A kind of method of extracting albumen powder from corn germ cake
Technical field
The invention belongs to protein engineering field, be specifically related to a kind of method of extracting albumen powder from corn germ cake.
Background technology
Maize germ is the byproduct of cornstarch processing, and source is abundanter at home, contains higher fat and protein.Be generally used at present production maize germ oil.In order to improve the oil productivity of plumule, tradition is all entered 100 ℃ of above heat treatments (also claiming to steam to fry) to plumule, object be to destroy plumule cell membrane, make protein coagulating sex change, reduce grease viscosity and make it aggegation and flow out.But only considered the recovery of the grease of 35-40% in plumule, reckoning without the germ protein that still contains 20% left and right in plumule cannot recycle.Corn germ protein is a kind of high-quality protein, mainly globulin and albumin, consists of, and these two kinds of albumen account for the more than 60% of total protein content.The amino acid of corn germ protein forms with the amino acid composition of Chicken Albumin closely similar, and biological value is high, and human protein's standard of recommending with FAO/WHO has good uniformity.Corn germ protein has good retentiveness, emulsibility and emulsion stability, can be used as food additives and is applied in cake, meat food, protein beverage and bakery product manufacture.
After maize germ liquefaction, the corn germ cake crude protein content of acquisition is 50%-60%.Due to high-temperature denatured, allow to very difficult proposition of full price albumen that the molten acid of alkali is carried, because enzymatic hydrolysis corn anus bud albumen action condition is gentle, degree of hydrolysis is easily controlled, and because enzyme has specificity, different enzyme hydrolysis same proteins can obtain the peptide section that different aminoacids forms, so enzymatic hydrolysis is the common method of producing at present corn germ protein biologically active peptide.Its biologically active peptide has special physiological function, is easily absorbed by the body, safe, can be used as the unsound specific crowd of digestive system function (alimentary canal protease hyposecretion patient, the elderly, anaphylaxis baby's etc.) meals dietary protein origin.Therefore germ protein is reclaimed in research from corn germ cake, to improve resource utilization, and is the social development new protein resource of nutrient health more.
In corn deep processing production process, produce the byproducts such as gluten protein powder and the plumule dregs of rice, utilize the former to extract prolamin and entered the commodity stage; The latter, except doing feed purposes, does not also have the report of GAP-associated protein GAP commodity so far.In the contained albumen of the plumule dregs of rice more than 60% is albumin and the molten globulin of salt.In Maize Production starch process, in the byproduct corn germ cake of generation, containing albumen, be 25% left and right, at present the plumule dregs of rice are substantially all to add in feed, to produce high protein feed.With corn germ cake, remove to produce high protein feed, added value of product is low.
Publication number is the Chinese patent of CN1095059A, a kind of method of producing amino acid by using corn chop is disclosed, it utilizes the corn chop pressing the oil is raw material, technological process is after the hydrolysis of the embryo dregs of rice, to leach starch, again by hydrolyzate neutralization, decolouring, with activated carbon filtration, from destainer, extract tyrosine; Its filtrate is concentrated, filtration, obtain containing leucic double salt, and remaining filtrate is containing 18 seed amino acids; Residual filtrate also can soy sauce processed, beverage.This patent application is to utilize the method extraction that the molten acid of alkali is carried to prepare the amino acid in the corn chop after corn oil through squeezing, and leaching process needs a large amount of bronsted lowry acids and bases bronsted lowries, easily contaminated environment; And it is that raw material extracts albumen that the method is not suitable for the corn chop that adopts high temperature steaming stir-fry mode to prepare after corn oil, and range of application is less.
Publication number be the patent of CN 102018092A disclose a kind of from corn germ cake method for extracting proteins, comprising: 1) to corn germ cake, add after water, add protease after regulating reaction temperature and pH value, be hydrolyzed; 2) after centrifuging and taking supernatant the enzyme that goes out are lived, obtain a zyme extract standby; 3) by step 2) precipitation after centrifugal adds water, regulates reaction temperature and pH value, after hydrolysis, after centrifuging and taking supernatant the enzyme that goes out work, obtains secondary zyme extract; 4) combining step 2) secondary zyme extract that zyme extract making and step 3) make, adjust pH, centrifuging and taking precipitation, washing, dry after, obtain.The present invention utilizes through steaming the corn germ cake of frying after extraction corn oil and produces corn germ protein matter for raw material, has solved because corn germ protein in raw material is due to high-temperature denatured the difficult problem that cannot extract with acid-base method.It is that raw material is produced corn germ protein matter that the method is applicable to through steaming the corn germ cake of frying after extraction corn oil, for the corn germ cake after lixiviate corn oil, is not suitable for, and range of application is narrower.
Summary of the invention
In order to solve above-mentioned technical problem, the invention provides a kind of new utilization and from corn germ cake, extract the method for albumen powder, this has wide range of applications, connect can use through steam frying squeezing and extract corn germ cake after corn oil for raw material extracts albumen powder, also can use corn germ cake after lixiviate corn oil to extract albumen powder for raw material.
The present invention realizes by following technical scheme:
A method of extracting albumen powder from corn germ cake, comprises following steps:
(1) corn germ cake pulverize after after 200 mesh sieves, add water, the weight ratio of amount of water and corn germ cake is 95:5, stirs and makes to become suspension, 85 ℃ of pasteurizations, the corn germ cake suspension liquid after being sterilized;
(2) the corn germ cake suspension after the sterilization obtaining of step (1) is lowered the temperature naturally, when suspension is stabilized to 40 ℃, with the NaOH solution of 0.1mol/l, adjusts pH value of solution to 8.0-8.5;
(3) add compound protease, addition is 0.04% of maize germ suspension weight, slowly stirs at being incubated 40-60 ℃, and mixing speed is turn/min of 10-12, maintains 4h, carries out enzymolysis, obtains enzymolysis liquid;
(4) enzymolysis liquid that step (3) obtains, add alkali protease Alacalase-2.4 liquid, the every 10g enzymolysis liquid of addition adds 1.7-2.0 μ L, and now enzymolysis liquid pH value is 8-9, temperature 40-60 ℃ is controlled in water-bath, constant temperature 30 minutes, carries out the dissolving of albumen, forms protein dissolution liquid, then in protein dissolution liquid, add papain, addition is that 10g protein dissolution liquid adds 1.0-5.0 μ L, and now pH value be 4-5,40-60 ℃ of continuation maintenance temperature 10 minutes;
(5) will be in step (4) the gained protein dissolution liquid enzyme that goes out in 100 ℃ of water-baths, after the enzyme that goes out, place frozen water water-bath and within 1-2 minute, be cooled to 25 ℃;
(6) step (5) gained protein dissolution liquid is put into centrifuge centrifugation, centrifuge speed 4000r/min, centrifugation time 10min, gets clear liquid and uses;
(7) clear liquid makes moisture evaporation through heating, obtains the thickness albumen powder of moisture content 18-22%, then obtain albumen powder product after 80 ℃ of oven for drying of excess temperature.
In the above-mentioned method of extracting albumen powder from corn germ cake, the compound protease that step (3) is added is the mixture of alkali protease Alacalase-2.4 and Protamex protease, and the two mixed weight is than being 1:3 or 2:3.
Alcalase is the protease that is applicable to pH neutrality, is applicable to the production status of my company's plumule dregs of rice, without adding extra adjusting product.
Protease P rotamex is a kind of inscribe and circumscribed protease of containing.Use its protein hydrolysate, there is no bitter taste, the taste naturally of retained product, and there is high added value.
In the above-mentioned method of extracting albumen powder from corn germ cake, described alkali protease Alacalase-2.4, enzymatic activity is 18000U/ml.
In the above-mentioned method of extracting albumen powder from corn germ cake, the activity of described Protamex liquid of protease is 20000U/ml.
In the above-mentioned method of extracting albumen powder from corn germ cake, the enzyme that step (3) is added is the mixture of alkali protease Alacalase-2.4 and Protamex protease, and the two mixed weight is than being 1:3.
In the above-mentioned method of extracting albumen powder from corn germ cake, the enzyme that step (3) is added is the mixture of alkali protease Alacalase-2.4 and Protamex protease, and the two mixed weight is than being 2:3.
In the above-mentioned method of extracting albumen powder from corn germ cake, described acid protease papain, enzymatic activity is 16000 U/ml.
In the above-mentioned method of extracting albumen powder from corn germ cake, the addition of step (4) neutral and alkali protease A lacalase-2.4 liquid is that every 10g enzymolysis liquid adds 1.8 μ L, and the addition of papain is that 10g protein dissolution liquid adds 3.0 μ L.
In the above-mentioned method of extracting albumen powder from corn germ cake, described corn germ cake is to extract a kind of in corn germ cake after corn oil or the corn germ cake after lixiviate corn oil or two kinds through steam frying squeezing.
Beneficial effect of the present invention is as follows:
(1) the present invention extracts the method for albumen powder to take maize germ as raw material from corn germ cake, is no matter corn germ protein or unmodified corn germ protein after high-temperature denatured, all can be used for extracting albumen powder.The method applied range, various maize germ raw materials all can.
(2) the present invention utilizes the plumule cake protein in alkali protease Alacalase-2.4 and Protamex protease and the pawpaw albumen waste residue plumule dregs of rice that industry produces to maize germ oil to be hydrolyzed, make it become soluble polypeptide, then by regulating the protein in pH value, precipitation zyme extract, the dry albumen powder that makes, technique is simple, energy consumption is low, is the recycling to the waste residue plumule dregs of rice, has greatly improved the economic benefit of maize germ comprehensive utilization;
(3) utilize the method for extracting albumen powder from corn germ cake of the present invention, make new product plumule cake protein, for realizing corn germ cake, extract commercially producing of albumen, the added value of product that improves corn germ cake provides technological reserve.
(4) the present invention can fully extract the protein in corn germ cake, and recovery rate can reach 70%~80%.
The specific embodiment
Below in conjunction with specific embodiment, the present invention is further described, so that those skilled in the art more understands the present invention, but does not therefore limit the present invention.
Embodiment of the present invention alkali protease Alacalase-2.4 used is purchased from lucky precious (Qingdao) bio tech ltd, it is active in being 18000U/ml, Protamex protease used is purchased from the not ended Science and Technology Ltd. of Beijing brilliant work, and its activity is 20000U/ml; Papain used is purchased from Zhengzhou De Xin chemical industry Industrial Co., Ltd., and its activity is 16000 U/ml.
Embodiment 1
A method of extracting albumen powder from corn germ cake, comprises following steps:
(1) through steam to fry squeezing extract corn germ cake 5kg after corn oil and pulverize after after 200 mesh sieves, add 95kg water, the weight ratio of amount of water and corn germ cake is 95:5, stirs and makes to become suspension, 85 ℃ of pasteurizations, the corn germ cake suspension liquid after being sterilized;
(2) the corn germ cake suspension after the sterilization obtaining of step (1) is lowered the temperature naturally, when suspension is stabilized to 40 ℃, with the NaOH solution of 0.1mol/l, adjusts pH value of solution to 8.0-8.5;
(3) add 0.04kg compound protease, the compound protease adding is the mixture of alkali protease Alacalase-2.40.01kg and Protamex proteinase-10 .03kg; At being incubated 55 ℃, slowly stir, mixing speed is 12 turn/min, maintains 4h, carries out enzymolysis, obtains enzymolysis liquid;
(4) enzymolysis liquid that step (3) obtains, add alkali protease Alacalase-2.4 liquid, the every 10g enzymolysis liquid of addition adds 1.8 μ L, and now enzymolysis liquid pH value is 8-9, temperature 50 C is controlled in water-bath, constant temperature 30 minutes, carries out the dissolving of albumen, forms protein dissolution liquid, then in protein dissolution liquid, add papain, addition is that 10g protein dissolution liquid adds 3.0 μ L, and now pH value is 4-5, continues to keep temperature 50 C 10 minutes;
(5) will be in step (4) the gained protein dissolution liquid enzyme that goes out in 100 ℃ of water-baths, after the enzyme that goes out, place frozen water water-bath and within 1-2 minute, be cooled to 25 ℃;
(6) step (5) gained protein dissolution liquid is put into centrifuge centrifugation, centrifuge speed 4000r/min, centrifugation time 10min, gets clear liquid and uses;
(7) clear liquid makes moisture evaporation through heating, obtains the thickness albumen powder of moisture content 18-22%, then obtain albumen powder product after 80 ℃ of oven for drying of excess temperature.
Get corn germ cake and extract the waste residue after protein, through utilizing Kjeldahl's method to detect, in waste residue, protein content is that the percent hydrolysis of 4.34%. protein is 96.3%, and as calculated, extraction rate of protein is 79.5%.
Embodiment 2
A method of extracting albumen powder from corn germ cake, comprises following steps:
(1) the corn germ cake 5kg after lixiviate corn oil pulverize after after 200 mesh sieves, add 95kg water, the weight ratio of amount of water and corn germ cake is 95:5, stirs and makes to become suspension, 85 ℃ of pasteurizations, the corn germ cake suspension liquid after being sterilized;
(2) the corn germ cake suspension after the sterilization obtaining of step (1) is lowered the temperature naturally, when suspension is stabilized to 40 ℃, with the NaOH solution of 0.1mol/l, adjusts pH value of solution to 8.0-8.5;
(3) add 0.04kg compound protease, the compound protease adding is the mixture of alkali protease Alacalase-2.40.016kg and Protamex proteinase-10 .024kg; At being incubated 40 ℃, slowly stir, mixing speed is 10 turn/min, maintains 4h, carries out enzymolysis, obtains enzymolysis liquid;
(4) enzymolysis liquid that step (3) obtains, add alkali protease Alacalase-2.4 liquid, the every 10g enzymolysis liquid of addition adds 1.8 μ L, and now enzymolysis liquid pH value is 8-9,40 ℃ of temperature are controlled in water-bath, constant temperature 30 minutes, carries out the dissolving of albumen, forms protein dissolution liquid, then in protein dissolution liquid, add papain, addition is that 10g protein dissolution liquid adds 3.0 μ L, and now pH value is 4-5, continue to keep 40 ℃ of temperature 10 minutes;
(5) will be in step (4) the gained protein dissolution liquid enzyme that goes out in 100 ℃ of water-baths, after the enzyme that goes out, place frozen water water-bath and within 1-2 minute, be cooled to 25 ℃;
(6) step (5) gained protein dissolution liquid is put into centrifuge centrifugation, centrifuge speed 4000r/min, centrifugation time 10min, gets clear liquid and uses;
(7) clear liquid makes moisture evaporation through heating, obtains the thickness albumen powder of moisture content 18-22%, then obtain albumen powder product after 80 ℃ of oven for drying of excess temperature.
Get corn germ cake and extract the waste residue after protein, through utilizing Kjeldahl's method to detect, in waste residue, protein content is that the percent hydrolysis of 5.12%. protein is 94.5%, and as calculated, extraction rate of protein is 74.2%.
Embodiment 3
A method of extracting albumen powder from corn germ cake, comprises following steps:
(1) through steaming the corn germ cake 2.5kg and the corn germ cake 2.5kg after lixiviate corn oil that fry after squeezing extraction corn oil, mix, after pulverizing after 200 mesh sieves, add 95kg water, the weight ratio of amount of water and corn germ cake is 95:5, stir and make to become suspension, 85 ℃ of pasteurizations, the corn germ cake suspension liquid after being sterilized;
(2) the corn germ cake suspension after the sterilization obtaining of step (1) is lowered the temperature naturally, when suspension is stabilized to 40 ℃, with the NaOH solution of 0.1mol/l, adjusts pH value of solution to 8.0-8.5;
(3) add 0.04kg compound protease, the compound protease adding is the mixture of alkali protease Alacalase-2.40.01kg and Protamex proteinase-10 .03kg; At being incubated 60 ℃, slowly stir, mixing speed is 12 turn/min, maintains 4h, carries out enzymolysis, obtains enzymolysis liquid;
(4) enzymolysis liquid that step (3) obtains, add alkali protease Alacalase-2.4 liquid, the every 10g enzymolysis liquid of addition adds 1.8 μ L, and now enzymolysis liquid pH value is 8-9, temperature 60 C is controlled in water-bath, constant temperature 30 minutes, carries out the dissolving of albumen, forms protein dissolution liquid, then in protein dissolution liquid, add papain, addition is that 10g protein dissolution liquid adds 3.0 μ L, and now pH value is 4-5, continues to keep temperature 60 C 10 minutes;
(5) will be in step (4) the gained protein dissolution liquid enzyme that goes out in 100 ℃ of water-baths, after the enzyme that goes out, place frozen water water-bath and within 1-2 minute, be cooled to 25 ℃;
(6) step (5) gained protein dissolution liquid is put into centrifuge centrifugation, centrifuge speed 4000r/min, centrifugation time 10min, gets clear liquid and uses;
(7) clear liquid makes moisture evaporation through heating, obtains the thickness albumen powder of moisture content 18-22%, then obtain albumen powder product after 80 ℃ of oven for drying of excess temperature.
Get corn germ cake and extract the waste residue after protein, through utilizing Kjeldahl's method to detect, in waste residue, protein content is that the percent hydrolysis of 4.89%. protein is 91.5%, and as calculated, extraction rate of protein is 75.6%.
Albumen powder prepared by the embodiment of the present invention and common albumen powder have carried out quality contrast.
Note: one-level is corn protein powder superior quality standard for feed, secondary be medium, three grades be off standard.
From the data of table 1, albumen powder prepared by method of the present invention, its quality is better than belonging to commercially available one-level albumen powder rank.