Degumming process of fen-flavor rapeseed oil

Abstract

The invention discloses a degumming process of fen-flavor rapeseed oil, which belongs to the technical field of food processing and comprises the following steps: (1) hydrating and degumming rapeseed crude oil; (2) ultrasonic-assisted treatment; (3) centrifugally separating to remove phospholipid; (4) water removal treatment; and (5) determining the phosphorus content in the degummed oil. Based on the cavitation effect of ultrasonic waves, the movement speed of substance particles can be accelerated when the ultrasonic waves propagate in liquid, and therefore many physical and chemical processes are completed in an accelerated mode. Meanwhile, non-hydrated phospholipids can be converted into hydrated phospholipids through ultrasonic waves, the hydrated phospholipids are removed through hydration, and compared with hydration degumming, the degumming rate is increased by 23.81%. According to the method, the phosphorus content in the degummed oil is reduced, the degumming rate is increased, the influence of the phosphorus content in the oil on the subsequent refining link is reduced, and the oil quality is enhanced.

Description

Technical Field

[0001] The invention relates to a degumming process of a light-fragrant flavor rapeseed oil, belonging to the technical field of food processing. Background Art

[0002] The main methods for preparing rapeseed oil are solvent extraction and physical pressing. The rapeseed oil prepared by these methods is usually crude oil. Crude rapeseed oil contains a large amount of phospholipids and cannot be eaten directly. It must be refined before it can be eaten. Traditional oil refining includes four steps: degumming, deacidification, decolorization and deodorization. Degumming is the first and most important step in oil refining, which has an important impact on subsequent refining steps.

[0003] In the alkali refining and deacidification process, if the oil contains more phospholipids, the phospholipids will undergo saponification reaction under the action of alkaline medium, thereby consuming part of the alkali and reducing the deacidification effect; in addition, the phospholipids in the crude oil will chelate with the metal ions in the oil to generate some difficult-to-remove melanin, such as amino sugars, which not only increases the difficulty of decolorization, but also deteriorates the quality of the oil; in industry, the deodorization temperature of oil is relatively high (about 260°C), and the phospholipids are thermally decomposed and converted into many non-volatile substances during the deodorization process, which remain in the oil, thereby affecting the stability of the deodorized oil. At the same time, phospholipids will coke and turn black at high temperatures, thereby deepening the color of the oil. Therefore, in order to improve the quality of edible oil, phospholipids must be removed through the degumming process. The phospholipids in crude oil can be divided into two categories according to their hydrophilicity: hydrated phospholipids and non-hydrated phospholipids. Hydrated phospholipids can be removed by hydration, while non-hydrated phospholipids need to be converted into hydrated phospholipids by physical or chemical methods, so that they absorb water and swell and then are removed by centrifugation.

[0004] In recent years, ultrasound has been used more and more widely in the field of food. Based on the cavitation effect and mechanical effect of ultrasound, it can not only effectively enhance the mass transfer efficiency and accelerate the reaction speed, but also convert non-hydratable phospholipids into hydratable phospholipids, greatly increase the degumming rate, and have no significant effect on the fatty acid composition of oils and fats. Therefore, the present invention introduces ultrasound into the hydration degumming process of crude rapeseed oil, in order to improve the degumming effect of crude rapeseed oil. Summary of the invention

[0005] The purpose of the present invention is to overcome the problem of low degumming efficiency during hydration degumming of traditional crude rapeseed oil, and to provide a degumming process for a fragrant flavored rapeseed oil. The technical scheme adopted is as follows:

[0006] (1) Hydration degumming treatment: weigh 30 g of crude rapeseed oil, heat it to 45-55° C., heat distilled water to the same temperature as the crude oil, add 8% by mass of distilled water to the crude oil, and mechanically stir for 25-30 min to perform hydration degumming treatment on the crude rapeseed oil;

[0007] (2) Ultrasonic-assisted treatment: ultrasonic treatment with a power of 65 W and a temperature of 45-55 °C for 10-20 min;

[0008] (3) Centrifugal separation: 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 oil;

[0009] (4) Water removal treatment: The upper layer of oil was subjected to rotary evaporation at 0.09 MPa and 70 °C to remove water;

[0010] (5) Determination of phosphorus content: 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.

[0011] Further preferably, the hydration temperature in step (1) is 55°C;

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

[0013] Further preferably, the ultrasonic power in step (2) is 65 W, the ultrasonic temperature is 55 ° C, and the ultrasonic treatment time is 10 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: In view of the problem that traditional hydration degumming can only remove hydrated phospholipids in oil and the degumming rate is low, ultrasonic waves are introduced. Ultrasonic waves, as a mechanical wave, will produce cavitation effect when propagating in liquid, promoting the conversion of non-hydratable phospholipids into hydrated phospholipids. At the same time, it can produce stirring and shearing effects on the interface, increase the contact area of ​​oil and water, make the hydrated phospholipids fully absorb water and swell, and be removed by centrifugation, which greatly increases the degumming rate and reduces the influence of phospholipids on subsequent oil refining, and has important application value. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

[0019] The present invention measures the degumming effect by the phosphorus content in the crude rapeseed oil after degumming, and the determination of the phosphorus content in the sample is carried out with reference to GB / T 5537-2008 "Determination of Phospholipid Content in Cereal and Oil Inspection". In order to make the purpose, technical scheme and advantages of the present invention clearer, 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: rapeseed 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 rapeseed oil in a beaker and heat it to 65° 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 rapeseed oil in a beaker and heat it to 65° C. After distilled water is heated to the same temperature as the crude oil, weigh 7% of distilled water by mass and add it to the crude oil, stir and hydrate it for 30 min; after hydration, place it to cool, use ultrasonic treatment with a power of 65 W, a temperature of 65° C., and a time of 10 min, stand it for 30 min, and then centrifuge it at 5000 r / min for 10 min; remove 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 rapeseed oil in a beaker and heat it to 65° C. After heating 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, place it to cool, use ultrasonic treatment with a power of 65 W, a temperature of 65° C., and a time of 10 min, stand it 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.

[0029] Example 3

[0030] (3) Weigh 30 g of crude rapeseed oil in a beaker and heat it to 65° C. After heating distilled water to the same temperature as the crude oil, weigh 9% of distilled water by mass and add it to the crude oil, stirring it for hydration for 30 min; after hydration, place it to cool, use ultrasonic treatment with a power of 65 W, a temperature of 65° C., and a time of 10 min, stand it 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 rapeseed oil in a beaker and heat it to 45° C. After distilled water is heated 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, place it to cool, use ultrasonic treatment with a power of 65 W, a temperature of 45° C., and a time of 10 min, stand it 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.

[0033] Example 5

[0034] (5) Weigh 30 g of crude rapeseed oil in a beaker and heat it to 55° C. After heating 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, place it to cool, use ultrasonic treatment with a power of 65 W, a temperature of 55° C., and a time of 10 min, stand it 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.

[0035] Example 6

[0036] (6) Weigh 30 g of crude rapeseed oil in a beaker and heat it to 55° C. After heating 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, place it to cool, use ultrasonic treatment with a power of 65 W, a temperature of 75° C., and a time of 15 min, stand it 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.

[0037] Example 7

[0038] (7) Weigh 30 g of crude rapeseed oil in a beaker and heat it to 55° C. After heating 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, place it to cool, use ultrasonic treatment with a power of 65 W, a temperature of 55° C., and a time of 20 min, stand it 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.

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

[0040]

[0041] The control example uses the traditional hydration degumming method to degumming rapeseed crude oil, and the degumming rate is 61.68%. Examples 1-7 use ultrasonic treatment with different condition parameters to assist hydration degumming to degumming rapeseed crude oil. By comparing the degumming rates of the control example and the example, it can be clearly seen that under the conditions of Example 5 (water addition amount of 8%, hydration temperature of 55°C, ultrasonic power of 65W, ultrasonic time of 10min), the degumming rate reaches a maximum value of 85.49%, which is 23.81% higher than that of hydration degumming alone, indicating that applying ultrasonic treatment during the degumming process of rapeseed crude oil can significantly increase the degumming rate of rapeseed crude oil.

[0042] In summary, the present invention effectively improves the degumming rate of rapeseed crude oil, reduces the phosphorus content in the oil after degumming, reduces the influence of phospholipids on subsequent refining links, and improves the quality of oil by introducing ultrasonic-assisted treatment. The present invention constructs a green food degumming system, reduces energy consumption, and realizes the maximum and optimal utilization of oil.

[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 degumming process for a light-flavored rapeseed oil, characterized in that: The following steps are involved: (1) Weigh 30 g of crude rapeseed oil, heat it to 45-55° C., heat distilled water to the same temperature as the crude oil, add 8% by mass of distilled water to the crude oil, stir with a DJ1C-100W power-enhancing electric stirrer, and hydrate the crude rapeseed oil for 25-30 minutes; (2) Ultrasonic treatment at a power of 65 W and a temperature of 45-55°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 for the hydration degumming in step (1) are: heating the crude rapeseed oil to 55° C. and adding distilled water at the same temperature to carry out hydration degumming.

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

4. The method according to claim 1, characterized in that The preferred parameters of the ultrasonic treatment in step (3) are: ultrasonic power of 65 W, ultrasonic temperature of 55° C., and ultrasonic time of 10 min.

5. The method according to claim 1, characterized in that The preferred parameters of the centrifugal treatment in step (4) are: centrifugal speed of 5000 r / min, and centrifugal time of 10 min.

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