterification reaction: 5g of recovered free fatty acids, 1.63g of glycerol, and 0.066g of CALB@MCF-C8 are mixed evenly and esterified at 40℃ for 2h. After the reaction, the secondary diglyceride mixture is obtained by centrifugation, in which the diglyceride content is 41%. After purification under the same molecular distillation conditions as in step S1, soybean oil rich in diglycerides is obtained, in which the diglyceride content is about 58%, and 1,3-diglycerides account for 90% of the total diglycerides.

[0057] Example 4 A method for preparing diglyceride edible oil using foam SiO2 enzyme arrays, employing the foam SiO2 enzyme arrays ANL@MCF-C8 and CALB@MCF-C8 prepared in Example 2, includes the following steps.

[0058] S1, Hydrolysis reaction: 100g of perilla seed oil, 60g of water, and 2g of ANL@MCF-C8 were mixed evenly and hydrolyzed at 45℃ for 1h. After the reaction, the primary diglyceride mixture was obtained by centrifugation, with a diglyceride content of 26% and a fatty acid content of 37%. ANL@MCF-C8 was recovered. The primary diglyceride mixture was purified by molecular distillation (process conditions: heating temperature 190℃, feed rate 15kg / h, vacuum degree 10Pa, scraper speed 300r / min) to obtain perilla seed oil rich in diglycerides, with a diglyceride content of 45%, and about 34g of free fatty acids were recovered.

[0059] S2, Esterification reaction: 5g of recovered free fatty acids, 4.89g of glycerol, and 0.495g of CALB@MCF-C8 were mixed evenly and esterified at 70℃ for 2h. After the reaction, the secondary diglyceride mixture was obtained by centrifugation, in which the diglyceride content was 62%. After purification under the same molecular distillation conditions as in step S1, perilla seed oil rich in diglycerides was obtained, in which the diglyceride content was about 82%, and 1,3-diglycerides accounted for 90% of the total diglycerides.

[0060] Example 5 A method for preparing diglyceride edible oil using foam SiO2 enzyme arrays, employing the foam SiO2 enzyme arrays ANL@MCF-C8 and CALB@MCF-C8 prepared in Example 2, includes the following steps.

[0061] S1, Hydrolysis reaction: 100g rapeseed oil, 40g water, and 3g ANL@MCF-C8 were mixed evenly and hydrolyzed at 25℃ for 8h. After the reaction, the primary diglyceride mixture was obtained by centrifugation, with a diglyceride content of 27% and a fatty acid content of 30%. ANL@MCF-C8 was recovered. The primary diglyceride mixture was purified by molecular distillation (process conditions: heating temperature 180℃, feed rate 12kg / h, vacuum degree 5Pa, scraper speed 250 r / min) to obtain rapeseed oil rich in diglycerides, with a diglyceride content of 44%, and about 27g of free fatty acids were recovered.

[0062] S2, Esterification reaction: 5g of recovered free fatty acids, 4.89g of glycerol, and 0.495g of CALB@MCF-C8 were mixed evenly and esterified at 80℃ for 12h. After the reaction, the secondary diglyceride mixture was obtained by centrifugation, in which the diglyceride content was 55%. After purification under the same molecular distillation conditions as in step S1, rapeseed oil rich in diglycerides was obtained, in which the diglyceride content was about 78%, and 1,3-diglycerides accounted for 90% of the total diglycerides.

[0063] Example 6 A method for preparing diglyceride edible oil using foamed SiO2 enzyme arrays, employing the enzyme arrays ANL@MCF-C8 and CALB@MCF-C8 prepared in Example 1, includes the following steps.

[0064] S1, Hydrolysis reaction: 100g flaxseed oil, 100g water, and 1g ANL@MCF-C8 are mixed evenly and hydrolyzed at 45℃ for 1h. After the reaction, the primary diglyceride mixture is obtained by centrifugation, with a diglyceride content of 25% and a fatty acid content of 36%. ANL@MCF-C8 is recovered. The primary diglyceride mixture is purified by molecular distillation (process conditions: heating temperature 190℃, feed rate 15kg / h, vacuum degree 10Pa, scraper speed 300r / min) to obtain flaxseed oil rich in diglycerides, with a diglyceride content of 42%, and about 32g of free fatty acids are recovered.

[0065] S2, Esterification reaction: 5g of recovered free fatty acids, 4.89g of glycerol, and 0.198g of CALB@MCF-C8 were mixed evenly and esterified at 80℃ for 2h. After the reaction, the secondary diglyceride mixture was obtained by centrifugation, in which the diglyceride content was 45%. After purification under the same molecular distillation conditions as in step S1, flaxseed oil rich in diglycerides was obtained, in which the diglyceride content was about 66%, and 1,3-diglycerides accounted for 90% of the total diglycerides.

[0066] Example 7 A method for preparing diglyceride edible oil using foam SiO2 enzyme arrays, employing the foam SiO2 enzyme arrays ANL@MCF-C8 and CALB@MCF-C8 prepared in Example 1, includes the following steps.

[0067] S1, Hydrolysis reaction: 100g rice bran oil, 50g water, and 1g ANL@MCF-C8 were mixed evenly and hydrolyzed at 35℃ for 8h. After the reaction, the primary diglyceride mixture was obtained by centrifugation, with a diglyceride content of 29% and a fatty acid content of 32%. ANL@MCF-C8 was recovered. The primary diglyceride mixture was purified by molecular distillation (process conditions: heating temperature 190℃, feed rate 15kg / h, vacuum degree 10Pa, scraper speed 300r / min) to obtain rice bran oil rich in diglycerides, with a diglyceride content of 44%, and about 28g of free fatty acids were recovered.

[0068] S2, Esterification reaction: 5g of recovered free fatty acids, 4.89g of glycerol, and 0.099g of CALB@MCF-C8 were mixed evenly and esterified at 65℃ for 2h. After the reaction, the secondary diglyceride mixture was obtained by centrifugation, in which the diglyceride content was 46%. After purification under the same molecular distillation conditions as in step S1, rice bran oil rich in diglycerides was obtained, in which the diglyceride content was about 68%, and 1,3-diglycerides accounted for 90% of the total diglycerides.

[0069] Example 8 A method for preparing diglyceride edible oil using foam SiO2 enzyme arrays, employing the foam SiO2 enzyme arrays NE@MCF-C8 and CALB@MCF-C8 prepared in Example 1, includes the following steps.

[0070] S1, Glycerolysis reaction: 100g flaxseed oil, 30g glycerol, 1g water, and 3g NE@MCF-C8 were mixed evenly and stirred at 55℃ for 12h. After the reaction, the primary diglyceride mixture was obtained by centrifugation, with a diglyceride content of 47% and a fatty acid content of 8%. NE@MCF-C8 was recovered. The primary diglyceride mixture was purified by molecular distillation (process conditions: heating temperature 190℃, feed rate 15kg / h, vacuum degree 10Pa, scraper speed 300r / min) to obtain flaxseed oil rich in diglycerides, with a diglyceride content of 56%, and about 6g of free fatty acids were recovered.

[0071] S2, Esterification reaction: 5g of recovered free fatty acids, 4.89g of glycerol, and 0.495g of CALB@MCF-C8 are mixed evenly and esterified at 70℃ for 2h. After the reaction, the secondary diglyceride mixture is obtained by centrifugation, in which the diglyceride content is 54%. After purification under the same molecular distillation conditions as in step S1, flaxseed oil rich in diglycerides is obtained, in which the diglyceride content is about 75%, and 1,3-diglycerides account for 90% of the total diglycerides.

[0072] Example 9 A method for preparing diglyceride edible oil using foam SiO2 enzyme arrays, employing the foam SiO2 enzyme arrays NE@MCF-C8 and CALB@MCF-C8 prepared in Example 2, includes the following steps.

[0073] S1, Glycerolysis reaction: 100g rice bran oil, 30g glycerol, 2g water, and 2g NE@MCF-C8 were mixed evenly and stirred at 60℃ for 12h. After the reaction, the primary diglyceride mixture was obtained by centrifugation, with a diglyceride content of 48% and a fatty acid content of 10%. NE@MCF-C8 was recovered. The primary diglyceride mixture was purified by molecular distillation (process conditions: heating temperature 190℃, feed rate 15kg / h, vacuum degree 10Pa, scraper speed 300r / min) to obtain rice bran oil rich in diglycerides, with a diglyceride content of 56%, and about 7g of free fatty acids were recovered.

[0074] S2, Esterification reaction: 5g of recovered free fatty acids, 4.89g of glycerol, and 0.297g of CALB@MCF-C8 were mixed evenly and esterified at 80℃ for 2h. After the reaction, the secondary diglyceride mixture was obtained by centrifugation, in which the diglyceride content was 53%. After purification under the same molecular distillation conditions as in step S1, rice bran oil rich in diglycerides was obtained, in which the diglyceride content was about 73%, and 1,3-diglycerides accounted for 90% of the total diglycerides.

[0075] Example 10 A method for preparing diglyceride edible oil using foam SiO2 enzyme arrays, employing the foam SiO2 enzyme arrays NE@MCF-C8 and CALB@MCF-C8 prepared in Example 2, includes the following steps.

[0076] S1, Glycerolysis reaction: 100g sunflower seed oil, 20g glycerol, 2g water, and 2g NE@MCF-C8 were mixed evenly and stirred at 55℃ for 12h. After the reaction, the primary diglyceride mixture was obtained by centrifugation, with a diglyceride content of 45% and a fatty acid content of 9%. NE@MCF-C8 was recovered. The primary diglyceride mixture was purified by molecular distillation (process conditions: heating temperature 190℃, feed rate 15kg / h, vacuum degree 10Pa, scraper speed 300r / min) to obtain sunflower seed oil rich in diglycerides, with a diglyceride content of 53%, and about 6g of free fatty acids were recovered.

[0077] S2, Esterification reaction: 5g of recovered free fatty acids, 4.89g of glycerol, and 0.495g of CALB@MCF-C8 were mixed evenly and esterified at 65℃ for 2h. After the reaction, the secondary diglyceride mixture was obtained by centrifugation, in which the diglyceride content was 54%. After purification under the same molecular distillation conditions as in step S1, sunflower seed oil rich in diglycerides was obtained, in which the diglyceride content was about 74%, and 1,3-diglycerides accounted for 90% of the total diglycerides.

[0078] Example 11 A method for preparing diglyceride edible oil using foam SiO2 enzyme arrays, employing the foam SiO2 enzyme arrays NE@MCF-C8 and CALB@MCF-C8 prepared in Example 1, includes the following steps.

[0079] S1, Glycerolysis reaction: 100g soybean oil, 10g glycerol, 2g water, and 1g NE@MCF-C8 are mixed evenly and stirred at 45℃ for 6h. After the reaction, the primary diglyceride mixture is obtained by centrifugation, with a diglyceride content of 40% and a fatty acid content of 17%. NE@MCF-C8 is recovered. The primary diglyceride mixture is purified by molecular distillation (process conditions: heating temperature 170℃, feed rate 10kg / h, vacuum degree 0.1Pa, scraper speed 200r / min) to obtain soybean oil rich in diglycerides, with a diglyceride content of 50%, and about 14g of free fatty acids are recovered.

[0080] S2, Esterification reaction: 5g of recovered free fatty acids, 1.63g of glycerol, and 0.066g of CALB@MCF-C8 are mixed evenly and esterified at 40℃ for 12h. After the reaction, the secondary diglyceride mixture is obtained by centrifugation, in which the diglyceride content is 42%. After purification under the same molecular distillation conditions as in step S1, soybean oil rich in diglycerides is obtained, in which the diglyceride content is about 65%, and 1,3-diglycerides account for 90% of the total diglycerides.

[0081] Example 12 A method for preparing diglyceride edible oil using foam SiO2 enzyme arrays, employing the foam SiO2 enzyme arrays NE@MCF-C8 and CALB@MCF-C8 prepared in Example 2, includes the following steps.

[0082] S1, Glycerolysis reaction: 100g perilla seed oil, 40g glycerol, 2g water, and 3g NE@MCF-C8 were mixed evenly and stirred at 65℃ for 12h. After the reaction, the initial diglyceride mixture was obtained by centrifugation, with a diglyceride content of 45% and a fatty acid content of 8%. The enzyme array NE@MCF-C8 was recovered. The initial diglyceride mixture was purified by molecular distillation (process conditions: heating temperature 190℃, feed rate 15kg / h, vacuum degree 10Pa, scraper speed 300r / min) to obtain perilla seed oil rich in diglycerides, with a diglyceride content of 54%, and about 6g of free fatty acids were recovered.

[0083] S2, Esterification reaction: 5g of recovered free fatty acids, 4.89g of glycerol, and 0.495g of CALB@MCF-C8 were mixed evenly and esterified at 70℃ for 2h. After the reaction, the secondary diglyceride mixture was obtained by centrifugation, in which the diglyceride content was 56%. After purification under the same molecular distillation conditions as in step S1, perilla seed oil rich in diglycerides was obtained, in which the diglyceride content was about 76%, and 1,3-diglycerides accounted for 90% of the total diglycerides.

[0084] Example 13 A method for preparing diglyceride edible oil using foam SiO2 enzyme arrays, employing the foam SiO2 enzyme arrays NE@MCF-C8 and CALB@MCF-C8 prepared in Example 2, includes the following steps.

[0085] S1, Glycerolysis reaction: 100g rapeseed oil, 30g glycerol, 2g water, and 2g NE@MCF-C8 were mixed evenly and stirred at 55℃ for 12h. After the reaction, the primary diglyceride mixture was obtained by centrifugation, with a diglyceride content of 49% and a fatty acid content of 10%. NE@MCF-C8 was recovered. The primary diglyceride mixture was purified by molecular distillation (process conditions: heating temperature 190℃, feed rate 15kg / h, vacuum degree 10Pa, scraper speed 300r / min) to obtain rapeseed oil rich in diglycerides, with a diglyceride content of 57%, and about 8g of free fatty acids were recovered.

[0086] S2, Esterification reaction: 5g of recovered free fatty acids, 4.89g of glycerol, and 0.148g of CALB@MCF-C8 were mixed evenly and esterified at 70℃ for 2h. After the reaction, the secondary diglyceride mixture was obtained by centrifugation, in which the diglyceride content was 52%. After purification under the same molecular distillation conditions as in step S1, rapeseed oil rich in diglycerides was obtained, in which the diglyceride content was about 74%, and 1,3-diglycerides accounted for 90% of the total diglycerides.

[0087] Example 14 Following the methods described in Examples 4 and 13, the foam SiO2 enzyme arrays ANL@MCF-C8 and NE@MCF-C8 were reused to prepare diglycerides through moderate hydrolysis and glycerolization of vegetable oils. The results are as follows... Figure 3 and Figure 4 As shown, after six repeated uses, the diglyceride content of both enzyme arrays was greater than 40%.

[0088] Comparative Example 1 This comparative example is the same as Example 4, except that the enzyme array carrier used is the MCF prepared in step S1 of Example 2, and the lipase was directly loaded without the treatment in step S2. The diglyceride content in the initial diglyceride mixture before purification was 26%, and after purification it was 40%; the diglyceride content in the secondary diglyceride mixture was 38%, and after purification it was 58%.

[0089] Comparative Example 2 This comparative example is the same as Example 13, except that the enzyme array uses the MCF prepared in step S1 of Example 2 as the carrier, and the lipase is directly loaded without the treatment in step S2. The diglyceride content in the initial diglyceride mixture before purification was 32%, and after purification it was 42%; the diglyceride content in the secondary diglyceride mixture was 38%, and after purification it was 60%.

[0090] Comparative Example 3 This comparative example is the same as Example 4, except that the foam SiO2 enzyme arrays involved are all replaced with the corresponding free lipases. The diglyceride content in the initial diglyceride mixture before purification was 24%, and after purification it was 39%; the diglyceride content in the secondary diglyceride mixture was 41%, and after purification it was 64%.

[0091] Comparative Example 4 This comparative example is the same as Example 13, except that the foam SiO2 enzyme arrays involved are all replaced with the corresponding free lipases. The diglyceride content in the initial diglyceride mixture before purification was 33%, and after purification it was 43%; the diglyceride content in the secondary diglyceride mixture was 42%, and after purification it was 61%.

[0092] Comparative Example 5 The carrier used in the immobilization step of Example 2 was replaced with LXET-1000 resin, and the rest was the same as in Example 2, to prepare the enzyme array. Hydrolysis and esterification reactions were performed according to the method of Example 4. The diglyceride content in the initial diglyceride mixture before purification was 24%, and after purification it was 39%; the diglyceride content in the secondary diglyceride mixture was 40%, and after purification it was 57%.

[0093] Comparative Example 6 The carrier used in the immobilization step of Example 2 was replaced with LXET-1000 resin, and the rest was the same as in Example 2, to prepare the enzyme array. Glycerolysis and esterification reactions were carried out according to the method of Example 13. The diglyceride content in the initial diglyceride mixture before purification was 37%, and after purification it was 48%; the diglyceride content in the secondary diglyceride mixture was 42%, and after purification it was 60%.

[0094] Table 1. Diglyceride content in different embodiments

[0095] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A foamed SiO2 enzyme array, characterized in that, The preparation method of the foam SiO2 enzyme array includes the following steps: S1, using tetraethyl orthosilicate and 1,2-bis(triethoxysilyl)ethane as a composite silicon source, was co-condensed to construct a framework. The framework was then extracted, washed, and dried using a mixed solution of hydrochloric acid and ethanol to obtain a foamed SiO2 carrier MCF with a hierarchical pore structure; the MCF had a specific surface area of ​​800~952 m². 2 / g, with mesopore size of 11~14nm and contact angle of 27°~30°; S2, MCF is dispersed in a hexane solution containing n-octyltrichlorosilane, ultrasonically treated, oscillated, and surface-hydrophobicated. After filtration, washing, and drying, hydrophobic foam SiO2 carrier MCF-C8 with a hierarchical pore structure is obtained; the specific surface area of ​​MCF-C8 is 432~500 m². 2 / g, with mesopore size of 11~13nm and contact angle of 99°~103°; S3, using MCF-C8 as a carrier, was prepared by loading Aspergillus niger lipase, Thermophilus spp. lipase, and Candida antarcticis lipase B onto the carrier via physical adsorption. This resulted in the preparation of foam SiO2 enzyme arrays ANL@MCF-C8 (highly efficient hydrolytic activity), NE@MCF-C8 (highly efficient glycerolysis activity), and CALB@MCF-C8 (highly efficient esterification activity). The loading capacities of ANL@MCF-C8, NE@MCF-C8, and CALB@MCF-C8 were 132–142 mg / g, 100–156 mg / g, and 130–150 mg / g, respectively.

2. The foamed SiO2 enzyme array according to claim 1, characterized in that, The cocondensation process described in step S1 specifically involves: stirring polyether P123, 1,3,5-trimethylbenzene, ammonium fluoride, and hydrochloric acid at 37°C for 1 hour; sequentially adding tetraethyl orthosilicate and 1,2-bis(triethoxysilyl)ethane, continuing stirring for 12 hours, then transferring to an autoclave for static hydrothermal aging for 24 hours, cooling, washing with anhydrous ethanol, and drying. The mass ratio of the polyether P123 to the volume ratio of 1,3,5-trimethylbenzene is 3~4 g: 3.45~4.6 mL; The mass ratio of polyether P123 to ammonium fluoride is 3~4:0.035~0.046; The volume ratio of 1,3,5-trimethylbenzene to hydrochloric acid is 3.45~4.6:15~20, and the concentration of hydrochloric acid is 1.6 mol / L; The mass ratio of tetraethyl orthosilicate to 1,2-bis(triethoxysilyl)ethane is 3~1:1~3; The mass ratio of polyether P123 to tetraethyl orthosilicate is 3~4:2.2~6.6; The static hydrothermal aging temperature is 100℃, the drying temperature is 60℃, and the time is 12h.

3. The foam SiO2 enzyme array according to claim 1, characterized in that, In step S1, the volume fraction of hydrochloric acid in the mixed solution of hydrochloric acid and ethanol is 1-2%, and the concentration of hydrochloric acid used is 12 mol / L. The extraction time was 6 hours, and the process was repeated three times. The ethanol used for washing; The drying temperature is 60℃ and the time is 12 hours.

4. The foam SiO2 enzyme array according to claim 1, characterized in that, In step S2, the volume ratio of n-octyltrichlorosilane to n-hexane in the n-octyltrichlorosilane solution is 0.46:

20. The mass ratio of MCF to the volume ratio of n-octyltrichlorosilane is 1 g: 0.46~1.30 mL; The ultrasonic treatment lasted for 10 minutes, the oscillation speed was 250 rpm, the temperature was 25°C, and the duration was 2 hours. The washing ethanol is used; the drying temperature is 60°C and the time is 12 hours.

5. The foamed SiO2 enzyme array according to claim 1, characterized in that, The physical adsorption method described in step S3 is specifically as follows: Enzyme solutions of Aspergillus niger lipase, Thermophilus spp. lipase and Candida antarcticis lipase B were prepared using phosphate buffer. Then, MCF-C8 soaked in ethanol was mixed with the enzyme solution, sonicated, vacuumed to remove gas from the pores, incubated on a shaker, centrifuged, the precipitate was collected, and freeze-dried to obtain the enzyme array. The concentration of the Aspergillus niger lipase solution was 125~150 mg / mL, and the concentration of the phosphate buffer was 50 mM / L with a pH of 5. The concentration of the lipase from *Thermophilic filamentosa* was 20-50 mg / mL, and the concentration of the prepared phosphate buffer was 50 mM / L with a pH of 7. The concentration of the Antarctic Candida lipase B enzyme solution was 40-60 mg / mL, and the concentration of the prepared phosphate buffer was 50 mM / L with a pH of 7. The ratio of MCF-C8 to enzyme solution is 1g:100mL, the sonication time is 5min, the vacuuming time is 5min, the shaking incubation temperature is 30℃, the rotation speed is 220rpm, and the time is 40min. The centrifugation speed was 8000 rpm and the time was 10 min.

6. A method for preparing edible oil rich in diglycerides using a foamed SiO2 enzyme array, characterized in that, The application of the foam SiO2 enzyme arrays ANL@MCF-C8 and CALB@MCF-C8 as described in claim 1 includes the following steps: S1, Hydrolysis reaction: Vegetable oil, water, and ANL@MCF-C8 are mixed evenly and subjected to hydrolysis reaction. After the reaction is completed, the primary diglyceride mixture is obtained by centrifugation and ANL@MCF-C8 is recovered. The primary diglyceride mixture is purified by molecular distillation to obtain edible oil rich in diglycerides and free fatty acids are recovered. S2, Esterification reaction: The recovered free fatty acids, glycerol, and CALB@MCF-C8 are mixed evenly and subjected to esterification reaction. After the reaction is completed, the secondary diglyceride mixture is obtained by centrifugation. After molecular distillation purification, edible oil rich in diglycerides is obtained.

7. The method according to claim 6, characterized in that, In step S1, the amount of ANL@MCF-C8 added is 0.5-3% of the mass of vegetable oil, the mass ratio of vegetable oil to water is 1:0.4-1:1, the hydrolysis reaction temperature is 25-45℃, and the time is 1-8h; the molecular distillation purification conditions are: heating temperature is 170-190℃, feed rate is 10-15kg / h, vacuum degree is 0.1-10Pa, and scraper rotation speed is 200-300r / min; In step S2, the amount of CALB@MCF-C8 added is 1-5% of the total mass of free fatty acids and glycerol, and the molar ratio of free fatty acids to glycerol is 1:1-1:3; the esterification reaction temperature is 40-80℃, and the time is 2-12h; the molecular distillation purification conditions are: heating temperature is 170-190℃, feed rate is 10-15kg / h, vacuum degree is 0.1-10Pa, and scraper rotation speed is 200-300r / min.

8. A method for preparing edible oil rich in diglycerides using a foamed SiO2 enzyme array, characterized in that, The application of the foam SiO2 enzyme arrays NE@MCF-C8 and CALB@MCF-C8 as described in claim 1 includes the following steps: S1, Glycerolysis reaction: Vegetable oil, glycerol, water, and NE@MCF-C8 are mixed evenly and stirred to react. After the reaction is completed, the mixture of primary diglycerides is obtained by centrifugation, and NE@MCF-C8 is recovered. The mixture of primary diglycerides is purified by molecular distillation to obtain edible oil rich in diglycerides, and free fatty acids are recovered. S2, Esterification reaction: The recovered free fatty acids, glycerol, and CALB@MCF-C8 are mixed evenly and subjected to esterification reaction. After the reaction is completed, the secondary diglyceride mixture is obtained by centrifugation. After molecular distillation purification, edible oil rich in diglycerides is obtained.

9. The method according to claim 8, characterized in that, In step S1, the amount of NE@MCF-C8 added is 1-3% of the mass of vegetable oil, the amount of water added is 1-2% of the mass of vegetable oil, the molar ratio of vegetable oil to glycerol is 1:1-1:4, the stirring reaction temperature is 45-65℃, and the reaction time is 6-12h; the molecular distillation purification conditions are: heating temperature is 170-190℃, feed rate is 10-15kg / h, vacuum degree is 0.1-10Pa, and scraper rotation speed is 200-300r / min; In step S2, the amount of CALB@MCF-C8 added is 1-5% of the total mass of free fatty acids and glycerol, and the molar ratio of free fatty acids to glycerol is 1:1-1:3; the esterification reaction temperature is 40-80℃, and the time is 2-12h; the molecular distillation purification conditions are: heating temperature is 170-190℃, feed rate is 10-15kg / h, vacuum degree is 0.1-10Pa, and scraper rotation speed is 200-300r / min.

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