CN1177024C - Method for producing edible rapeseed protein and oil by aqueous method - Google Patents

Abstract

The present invention relates to a method for producing edible rapeseed protein and oil by an aqueous method. The water solution of sodium sulfite is mixed with rapeseeds; the mixture is processed by jordaning with a pulp residue separator to remove coarse fiber; the pH value of pulp is regulated, and oil and partial protein are precipitated; the oil of the deposition is released by dehydration; the protein is separated with oil by adding hot water; the protein of the concentrated solution is centrifuged or filtrated. The present invention has the advantages of low cost and high extraction rate of protein and oil, and simultaneously, the adverse nutrition factors are removed; the obtained protein and oil can both reach the edible product standard.

Description

Method for producing edible rapeseed protein and oil by aqueous method

technical field

The invention relates to the field of agricultural and sideline product processing, in particular to a method for producing edible rapeseed protein and oil by water preparation.

Background technique

Rapeseed contains relatively unfavorable nutritional factors, including 1.2-2.5% phytic acid, 3-7% glucosinolates (low glucosinolate varieties are about 3.5‰), 0.8-1.6% phenolic compounds, about 2.5% cottonseed Sugar and stachyose, if they are not removed, will hinder the growth and development of animals even if they are used as feed, but if eaten within a safe range, they will have a certain health effect, so it is very necessary to effectively separate them through processing of.

The current rapeseed processing methods are as follows: the first one is to extract the oil after heating, steaming and frying. This method will cause protein denaturation and blackening of the color, which will reduce the reuse value of the dry cake; the second is After mechanical pre-pressing, the oil is extracted with a solvent. The initial equipment investment of this method is large, and the use of flammable and explosive solvents has the risk of fire and explosion, which leads to high management costs; the third method is through After mechanical pre-pressing, the dry cake with an oil content of about 10% is obtained, and then the protein and oil in the dry cake are extracted with an aqueous solution. This is a "Ninth Five-Year Plan" research project completed by the inventor in the early stage; the fourth method is After the rapeseed is crushed mechanically, the protein is extracted with acid, and then the oil is extracted with an aqueous solution. This is a personal invention patent obtained by the inventor.

Contents of the invention

The object of the present invention is to provide a method for extracting edible rapeseed protein and oil simultaneously directly from untreated raw rapeseed by water preparation. This method is produced by the water preparation method, and the production equipment and operation procedures adopted are simpler, and it is suitable for both large-scale industrial production and small-scale family factories. The product is of higher quality, so the cost is low and the protein and oil extraction rate is high, and the unfavorable nutritional factors can be removed at the same time.

The method is implemented through the following steps in turn:

1. Put the rapeseed into the 5/1000000-1/1000 sodium sulfite aqueous solution which is 2-15 times its weight, and use a pulp separator equipped with a 50-200 mesh screen to refine the pulp to remove the crude fiber, and repeat the above step 2 -3 times;

2. Use centrifugation or fine filtration to remove all residues in the slurry, then adjust the pH of the obtained slurry to 2-11, and use a centrifuge, filter or suspension separator to separate the precipitated part mainly containing oil and protein and other supernatant of water-soluble substances;

3. Dehydrate the precipitate with vacuum or conventional dehydration methods to make the water content reach 10-50% to break the emulsion, add 60-100 ℃ hot water 1-10 times the weight of the precipitate, and use a suspension separator to separate the protein solution and oil Separate, or use a conical static separator with a heating device to heat for 1-5 hours to separate the protein solution and oil;

4. Use an ultrafilter with a molecular weight cut-off of 5,000-100,000 to concentrate the protein in the above supernatant and the protein solution obtained later to make the concentration reach 1-5%, adjust its pH to 2-11, and use centrifugation or filtration The way to collect protein precipitates, spray-dried to isolate protein products.

The invention has the advantages of low cost, high protein and oil extraction rate, and can remove unfavorable nutritional factors therein, and the obtained protein and oil can all meet the edible standard.

Detailed ways:

Example 1:

Weigh 100 kilograms of rapeseed and put it into 500 kilograms of 5/10000 sodium sulfite aqueous solution, use a pulp and residue separator equipped with a 50-mesh screen to refine the pulp to remove coarse fibers, repeat the above steps twice, and use a centrifuge to remove the pulp. Residue, the obtained slurry is adjusted to pH 5.5, and the sediment part mainly containing oil and the supernatant containing protein and other water-soluble substances are separated by a suspension separator, and the sediment is subjected to conventional dehydration to make the water content reach 30%. Milk, add hot water at 100°C that is 1 times the weight of the precipitate, use a suspension separator to separate the protein solution from the oil, and use an ultrafilter with a molecular weight cut-off of 5000 to concentrate the protein in the above supernatant and the protein solution obtained later to make After the concentration reaches 2%, the pH is adjusted to 4, the protein precipitate is collected by a centrifuge, and the isolated protein product is obtained by spray drying.

Example 2:

Weigh 200 kilograms of rapeseed and put it into 400 kilograms of 1/1000 sodium sulfite aqueous solution, use a slurry separator equipped with a 120-mesh screen to refine the pulp to remove the crude fiber, repeat the above steps 3 times, and use a centrifuge to remove the pulp. Residue, the resulting slurry is adjusted to a pH of 2, and a centrifuge is used to separate the precipitate mainly containing oil and the supernatant containing protein and other water-soluble substances, and the precipitate is vacuum dehydrated to make the water content reach 50% to break the emulsion. Add 80°C hot water five times the weight of the precipitate, and use a cone-shaped static separator to heat for 5 hours to separate the protein solution from the oil, and use ultrafiltration with a molecular weight cut-off of 50,000 to concentrate the protein in the above supernatant and the protein solution obtained later. After the concentration reaches 5%, the pH is adjusted to 11, the protein precipitate is collected by a centrifuge, and the isolated protein product is obtained by spray drying.

Example 3:

Weigh 200 kg of rapeseed and put it into 3,000 kg of 5/1,000,000 sodium sulfite aqueous solution, use a pulp and residue separator equipped with a 200-mesh screen to remove coarse fibers, repeat the above steps 3 times, and use fine filtration to remove the pulp. Then adjust the pH of the obtained slurry to 11, use a filter to separate the precipitate mainly containing oil and the supernatant containing protein and other water-soluble substances, and vacuum dehydrate the precipitate to make its water content reach 10%. Milk, add 60 ℃ hot water 10 times the weight of the precipitate, use a conical static separator with a heating device to heat for 1 hour to separate the protein solution from the oil, use an ultrafilter with a molecular weight cut-off of 100,000 to concentrate the above supernatant and obtain After the concentration of the protein in the protein solution reaches 1%, the pH is adjusted to 6, the protein precipitate is collected by centrifugation or filtration, and the separated protein product is obtained by spray drying.

Example 4:

Weigh 100 kg of rapeseed and put it into 1,000 kg of 1/100,000 sodium sulfite aqueous solution, use a pulp and residue separator equipped with a 200-mesh screen to remove coarse fibers, repeat the above steps 3 times, and use fine filtration to remove the pulp. Then adjust the pH of the obtained slurry to 8, use a filter to separate the precipitate mainly containing oil and the supernatant containing protein and other water-soluble substances, and vacuum dehydrate the precipitate to make the water content reach 10%. Milk, add 60 ℃ hot water 10 times the weight of the precipitate, use a conical static separator with a heating device to heat for 3 hours to separate the protein solution and oil, use an ultrafilter with a molecular weight cut-off of 10,000 to concentrate the above supernatant and obtain After the protein in the protein solution reaches a concentration of 3%, its pH is adjusted to 6, and the protein precipitate is collected by centrifugation or filtration, and spray-dried to obtain an isolated protein product.

Claims (1)

1. A method for producing edible rapeseed protein and oil by water preparation, characterized in that it comprises the following steps successively: (1) Put the rapeseed into 5/1000000-1/1000 sodium sulfite aqueous solution which is 2-15 times its weight, and remove the crude fiber with a slurry separator equipped with a 50-200 mesh screen, and repeat the above steps 2-3 times; (2) Use centrifugation or fine filtration to remove the residue in the slurry, then adjust the pH of the resulting slurry to 2-11, and use a centrifuge, filter or suspension separator to separate the fat-containing precipitate and the protein-containing and Supernatants of other water-soluble substances; (3) Dehydrate the precipitate with vacuum or conventional dehydration methods to make the water content reach 10-50% to break the emulsion, add 60-100°C hot water 1-10 times the weight of the precipitate, and use a suspension separator to separate the protein solution and Separate the oil, or use a conical static separator with a heating device to heat for 1-5 hours to separate the protein solution from the oil; (4) Concentrate the protein in the above-mentioned supernatant and the protein solution obtained later by using an ultrafilter with a molecular weight cut-off of 5000-100000, after making its concentration reach 1-5%, adjust its pH to 2-11, and use centrifugation or The protein precipitate is collected by filtration, and spray-dried to obtain the isolated protein product.