A moderate processing technology for zero-trans sunflower seed oil

Abstract

This invention belongs to the field of oil processing, specifically relating to a moderate processing technology for zero-trans-fatty acid sunflower seed oil. This technology effectively removes harmful components such as TFA, impurities, and free fatty acids from crude oil, while maximizing the retention of natural nutrients such as vitamin E and phytosterols. This method not only improves the edible safety and oxidative stability of sunflower seed oil but also significantly enhances its flavor and color, meeting market demand for high-quality, high-nutrient, zero-trans-fatty acid healthy sunflower seed oil.

Description

Technical Field

[0001] This invention belongs to the field of oil processing, specifically relating to a moderate processing technology for zero-trans sunflower seed oil. Background Technology

[0002] Sunflower seed oil is a high-quality edible vegetable oil with a pleasant aroma and pure taste. It is rich in unsaturated fatty acids, vitamin E, sterols, squalene, polyphenols, and other beneficial active ingredients. Zero-trans sunflower seed oil is a special type of sunflower seed oil produced through a specific process, with extremely low trans fatty acid content to meet the needs of a healthy diet.

[0003] Trans fatty acids (TFAs) are a general term for unsaturated fatty acids containing trans-nonconjugated double bonds. They are non-essential fatty acids for the human body, originating from both the meat and dairy products of ruminant animals and the processing of vegetable oils. The structural characteristics of TFAs give them higher melting points and thermodynamic stability, making them difficult to remove during processing and potentially causing serious health hazards. Studies have shown that the main harm of TFAs is that they increase low-density lipoprotein cholesterol (LDL-C) levels and decrease high-density lipoprotein cholesterol (HDL-C) levels, exacerbating atherosclerosis and cardiovascular disease, thereby increasing the risk of coronary heart disease. Furthermore, TFAs may interfere with lipid metabolism, increasing the potential risk of type II diabetes, female infertility, Alzheimer's disease, and adversely affecting the growth and development and nervous system function of infants and young children. Both domestic and international regulatory authorities have imposed strict controls on TFA. The WHO has proposed to eliminate industrially produced TFA by 2023. The EU stipulates that TFA should be ≤2g per 100g of fat. The US FDA stipulates that TFA should be controlled below 0.5%. my country also requires hydrogenated oils to be labeled with TFA content and allows the labeling of "zero trans" when TFA is ≤0.3g / 100g. At the same time, the use of hydrogenated oils (TFA ≤3% total fatty acids) is prohibited in infant formula.

[0004] Therefore, there is an urgent need for a new processing technology for zero-trans-sunflower seed oil that can not only effectively remove harmful components such as TFA and impurities, but also better retain nutrients such as vitamin E and phytosterols. Summary of the Invention

[0005] In view of the problems in the prior art, the purpose of this invention is to provide a method for moderately processing sunflower seed oil with zero trans fatty acids. This method effectively removes impurities, free fatty acids, TFA, and harmful components such as benzo[a]pyrene from crude oil while maximally retaining natural nutrients such as vitamin E, phytosterols, and squalene. This invention not only improves the food safety and oxidative stability of sunflower seed oil but also significantly enhances its flavor and color, meeting market demand for high-quality, high-nutrition, and zero-trans-fatty-acid healthy sunflower seed oil.

[0006] Specifically, the technical solution of the present invention is: a method for moderately processing sunflower seed oil with zero trans fatty acids, comprising the following steps: A. Screening and Conditioning: After the sunflower seeds are dehulled and peeled, they enter an intelligent vibrating screen to remove sunflower seeds with shells, peels, and broken seeds. Then, they are conveyed to a grading and screening machine to screen out plump sunflower seeds. The sunflower seeds are preheated with hot air and then heated and stirred by infrared radiation to complete the conditioning process. B. Pressing, filtration and degumming: The sunflower seeds after infrared heating treatment are fed into a twin-screw oil press. The pressing temperature and speed are controlled to obtain virgin sunflower seed crude oil. The oil is then filtered through a hollow fiber ultrafiltration membrane to obtain sunflower seed essential oil. C. Immobilized Enzyme Refining: Porous ceramics were dispersed in phosphate buffer, and an enzyme solution containing Aspergillus oryzae lipase and neutral protease was added. After stirring at room temperature, the immobilized enzyme was obtained by filtration and vacuum drying to obtain porous ceramic immobilized enzyme. Sunflower seed oil obtained in step B and purified water were taken, and then the prepared immobilized enzyme was added. The reaction was carried out under controlled temperature. After centrifugation and filtration, the filtrate was collected, and the oil layer, emulsion layer, aqueous layer, and precipitate were separated. The oil layer obtained by repeating the above centrifugation operation on the emulsion layer was combined with the oil layer obtained above to obtain zero-trans sunflower seed oil.

[0007] Preferably, in the method, in step A, the temperature of the hot air preheating is 40~60℃.

[0008] Preferably, in the method, in step A, the infrared radiation physical field parameters are set to a short-wave infrared wavelength range of 0.7~1.1μm and a mid-wave infrared wavelength range of 4~7.8μm, wherein the short-wave:mid-wave infrared power ratio is 1.5~3.0:1. Preferably, in the method, the infrared heating temperature is 120~160℃, and the stirring time is 0.5~1h.

[0009] Preferably, in the method, in step B, the pressing temperature is 60~90℃ and the rotation speed is 100~200r / min.

[0010] Preferably, in the method, in step B, the hollow fiber ultrafiltration membrane is polyethersulfone or polyvinylidene fluoride with a pore size of 0.01~0.03μm.

[0011] Preferably, in the method, in step C, the weight ratio of the porous ceramic to the protein content of the enzyme is 1:20~24.

[0012] Preferably, in the method, in step C, the protein ratio of Aspergillus oryzae lipase to neutral protease is 1.3~1.5:1.

[0013] In one embodiment of the present invention, the Aspergillus oryzae lipase has a concentration of 5.7 × 10⁻⁶. 5 The activity of the neutral protease was 6.1 × 10 U / g. 5 U / g.

[0014] Preferably, in the method, in step C, the weight ratio of the immobilized enzyme to sunflower seed oil is 1:20~30.

[0015] Preferably, in the method, in step C, the immobilized enzyme reaction is carried out at a temperature of 35-45°C for 8-10 hours.

[0016] Preferably, in the method, during step C, when centrifuging and collecting the filtrate, the rotation speed is 2000~3000 r / min, and the centrifugation time is 0.5~1 h.

[0017] The enzymes used in this invention are not limited to specific sources and can be made in-house or purchased commercially available products using methods in the prior art.

[0018] The zero-trans-fatty acid sunflower seed oil processing technology provided by this invention is a precise and controllable processing method. Its core objective is to maximize the retention of natural nutrients in the oil, efficiently remove harmful substances, and effectively inhibit their formation during processing. The technical solution of this invention, while ensuring that the oil quality, odor, and color meet standard requirements, significantly retains trace nutrients such as vitamin E and phytosterols in sunflower seed oil, and strictly controls the trans-fatty acid (TFA) content to ≤0.3%, achieving a synergistic improvement in nutritional retention and safety.

[0019] Compared with the prior art, the present invention has the following outstanding advantages: 1. The processing method of the present invention can not only efficiently remove impurities and harmful components such as trans fatty acids contained in sunflower seed oil, but also significantly retain active ingredients with nutritional value such as vitamin E and phytosterols, thereby improving the quality and safety of the oil while better maintaining its natural nutritional value. 2. This invention uses infrared radiation conditioning combined with a twin-screw oil press for pressing, which can effectively avoid the damage of heat-sensitive components such as vitamin E to high temperatures; at the same time, hollow fiber ultrafiltration membrane filtration and degumming efficiently remove phospholipids and other pectin-soluble impurities from the oil, thereby improving the quality of the oil while better preserving active ingredients and achieving precise degumming. 3. This invention employs an immobilized enzyme refining process. On one hand, it utilizes lipase to catalyze the esterification reaction between free fatty acids and methanol, improving refining efficiency. Simultaneously, it leverages neutral proteases to hydrolyze lipoprotein complexes, further enhancing the refining effect. On the other hand, this immobilized enzyme system possesses excellent thermal stability and pH tolerance, significantly enhancing enzyme catalytic activity. Furthermore, the enzyme exhibits good reusability, allowing for reuse more than 20 times, substantially reducing operating costs. Moreover, the green refining technology employed in this invention effectively avoids the extensive use of organic solvents in traditional processes, reducing environmental pollution and eliminating safety hazards such as flammability and explosiveness, making the overall process safer and more environmentally friendly. Detailed Implementation

[0020] The following specific embodiments further illustrate the present invention, but do not limit the scope of the present invention in any way. Those skilled in the art can make various modifications or improvements based on the basic idea of ​​the present invention, but as long as they do not depart from the basic idea of ​​the present invention, they are all within the scope of the present invention.

[0021] Example 1 A. Screening and Conditioning: Take 5 kg of sunflower seeds, remove the shells and husks, and then put them into an intelligent vibrating screen to remove sunflower seeds with shells, husks, and broken seeds. Then, convey them to a grading and screening machine to screen out plump sunflower seeds. Preheat the sunflower seeds to 40~50℃ with hot air. Then, turn on the infrared radiation heating treatment. The infrared radiation physical field parameters are set as follows: short-wave infrared wavelength range of 0.9~1.1μm, mid-wave infrared wavelength range of 6.2~7.8μm, short-wave:mid-wave infrared power ratio of 1.5:1, heating temperature set to 120℃, stir and heat for 1 hour, and then the conditioning is completed. B. Pressing, filtration and degumming: The sunflower seeds after infrared heating treatment are fed into a twin-screw oil press. The pressing temperature is controlled at 60℃ and the rotation speed of the twin-screw oil press is 100r / min to obtain virgin sunflower seed crude oil. The crude oil is then filtered through a polyethersulfone hollow fiber ultrafiltration membrane with a pore size of 0.01m to obtain sunflower seed essential oil. C. Immobilized Enzyme Refining: 5.0 g of porous ceramic was dispersed in 500 mL of phosphate buffer (30 mM, pH 5.5), and an enzyme solution containing 57 mg of Aspergillus oryzae lipase and 43 mg of neutral protease (5.7 × 10⁻⁶ g / mL of Aspergillus oryzae lipase) was added. 5 The activity of the neutral protease was 6.1 × 10 U / g. 5(U / g, the enzyme activity in the following examples is the same). After stirring at room temperature for 1 hour, the immobilized enzyme was obtained by filtration and vacuum drying for 6 hours to obtain a porous ceramic immobilized enzyme. Take 80g of sunflower seed oil and 60g of purified water obtained in step B, and then add 4g of the prepared immobilized enzyme. React at 35℃ for 10 hours. Collect the filtrate by filtration, centrifuge at 2000r / min for 0.5 hours to separate the oil layer, emulsion layer, water layer and precipitate. Repeat the above centrifugation operation on the emulsion layer, and combine the resulting oil layer with the aforementioned oil layer to obtain the final product.

[0022] Example 2 A. Screening and Conditioning: Take 5 kg of sunflower seeds, remove the shells and husks, and then put them into an intelligent vibrating screen to remove sunflower seeds with shells, husks, and broken seeds. Then, convey them to a grading and screening machine to screen out plump sunflower seeds. Preheat the sunflower seeds to 50~60℃ with hot air. Then, turn on the infrared radiation heating treatment. The infrared radiation physical field parameters are set as follows: short-wave infrared wavelength range of 0.7~0.9μm, mid-wave infrared wavelength range of 4~6.1μm, short-wave:mid-wave infrared power ratio of 3.0:1, heating temperature set to 160℃, stir and heat for 30 minutes, and then the conditioning is completed. B. Pressing, filtration and degumming: The sunflower seeds after infrared heating treatment are fed into a twin-screw oil press. The pressing temperature is controlled at 90℃ and the speed of the twin-screw oil press is 200r / min to obtain virgin sunflower seed crude oil. The crude oil is then filtered through a polyvinylidene fluoride hollow fiber ultrafiltration membrane with a pore size of 0.03m to obtain sunflower seed essential oil. C. Immobilized Enzyme Refining: 5.0 g of porous ceramic was dispersed in 500 mL of phosphate buffer (30 mM, pH 5.5), and an enzyme solution containing 72 mg of Aspergillus oryzae lipase and 48 mg of neutral protease was added. After stirring at room temperature for 1 h, the immobilized enzyme was obtained by filtration and vacuum drying for 6 h to obtain porous ceramic immobilized enzyme. 120 g of sunflower seed oil obtained in step B and 100 g of purified water were taken, and then 4 g of the prepared immobilized enzyme was added. The reaction was carried out at 45 °C for 8 h. The filtrate was collected by filtration and centrifuged at 3000 r / min for 0.5 h to separate the oil layer, emulsion layer, aqueous layer, and precipitate. The emulsion layer was centrifuged again as described above, and the resulting oil layer was combined with the aforementioned oil layer to obtain the final product.

[0023] Comparative Example 1 A. Screening and conditioning: Take 5kg of sunflower seed raw material, remove the shells and husks and then put it into an intelligent vibrating screen to remove sunflower seeds with shells, husks and broken ones. Then it is conveyed to a grading and screening machine to screen out plump sunflower seeds. Preheat the sunflower seeds to 40~50℃ with hot air. Then continue to use hot air to heat at 120℃ and stir for 1 hour to end the conditioning. B. Pressing, filtration and degumming: The sunflower seeds after infrared heating treatment are fed into a twin-screw oil press. The pressing temperature is controlled at 60℃ and the rotation speed of the twin-screw oil press is 100r / min to obtain virgin sunflower seed crude oil. The crude oil is then filtered through a polyethersulfone hollow fiber ultrafiltration membrane with a pore size of 0.01m to obtain sunflower seed essential oil. C. Immobilized Enzyme Refining and Deodorization: 5.0 g of porous ceramic was dispersed in 500 mL of phosphate buffer (30 mM, pH 5.5), and an enzyme solution containing 57 mg of Aspergillus oryzae lipase and 43 mg of neutral protease was added. After stirring at room temperature for 1 h, the immobilized enzyme was obtained by filtration and vacuum drying for 6 h to obtain porous ceramic immobilized enzyme. 80 g of sunflower seed oil and 60 g of purified water obtained in step B were taken, and then 4 g of the prepared immobilized enzyme was added. The reaction was carried out at 35 °C for 10 h. The filtrate was collected by filtration and centrifuged at 2000 r / min for 0.5 h to separate the oil layer, emulsion layer, water layer, and precipitate. The emulsion layer was centrifuged again as described above, and the resulting oil layer was combined with the aforementioned oil layer to obtain the final product.

[0024] Comparative Example 2 A. Screening and Conditioning: Take 5 kg of sunflower seeds, remove the shells and husks, and then put them into an intelligent vibrating screen to remove sunflower seeds with shells, husks, and broken seeds. Then, convey them to a grading and screening machine to screen out plump sunflower seeds. Preheat the sunflower seeds to 40~50℃ with hot air. Then, turn on the infrared radiation heating treatment. The infrared radiation physical field parameters are set as follows: short-wave infrared wavelength range of 0.9~1.1μm, mid-wave infrared wavelength range of 6.2~7.8μm, short-wave:mid-wave infrared power ratio of 1.5:1, heating temperature set to 120℃, stir and heat for 1 hour, and then the conditioning is completed. B. Pressing, filtration and degumming: The sunflower seeds after infrared heating treatment are fed into a twin-screw oil press, the pressing temperature is controlled at 180℃, and the speed of the twin-screw oil press is 100r / min to obtain virgin sunflower seed crude oil, which is then filtered through a polyethersulfone hollow fiber ultrafiltration membrane with a pore size of 0.01m to obtain sunflower seed essential oil. C. Immobilized Enzyme Refining: 5.0 g of porous ceramic was dispersed in 500 mL of phosphate buffer (30 mM, pH 5.5), and an enzyme solution containing 57 mg of Aspergillus oryzae lipase and 43 mg of neutral protease was added. After stirring at room temperature for 1 h, the immobilized enzyme was obtained by filtration and vacuum drying for 6 h to obtain porous ceramic immobilized enzyme. 80 g of sunflower seed oil and 60 g of purified water obtained in step B were taken, and then 4 g of the prepared immobilized enzyme was added. The reaction was carried out at 35 °C for 10 h. The filtrate was collected by filtration and centrifuged at 2000 r / min for 0.5 h to separate the oil layer, emulsion layer, aqueous layer, and precipitate. The emulsion layer was centrifuged again as described above, and the resulting oil layer was combined with the previous oil layer to obtain the final product.

[0025] Comparative Example 3 A. Screening and Conditioning: Take 5 kg of sunflower seeds, remove the shells and husks, and then put them into an intelligent vibrating screen to remove sunflower seeds with shells, husks, and broken seeds. Then, convey them to a grading and screening machine to screen out plump sunflower seeds. Preheat the sunflower seeds to 40~50℃ with hot air. Then, turn on the infrared radiation heating treatment. The infrared radiation physical field parameters are set as follows: short-wave infrared wavelength range of 0.9~1.1μm, mid-wave infrared wavelength range of 6.2~7.8μm, short-wave:mid-wave infrared power ratio of 1.5:1, heating temperature set to 120℃, stir and heat for 1 hour, and then the conditioning is completed. B. Pressing, Filtration and Degumming: The sunflower seeds after infrared heating treatment are fed into a twin-screw oil press. The pressing temperature is controlled at 60℃ and the speed of the twin-screw oil press is 100r / min to obtain crude sunflower seed oil. The oil is then filtered through a filter press using a 100-mesh filter cloth to obtain sunflower seed essential oil. C. Immobilized Enzyme Refining: 5.0 g of porous ceramic was dispersed in 500 mL of phosphate buffer (30 mM, pH 5.5), and an enzyme solution containing 57 mg of Aspergillus oryzae lipase and 43 mg of neutral protease was added. After stirring at room temperature for 1 h, the immobilized enzyme was obtained by filtration and vacuum drying for 6 h to obtain porous ceramic immobilized enzyme. 80 g of sunflower seed oil and 60 g of purified water obtained in step B were taken, and then 4 g of the prepared immobilized enzyme was added. The reaction was carried out at 35 °C for 10 h. The filtrate was collected by filtration and centrifuged at 2000 r / min for 0.5 h to separate the oil layer, emulsion layer, aqueous layer, and precipitate. The emulsion layer was centrifuged again as described above, and the resulting oil layer was combined with the previous oil layer to obtain the final product.

[0026] Comparative Example 4 A. Screening and Conditioning: Take 5 kg of sunflower seeds, remove the shells and husks, and then put them into an intelligent vibrating screen to remove sunflower seeds with shells, husks, and broken seeds. Then, convey them to a grading and screening machine to screen out plump sunflower seeds. Preheat the sunflower seeds to 40~50℃ with hot air. Then, turn on the infrared radiation heating treatment. The infrared radiation physical field parameters are set as follows: short-wave infrared wavelength range of 0.9~1.1μm, mid-wave infrared wavelength range of 6.2~7.8μm, short-wave:mid-wave infrared power ratio of 1.5:1, heating temperature set to 120℃, stir and heat for 1 hour, and then the conditioning is completed. B. Pressing, filtration and degumming: The sunflower seeds after infrared heating treatment are fed into a twin-screw oil press. The pressing temperature is controlled at 60℃ and the rotation speed of the twin-screw oil press is 100r / min to obtain virgin sunflower seed crude oil. The crude oil is then filtered through a polyethersulfone hollow fiber ultrafiltration membrane with a pore size of 0.01m to obtain sunflower seed essential oil. C. Refining: The sunflower seed oil obtained in step B is decolorized using bleaching clay. The decolorized oil is then directly heated to 205°C by heat exchange with the oil outlet of the packed tower via a heat exchanger. It then enters a plate tower and undergoes 1% direct steam stripping for 60 minutes under a vacuum of 0-10 Torr. After flowing out of the plate tower, it is pumped into a heater and heated to 225°C. It then flows into a packed tower and undergoes 2% direct steam stripping for 10 minutes. After flowing out of the packed tower, it undergoes heat exchange in a heat exchanger and is gradually cooled to 30-45°C by cooling water before fine filtration to obtain the final product.

[0027] Verification Experiment Example 1. Basic Indicators Basic indicators of sunflower seed oil: The basic indicators of the sunflower seed oil obtained from the examples and comparative examples were measured according to the following test methods, and the results are shown in Table 1 and Table 2.

[0028] Color: GB / T22460-2008 "Determination of color of animal and vegetable oils".

[0029] VE: GB / T26635-2011 Determination of Tocopherol and Tocotrienol Content in Animal and Vegetable Oils by High Performance Liquid Chromatography. The VE loss rate is the difference between the VE content in crude virgin sunflower seed oil and the VE content in the final product.

[0030] Sterols: GB / T25223-2010 Determination of sterol composition and total sterols in animal and vegetable oils by gas chromatography. The sterol loss rate is the difference between the sterol content in crude sunflower seed oil and the sterol content in the final product.

[0031] Oil yield: The obtained sunflower seed oil was left to stand in a constant temperature storage room at 2℃ for 48 hours and then filtered. The mass of the residue after filtration was recorded. The sunflower seed cake produced by oil pressing was collected and weighed. The ratio of the mass of sunflower seed oil to the mass of sunflower seed kernels obtained in each batch is the oil yield, as shown in the following formula: Y=(m1-m2) / m1×100%, where m1 is the mass of sunflower seed kernels and m2 is the mass of residue after filtration.

[0032] Flavor evaluation is conducted by a panel of 15-20 professional sensory evaluation members. The results are scored using a median score on a 5-point scale, with 1 indicating "strongly dislike," 2 indicating "dislike," 3 indicating "neutral," 4 indicating "like," and 5 indicating "strongly like." If off-flavors such as fishy, ​​grassy, ​​vegetable-like, oxidized, or hot white clay are present, a score of 1 or 2 should be selected.

[0033] Acid value: determined according to GB5009.229 "National Food Safety Standard - Determination of Acid Value in Food"; Peroxide value: determined according to GB / T5009.227 "National Food Safety Standard - Determination of Peroxide Value in Food". For the determination of acid value (AV) and peroxide value (PV), in the long-term stability study, sunflower seed oil was packaged in PET bottles, with two bottles for each example or comparative example, and stored on a shelf at 25°C for 18 months before the acid value and peroxide value were tested.

[0034] Other methods and materials not mentioned in the embodiments are conventional methods and materials in the art.

[0035] Table 1 Basic Indicators of Sunflower Seed Oil Table 2 Stability of Sunflower Seed Oil 2. Performance Verification Frying experiment: First, the samples obtained from each example and the comparative example were adjusted to the same level by adding vitamin E and sterols. Then, 2000g of each sample with the same vitamin E and sterol content was weighed and placed in a pot and heated to 180℃. 100g of fries were weighed each time and fried for 3 minutes. One batch was fried every hour. After 15 batches of frying, the relative changes in the acid value of the oil, color, polar substance content, and oil content of the fries were measured. The results are shown in Table 3.

[0036] Table 3. Frying properties of sunflower seed oil

Claims

1. A moderate processing technology for zero-trans-sunflower seed oil, characterized in that, Includes the following steps: A. Screening and Conditioning: After the sunflower seeds are dehulled and peeled, they enter an intelligent vibrating screen to remove sunflower seeds with shells, peels, and broken seeds. Then, they are conveyed to a grading and screening machine to screen out plump sunflower seeds. The sunflower seeds are preheated with hot air and then heated and stirred by infrared radiation to complete the conditioning process. B. Pressing, filtration and degumming: The sunflower seeds after infrared heating treatment are fed into a twin-screw oil press. The pressing temperature and speed are controlled to obtain virgin sunflower seed crude oil. The oil is then filtered through a hollow fiber ultrafiltration membrane to obtain sunflower seed essential oil. C. Immobilized Enzyme Refining: Porous ceramics were dispersed in phosphate buffer, and an enzyme solution containing Aspergillus oryzae lipase and neutral protease was added. After stirring at room temperature, the immobilized enzyme was obtained by filtration and vacuum drying to obtain porous ceramic immobilized enzyme. Sunflower seed oil obtained in step B and purified water were taken, and then the prepared immobilized enzyme was added. The reaction was carried out under controlled temperature. After centrifugation and filtration, the filtrate was collected and the oil layer, emulsion layer, water layer and precipitate were separated. The oil layer obtained by repeating the above centrifugation operation on the emulsion layer was combined with the above oil layer to obtain zero trans-sunflower seed oil. In step A, the infrared radiation physical field parameters are set as follows: short-wave infrared wavelength range of 0.7~1.1μm, mid-wave infrared wavelength range of 4~7.8μm, short-wave:mid-wave infrared power ratio of 1.5~3.0:1, infrared heating temperature of 120~160℃, and stirring time of 0.5~1h; in step B, pressing temperature of 60~90℃, rotation speed of 100~200r / min, hollow fiber ultrafiltration membrane of polyethersulfone or polyvinylidene fluoride, pore size of 0.01~0.03μm; in step C, the weight ratio of porous ceramic to enzyme protein is 1:20~24, the protein ratio of Aspergillus oryzae lipase to neutral protease is 1.3~1.5:1, and the weight ratio of immobilized enzyme to sunflower seed oil is 1:20~30.

2. The processing technology as described in claim 1, characterized in that, In step C, the immobilized enzyme reaction is carried out at a temperature of 35-45℃ for 8-10 hours.

3. The processing technology as described in claim 1, characterized in that, In step C, when centrifuging and filtering to collect the filtrate, the rotation speed is 2000~3000 r / min, and the centrifugation time is 0.5~1 h.

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