Preparation method of high-oryzanol rice bran oil
The rice bran oil preparation process using low-temperature extraction and a specific decolorizing agent combination solves the problem of oryzanol loss, achieving efficient preparation of high-oryzanol rice bran oil and improving nutritional value and product stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GAOAN QINGHE GREASE CO LTD
- Filing Date
- 2026-02-28
- Publication Date
- 2026-05-12
AI Technical Summary
In the current rice bran oil preparation process, the content of oryzanol is severely lost, resulting in a reduction in nutritional value. Furthermore, adding natural oryzanol is costly and poses quality problems.
The rice bran oil preparation process was adjusted by employing low-temperature extraction, enzymatic degumming, vacuum decolorization, and a combination of specific decolorizing agents. This included using decolorizing agents such as activated clay, silica gel, and attapulgite, and controlling process parameters such as temperature and vacuum level to ensure the efficient retention of oryzanol.
It significantly increases the oryzanol content in rice bran oil to over 2.3%, reduces production costs, meets health and nutrition standards, and has good product stability.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of rice bran oil preparation technology, specifically relating to a method for preparing high-oryzanol rice bran oil. Background Technology
[0002] Rice bran oil is rich in unsaturated fatty acids, with oleic acid, linoleic acid, and linolenic acid accounting for over 80%, primarily oleic and linoleic acid. Refined rice bran oil contains approximately 38% linoleic acid and 42% oleic acid, a ratio close to 1:1, meeting the World Health Organization's recommended optimal oleic acid-to-linoleic acid ratio. From a modern nutritional perspective, this ratio of oil has high nutritional value and is known internationally as a "healthy and nutritious oil." Oryzanol content is a key nutritional indicator of rice bran oil, due to its various active functions such as anti-inflammatory, lipid-lowering, and nerve-regulating properties. Crude rice bran oil contains 1.5%-3% oryzanol, but after physical / chemical refining processes, only 0.6%-1.8% of oryzanol remains in the finished product, significantly reducing its nutritional value. Because oryzanol is highly sensitive to light, heat, and oxygen, it is easily decomposed. In the degumming stage of rice bran oil production, traditional acid degumming leads to oryzanol decomposition. In the deacidification stage, because oryzanol is acidic, it easily reacts with alkali during alkali refining, entering the soapberry phase. The adsorbents used in decolorization also adsorb some oryzanol, and the high-temperature deodorization process easily results in significant oryzanol loss. Currently, many studies are being conducted to reduce oryzanol loss during rice bran oil refining and retain more nutrients.
[0003] For example, Chinese Patent Publication No. CN121249434A discloses a method for producing extra-high oryzanol rice bran oil. This method includes the following steps: adding wood-based activated carbon to deacidified oil for oryzanol adsorption; filtering to obtain high-oryzanol activated carbon; adding food-grade ethanol to the high-oryzanol activated carbon and stirring to remove the solid phase of the activated carbon, obtaining an ethanol eluent containing oryzanol; mixing the ethanol eluent with the deacidified oil, and then evaporating the ethanol to obtain an intermediate product of extra-high oryzanol rice bran oil; subjecting the intermediate product to secondary decolorization, physical deodorization, and winterization degreasing to obtain the finished extra-high oryzanol rice bran oil. This invention enables the simultaneous and stable production of extra-high oryzanol rice bran oil with an oryzanol content ≥4% (40000ppm) and light-colored rice bran oil with a color conforming to the national standard GB19112 Grade 1 for rice bran oil. The method is simple, safe, and inexpensive. However, this method involves first extracting oryzanol from rice bran and then mixing it with low-oryzanol rice bran oil in a certain proportion to increase the oryzanol content. The process is similar to directly adding natural oryzanol, but the cost also increases due to the increased production steps.
[0004] Another method is to add natural oryzanol to rice bran oil, but this method has the following drawbacks: (a) Natural oryzanol is expensive, which greatly increases the processing cost of rice bran oil (for example, adding 1% oryzanol is equivalent to increasing the cost of rice bran oil by about 5,000 yuan / ton); (b) There are potential product quality problems. Rice bran oil with added oryzanol is prone to secondary precipitation of oryzanol during storage.
[0005] Therefore, it is essential to find a reasonable and effective method for preparing rice bran oil with high oryzanol content, which can significantly increase the oryzanol content in the finished rice bran oil and enhance its nutritional components. Summary of the Invention
[0006] To address the shortcomings of existing technologies, this invention provides a method for preparing high-oryzanol rice bran oil. By adjusting the rice bran oil preparation process and using a self-made decolorizing agent, the retention rate of oryzanol is significantly improved, increasing the oryzanol content in the rice bran oil from the original 0.6-1.8% to over 2.3%. To achieve the above objective, the technical solution of this invention is as follows: A method for preparing high-oryzanol rice bran oil, using purified rice bran as raw material, includes the following steps: (1) Preparation of crude rice bran oil: The rice bran after impurity removal is washed and dried, and the mixed oil is obtained by low-temperature extraction, and then the crude rice bran oil is obtained by solvent oil separation. (2) Degumming: After the crude rice bran oil is heated to 50-60℃ by a heater, it is pumped into a degumming reactor, then phospholipase is added and stirred. After being fully mixed, it is heated to 85-92℃ by a heater, and then deionized water of the same temperature is added for hydration and degumming to obtain degummed oil. (3) Dehydration: Dehydrate the degummed oil under vacuum conditions to reduce the moisture content to below 0.1%. After dehydration, cool the oil temperature to below 65°C under vacuum conditions. (4) Decolorization: The dehydrated rice bran oil is heated to 80-90℃ and then introduced into a vacuum decolorization tower for vacuum decolorization. The vacuum degree of vacuum decolorization is maintained above 0.07 MPa. Then, a decolorizing agent is added to the dehydrated rice bran oil for decolorization. After decolorization, the decolorized oil is filtered. (5) Deacidification: After being preheated by a heat exchanger, the decolorized oil enters the physical deacidification tower for physical deacidification to produce deacidified oil; (6) Dewaxing: The deacidified oil is poured into the crystallization tank for cooling. At the same time, the rice bran oil in the crystallization tank is stirred at a stirring speed of 20-30 r / min, so that the temperature of the rice bran oil is evenly reduced to 23-26℃ within 10-12 hours. Then, the stirring is continued at the above speed and the oil temperature is kept constant for crystal growth. After crystal growth, the high oryzanol rice bran oil is obtained by low-temperature filtration.
[0007] Preferably, the low-temperature extraction temperature in step (1) is 15-20℃.
[0008] Preferably, in step (2), the amount of phospholipase added is 65ppm-70ppm of the mass of crude rice bran oil, and the amount of deionized water added is 4-6% of the mass of crude rice bran oil.
[0009] Preferably, the vacuum conditions in step (3) are a temperature of 80-90℃ and a vacuum degree greater than 0.06 MPa.
[0010] Preferably, the decolorizing agent in step (4) is a mixture of activated clay, silica gel, attapulgite, and activated carbon in a mass ratio of 2-3:1-2:3-4:1.
[0011] Preferably, the amount of decolorizing agent used in step (4) is 3-4% of the mass of the dehydrated rice bran oil.
[0012] Preferably, the decolorization time in step (4) is 20-30 minutes.
[0013] Preferably, in step (5), the temperature of the deacidification tower is 240-250℃, the pressure is -0.1mpa, and the deacidification time is 60-80 minutes.
[0014] Preferably, the crystal growth time in step (6) is 60-70 hours.
[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention utilizes a low-temperature extraction process to achieve a oryzanol retention rate of over 97% in crude rice bran oil. An enzymatic degumming process further enhances the oryzanol retention rate to over 96%. During the decolorization stage, activated clay removes most natural pigments, while silica gel adsorbs phospholipids, saponifications, and other processing pigments. Attapulgite clay reduces the adsorption of nutrients such as oryzanol and sterols, significantly preserving the oryzanol in rice bran oil. This invention can stably produce products with an oryzanol content of over 2.3%, higher than the maximum oryzanol content of 1.8% currently labeled on commercially available rice bran oil. This effectively reduces daily fat intake while maintaining the same efficacy, aligning with current societal advocacy for low-oil and low-salt diets. Detailed Implementation
[0016] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. 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. Example
[0017] A method for preparing high-oryzanol rice bran oil, using purified rice bran as raw material, includes the following steps: (1) Preparation of crude rice bran oil: The rice bran after impurity removal is washed and dried, and the mixed oil is obtained by low temperature extraction at 20℃, and then the crude rice bran oil is obtained by solvent oil separation. (2) Degumming: After the crude rice bran oil is heated to 55°C by a heater, it is pumped into a degumming reactor. Then, phospholipase is added and stirred. The amount of phospholipase added is 65 ppm of the mass of the crude rice bran oil. After thorough mixing, it is heated to 88°C by a heater. Then, deionized water at the same temperature is added for hydration and degumming. The amount of deionized water added is 6% of the mass of the crude rice bran oil, and degummed oil is obtained. (3) Dehydration: Dehydrate the degummed oil under vacuum conditions. The vacuum conditions are 85°C and the vacuum degree is greater than 0.06 MPa. Reduce the moisture content to below 0.1%. After dehydration, cool the oil temperature to below 65°C under vacuum. (4) Decolorization: The dehydrated rice bran oil is heated to 86°C and then introduced into a vacuum decolorization tower for vacuum decolorization. The vacuum degree is maintained above 0.07 MPa. Then, a decolorizing agent is added to the dehydrated rice bran oil for decolorization. The amount of decolorizing agent is 4% of the mass of the dehydrated rice bran oil. The decolorizing agent is a mixture of activated clay, silica gel, attapulgite clay and activated carbon in a mass ratio of 2:1:3:1. The decolorization time is 20 minutes. After decolorization, the decolorized oil is obtained by filtration. (5) Deacidification: After being preheated by a heat exchanger, the decolorized oil enters the physical deacidification tower for physical deacidification. The temperature of the deacidification tower is 240℃, the pressure is -0.1mpa, the deacidification time is 60 minutes, and deacidified oil is produced. (6) Dewaxing: The deacidified oil is poured into the crystallization tank for cooling. At the same time, the rice bran oil in the crystallization tank is stirred at a stirring speed of 20 r / min so that the temperature of the rice bran oil is uniformly reduced to 24°C within 10 hours. Then, the stirring is continued at the above speed and the oil temperature is kept constant for crystal growth. The crystal growth time is 62 hours. After the crystal growth is completed, the high oryzanol rice bran oil is obtained by low-temperature filtration. Example
[0018] A method for preparing high-oryzanol rice bran oil, using purified rice bran as raw material, includes the following steps: (1) Preparation of crude rice bran oil: The rice bran after impurity removal is washed and dried, and the mixed oil is obtained by low temperature extraction at 20℃, and then the crude rice bran oil is obtained by solvent oil separation. (2) Degumming: After the crude rice bran oil is heated to 55°C by a heater, it is pumped into a degumming reactor. Then, phospholipase is added and stirred. The amount of phospholipase added is 65 ppm of the mass of the crude rice bran oil. After thorough mixing, it is heated to 88°C by a heater. Then, deionized water at the same temperature is added for hydration and degumming. The amount of deionized water added is 6% of the mass of the crude rice bran oil, and degummed oil is obtained. (3) Dehydration: Dehydrate the degummed oil under vacuum conditions. The vacuum conditions are 85°C and the vacuum degree is greater than 0.06 MPa. Reduce the moisture content to below 0.1%. After dehydration, cool the oil temperature to below 65°C under vacuum. (4) Decolorization: The dehydrated rice bran oil is heated to 86°C and then introduced into a vacuum decolorization tower for vacuum decolorization. The vacuum degree is maintained above 0.07 MPa. Then, a decolorizing agent is added to the dehydrated rice bran oil for decolorization. The amount of decolorizing agent is 3.5% of the mass of the dehydrated rice bran oil. The decolorizing agent is a mixture of activated clay, silica gel, attapulgite clay and activated carbon in a mass ratio of 2:1:3:1. The decolorization time is 25 minutes. After decolorization, the decolorized oil is obtained by filtration. (5) Deacidification: After being preheated by a heat exchanger, the decolorized oil enters the physical deacidification tower for physical deacidification. The temperature of the deacidification tower is 245℃, the pressure is -0.1mpa, the deacidification time is 60 minutes, and deacidified oil is produced. (6) Dewaxing: The deacidified oil is poured into the crystallization tank for cooling. At the same time, the rice bran oil in the crystallization tank is stirred at a stirring speed of 25 r / min so that the temperature of the rice bran oil is uniformly reduced to 24°C within 10 hours. Then, the stirring is continued at the above speed and the oil temperature is kept constant for crystal growth. The crystal growth time is 62 hours. After the crystal growth is completed, the high oryzanol rice bran oil is obtained by low-temperature filtration.
[0019] Comparative Example 1 A method for preparing high-oryzanol rice bran oil, using purified rice bran as raw material, includes the following steps: (1) Preparation of crude rice bran oil: The rice bran after impurity removal is washed and dried, and the mixed oil is obtained by low temperature extraction at 20℃, and then the crude rice bran oil is obtained by solvent oil separation. (2) Degumming: After the crude rice bran oil is heated to 55°C by a heater, it is pumped into a degumming reactor. Then, phospholipase is added and stirred. The amount of phospholipase added is 65 ppm of the mass of the crude rice bran oil. After thorough mixing, it is heated to 95°C by a heater. Then, deionized water at the same temperature is added for hydration and degumming. The amount of deionized water added is 6% of the mass of the crude rice bran oil, and degummed oil is obtained. (3) Dehydration: Dehydrate the degummed oil under vacuum conditions. The vacuum conditions are 85°C and the vacuum degree is greater than 0.06 MPa. Reduce the moisture content to below 0.1%. After dehydration, cool the oil temperature to below 65°C under vacuum. (4) Decolorization: The dehydrated rice bran oil is heated to 85°C and then introduced into a vacuum decolorization tower for vacuum decolorization. The vacuum degree is maintained above 0.07 MPa. Then, a decolorizing agent is added to the dehydrated rice bran oil for decolorization. The amount of decolorizing agent is 4% of the mass of the dehydrated rice bran oil. The decolorizing agent is a mixture of activated clay, silica gel, attapulgite clay and activated carbon in a mass ratio of 2:1:3:1. The decolorization time is 20 minutes. After decolorization, the decolorized oil is obtained by filtering through a closed bottom discharge filter. (5) Deacidification: After being preheated by a heat exchanger, the decolorized oil enters the physical deacidification tower for physical deacidification. The temperature of the deacidification tower is 280℃, the pressure is -0.1mpa, the deacidification time is 60 minutes, and deacidified oil is produced. (6) Dewaxing: The deacidified oil is poured into the crystallization tank for cooling. At the same time, the rice bran oil in the crystallization tank is stirred at a stirring speed of 20 r / min so that the temperature of the rice bran oil is uniformly reduced to 23°C within 10 hours. Then, the stirring is continued at the above speed and the oil temperature is kept constant for crystal growth. The crystal growth time is 63 hours. After the crystal growth is completed, the high oryzanol rice bran oil is obtained by low-temperature filtration.
[0020] Comparative Example 2 A method for preparing high-oryzanol rice bran oil, using purified rice bran as raw material, includes the following steps: (1) Preparation of crude rice bran oil: The rice bran after impurity removal is washed and dried, and mixed oil is obtained by solvent extraction, and then crude rice bran oil is obtained by solvent oil separation. (2) Degumming: After the crude rice bran oil is heated to 38°C by a heater, it is pumped into a degumming reactor. Then, phospholipase is added and stirred. The amount of phospholipase added is 65 ppm of the mass of the crude rice bran oil. After thorough mixing, it is heated to 88°C by a heater. Then, deionized water at the same temperature is added for hydration and degumming. The amount of deionized water added is 6% of the mass of the crude rice bran oil, and degummed oil is obtained. (3) Dehydration: Dehydrate the degummed oil under vacuum conditions. The vacuum conditions are 85°C and the vacuum degree is greater than 0.06 MPa. Reduce the moisture content to below 0.1%. After dehydration, cool the oil temperature to below 65°C under vacuum. (4) Decolorization: The dehydrated rice bran oil is heated to 86°C and then introduced into a vacuum decolorization tower for vacuum decolorization. The vacuum degree is maintained above 0.07 MPa. Then, a decolorizing agent is added to the dehydrated rice bran oil for decolorization. The amount of decolorizing agent is 4% of the mass of the dehydrated rice bran oil. The decolorizing agent is a mixture of activated clay, silica gel, attapulgite clay and activated carbon in a mass ratio of 2:1:3:1. The decolorization time is 20 minutes. After decolorization, the decolorized oil is obtained by filtration. (5) Deacidification: After being preheated by a heat exchanger, the decolorized oil enters the physical deacidification tower for physical deacidification. The temperature of the deacidification tower is 240℃, the pressure is -0.1mpa, the deacidification time is 60 minutes, and deacidified oil is produced. (6) Dewaxing: The deacidified oil is poured into the crystallization tank for cooling. At the same time, the rice bran oil in the crystallization tank is stirred at a stirring speed of 20 r / min so that the temperature of the rice bran oil is uniformly reduced to 24°C within 10 hours. Then, the stirring is continued at the above speed and the oil temperature is kept constant for crystal growth. The crystal growth time is 62 hours. After the crystal growth is completed, the high oryzanol rice bran oil is obtained by low-temperature filtration.
[0021] Comparative Example 3 A method for preparing high-oryzanol rice bran oil, using purified rice bran as raw material, includes the following steps: (1) Preparation of crude rice bran oil: The rice bran after impurity removal is washed and dried, and the mixed oil is obtained by low temperature extraction at 20℃, and then the crude rice bran oil is obtained by solvent oil separation. (2) Degumming: After the crude rice bran oil is heated to 55°C by a heater, it is pumped into a degumming reactor. Then, phospholipase is added and stirred. The amount of phospholipase added is 65 ppm of the mass of the crude rice bran oil. After thorough mixing, it is heated to 88°C by a heater. Then, deionized water at the same temperature is added for hydration and degumming. The amount of deionized water added is 6% of the mass of the crude rice bran oil, and degummed oil is obtained. (3) Dehydration: Dehydrate the degummed oil under vacuum conditions. The vacuum conditions are 85°C and the vacuum degree is greater than 0.06 MPa. Reduce the moisture content to below 0.1%. After dehydration, cool the oil temperature to below 65°C under vacuum. (4) Decolorization: The dehydrated rice bran oil is heated to 86°C and then introduced into a vacuum decolorization tower for vacuum decolorization. The vacuum degree is maintained above 0.07 MPa. Then, a decolorizing agent is added to the dehydrated rice bran oil for decolorization. The amount of decolorizing agent is 4% of the mass of the dehydrated rice bran oil. The decolorizing agent is activated clay. The decolorization time is 20 minutes. After decolorization, the decolorized oil is obtained by filtration. (5) Deacidification: After being preheated by a heat exchanger, the decolorized oil enters the physical deacidification tower for physical deacidification. The temperature of the deacidification tower is 240℃, the pressure is -0.1mpa, the deacidification time is 60 minutes, and deacidified oil is produced. (6) Dewaxing: The deacidified oil is poured into the crystallization tank for cooling. At the same time, the rice bran oil in the crystallization tank is stirred at a stirring speed of 20 r / min so that the temperature of the rice bran oil is uniformly reduced to 24°C within 10 hours. Then, the stirring is continued at the above speed and the oil temperature is kept constant for crystal growth. The crystal growth time is 62 hours. After the crystal growth is completed, the high oryzanol rice bran oil is obtained by low-temperature filtration.
[0022] Comparative Example 4 A method for preparing high-oryzanol rice bran oil, using purified rice bran as raw material, includes the following steps: (1) Preparation of crude rice bran oil: The rice bran after impurity removal is washed and dried, and the mixed oil is obtained by low temperature extraction at 20℃, and then the crude rice bran oil is obtained by solvent oil separation. (2) Degumming: After the crude rice bran oil is heated to 55°C by a heater, it is pumped into a degumming reactor. Then, phospholipase is added and stirred. The amount of phospholipase added is 65 ppm of the mass of the crude rice bran oil. After thorough mixing, it is heated to 88°C by a heater. Then, deionized water at the same temperature is added for hydration and degumming. The amount of deionized water added is 6% of the mass of the crude rice bran oil, and degummed oil is obtained. (3) Dehydration: Dehydrate the degummed oil under vacuum conditions. The vacuum conditions are 85°C and the vacuum degree is greater than 0.06 MPa. Reduce the moisture content to below 0.1%. After dehydration, cool the oil temperature to below 65°C under vacuum. (4) Decolorization: The dehydrated rice bran oil is heated to 86°C and then introduced into a vacuum decolorization tower for vacuum decolorization. The vacuum degree is maintained above 0.07 MPa. Then, a decolorizing agent is added to the dehydrated rice bran oil for decolorization. The amount of decolorizing agent is 4% of the mass of the dehydrated rice bran oil. The decolorizing agent is a mixture of activated clay and activated carbon in a mass ratio of 2:1. The decolorization time is 20 minutes. After decolorization, the decolorized oil is obtained by filtration. (5) Deacidification: After being preheated by a heat exchanger, the decolorized oil enters the physical deacidification tower for physical deacidification. The temperature of the deacidification tower is 240℃, the pressure is -0.1mpa, the deacidification time is 60 minutes, and deacidified oil is produced. (6) Dewaxing: The deacidified oil is poured into the crystallization tank for cooling. At the same time, the rice bran oil in the crystallization tank is stirred at a stirring speed of 20 r / min so that the temperature of the rice bran oil is uniformly reduced to 24°C within 10 hours. Then, the stirring is continued at the above speed and the oil temperature is kept constant for crystal growth. The crystal growth time is 62 hours. After the crystal growth is completed, the high oryzanol rice bran oil is obtained by low-temperature filtration.
[0023] The content of oryzanol before and after low-temperature extraction in step (1) and before and after degumming in step (2) of Example 1 was detected, and the results are shown in Table 1 below: Table 1
[0024] The high-oryzanol rice bran oils prepared in Examples 1-2 and Comparative Examples 1-4 were tested, and the results are shown in Table 2 below: Table 2
[0025] As shown in Table 2, compared with Comparative Example 1, Example 1 resulted in a significant reduction in oryzanol content in the finished rice bran oil due to the excessively high deacidification temperature causing substantial decomposition of oryzanol. Because Example 1 and Comparative Examples 3-4 used different decolorizing agents, the retention rate of oryzanol during the decolorization process varied considerably. The decolorizing agent used in Example 1 maximized the retention of oryzanol in the rice bran oil. Compared with Comparative Example 2, Example 1 employed low-temperature extraction technology, resulting in a higher oryzanol retention rate and a higher oryzanol content in the finished rice bran oil compared to solvent extraction technology.
[0026] In conclusion, the present invention provides a method for preparing high-oryzanol rice bran oil. By adjusting the parameters of the rice bran oil preparation process and the decolorizing agent, the retention rate of oryzanol can be significantly improved, increasing the oryzanol content in the rice bran oil from the original 0.6-1.8% to over 2.3%.
[0027] The above description is merely an embodiment of the present invention. It should be noted that, for those skilled in the art, various changes, modifications, substitutions and variations can be made to these embodiments without departing from the technical principles of the present invention. These changes, modifications, substitutions and variations should also be considered within the scope of protection of the present invention.
Claims
1. A method for preparing high-oryzanol rice bran oil, wherein the rice bran is purified of impurities as raw material, characterized in that, Includes the following steps: (1) Preparation of crude rice bran oil: The rice bran after impurity removal is washed and dried, and the mixed oil is obtained by low-temperature extraction, and then the crude rice bran oil is obtained by solvent oil separation. (2) Degumming: After the crude rice bran oil is heated to 50-60℃ by a heater, it is pumped into a degumming reactor, then phospholipase is added and stirred. After being fully mixed, it is heated to 85-92℃ by a heater, and then deionized water of the same temperature is added for hydration and degumming to obtain degummed oil. (3) Dehydration: Dehydrate the degummed oil under vacuum conditions to reduce the moisture content to below 0.1%. After dehydration, cool the oil temperature to below 65°C under vacuum conditions. (4) Decolorization: The dehydrated rice bran oil is heated to 80-90℃ and then introduced into a vacuum decolorization tower for vacuum decolorization. The vacuum degree of vacuum decolorization is maintained above 0.07 MPa. Then, a decolorizing agent is added to the dehydrated rice bran oil for decolorization. After decolorization, the decolorized oil is filtered. (5) Deacidification: After being preheated by a heat exchanger, the decolorized oil enters the physical deacidification tower for physical deacidification to produce deacidified oil; (6) Dewaxing: The deacidified oil is poured into the crystallization tank for cooling. At the same time, the rice bran oil in the crystallization tank is stirred at a stirring speed of 20-30 r / min, so that the temperature of the rice bran oil is evenly reduced to 23-26℃ within 10-12 hours. Then, the stirring is continued at the above speed and the oil temperature is kept constant for crystal growth. After crystal growth, the high oryzanol rice bran oil is obtained by low-temperature filtration.
2. The method for preparing high-vitamin Bran Oil according to claim 1, characterized in that, The low-temperature extraction temperature in step (1) is 15-20℃.
3. The method for preparing high-oryzanol rice bran oil according to claim 1, characterized in that, In step (2), the amount of phospholipase added is 65ppm-70ppm of the mass of crude rice bran oil, and the amount of deionized water added is 4-6% of the mass of crude rice bran oil.
4. The method for preparing high-vitamin Bran Oil according to claim 1, characterized in that, In step (3), the vacuum conditions are a temperature of 80-90℃ and a vacuum degree greater than 0.06 MPa.
5. The method for preparing high-vitamin Bran Oil according to claim 1, characterized in that, The decolorizing agent in step (4) is a mixture of activated clay, silica gel, attapulgite clay and activated carbon in a mass ratio of 2-3:1-2:3-4:
1.
6. The method for preparing high-vitamin Bran Oil according to claim 1, characterized in that, In step (4), the amount of decolorizing agent used is 3-4% of the mass of the dehydrated rice bran oil.
7. The method for preparing high-vitamin Bran Oil according to claim 1, characterized in that, The decolorization time in step (4) is 20-30 minutes.
8. The method for preparing high-vitamin Bran Oil according to claim 1, characterized in that, In step (5), the temperature of the deacidification tower is 240-250℃, the pressure is -0.1mpa, and the deacidification time is 60-80 minutes.
9. The method for preparing high-oryzanol rice bran oil according to claim 1, characterized in that, The crystal growth time in step (6) is 60-70 hours.