A method for the production of a rapeseed oil

Abstract

The application discloses a preparation method of rapeseed oil, which comprises the following steps: S1, cleaning and drying; S2, crushing; S3, preparing an enzyme solution; S4, ultrasonic enzymolysis of rapeseed; S5, cold pressing; and S6, refining; the preparation method provided by the application is simple in steps, high in oil yield, and does not need to separately perform the steps of deacidification, deodorization and degumming, so that the processing technology is greatly shortened, and the production cost is reduced; the important nutritional components in the rapeseed can be effectively preserved by using ultrasonic enzymolysis and low-temperature cold pressing, so that the important nutritional components are prevented from being oxidized or damaged by high temperature, and the nutritional value is improved; in addition, the rapeseed oil is pure in color, clear and transparent, and free of peculiar smell.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of edible oil processing, in particular to a preparation method of rapeseed oil. BACKGROUND

[0002] Rapeseed oil, also known as rapeseed oil, rapeseed oil, and canola oil, is one of the main edible oils in China, mainly from the seeds of Brassica napus L. and Brassica campestris L. (containing 22% to 49% oil, with an average of 40%). Rapeseed is one of the main oil crops in China, with an annual output of more than 14.5 million tons nationwide. The human body can absorb up to 99% of rapeseed oil. It has the effects of softening blood vessels and delaying aging, and contains phospholipids and low levels of cholesterol, which can promote the development of blood vessels, nerves, and brain without causing long-term consumption of increased cholesterol levels. The existing rapeseed is processed into rapeseed oil, and the rapeseed oil contains a small amount of erucic acid and sinigrin and other substances. Due to the presence of glucosidase in plants, sinigrin is affected by hydrolysis, and its hydrolysis products contain sulfides such as thiocyanate and isothiocyanate, and nitrile. The thiocyanate and isothiocyanate can cause human goiter by preventing the body's thyroid gland from absorbing iodine. Nitrile can inhibit the growth of animals and cause animal death, and also has a certain effect on the human body, with strong toxicity. Even some sinigrin can cyclize to form oxazolidine thione under certain conditions, which is not conducive to the growth and development of the human body after long-term consumption. Rapeseed oil contains 20% to 50% erucic acid. Studies have shown that animals consuming a considerable amount of erucic acid can cause a large accumulation of triglycerides in the myocardium, with erucic acid as the main component of triglycerides. Long-term infiltration of myocardial mononuclear cells can cause myocardial fibrosis, and even lead to pericardial effusion. In addition, erucic acid can cause liver cirrhosis. Long-term consumption is not conducive to the growth and development of the human body, and the nutritional value is not high. Therefore, we propose a preparation method of rapeseed oil. SUMMARY

[0003] In view of the above defects of the prior art, the present application provides a preparation method of rapeseed oil to solve the problems raised in the background art.

[0004] To achieve the above-mentioned purpose, the present application provides the following technical scheme:

[0005] A preparation method of rapeseed oil, comprising the following steps:

[0006] S1, cleaning and drying: take fresh rapeseed and add 2 to 6 times the amount of water to clean the starch, and then dry to a residual moisture content of 7 to 15%;

[0007] S2, crushing: crushing the rapeseed prepared in step S1, and the particle size after crushing is 70 to 90 mesh;

[0008] S3, enzyme liquid configuration: mixed xylanase, pectinesterase, sulfatase, mannanase according to mass ratio 1-6:1-8:2-8:3-15 into compound enzyme, dissolved the compound enzyme into neutral phosphate buffer to obtain enzyme liquid, wherein the mass ratio of compound enzyme to neutral phosphate buffer is 1-4:2-15;

[0009] S4, rapeseed ultrasonic enzymolysis: the enzyme liquid prepared in step S3 is sprayed into the rapeseed prepared in step S2, the volume ratio of enzyme liquid to rapeseed is 1-3:3-10, and the total mass of 2-6 times of distilled water is added to make it uniform, and ultrasonic assisted enzymolysis treatment is carried out every 90-120 min during enzymolysis; after the enzymolysis is completed, the enzyme is inactivated, first centrifuged at 4000-5000 r / min for 20-30 min to obtain the first bottom residue and the first oil-water mixture, and the first oil-water mixture is continuously centrifuged at 6500-7500 r / min for 20-30 min to obtain the second bottom residue and the second oil-water mixture, and the upper oil layer of the second oil-water mixture is taken to obtain the crude rapeseed oil;

[0010] S5, cold pressing: the first bottom residue and the second bottom residue obtained in step S4 are pressed to obtain crude rapeseed oil, the filter residue feeding temperature is controlled at 35-45℃, the barrel temperature is 60-75℃, the pressure is 20-28Mpa, and the pressing time is 500-800s, and the crude rapeseed oil is filtered;

[0011] S6, refining: taking the crude rapeseed oil prepared in steps S4 and S5, adding 0.1-0.7 times the total mass of activated clay to adsorb the pigment in the oil, and centrifuging at 6000-7000 r / min for 5-10 min to remove the activated clay, and the rapeseed oil is obtained.

[0012] Preferably, in step S1, 4 times the total mass of water starch is added, the water content is 10%, and the water: starch in the water starch is 3:1.

[0013] Preferably, in step S2, the particle size is 80 mesh.

[0014] Preferably, the xylanase is purchased from Guangzhou Huayu Biological Technology Co., Ltd., and is food grade; the pectinesterase is purchased from Yingxin Laboratory, CAS No.: 9025-98-3; the sulfatase is purchased from the brand of Macklin, and the item number is S913859-5KU; and the mannanase is purchased from Shanxi Zhongnuo Biological Technology Co., Ltd.

[0015] Preferably, in step S3, the mass ratio of xylanase, pectinesterase, sulfatase, and mannanase is 3:4:4:9, and the mass ratio of compound enzyme to neutral phosphate buffer is 1:8.

[0016] Preferably, the mass ratio of the enzyme solution to rapeseed in step S4 is 1:6, 3 times the total mass of distilled water is added, and ultrasonic-assisted enzymatic hydrolysis treatment is performed every 100 min; the first oil-water mixture is centrifuged at 4500 r / min for 25 min, and then the first oil-water mixture is centrifuged at 7000 r / min for 25 min.

[0017] Preferably, the feeding temperature in step S5 is controlled at 40℃, the barrel temperature is 70℃, the pressure is 25Mpa, and the pressing time is 700s.

[0018] Preferably, in step S6, 0.5 times the total mass of activated clay is added, and centrifugation is performed at 6500 r / min for 8 min.

[0019] Compared with the prior art, the beneficial effects of the present application are: the present application discloses a preparation method of rapeseed oil, the preparation method provided by the present application has simple steps, high oil yield, and does not need to separately perform the steps of deacidification, deodorization and degumming, greatly shortens the processing technology, and reduces the production cost, the present application uses ultrasonic enzymolysis and low-temperature cold pressing, can effectively preserve important nutritional ingredients in rapeseed, avoids oxidation or high-temperature damage of the important nutritional ingredients, improves the nutritional value, in addition, the rapeseed oil has pure color, clear transparency and no odor, and the content of erucic acid in Example 3 is 15.3%. DETAILED DESCRIPTION

[0020] The technical solutions of the present application will be further described in detail in combination with specific embodiments.

[0021] Example 1

[0022] The preparation method of rapeseed oil in this embodiment comprises the following steps:

[0023] S1, cleaning and drying: fresh rapeseed is taken, cleaned with 2 times the total mass of water starch, and then dried to a residual water content of 7%, and the water: starch in the water starch is 3:1;

[0024] S2, crushing: the rapeseed prepared in step S1 is crushed, and the particle size after crushing is 70 mesh;

[0025] S3, preparation of enzyme solution: xylanase, pectin esterase, sulfatase and mannanase are mixed in a mass ratio of 1:1:2:3 to form a composite enzyme, and the composite enzyme is dissolved in a neutral phosphate buffer solution to obtain an enzyme solution, wherein the mass ratio of the composite enzyme to the neutral phosphate buffer solution is 1:2;

[0026] S4, ultrasonic enzymolysis of rapeseed: the enzyme solution prepared in step S3 is sprayed into the rapeseed prepared in step S2, the volume ratio of the enzyme solution to the rapeseed is 1:3, 2 times of the total mass of distilled water is added to make it uniform, and ultrasonic assisted enzymolysis treatment is performed every 90 min during the enzymolysis; after the enzymolysis is completed, the enzyme is inactivated, first centrifuged at 4000 r / min for 20 min to obtain first bottom residue and first oil-water mixture, and the first oil-water mixture is continuously centrifuged at 6500 r / min for 20 min to obtain second bottom residue and second oil-water mixture, the upper oil layer of the second oil-water mixture is taken to obtain crude rapeseed oil;

[0027] S5, cold pressing: the first bottom residue and the second bottom residue obtained in step S4 are subjected to oil pressing, the feeding temperature of the filter residue is controlled at 35℃, the barrel temperature is 60℃, the pressure is 20Mpa, and the pressing time is 500s, and the crude rapeseed oil is obtained after filtration;

[0028] S6, refining: the crude rapeseed oil prepared in steps S4 and S5 is taken, 0.1 times of the total mass of activated clay is added to adsorb the pigment in the oil, and centrifuged at 6000 r / min for 5 min to remove the activated clay, and the rapeseed oil is obtained.

[0029] Example 2

[0030] The preparation method of rapeseed oil in this embodiment comprises the following steps:

[0031] S1, cleaning and drying: fresh rapeseed is taken and cleaned with 10 times of the total mass of water starch, and then dried to a residual water content of 15%, the water to starch ratio in the water starch is 3:1;

[0032] S2, crushing: the rapeseed prepared in step S1 is crushed, and the particle size after crushing is 90 mesh;

[0033] S3, preparation of enzyme solution: xylanase, pectinesterase, sulfatase and mannanase are mixed in a mass ratio of 6:8:8:15 to form a composite enzyme, and the composite enzyme is dissolved in a neutral phosphate buffer solution to obtain an enzyme solution, wherein the mass ratio of the composite enzyme to the neutral phosphate buffer solution is 4:15;

[0034] S4, ultrasonic enzymolysis of rapeseed: the enzyme solution prepared in step S3 is sprayed into the rapeseed prepared in step S2, the volume ratio of the enzyme solution to the rapeseed is 3:10, 6 times of the total mass of distilled water is added to make it uniform, and ultrasonic assisted enzymolysis treatment is performed every 120 min during the enzymolysis; after the enzymolysis is completed, the enzyme is inactivated, first centrifuged at 5000 r / min for 30 min to obtain first bottom residue and first oil-water mixture, and the first oil-water mixture is continuously centrifuged at 7500 r / min for 30 min to obtain second bottom residue and second oil-water mixture, the upper oil layer of the second oil-water mixture is taken to obtain crude rapeseed oil;

[0035] S5, cold pressing: the first bottom residue and the second bottom residue obtained in step S4 are subjected to oil pressing, the filter residue feeding temperature is controlled at 45℃, the barrel temperature is 75℃, the pressure is 28Mpa, the pressing time is 800s, and the crude rapeseed oil is obtained by filtration;

[0036] S6, refining: the crude rapeseed oil obtained in step S4 and step S5 is taken, 0.7 times of the total mass of activated clay is added to adsorb the pigment in the oil, centrifugation is performed at 7000r / min for 10min, and the activated clay is removed, and the rapeseed oil is obtained.

[0037] Example 3

[0038] The preparation method of the rapeseed oil in this embodiment comprises the following steps:

[0039] S1, cleaning and drying: fresh rapeseed is taken, and 4 times of the total mass of water is added for starch cleaning, and then drying is performed until the residual water content is 10%, and the water: starch in the starch is 3:1;

[0040] S2, crushing: the rapeseed obtained in step S1 is crushed, and the particle size after crushing is 80 mesh;

[0041] S3, enzyme solution preparation: xylanase, pectinesterase, sulfatase and mannanase are mixed in a mass ratio of 3:4:4:9 to form a composite enzyme, and the composite enzyme is dissolved in a neutral phosphate buffer solution to obtain an enzyme solution, wherein the mass ratio of the composite enzyme to the neutral phosphate buffer solution is 1:8;

[0042] S4, ultrasonic enzymolysis of rapeseed: the enzyme solution obtained in step S3 is sprayed onto the rapeseed obtained in step S2, the volume ratio of the enzyme solution to the rapeseed is 1:6, 3 times of the total mass of distilled water is added to make it uniform, and ultrasonic assisted enzymolysis treatment is performed every 100min during the enzymolysis; after the enzymolysis is completed, the enzyme is inactivated, first centrifuged at 4500r / min for 25min to obtain the first bottom residue and the first oil-water mixture, and then the first oil-water mixture is continuously centrifuged at 7000r / min for 25min to obtain the second bottom residue and the second oil-water mixture, the upper oil layer of the second oil-water mixture is taken, and the crude rapeseed oil is obtained;

[0043] S5, cold pressing: the first bottom residue and the second bottom residue obtained in step S4 are subjected to oil pressing, the filter residue feeding temperature is controlled at 45℃, the barrel temperature is 75℃, the pressure is 28Mpa, the pressing time is 800s, and the crude rapeseed oil is obtained by filtration;

[0044] S6, refining: the crude rapeseed oil obtained in step S4 and step S5 is taken, 0.7 times of the total mass of activated clay is added to adsorb the pigment in the oil, centrifugation is performed at 7000r / min for 10min, and the activated clay is removed, and the rapeseed oil is obtained.

[0045] Comparative Example 1

[0046] Compared with Example 3, the difference lies in that pure water is used instead of water starch in step S1, and the rest of the steps and ingredients remain unchanged.

[0047] S1, cleaning and drying: fresh rapeseed is taken and cleaned with 4 times the total mass of pure water, and then dried to a residual moisture content of 10%;

[0048] S2, crushing: the rapeseed prepared in step S1 is crushed, and the particle size after crushing is 80 mesh;

[0049] S3, enzyme solution preparation: xylanase, pectinesterase, sulfatase, and mannanase are mixed in a mass ratio of 3:4:4:9 to form a composite enzyme, and the composite enzyme is dissolved in a neutral phosphate buffer to obtain an enzyme solution, wherein the mass ratio of the composite enzyme to the neutral phosphate buffer is 1:8;

[0050] S4, ultrasonic enzymolysis of rapeseed: the enzyme solution prepared in step S3 is sprayed onto the rapeseed prepared in step S2, the volume ratio of the enzyme solution to the rapeseed is 1:6, 3 times the total mass of distilled water is added to make it uniform, and ultrasonic assisted enzymolysis treatment is performed every 100 min during the enzymolysis; after the enzymolysis is completed, the enzyme is inactivated, first centrifuged at 4500 r / min for 25 min to obtain the first bottom residue and the first oil-water mixture, and then the first oil-water mixture is centrifuged at 7000 r / min for 25 min to obtain the second bottom residue and the second oil-water mixture. The upper oil layer of the second oil-water mixture is taken to obtain crude rapeseed oil;

[0051] S5, cold pressing: the first bottom residue and the second bottom residue obtained in step S4 are pressed to obtain crude rapeseed oil, the filter residue is fed at a temperature of 40℃, the barrel temperature is 70℃, the pressure is 25Mpa, and the pressing time is 700s. The crude rapeseed oil is obtained by filtering;

[0052] S6, refining: the crude rapeseed oil prepared in steps S4 and S5 is taken, and 0.5 times the total mass of activated clay is added to adsorb the pigment in the oil, and then centrifuged at 6500 r / min for 8 min to remove the activated clay, and the rapeseed oil is obtained.

[0053] Comparative Example 2

[0054] Compared with Example 3, the difference lies in that no mannanase is added in step S3, and the rest of the steps and ingredients remain unchanged.

[0055] S1, cleaning and drying: fresh rapeseed is taken and cleaned with 4 times the total mass of water starch, and then dried to a residual moisture content of 10%, and the water starch has a water: starch ratio of 3:1;

[0056] S2, crushing: the rapeseed prepared in step S1 is crushed, and the particle size after crushing is 80 mesh;

[0057] S3, enzyme solution preparation: mixed xylanase, pectinesterase and sulfatase according to mass ratio 3:4:4 to form a compound enzyme, and the compound enzyme was dissolved in neutral phosphate buffer to obtain an enzyme solution, wherein the mass ratio of the compound enzyme to the neutral phosphate buffer was 1:8;

[0058] S4, rapeseed ultrasonic enzymolysis: the enzyme solution prepared in step S3 was sprayed onto the rapeseed prepared in step S2, the volume ratio of the enzyme solution to the rapeseed was 1:6, 3 times the total mass of distilled water was added to make it uniform, and ultrasonic assisted enzymolysis treatment was performed every 100 min during the enzymolysis; after the enzymolysis was completed, the enzyme was inactivated, first centrifuged at 4500 r / min for 25 min to obtain a first bottom residue and a first oil-water mixture, the first oil-water mixture was continuously centrifuged at 7000 r / min for 25 min to obtain a second bottom residue and a second oil-water mixture, and the upper oil layer of the second oil-water mixture was taken to obtain crude rapeseed oil;

[0059] S5, cold pressing: the first bottom residue and the second bottom residue obtained in step S4 were subjected to oil pressing, the filter residue feeding temperature was controlled at 40℃, the barrel temperature was 70℃, the pressure was 25Mpa, the pressing time was 700s, and the crude rapeseed oil was obtained by filtration;

[0060] S6, refining: the crude rapeseed oil prepared in steps S4 and S5 was taken, 0.5 times the total mass of activated clay was added to adsorb the pigment in the oil, and centrifuged at 6500 r / min for 8 min to remove the activated clay, and the rapeseed oil was obtained.

[0061] Comparative Example 3

[0062] Compared with Example 3, the difference lies in that in step S3, mustard enzyme is used instead of compound enzyme, and the rest of the steps and ingredients remain unchanged.

[0063] S1, cleaning and drying: fresh rapeseed was taken and cleaned with 4 times the total mass of water starch, and then dried to a residual water content of 10%, and the water: starch in the water starch was 3:1;

[0064] S2, crushing: the rapeseed prepared in step S1 was crushed, and the particle size after crushing was 80 mesh;

[0065] S3, enzyme solution preparation: the mustard enzyme was dissolved in neutral phosphate buffer to obtain an enzyme solution, wherein the mass ratio of the compound enzyme to the neutral phosphate buffer was 1:8;

[0066] S4, rapeseed ultrasonic enzymolysis: the enzyme solution prepared in step S3 is sprayed into the rapeseed prepared in step S2, the volume ratio of the enzyme solution to the rapeseed is 1:6, 3 times of the total mass of distilled water is added to make it uniform, and ultrasonic assisted enzymolysis treatment is carried out every 100 min during the enzymolysis; after the enzymolysis is completed, the enzyme is inactivated, first centrifuged at 4500 r / min for 25 min to obtain the first bottom residue and the first oil-water mixture, the first oil-water mixture is continuously centrifuged at 7000 r / min for 25 min to obtain the second bottom residue and the second oil-water mixture, and the upper oil layer of the second oil-water mixture is taken to obtain the crude rapeseed oil;

[0067] S5, cold pressing: the first bottom residue and the second bottom residue obtained in step S4 are subjected to oil pressing, the residue feeding temperature is controlled at 40℃, the barrel temperature is 70℃, the pressure is 25Mpa, the pressing time is 700s, and the crude rapeseed oil is obtained after filtration;

[0068] S6, refining: the crude rapeseed oil prepared in steps S4 and S5 is taken, 0.5 times of the total mass of activated clay is added to adsorb the pigment in the oil, and centrifuged at 6500 r / min for 8 min to remove the activated clay, and the rapeseed oil is obtained.

[0069] Comparative example 4

[0070] Compared with example 3, the difference is that there is no ultrasonic assistance in step S4, and the rest of the steps and ingredients remain unchanged.

[0071] S1, cleaning and drying: fresh rapeseed is taken and cleaned with 4 times of the total mass of water starch, and then dried to a residual water content of 10%, the water: starch in the water starch is 3:1;

[0072] S2, crushing: the rapeseed prepared in step S1 is crushed, and the particle size after crushing is 80 mesh;

[0073] S3, preparation of enzyme solution: xylanase, pectinesterase, sulfatase and mannanase are mixed in a mass ratio of 3:4:4:9 to form a composite enzyme, and the composite enzyme is dissolved in a neutral phosphate buffer to obtain an enzyme solution, wherein the mass ratio of the composite enzyme to the neutral phosphate buffer is 1:8;

[0074] S4, rapeseed enzymolysis: the enzyme solution prepared in step S3 is sprayed into the rapeseed prepared in step S2, the volume ratio of the enzyme solution to the rapeseed is 1:6, 3 times of the total mass of distilled water is added to make it uniform, and ultrasonic assisted enzymolysis treatment is carried out every 100 min during the enzymolysis; after the enzymolysis is completed, the enzyme is inactivated, first centrifuged at 4500 r / min for 25 min to obtain the first bottom residue and the first oil-water mixture, the first oil-water mixture is continuously centrifuged at 7000 r / min for 25 min to obtain the second bottom residue and the second oil-water mixture, and the upper oil layer of the second oil-water mixture is taken to obtain the crude rapeseed oil;

[0075] S5, cold pressing: the first bottom residue and the second bottom residue obtained in step S4 are subjected to oil pressing, the residue feeding temperature is controlled at 40°C, the barrel temperature is 70°C, the pressure is 25Mpa, the pressing time is 700s, and the crude rapeseed oil is obtained by filtration;

[0076] S6, refining: the crude rapeseed oil obtained in step S4 and step S5 is taken, 0.5 times of activated clay is added to adsorb the pigment in the oil, centrifugation is performed at 6500r / min for 8min, and the activated clay is removed, and the rapeseed oil is obtained.

[0077] Comparative example 5

[0078] Compared with example 3, the difference is that high-temperature frying is used to press the rapeseed in step S5 instead of cold pressing, and the rest of the steps and ingredients remain unchanged.

[0079] S1, cleaning and drying: fresh rapeseed is taken, and the total mass of 4 times of water is added to clean the rapeseed, and then the rapeseed is dried to a residual water content of 10%, and the water: starch in the water starch is 3:1;

[0080] S2, crushing: the rapeseed obtained in step S1 is crushed, and the particle size after crushing is 80 mesh;

[0081] S3, enzyme solution preparation: xylanase, pectinesterase, sulfatase and mannanase are mixed in a mass ratio of 3:4:4:9 to form a composite enzyme, and the composite enzyme is dissolved in a neutral phosphate buffer solution to obtain an enzyme solution, wherein the mass ratio of the composite enzyme to the neutral phosphate buffer solution is 1:8;

[0082] S4, ultrasonic enzyme hydrolysis of rapeseed: the enzyme solution obtained in step S3 is sprayed onto the rapeseed obtained in step S2, the volume ratio of the enzyme solution to the rapeseed is 1:6, 3 times of distilled water is added to make it uniform, and ultrasonic assisted enzyme hydrolysis treatment is performed every 100min during enzyme hydrolysis; after enzyme hydrolysis, the enzyme is inactivated, first centrifuged at 4500r / min for 25min to obtain the first bottom residue and the first oil-water mixture, and then the first oil-water mixture is continuously centrifuged at 7000r / min for 25min to obtain the second bottom residue and the second oil-water mixture, the upper oil layer of the second oil-water mixture is taken, and the crude rapeseed oil is obtained;

[0083] S5, high-temperature frying and pressing: the first bottom residue and the second bottom residue obtained in step S4 are put into a thick-walled drum frying pan for frying, the temperature is 130-150°C, the frying time is 30-50min, after frying, the crude rapeseed oil is obtained by pressing 2-3 times in an oil press.

[0084] S6, refining: the crude rapeseed oil obtained in step S4 and step S5 is taken, 0.5 times of activated clay is added to adsorb the pigment in the oil, centrifugation is performed at 6500r / min for 8min, and the activated clay is removed, and the rapeseed oil is obtained.

[0085] Extraction rate of rapeseed oil

[0086] The extraction rates of the rapeseed oil prepared in Examples 1-3 and Comparative Examples 1-5 were detected respectively, wherein the calculation formula of the extraction rate was: extraction rate (%) = mass of extracted rapeseed oil (g) / weight of raw material (g), and the results were shown in Table 1:

[0087] Table 1 Extraction rate of rapeseed oil

[0088] No. Extraction rate (%) Example 1 91.8 Example 2 93.5 Example 3 96.2 Comparative Example 1 92.1 Comparative Example 2 80.2 Comparative Example 3 62.3 Comparative Example 4 76.5 Comparative Example 5 83.6

[0089] As shown in Table 1, the extraction rate of Example 3 was the highest, and the use of pure water instead of water starch in Comparative Example 1 had little effect on the extraction rate, which was speculated to possibly affect the color of rapeseed oil; the extraction rate of Comparative Example 2 without adding mannanase was lower than that of Example 3, indicating that the hemicellulose hydrolyzing enzyme such as mannanase could hydrolyze polysaccharides and promote the conversion of polysaccharide components in rapeseed into triglycerides, phospholipids, steroids and the like; the use of mustard enzyme instead of complex enzyme in Comparative Example 3 reduced the extraction rate, indicating that the addition of complex enzyme was beneficial to the hydrolysis of rapeseed and the release of its own fat and lipids; without ultrasonic treatment in Comparative Example 4, the plant cell wall of rapeseed could not be destroyed, resulting in that the complex enzyme could not contact with the rapeseed, and thus the further extraction of its components was affected, and the extraction rate was reduced; in Comparative Example 5, the extraction rate of rapeseed oil prepared by high-temperature roasting was lower than that of low-temperature cold pressing, and the rapeseed oil prepared at high temperature was easy to produce harmful substances.

[0090] Oil quality detection

[0091] 1.1 Test raw materials

[0092] Rapeseed oil prepared in Examples 1-3, Comparative Example 1 and Comparative Example 3

[0093] 1.2 Test method

[0094] According to GB / T 1536-2021, relative density test: according to GB / T 5526; fatty acid composition test: according to GB 5009.168; transparency, odor and taste test: according to GB / T 5525; color test: according to GB / T 5009.37; moisture and volatile matter test: according to GB 5009.236; insoluble impurity content test: according to GB / T 15688; acid value test: according to GB 5009.229; peroxide value test: according to GB 5009.227; solvent residue: according to GB 5009.262; heating test: according to GB / T 5531; soap content test: according to GB / T 5533; freezing test: according to GB / T 35877; smoke point test: according to GB / T 20795.

[0095] 1.3 Test results were shown in Table 2

[0096] Table 2 oil quality detection

[0097]

[0098]

[0099]

[0100] From the data of Table 2, it can be seen that Examples 1-3 meet the national pressed rapeseed oil secondary quality standards. Compared with Comparative Example 1, Comparative Example 1 did not use water starch to clean the rapeseed, and the impurities on the surface of the rapeseed could not be cleaned with pure water, resulting in brownish color, dark color, and turbidity (20℃), which shows that using water starch to clean the rapeseed is a very necessary step in the present application. Compared with Comparative Example 3, Example 3 used a composite enzyme, and the xylanase, pectin esterase, sulfatase, and mannanase of the composite enzyme could hydrolyze glucosinolates and erucic acid in the rapeseed, and the hydrolysis effect was better than using sinapinase. The content of erucic acid was: Example 3: 15.3%; Comparative Example 3: 52.1%. The rapeseed oil prepared by the present application is safe and healthy, and the preparation steps are simple and convenient, and easy to operate.

[0101] The above description is merely preferred embodiments of the present application, and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for the production of a rapeseed oil, characterized in that, The method comprises the following steps: S1, cleaning and drying: fresh rapeseeds are added into water starch for cleaning and drying; S2, crushing: the rapeseeds prepared in step S1 are crushed; S3, preparing enzyme solution: xylanase, pectinesterase, sulfatase and mannanase are mixed according to a mass ratio of 1-6:1-8:2-8:3-15 to form a composite enzyme, and the composite enzyme is dissolved in a neutral phosphate buffer solution to obtain an enzyme solution, wherein the mass ratio of the composite enzyme to the neutral phosphate buffer solution is 1-4:2-15; S4, ultrasonic-assisted enzymolysis of rapeseeds: the enzyme solution prepared in step S3 is sprayed on the crushed rapeseeds prepared in step S2, the volume ratio of the enzyme solution to the rapeseeds is 1-3:3-10, and 2-6 times the total mass of distilled water is added to uniformly stir the mixture, and ultrasonic-assisted enzymolysis treatment is performed every 90-120 min during the enzymolysis; after the enzymolysis is completed, the enzyme is inactivated, and the mixture is centrifuged at 4000-5000 r / min for 20-30 min to obtain a first bottom residue and a first oil-water mixture, the first oil-water mixture is further centrifuged at 6500-7500 r / min for 20-30 min to obtain a second bottom residue and a second oil-water mixture, and the upper oil layer of the second oil-water mixture is taken to obtain crude rapeseed oil; S5, cold pressing: the first bottom residue and the second bottom residue obtained in step S4 are pressed to obtain crude rapeseed oil, the feeding temperature of the residue is controlled at 35-45℃, the barrel temperature is 60-75℃, the pressure is 20-28 Mpa, and the pressing time is 500-800 s; S6, refining: the crude rapeseed oil prepared in steps S4 and S5 is taken, active white clay is added to adsorb the pigment in the oil, and the mixture is centrifuged to remove the active white clay, thereby obtaining rapeseed oil.

2. A method of producing a canola oil according to claim 1, characterised in that, In step S1, 2-10 times the total mass of water starch is added, and the residual amount of water after drying is 7-15%, and the water starch has a water:solid ratio of 3:

1.

3. A method of producing a canola oil according to claim 1, characterised in that, In step S2, the particle size is 70-90 mesh.

4. A process for the preparation of a rapeseed oil according to claim 1, characterized in that, In step S3, the mass ratio of xylanase, pectinesterase, sulfatase and mannanase is 3:4:4:9, and the mass ratio of the composite enzyme to the neutral phosphate buffer solution is 1:

8.

5. A process for the preparation of a canola oil according to claim 1, characterized in that, In step S4, the volume ratio of the enzyme solution to the rapeseeds is 1:6, 3 times the total mass of distilled water is added, and ultrasonic-assisted enzymolysis treatment is performed every 100 min; the mixture is first centrifuged at 4500 r / min for 25 min, and then the first oil-water mixture is centrifuged at 7000 r / min for 25 min.

6. A process for the preparation of a canola oil according to claim 1, characterized in that, In step S5, the feeding temperature is controlled at 40℃, the barrel temperature is 70℃, the pressure is 25 Mpa, and the pressing time is 700 s.

7. A process for the preparation of a canola oil according to claim 1, characterized by, In step S6, 0.1-0.7 times the total mass of active white clay is added, and the mixture is centrifuged at 6000-7000 r / min for 5-10 min.

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