CN1740189A

CN1740189A - Method of extracting and separating soybean protein

Info

Publication number: CN1740189A
Application number: CN 200510019452
Authority: CN
Inventors: 万端极; 王广润; 周国华; 袁颂东; 赵春玲
Original assignee: WUHAN HUGONGDA MEMBRANE TECHNOLOGY Co Ltd
Current assignee: WUHAN HUGONGDA MEMBRANE TECHNOLOGY Co Ltd
Priority date: 2005-09-20
Filing date: 2005-09-20
Publication date: 2006-03-01

Abstract

The method of extracting and separating soybean protein includes the following steps: 1. adding water in 12-18 times at 45-55 deg.c into crushed soybean dregs, adding sodium hydroxide solution to regulating pH value to 8-9 and stirring to form protein emulsion; 2. filtering the protein emulsion in plate-frame filter to eliminate insoluble dreg and fiber; 3. membrane system separation and concentration to obtain liquid protein with water content of 85 %; 4. adding small amount of hydrochloric acid solution into the liquid protein to regulate pH value to 7; and 5. spray drying the neutralized liquid protein to produce soybean protein. The present invention has the advantages of no protein denaturation, low production cost, high protein yield, and high production efficiency.

Description

A kind of method of extracting soybean protein isolate

Technical field

The present invention relates to a kind of method of extracting soybean protein isolate, particularly a kind of novel method of using the inorganic ceramic membrane technique to extract soybean protein isolate.

Background technology

Protein is the main composition of biological cell.Soy-protein has good trophic function, can replenish the energy of needed by human, strengthens the immunizing power of human body, has certain effect to preventing and treating diseases such as heart trouble, diabetes, cancer.The protein content of soybean protein isolate is not less than 90%, is the highest soy-protein goods of purity.

Soybean protein isolate is to obtain from extracted soybean oil low temperature soy meal afterwards, and protein content is about 45% in the low temperature soy meal, and proteic relative molecular weight is between 8000～600000, and iso-electric point is pH4.5.Current at present technology is that molten through alkali after the low temperature soy meal pulverizing, operations such as acid is heavy, centrifugation, drying are extracted the soybean protein isolate goods.Wherein acid is heavy is meant for albumen is separated out from alkaline solution, adopts to add acid and transfer to iso-electric point and make albumen precipitation, so that isolating method.

The defective that above-mentioned technology exists is:

1, passed through sour heavy operation after, can cause protein denaturation;

2, the heavy operation of acid need be used a large amount of hydrochloric acid, has improved production cost, has also increased the inorganic salt in the system simultaneously, influence albumen precipitation, causes protein yield not high, usually alkali molten after protein yield only be about 85%, the highlyest be no more than 90%;

3, owing to add a large amount of hydrochloric acid, make extracted whey water COD after the albumen up to 20,000 mg/L about, the products such as oligose that the comprehensive utilization whey water is extracted have wherein increased difficulty, have also increased the cost of waste water control simultaneously.

For soybean protein isolate is separated from protein emulsion, Chinese patent application has proposed to use the method for plate-type hyperfiltration membrane protein isolate number 200310107703.6 " the ultra-filtration membrane isolation technique prepares the method for soybean protein isolate ".Its major defect is:

1, the film working area on the board-like filter plant unit surface is little, efficient is low;

2, board-like filtration fenestra easily stops up, and system cleans and recovers very difficult;

3, membrane material is an organic materials, and acid-proof alkaline is poor, and work-ing life is short.

Summary of the invention

The present invention provides a kind of method of using Inorganic Ceramic Membranes to extract soybean protein isolate in order to overcome above-mentioned many disadvantages, and the main process of its technical scheme is as follows:

1, alkali is molten: the low temperature soybean meal after will pulverizing adds 12～18 times water, and water temperature is 45～55 ℃, adds sodium hydroxide adjust pH to 8～9, and stirs, and the protein in the dregs of beans is dissolved in the basic solution, forms protein emulsion.

2, coarse filtration: hand over plate filter to remove insoluble sludge and fiber protein emulsion, filter screen is selected 60～100 orders.

3, membrane sepn: it is concentrated to hand over the film system to separate the protein emulsion behind the Plate Filtration, and its filtrate is the albumin milk clear water, but otherwise processed is extracted products such as oligose wherein; Its concentrated solution is moisture about 85% liquid protein.The film system is the cross flow filter mode, system pressure 0.6～0.8MPa, and 45～55 ℃ of working temperatures, membrane material is an inorganic ceramic film, membrane pore size is 20～40nm.

4, neutralization: in liquid protein, add small amount of hydrochloric acid, adjust pH to 7.

5, drying: the liquid protein after will neutralizing hands over spraying drying to form the soybean protein isolate goods.

Its advantage of technical scheme provided by the present invention is:

1, owing to cancelled sour heavy operation, avoided protein-denatured possibility;

2, reduce the hydrochloric acid usage quantity, reduced production cost;

3, improved proteic yield, the molten back of alkali protein yield can reach more than 95%;

4, cancelled sour heavy operation after, improved the treatment condition of whey water, be convenient to extract wherein product such as oligose;

5, adopt inorganic ceramic film cross flow filter system, easy to operate, clean easily, improved working efficiency.

Embodiment

Certain factory's year is handled 7500 tons of soybean low temperature soy meals, protein content in its dregs of beans is about 45%, calculate at 300 days on working days per year, handle 25 tons of dregs of beans average every day, by traditional alkali extraction and acid precipitation explained hereafter, produce about 2250 tons of soybean protein isolates per year, by technical scheme production of the present invention, produce soybean protein isolate per year and can reach more than 2500 tons, its recovery rate improves 11%.

Specific embodiments is as follows:

1, alkali is molten: the warm water soaking that the low temperature soy meal after 25 tons of pulverizing is added 15 times, its dregs of beans particle diameter is about 0.2mm, and water temperature is 50 ℃, and adding concentration is 30% sodium hydroxide solution, adjust pH to 8.5, it is stirred, made the abundant stripping of albumen in the dregs of beans, formed about 400 tons of protein emulsion, churning time is 60 minutes, the protein dissolution rate is about 80%, in the emulsion the dissolved protein content be about 2.25%, have about 9 tons.

2, coarse filtration: 400 tons of protein emulsions are handed over Plate Filtration, remove about 30 tons of insoluble sludge and fiber, leach 370 tons of protein emulsions, the sheet frame filter screen is 80 orders.

3, membrane sepn: it is concentrated to hand over the film system to separate the protein emulsion behind the Plate Filtration, and its filtrate is the albumin milk clear water, and about 310 tons, but otherwise processed is extracted products such as oligose wherein, and is made the water reuse; Its concentrated solution is about 60 tons of the liquid protein of water content 85%.The film system is the cross flow filter mode, system pressure 0.7MPa, and 50 ℃ of working temperatures, membrane material is an inorganic ceramic film, and membrane pore size is 30nm, and its proteic recovery rate is not less than 95%, is about 8.55 tons.

4, neutralization: a small amount of concentration of adding is 30% hydrochloric acid soln in through the spissated 60 tons of liquid proteins of film system, adjust pH to 7.

5, drying: liquid protein after will neutralizing is handed over spray drying treatment, receive 8.6 tons in soybean protein isolate goods, wherein the protein contents on dry basis is 95%.

Claims

1, a kind of method of extracting soybean protein isolate, may further comprise the steps: (1), alkali are molten: the water that 12～18 times of soybean meal addings after will pulverizing and temperature are 45～55 ℃, add sodium hydroxide solution adjust pH to 8～9, and stir, protein in the dregs of beans is dissolved in the basic solution, forms protein emulsion; (2), coarse filtration: hand over plate filter to remove insoluble sludge and fiber protein emulsion; (3), membrane sepn: it is concentrated to hand over the film system to separate the protein emulsion behind the Plate Filtration, and its filtrate is the albumin milk clear water, and its concentrated solution is moisture 85% liquid protein; (4), neutralization: in liquid protein, add small amount of hydrochloric acid solution, adjust pH to 7; (5), drying: the liquid protein liquid after will neutralizing is spray-dried, makes soybean protein isolate.

2, method according to claim 1 is characterized in that: the film system in the described membrane sepn step is the cross flow filter mode, system pressure 0.6～0.8MPa, and 45～55 ℃ of working temperatures, membrane material is an inorganic ceramic film, membrane pore size is 20～40nm.

3, method according to claim 1 is characterized in that: filter screen is 60～100 orders in the described coarse filtration step.