Ultrasonic-assisted peanut crude oil hydration degumming method

Abstract

The invention discloses an ultrasonic-assisted peanut crude oil hydration degumming method, which belongs to the technical field of food processing, and comprises the following steps: (1) peanut crude oil hydration degumming treatment; (2) ultrasonic-assisted treatment; (3) centrifugally separating to remove phospholipid; and (4) determining the phosphorus content in the degummed oil. According to the method, non-hydrated phospholipids are promoted to be converted into hydrated phospholipids by utilizing the cavitation effect of ultrasonic waves. Meanwhile, the contact area between the crude oil and water is increased through ultrasonic treatment, so that hydrated phospholipid and other impurities in the crude oil are more easily dissolved in water and are removed through water absorption swelling centrifugal separation, and the degumming rate is increased by 27.43% compared with that of only hydration degumming treatment. According to the invention, grease loss is reduced, grease quality is enhanced, and green degumming efficiency of grease and improvement of oil yield of a degumming section are realized.

Description

Technical Field

[0001] The invention relates to an ultrasound-assisted hydration degumming method for peanut crude oil, belonging to the technical field of food processing. Background Art

[0002] Crude oil is obtained by pressing or extracting oil, which contains a large amount of impurities such as phospholipids, pigments, natural toxins, etc., so it cannot be used directly for consumption. Crude oil can only be used for consumption after refining. Traditional oil refining mainly includes four stages: degumming, deacidification, decolorization and deodorization. The process of removing phospholipids and other gums in vegetable oil is called degumming.

[0003] Degumming is the first and most important step in oil refining, and has a great impact on subsequent refining. In the degumming process, the presence of phospholipids will cause the emulsification of oil, increase the refining consumption and the amount of alkali used; in the decolorization process, it will also increase the amount of decolorizer and oil consumption, and make filtration difficult; in the deodorization stage, the presence of phospholipids will increase the peroxide value of the "deodorized" oil, deteriorate the stability, and produce "reverse color" and "reverse taste". In addition, the presence of phospholipids will make it very difficult to dewax some vegetable oils. It hinders the crystallization of solid wax at low temperatures and increases the loss of oil. Therefore, when producing high-quality edible oils, it must be removed through the degumming and refining process. The phospholipids in vegetable oils can be divided into two categories according to their hydrophilicity: hydrated phospholipids and non-hydrated phospholipids. Due to their hydrophilicity, hydrated phospholipids will absorb water and swell and precipitate by adding water and mixing during the degumming process, while non-hydrated phospholipids need to be converted into hydrated phospholipids and removed.

[0004] In recent years, ultrasonic technology has been more and more widely used in the fields of food, medicine, etc. Compared with the traditional hydration degumming method of vegetable oil, the cavitation effect of ultrasonic wave can significantly increase the degumming speed of oil and fat, and has no significant effect on the fatty acid composition of oil and fat. Therefore, the present invention introduces ultrasonic wave into the hydration degumming process of peanut crude oil, in order to improve the degumming effect of peanut crude oil. Summary of the invention

[0005] The purpose of the present invention is to overcome the problem of low degumming efficiency during traditional hydration degumming of crude peanut oil, and to provide a method for hydration degumming of crude peanut oil assisted by ultrasound. The technical scheme adopted is as follows:

[0006] (1) Weigh 30 g of crude peanut oil, heat it to 65-75° C., heat distilled water to the same temperature as the crude oil, add 9% by mass of distilled water to the crude oil, and stir to hydrate the crude peanut oil for 20-30 minutes;

[0007] (2) Ultrasonic treatment at a power of 65 W and a temperature of 65-75°C for 10-20 min;

[0008] (3) After the ultrasonic treatment, the mixture was allowed to stand for 30 min and centrifuged at 5000 r / min for 10 min to obtain the upper layer of oil;

[0009] (4) removing water from the upper oil layer by rotary evaporation at 0.09 MPa and 70°C;

[0010] (5) Determine the phosphorus content in accordance with GB / T5537-2008 “Determination of phospholipid content in grain and oil inspection” and calculate the degumming rate.

[0011] Further preferably, the hydration temperature in step (1) is 75°C;

[0012] More preferably, the stirring and hydration time in step (1) is 30 min;

[0013] Further preferably, the ultrasonic power in step (2) is 65 W, the ultrasonic temperature is 75 ° C, and the ultrasonic treatment time is 15 min;

[0014] Further preferably, the preferred parameters of the centrifugal treatment in step (3) are: centrifugal speed of 5000 r / min, and centrifugal time of 10 min.

[0015] Beneficial effects of the present invention: The present invention introduces ultrasound on the basis of hydration degumming. As a physical means, ultrasound produces a cavitation effect when acting on a liquid system, and the formed micro-jet can produce stirring and shearing effects on the interface to increase the mass transfer power in the reaction process, increase the interface area, greatly promote the transformation of non-hydratable phospholipids to hydratable phospholipids, enhance the degumming effect, not only reduce the loss of neutral oil in oil refining, improve the oil yield, but also have important application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Attached Figure 1 :Ultrasound-assisted hydration degumming process flow chart of peanut oil

[0017] Attached Figure 2 :Photos of degummed oil after different treatment methods (a-crude peanut oil; b-hydration degummed oil; c-ultrasound-assisted hydration degummed oil)

[0018] Attached Figure 3 :Effects of different treatment methods on degumming rate of peanut crude oil DETAILED DESCRIPTION

[0019] The present invention measures the degumming effect by the phosphorus content in the crude peanut oil after degumming, and the phosphorus content in the sample is determined in accordance with GB / T 5537-2008 "Determination of Phospholipid Content in Cereals and Oils Inspection". In order to make the purpose, technical scheme and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with specific examples, but the present invention is not limited to the following examples:

[0020] The main raw materials, reagents and experimental equipment used in the examples are as follows:

[0021] (1) Main raw materials and reagents: peanut oil, zinc oxide, hydrochloric acid, sulfuric acid, hydrazine sulfate, sodium molybdate, etc.;

[0022] (2) Experimental equipment: ultrasonic cell disruptor, water bath, blender, small electric furnace, muffle furnace, UV spectrophotometer.

[0023] Comparison example

[0024] (1) Weigh 30 g of crude peanut oil in a beaker and heat it to 45° C. After distilled water is heated to the same temperature as the crude oil, weigh 5% by mass of distilled water and add it to the crude oil, stir to hydrate it for 30 minutes, let it stand and cool for 30 minutes, and then centrifuge it at 5000 r / min for 10 minutes; remove the water from the upper oil layer by rotary evaporation at 0.09 MPa and 70° C.; take 3 g of the oil phase and determine the phosphorus content according to GB / T 5537-2008 "Determination of phospholipid content in grain and oil inspection", and calculate the degumming rate.

[0025] Example 1

[0026] (1) Weigh 30 g of crude peanut oil in a beaker and heat it to 65° C. After heating distilled water to the same temperature as the crude oil, weigh 6% of distilled water by mass and add it to the crude oil, stir and hydrate it for 30 min; after hydration, let it cool, use ultrasonic treatment with a power of 65 W, a temperature of 65° C., and a time of 10 min, let it stand for 30 min, and then centrifuge it at 5000 r / min for 10 min; remove the water from the upper oil layer by rotary evaporation at 0.09 MPa and 70° C.; take 3 g of the oil phase and determine the phosphorus content according to GB / T5537-2008 "Determination of phospholipid content in grain and oil inspection", and calculate the degumming rate.

[0027] Example 2

[0028] (2) Weigh 30 g of crude peanut oil in a beaker and heat it to 65°C. Heat distilled water to the same temperature as the crude oil, weigh 7% by mass of distilled water and add it to the crude oil, stir and hydrate it for 30 min; after hydration, let it cool, use ultrasonic treatment with a power of 65 W, a temperature of 65°C, and a time of 10 min, let it stand for 30 min, and then centrifuge it at 5000 r / min for 10 min; remove the water from the upper oil layer by rotary evaporation at 0.09 MPa and 70°C; take 3 g of the oil phase and determine the phosphorus content in accordance with GB / T5537-2008 "Determination of phospholipid content in grain and oil inspection", and calculate the degumming rate.

[0029] Example 3

[0030] (3) Weigh 30 g of crude peanut oil in a beaker and heat it to 65° C. Heat distilled water to the same temperature as the crude oil, weigh 9% by mass of distilled water and add it to the crude oil, stir and hydrate it for 30 min; after hydration, cool it down, use ultrasonic treatment with a power of 65 W, a temperature of 65° C., and a time of 10 min, let it stand for 30 min, and then centrifuge it at 5000 r / min for 10 min; remove the water from the upper oil layer by rotary evaporation at 0.09 MPa and 70° C.; take 3 g of the oil phase and determine the phosphorus content according to GB / T5537-2008 "Determination of phospholipid content in grain and oil inspection", and calculate the degumming rate.

[0031] Example 4

[0032] (4) Weigh 30 g of crude peanut oil in a beaker and heat it to 65° C. Heat distilled water to the same temperature as the crude oil, weigh 8% by mass of distilled water and add it to the crude oil, stir and hydrate it for 30 min; after hydration, let it cool, use ultrasonic treatment with a power of 65 W, a temperature of 65° C., and a time of 10 min, let it stand for 30 min, and then centrifuge it at 5000 r / min for 10 min; remove the water from the upper oil layer by rotary evaporation at 0.09 MPa and 70° C.; take 3 g of the oil phase and determine the phosphorus content in accordance with GB / T5537-2008 "Determination of phospholipid content in grain and oil inspection", and calculate the degumming rate.

[0033] Example 5

[0034] (5) Weigh 30 g of crude peanut oil in a beaker and heat it to 75°C. Heat distilled water to the same temperature as the crude oil, weigh 8% by mass of distilled water and add it to the crude oil, and stir to hydrate it for 30 minutes; after hydration, let it cool, use ultrasonic treatment with a power of 65W, a temperature of 75°C, and a time of 15 minutes, let it stand for 30 minutes, and then centrifuge it at 5000r / min for 10 minutes; remove the water from the upper oil layer by rotary evaporation at 0.09Mpa and 70°C; take 3 g of the oil phase and determine the phosphorus content in accordance with GB / T5537-2008 "Determination of phospholipid content in grain and oil inspection", and calculate the degumming rate.

[0035] Example 6

[0036] (6) Weigh 30 g of crude peanut oil in a beaker and heat it to 75° C. Heat distilled water to the same temperature as the crude oil, weigh 8% by mass of distilled water and add it to the crude oil, and stir to hydrate it for 30 minutes; after hydration, let it cool, use ultrasonic treatment with a power of 65 W, a temperature of 75° C., and a time of 10 minutes, let it stand for 30 minutes, and then centrifuge it at 5000 r / min for 10 minutes; remove the water from the upper oil layer by rotary evaporation at 0.09 MPa and 70° C.; take 3 g of the oil phase and determine the phosphorus content in accordance with GB / T5537-2008 "Determination of phospholipid content in grain and oil inspection", and calculate the degumming rate.

[0037] Example 7

[0038] (7) Weigh 30 g of crude peanut oil in a beaker and heat it to 75°C. Heat distilled water to the same temperature as the crude oil, weigh 8% by mass of distilled water and add it to the crude oil, stirring it for hydration for 30 min; after hydration, let it cool, use ultrasonic treatment with a power of 65 W, a temperature of 85°C, and a time of 20 min, let it stand for 30 min, and then centrifuge it at 5000 r / min for 10 min; remove the water from the upper oil layer by rotary evaporation at 0.09 MPa and 70°C; take 3 g of the oil phase and determine the phosphorus content in accordance with GB / T5537-2008 "Determination of phospholipid content in grain and oil inspection", and calculate the degumming rate.

[0039] Table 1 Degumming effect of peanut crude oil in different embodiments

[0040]

[0041] The control example uses the traditional hydration degumming method to degumming the peanut crude oil, and the degumming rate is 62.35%. Examples 1-7 use ultrasonic treatment with different condition parameters to assist hydration degumming to degumming the peanut crude oil. By comparing the degumming rates of the control example and the examples, it can be clearly seen that under the conditions of Example 5 (water addition amount of 8%, hydration temperature of 75°C, ultrasonic power of 65W, ultrasonic time of 15min), the degumming rate reaches a maximum value of 89.78%, which is 27.43% higher than that of hydration degumming alone, indicating that applying ultrasonic treatment during the degumming process of peanut crude oil can significantly increase the degumming rate of peanut crude oil.

[0042] In summary, the present invention effectively improves the degumming rate of peanut crude oil, reduces the phosphorus content in the oil after degumming, improves the color of the oil, and reduces the loss of neutral oil during the refining process by introducing ultrasonic assisted treatment. The present invention improves the grain processing conversion rate, promotes the improvement of the overall quality level of oil, and realizes the improvement of the green degumming efficiency of oil and the oil yield of the degumming section.

[0043] The above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the embodiments here. Any obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. A method for ultrasonic-assisted hydration degumming of peanut crude oil, characterized in that: The following steps are involved: (1) Weigh 30 g of crude peanut oil, heat it to 65-75° C., heat distilled water to the same temperature as the crude oil, add 9% by mass of distilled water to the crude oil, stir with a DJ1C-100W power-enhancing electric stirrer, and hydrate the crude peanut oil for 25-30 minutes; (2) Ultrasonic treatment at a power of 65 W and a temperature of 65-75°C for 10-20 min; (3) After the ultrasonic treatment, the mixture was allowed to stand for 30 min and centrifuged at 5000 r / min for 10 min to obtain the upper layer of oil; (4) removing water from the upper layer of oil by rotary evaporation at 0.09 MPa and 70°C; (5) Determine the phosphorus content in accordance with GB / T 5537-2008 “Determination of phospholipid content in grain and oil inspection” and calculate the degumming rate.

2. The method according to claim 1, characterized in that: The preferred parameters of step (1) are: heating the crude peanut oil to 75° C. and adding distilled water at the same temperature for hydration.

3. The method according to claim 1, characterized in that The preferred parameters of step (1) are: stirring and hydration time is 30 min.

4. The method according to claim 1, characterized in that: The preferred parameters of the ultrasonic treatment in step (2) are: ultrasonic power of 65 W, ultrasonic temperature of 75° C., and ultrasonic time of 15 min.

5. The method according to claim 1, characterized in that The preferred parameters of the centrifugal treatment in step (3) are: centrifugal speed of 5000 r / min, and centrifugal time of 10 min.

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