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CN-122012173-A - Preparation method of oryzanol rice bran oil

CN122012173ACN 122012173 ACN122012173 ACN 122012173ACN-122012173-A

Abstract

The invention discloses a preparation method of oryzanol rice bran oil, which belongs to the technical field of rice bran oil preparation and takes rice bran after impurity removal as a raw material. The invention greatly improves the retention rate of oryzanol by adjusting the preparation process of the rice bran oil and using the self-made decolorizer, so that the oryzanol content in the rice bran oil is improved to more than 2.3 percent from the original 0.6 to 1.8 percent.

Inventors

  • ZHANG WENHAN
  • LIU KAN

Assignees

  • 高安市清河油脂有限公司

Dates

Publication Date
20260512
Application Date
20260228

Claims (9)

  1. 1. The preparation method of the oryzanol rice bran oil takes the rice bran after impurity removal as a raw material and is characterized by comprising the following steps: (1) Preparing rice bran crude oil, namely cleaning and drying the rice bran subjected to impurity removal, extracting at a low temperature to obtain mixed oil, and extracting solvent oil to obtain rice bran crude oil; (2) Degumming, namely heating crude rice bran oil to 50-60 ℃ by a heater, pumping the rice bran oil into a degumming reaction kettle, adding phospholipase to stir, heating the rice bran oil to 85-92 ℃ by the heater after fully mixing, and adding deionized water with the same temperature to carry out hydration degumming to obtain degummed oil; (3) Dewatering, namely dewatering the degummed oil under vacuum condition, reducing the water content to below 0.1%, and cooling the oil temperature to below 65 ℃ under vacuum state after dewatering; (4) Decolorizing by heating dehydrated rice bran oil to 80-90deg.C, vacuum decolorizing in vacuum decolorizing tower with vacuum degree maintained above 0.07mpa, decolorizing by adding decolorizing agent into dehydrated rice bran oil, and filtering to obtain decolorized oil; (5) The deacidification step, namely, the decolored oil is preheated by a heat exchanger and then enters a physical deacidification tower to be subjected to physical deacidification, so as to produce deacidified oil; (6) Dewaxing, namely pumping deacidified oil into a crystallization tank for cooling, stirring rice bran oil in the crystallization tank at the stirring speed of 20-30r/min, uniformly reducing the temperature of the rice bran oil to 23-26 ℃ within 10-12 hours, continuously stirring at the rotating speed, maintaining the temperature unchanged, carrying out crystal growing, and filtering at a low temperature after the crystal growing is finished to obtain the high oryzanol rice bran oil.
  2. 2. The method for preparing rice bran oil containing oryzanol according to claim 1, wherein the low temperature extraction temperature in the step (1) is 15-20 ℃.
  3. 3. The method for preparing rice bran oil with high oryzanol content according to claim 1, wherein the amount of phospholipase added in the step (2) is 65ppm-70ppm of the crude rice bran oil, and the amount of deionized water added is 4-6% of the crude rice bran oil.
  4. 4. The method for preparing rice bran oil containing oryzanol according to claim 1, wherein the vacuum condition in the step (3) is a temperature of 80-90 ℃ and a vacuum degree is more than 0.06mpa.
  5. 5. The preparation method of the oryzanol rice bran oil according to claim 1, wherein the decoloring agent in the step (4) is formed by mixing activated clay, silica gel, attapulgite and activated carbon according to a mass ratio of 2-3:1-2:3-4:1.
  6. 6. The method for preparing rice bran oil containing oryzanol according to claim 1, wherein the amount of the decoloring agent in the step (4) is 3-4% of the mass of the dehydrated rice bran oil.
  7. 7. The method for preparing rice bran oil containing oryzanol according to claim 1, wherein the decoloring time in the step (4) is 20 to 30 minutes.
  8. 8. The method for preparing rice bran oil containing oryzanol according to claim 1, wherein the deacidification tower in the step (5) has a temperature of 240-250 ℃, a pressure of-0.1 mpa and a deacidification time of 60-80 minutes.
  9. 9. The method for preparing rice bran oil containing oryzanol according to claim 1, wherein the crystal growth time in the step (6) is 60-70 hours.

Description

Preparation method of oryzanol rice bran oil Technical Field The invention belongs to the technical field of rice bran oil preparation, and particularly relates to a preparation method of high oryzanol rice bran oil. Background The rice bran oil is rich in unsaturated fatty acid, wherein the content of oleic acid, linoleic acid and linolenic acid is up to more than 80%, the oleic acid and the linoleic acid are mainly, the refined rice bran oil contains about 38% of linoleic acid and about 42% of oleic acid, the ratio of the oleic acid to the linoleic acid is close to 1:1, the best standard of the ratio of oleic acid to linoleic acid recommended by the International health organization is met, and from the viewpoint of modern nutrition, the grease with the ratio has higher nutritive value and is called as 'healthy nutritive oil' abroad. Oryzanol content is a characteristic nutrition index of rice bran oil, and has various active functions of anti-inflammatory, blood lipid reducing, nerve regulating and the like. The oryzanol content in the rice bran crude oil is 1.5% -3%, but the oryzanol remained in the finished rice bran oil is only 0.6% -1.8% after the processing steps of physical refining/chemical refining and the like, so that the nutritional value is greatly reduced. Since oryzanol is sensitive to light, heat and oxygen and is easy to decompose, the oryzanol is decomposed by the traditional acid method in the degumming process of rice bran oil preparation, and the oryzanol is easy to react with alkali to enter the gleditsia sinensis in the deacidification process because the oryzanol is acidic in alkali refining. The adsorbent used in decolorization also adsorbs a part of oryzanol, and a large amount of oryzanol is easily lost due to high temperature treatment of deodorization. There have been many studies to reduce oryzanol loss during rice bran oil refining to preserve more nutrients. For example, chinese patent publication No. CN121249434A discloses a production method of extra-high oryzanol rice bran oil. The method comprises the steps of adding wood activated carbon into deacidified oil, performing oryzanol adsorption operation, filtering to obtain high oryzanol activated carbon, adding food-grade ethanol into the high oryzanol activated carbon, stirring, removing active carbon solid phase to obtain ethanol analysis liquid containing oryzanol, mixing the ethanol analysis liquid with the deacidified oil, evaporating ethanol to obtain an intermediate product of the ultrahigh oryzanol rice bran oil, and performing secondary decolorization, physical deodorization and winterization degreasing on the intermediate product of the ultrahigh oryzanol rice bran oil to obtain the finished product of the ultrahigh oryzanol rice bran oil. The invention can stably produce the ultra-high oryzanol rice bran oil with oryzanol content more than or equal to 4% (40000 ppm) and the light-color rice bran oil with color conforming to national standard GB19112 of rice bran oil, and has simple and safe method and low cost. However, the method is to extract oryzanol from rice bran and mix the oryzanol with low oryzanol rice bran oil according to a certain proportion so as to increase oryzanol content, and the process is similar to that of directly adding natural oryzanol, and meanwhile, the cost is increased due to the increase of production procedures. A further method is to add natural oryzanol to rice bran oil, but this method has the disadvantages that (a) natural oryzanol is expensive, the processing cost of rice bran oil is greatly increased (about 5000 yuan per ton of rice bran oil is increased by taking the addition of 1% oryzanol as an example), and (b) the rice bran oil added with oryzanol has potential product quality problems, and secondary precipitation of oryzanol is easy to occur in the storage process. Therefore, it is necessary to find a reasonable and effective preparation method of rice bran oil with high oryzanol content, which can remarkably improve oryzanol content in the finished rice bran oil and increase nutritional ingredients of the rice bran oil. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a preparation method of high oryzanol rice bran oil, which greatly improves the retention rate of oryzanol by adjusting the preparation process of the rice bran oil and using self-made decolorizer, so that the oryzanol content in the rice bran oil is improved to more than 2.3 percent from original 0.6 to 1.8 percent, and the technical scheme of the invention is as follows: The preparation method of the oryzanol rice bran oil takes the rice bran after impurity removal as a raw material, and comprises the following steps: (1) Preparing rice bran crude oil, namely cleaning and drying the rice bran subjected to impurity removal, extracting at a low temperature to obtain mixed oil, and extracting solvent oil to obtain rice bran crude oil; (2) Degumming, namely heating crude