Патент USA US2359204код для вставки
Patented‘ Sept. Z6, 1944' ' 2,359,204 uNl'raD STATES PATENT (OFFICE. - METHOD or PREPARING» zam SOLUTIONS nmno'rnr mom GLUTEN Roy. E..Coieman, Chicago, 111., assignor to Time, Incorporated, a corporation of New York ' No Drawing. Original application November 30. .1942, Serial No. 467,402. Divided and this ap-' ' piication October 25,- 1943,‘ Serial No. 507,599 ‘ This invention relates to methods 11 Claims. (01. 106-153) of prepar preferably between about 140° to about 150° F., ing commercially usable solutions and coating for a short period oi’ time generally not exceed ing about three hours. It is preferred that the compositions of prolamines or prolamine-con taining proteins directly from glutens, either vextraction time be not longer than about one- ' com, wheat, barley, etc. It is particularly di 5 half to about one hour since within this time rected to such methods which will produce solu and at the temperatures stated, the zein in the tions and coating compositions of the alcohol gluten is extracted and is not deleteriously af ' soluble portion of corn gluten, of controlled so- ' lution and gelling characteristics. - This application is a division of my copending application, Serial No. 467,402, iiled November 30, 1942. ‘ fected. 10' ‘ The extract solution obtained as above de scribed is now separated from the residual gluten by'?ltration, pressing, centrifugal separation or » in any other desirable manner and is distilled Heretoiore, in the preparations of zein solu or otherwise treated to remove all or some of the tions and coating compositions,‘ including the diluent, as desired. It may be ?ltered prelimi substantally non-aqueous ‘rein solutions and 15 narily to the step of removing the diluent, if coating compositions of ‘controlled solution and necessary. The resulting residue is a solution of gelling characteristics as described in my prior zein or zein-containing protein in the base sol Patent No. 2,185,110, granted December 26, 1939, vent alone with all of the diluent from the ex- . for example, the zein is initially isolated irom tract solution removed, or in .the base solvent and that portion of the diluent which has not corn gluten and ‘thendissolved in suitable sol vents to form the desired solutions. To isolatev - ‘been removed. The residual gluten, which still zein from corn gluten as a commercially usable contains some protein, may be freed from re-i powder is a laborious and expensive process, in tained solvent by washing and recoveredior' . further use as a cattle food or for other purposes. volving steps‘ of precipitation, settling, ?ltering, washing and ‘ The solubility of the zein in zein solvents and the solution ch..racteristics such- as stability and gelling tendencies are largely dependent upon the care exercised in _ carrying out the steps'oi the process. The resulting zein or zein-containing solutions in accordance with the present invention, over a wide range of concentrations, are stable on , standing at temperatures of 80° F. and below and do not-separate even when cooled to tem In accordance ‘with the present invention I v30 peratures of 50 to 70° F. and somewhat below. prepare solutions ofv zein or' zein-containing proteins directly from corn gluten under condi tions that will readily produce awideyariety oi ‘When cooled even to temperatures'as low as 10° above zero or to zero, solutions prepared in ac cordance with the present invention may sepa rate and become solid: however, on heating bility characteristics are concerned, and thereby 35 again to temperatures of from about 45° to 70° avoid the expense and objections incident to ' F., a re-solution is eiiected, either without stir the preliminary isolation or zein in powder form. ring or with slight stirring, and the solutions In carrying out the present invention, corn return to their normal. form at the reheating gluten, for example, .in granular ‘or powdered temperatures. Ingeneral, these solutions are form, is treated with .a suitable solvent mixture, 40 substantially non-gelling and have but a slight without the establishment‘ oiap'eeial conditions ' tendency to increase in viscosity; that is,‘ to of hydrogen ion concentration either in the sol thicken or become heavier in body. In many vent or‘ in the gluten,.- to extract the rein from instances they exhibit practically no tendency the gluten. The solvent mixture comprises a to thicken or to gel over practical periods ofv base solvent having a boiling point above about 45 time in the order of about 3 to 6 months and 125° (2., preferably above about 150‘ C. and a even up to one 'year and longer. These solu diluent or extender having a boiling point be tions remain stable and reasonably constant in ' low about 125° C. and, preierably, or about 100° their characteristics" during the periods neces C. and below. The base solvent is itself a sol sary for transportation and distribution, either zein products in so far as properties and solu vent for zein and the diluent maybe, and pret erably is. also a solvent for zein. ‘ The base sol vents and diluents in accordance. with the pres ent invention will be defined fully hereafter. The extraction is carried out at elevated tem- ' in bulk or inpackages, or for storage for reason able periods of time, and hence their field of ap ,p'licability is greatly increased. In general, in the concentration of zein orv other prolamine in commercially usable solutions peratures, say from about 1209' to about 170° lit, -_55 containing about 12 to [30% of protein, the 2 2,869,204 amount of base solvent necessary to obtain these concentrations in the ?nal solutions is in and of itself insu?lcient to give the proper relation between solvent and gluten ,for effective extrac tion results. If large amounts of the relatively high boiling point base solvents are used, suill eient to give the proper relation between solvent and gluten, the extraction results are not sum ciently effective and, moreover, the cost ot‘treat; ing the extracts to obtain the desired solids con kinds of solvents which may be used as base sol vents in accordance with the present invention than is-disclosed‘herein, reference is made to the description of these solvents in‘ my prior Patent centration is so prohibitive as to make this pro cohol, cyclohexanol, iurfuryl alcohol, tetrahy No, 2,185,110. ' Examples of base solvents in accordance with the present invention are the glycols such as di ethylene glycol, propylene glycol, trlethylene gly col and mixtures thereof, including mixtures which contain ethylene glycol; diacetone alcohol: closed chain cyclic alcohols such as benzyl ai cedure commercially unfeasible. The desired solvent to gluten ratio in accord ance with the present invention is secured by adding to the desired amount of relatively high boiling point base solvent or mixture of base sol drofurfuryl alcohol and mixtures of closed chain alcohols; glycol others such as ethylene glycol mono-methyl ether, diethylene glycol mono methyl ether, ethylene glycol mono-ethyl ether, diethylene glycol mono-ethyl and mixtures of vents one or more of the so-called relatively low glycol ethers; mixtures of two or more of the boiling point diluent solvents. To obtain e?ec tive extraction results, the solvent to gluten ratio should be in the order of about 21/2 to 10 parts by weight of the former to about 1 part by weight foregoing enumerated base solvents; mixtures of one or more of the foregoing base solvents with glycerine, or other solvents or mixtures of sol vents, providing the mixture has the required of the latter. Due to the presence of a diluent polar to non-polar radical balance and the re or extender in the extracting solvent, the solvent quired relatively high boiling point. It is to be to gluten ratio may be less than that which would be required with a base solvent alone and, not 25 understood that the foregoing speci?cally men tioned solvents or mixtures of solvents is not in withstanding the lower solvent to gluten ratio, tended to- be inclusive of all the base solvents the extraction results are generally more eilec which may be used in accordance with the pres .tive. The diluent solvent or extender must have ent invention since they are merely set forth for a lower boiling point and distillation range than illustrative purposes. the base solvent. It is preferred that these allDiluent solvents . uent solvents or extenders be of substantially lower boiling point and distillation range than The diluent solvents or extenders in accord- the base solvent, as pointed out above. ' . ance with the present invention may be, suit ably, a single solvent or a solvent mixture which Base solvents , The base solvents are relatively high boiling may or may notbe a solvent for zein or other one hand, having 53% hydroxyl and 47% hydro within the percentage range stated. For con venience herein I ‘term these alcoholic solvents prolamine, as desired. It is preferred, however, compounds or mixtures of compounds as pointed that the diluent or extender be a solvent for zein. out above and have asultable balance between Thus, the extending. solvent may be one or more ' the hydrocarbon constituents or radicals present in the solvent or solvent mixtures and the polar 4.0 of the well-known alcoholic zein solvents such as anhydrous methanol, or constant boiling point constituents or radicals present therein. A cer mixtures (azeotropes) of aliphatic alcohols such tain proportion of hydroxyl radicals in the base as 95%-ethyl alcohol and 91% isopropyl alcohol. solvents is required to secure solvent action. For convenience herein I term these alcoholic Other polar radicals such as —O— (ether oxy gen), —Cl, —NH: and COOH appear to aid or 45 solvents "concentrated alcohol solvents.” The ‘ diluent solvents may also beone or more of the cooperate with the —OH in securing the nec concentrated alcohol solvents containing addi essary conditions of polarity in the base solvents tional amounts of water, say from 40% to 50% in (in which term I include mixtures oi’ base sol anhydrous methanol or in excess of that present vents) ,for solvent action.‘ ' The proportion of polar radicals to hydrocar 50 in the azeotropes 95% alcohol and 91% isopropyl alcohol. Greater or lesser amounts of water than bon or non-polar radicals which I have found to as stated may be used; however, best results are be desirable lies within a range which extends obtained with the use of added amounts of water between the limits oi! absolute methanol on the carbon radicals, and absolute ethanol on the _ _“aqueous alcohol mixtures." other hand having 37% hydroxyl and 63% hy Another class of diluent solvents in accord-. .ance with the present invention’ comprises mix tures of an azeotropic concentrated alcohol sol cals. This range is approximate and may vary ‘somewhat depending on the solvent or solvent 60 vent with a non-solvent and water. Examples of such diluents are mixtures of 95% ethyl alco mixture used. The limits of this range are inhol or 91% lsopropyl alcohol with dichlorethyl dicative of solvent properties and provide a close ene, trichlorethylene, ethyl acetate, benzene, cy and adequate guide to‘ enable the operator, .by clohexane, etc., and water. In‘this class 01' d'ilu simple experimentation, to determine the re ent solvents I, also include non-aqueous azeo quired balance of polar and hydrocarbon radi drocarbon radicals. The benzyl radical acts as it it were intermediate the methyl and ethyl radi cals in the base solvent or mixture of base 501- > vents in accordance with the present invention. It may be stated that the base solvents in ,-tropic mixtures of anhydrous methyl alcohol ' with hexane, cyclohexane, benzene, carbon tetra chloride, dichlorethylene, trichlorethylene,v ace accordance with the present invention may be tone, methyl acetate, ethylacetate, methyl ethyl - described in my prior Patent No. 2,185,110 which ture, methyl alcohol, is a zein solvent. In addition to the foregoing, wherein at least any one of the solvents or mixture of solvents 70 ketone, etc. because one constituent of, the mix- - has the required balance of polar and non-polar one constituent of a diluent solvent mixture is a radicals, anda boiling point above about 125° C., preferably, above about 150° C. as pointed“ out above. For a more‘ complete description of the 1: zein solvent, thediluent ‘solvents may be suitable azeotropic mixtures. which are acid protein sol 3. 2,8579,204 - vents wherein the individual constituents of the mixture are non-solvents for zein proteins. Thus, they may be azeotropic mixtures of water on the one hand and dioxan or butyl alcohol on the other. Dioxan forms with water a constant boiling point mixture containing 80% dioxan _ expected, and some of them may undergo changes - (apparent insolubility, for example) , during the diluent and water removal which affect the sol vent characteristics of the zein and zein-contain ing proteins in the base solvent utilized. These ‘ changes, where they take place, are not of a boiling at 86.9” C.; and butyl alcohol forms with I permanent character and it is possible to effect water a constant boiling point mixture contain a, re-solution of. the zein or zein-containing pro ing 63% butyl alcohol boiling at 92° C. They teins in the base solvents by the addition of a may also be suitable aqueous azeoti‘opic mix-' 10 small amount or water, say in the‘ order of from tures which are non~solvents for zein proteins about 1 to 3% by weight, ‘or an equivalent such as ethyl methyl ketone and water. And amount of- other highly hydroxylated compound, they may also be non-aqueous azeotropic mix such as methyl or ethyl alcohol or a mixture of " tures of anhydrous ethylalcohol or anhydrous such compounds. ' isopropyl alcohol with hexane, cyclohexane, ben 15 In the preparation of usable solutions having zene, carbon tetrachloride, dichlorethylene, tri a. wide ?eld of applicability, I prefer that the chlorethylene, acetone, methyl acetate, ethyl ace tate, methyl ethyl ketone, etc. , removal of diluent and waterbe controlled so The diluents may also be suitable non-solvents of low polarity characterized by the presence of - to 3% by weight of water or an equivalent —O—, --Cl, —NHz, —COOH groups, etc. Exam ples of such diluents are dioxan, dichlorpentane, ethylene dichloride, dichlorethyl ether, etc. They . may, also be miscible hydrocarbons such as ben as to leave in the ?nal solutions at least about 1 20. amount of other highly hydroxylaled compound, preferably water. Where this is not possible,‘ wa ter may be added to the ?nal solution, in the amounts stated. While water is, in general, not essential constituent of some of the solutions ' zene, hydrogenated naphtha, etc. Or they may 25 an formed in accordance with the present invention, be suitable non-solvents of high polarity such as the solutions are generally of an improved char anhydrous ethanol, anhydrous isopropanol or acter when they contain small amounts of water. The solutions may contain larger amounts of In general, extracting solvents consisting of water, say between 5 to 10%, or even more. or including the aqueous alcohol mixtures are 30 As already pointed out, the type ‘or character capable of extracting larger amounts of zein pro of the zein-containing protein produced by the water. . ~ - tein from gluten than are the extracting solvents extraction is in no, small part dependent on the consisting of or including a concentrated alco character of the extraction solvents used. This hol solvent. It has been noted that for practi condition is particularly pronounced when the cal extraction procedures‘, using either a concen 35 highly aqueous alcohols or the high water trated alcohol solvent alone or an aqueous alco hol mixture alone, approximately 21/2 parts by a azeotropes'such as dioxan-water or n-butyl alco hol-water mixtures are used as diluents.v Not only‘ do these diluents e?ect the extraction of a weight of solvent to l‘ of gluten may be used. At this concentration, with gluten containing ap larger amount of the ‘zein-containing protein proximately 60% total protein, the extract solu 40 than do the more concentrated alcohols, but ~ tions of the concentrated alcohol'solvent contain‘ they also produce by their extraction a type 01" a maximum zein protein content of approxi ' zein protein which generally produces solutions ' mately 10% whereas the extract solutions of the having a high viscosity and pronounced colloidal aqueous alcohol mixture solvents contain a'maxi consistency. On the other hand the zein pro-' mum ‘zein protein content of from about 12% to 45 tein produced with the concentrated alcohols; about 15% and even up to 20%. In addition,’ the and less aqueous diluents tends to produce solu aqueous alcohol mixture solvents are capable of tions having a lower viscosity and a lesser col extracting a substantially larger proportion of lcidal consistency. It is thus evident that vari a desirable type of zein present in the protein of ous types ofv zein protein having substantially the gluten than are the concentrated alcohol sol— 50 di?'erent properties can be produced by proper vents. . ' Zein solutions-of a desired concentration and of a wide applicability can be obtained directly from gluten by having in the ?nal solution as the only solvent or as the main solvent for zein, a relatively high boiling point solvent having the required balance of polar and non-polar radicals as described herein. It is now well established selection and composition of the diluents. - From the'"~_foregoing it is manifest that the nature'and properties of the ?nished solution will be determined by the nature of the base solvent, the amount of zein protein present in the solution and the type or character of the zein ‘protein extracted by the particular diluent used. It is apparent that with the solveritand diluent combinations possible, a wide variety of tical usability of zein solutions are in no small 60, solutions for many uses can be produced by the that the ‘viscosity, gelling tendencies, and prac ' part dependent upon the character of the solvent in which the zein is dissolved. Zein or zein-containing extract solutions con taining any one or more of the foregoing base methods of the present invention. ' : Within the range of the many possible com; binations and the methods in accordance with , the present invention, solutions may be pro solvents in accordance with the present inven 05 duced which require further adjustment or tion, may be boiled, distilled or otherwise treated modi?cation in order to secure improved solu to remove part or all of the diluent. It is evident tion or desired stability and controlled gelling that practically all 01' the diluent, including any properties. vSuch adjustments or modi?cations water carried from the gluten to the extract solu-' can be readily eifected by the use of rosin, fatty . tion, may be removed, thereby obtaining solutions 70 vacids,'compatible amines such as monoethanol of zein or zein-containing. proteins, in the base amine, triethanolamine, etc., amine soaps of ' solvent which, for all'pralctical purposes, are sub rosin or fatty acids,v or by the various methods stantially anhydrous. vSuch solutions vary wide and materials for producing stable, controlled ly in character, depending upon the choice of "gelling, zein solutions described in my issued ’ solvents or solvent mixtures used, as is to be 75 ‘Patents Nos. 2,185,122; 2,246,779 and 2,298,548. _ 4-, . 2,359,204 . ethylene glycol and 25% of ethylene glycol mono The addition of'suita'hle materials for, effecting desired modification or adjustment may be made to the extract solution before distilling of! the ethyl ether was added to 30 parts of powdered gluten. The procedure was as in Example 1 ex cept that the extraction temperature was 140', I". diluent or to the final solution. The preferable The resulting residue was a_solution of fzein-con taining proteins principally in the glycol and gly procedure and materials with particular solu tions may be readily determined by experimenta col ether mixture. ‘ tion. 1 Example 7.-A solvent mixture containing 60 parts of a mixture consisting of 90% of 91% iso 10 propane] and 10% or water, and 40 parts of a mixture consisting of 75% of diethylene glycol ance with the present invention. In the exam pics and elsewhere throughout thespeci?cation, , - and 25% of ethylene glycol monomethyl ether was added to 30 parts of powdered gluten. The pro the term “parts" indicates parts by weight. w ' cedure was as in Example 1 except that the ex Example 1.—A solvent mixture containing '12 traction temperature was 140° F. The resulting parts of anhydrous isopropyl alcohol (99%), 40 residue was a solution of the min-containing pro parts of diethylene gylcol and 8 parts of ethyl teins principally in the glycol and glycol ether ' ene' glycol was added to 30 parts of powdered mixture. gluten in a vessel. The mixture was heated to _ Example 8.—A solvent mixture containing 60 about 160° F. and held at about that tempera ture for about 1/2 hour with stirring to extract 20 parts of a mixture consisting of 80% of denatured 95% ethyl alcohol ("Paco") and 20% of water. ‘the zein-containing proteins from the gluten. and 40 parts of a mixture consisting of 75% of The mixture was then ‘forced through a ?lter to diethylene glycol and 25% of benzyl alcohol was separate the zein-containing extract and the In the following examples I disclose illus trative methods for producing zein or zein-con taining solutions directly from gluten in accord added to 30 parts of powdered gluten. - The pro cedure was as in Example 1 except that the ex traction temperature was 140° F. The resulting residue was a solution of the zein-containing pro extract was then slowly heated to about 250°‘ F. and held at about that temperature with stirring until cessation of visible boiling. The residue was a solution of zein-containing proteins principal teins principally in the glycol and benz'yl‘ alcohol ly in the mixture of glycols. In the following examples the manipulative mixture. ' v ’ At the cessation of boiling as referred to in procedures were the same as those set forth in . the examples some proportion of the lower boil Example 1, with the exceptions hereinafter ing constituents of the diluent originally used re mains in the ?nal solution. The proportion there of so remaining depends upon the iinaltemperaé Example 2.—~A solvent lmixturecontaining 72 Q parts-of anhydrous denatured. alcohol (“Paco”), 35 ture and the boiling point curve of the mixture. Considerable proportions'of the diluent or of its d0 parts of diethylene glycol and 8 [parts of noted, and in each instance the extracts were heated until cessation of visible boiling. . constituents, including water. may remain with ethylene glycol was added to 30 parts of pow out causing gelling of the ?nal solution in reason able periods of time.’ This is particularly true ' dered gluten. The procedure was as in Example 1 and the resulting residue was a solution of where the glycols are used. In this respect the zein-containing proteins principally in the mix ture of glycols. . ?nal solutions show differences from solutions of - commercial zein containing large amounts of Example 3.—A solvent mixture containing '72 ~ water as in the prior art, apparently by reason of parts of 91% isopropanol and 48 parts of a mix ture consisting of 88.9% of propylene glycol and 11.1% of diethylene glycol monoethyl ether was added to 36 parts of powdered gluten. The pro cedure was as in Example 1 except that the ex traction temperature was 180° F. The result ing residue was. a solution of min-containing proteins principally in the glycol and glycol ether mixture. Example 4.—A solvent mixture containing so parts of denatured 95% alcohol (“Paco”). and to parts of a mixture consisting of ‘75% of di ethylene glycol and 25% benzyl alcohol was added to as parts of powdered vgluten. The procedure was as in Example 1 except that the extraction temperature was 140° F. The result ing residue was a solution of zein-containing ' proteins principally in the diethylene glycol and benzyl alcohol mixture. Example 5.-A solvent mixture containing 60 parts of anhydrous synthetic methanol and 40 parts of a solvent mixture consisting of 75% some changes in the character or structure of the zein-containing proteins of the corn gluten 45 ‘ 50 taking place in the process of the present inven tion, the nature of which changes is not as yet understood. In general and in?uenced by the type and amount of zein protein present, the solutions pre pared as described above and the coating com positions prepared therefrom have the properties, particularly when heated, of being able to "give up” their solvent or solvents readily, and when applied to any surface they quickly and readily form‘ tough, ?exible, non-tacky, hard and 8811-. : erally transparent coatings even when retaining some solvent. The coatings formed by these sein ~containing solutions and coating compositions are very strong and have adherent properties. In 60 these-solutions. and coating compositions the film forming properties thereof can be built up to pro duce films of great toughness, ?exibility, hard ness and gloss. Under normal temperature con of diethylene glycol and 25% of ethylene 8111200] 66 ditions, many of the zein-containing solutions or coating compositions. will produce non-blushing monoethyl ether was added to to parts of pow dered gluten. The procedure was as in Example 1 except that the extraction temperature was 140° F. The resulting residue was a solution of the hem-containing proteins principally in the diethylene glycol and glycol ether mixture. coatings on drying, without the aid of supple meritary anti-blushing agents as in the prior art. The coating compositions prepared from the above solutions may be modified and used as fully . described in. the aforementioned application, Be ria-l No. 467,402. Example 6.-—A solvent mixture containing 69 While my invention has been described in con parts of a mixture consisting oi 80% or denatured nection with certain speci?c examples, it is, of %% ethyl alcohol (“Paco") and 20% of water, to parts of a mixture consisting of 75% oi di- my course, obvious it' is not to be construed as lim ~ 2,359,204 ited to these examples or to‘ the details of the ' to form the aforesaid solution. 4. The method of preparing directly from gluten a solution of zein-containing proteins in a mixture of solvents comprising as essential sol vent constituents for the zein-containing pro ' In the claims, the expression “an elevated tem perature in the order of about 120° F. to about 170° F." is not to be construed as a precise critical ' teins, a mixture of solvents each having a boil ing point above about 150° C. and having a pro-, portion of polar to non-polar radicals which lies within a' range extending between the limits of range, but, rather, as a range of temperatures indicative of the elevated temperature at which - the extractions may be carried out. I claim: ' I ' 1. The method of preparing directly from 5 substantially all of the diluent from the extract methods set forth therein, since obvious changes in materials, proportions and method details will be apparent from the foregoin~ . ' the proportion of polar to non-polar radicals of’ methanoland the proportion of polar to non gluten a solution of zein-containing proteins in a polar radicals of ethanol, which comprises con- ' mixture of solvents comprising as essential sol tacting gluten with a solvent mixture at an ele vent constituents for the min-containing pro vated temperature in the order of about 120°_ teins, a mixture of solvents each having a boil F. to about 170° F. to extract zein-containing ing point above about 125° C. and having a proproteins from the gluten, said solvent mixture‘ portion of polar to non-polar radicals which lies comprising the aforesaid zein-containing pro within a range extending between the limits of tein solvents having boiling points above about the proportion of polar to non-polar radicals of 20 150° C. and a miscible diluent therefor having methanol and the proportion of polar to non a boiling point'below about 125° 0., said diluent polar radicals of ethanol, which comprises con being a solvent for said zein-containing proteins, tacting gluten with a solvent mixture at an ele separating the extract from the residual gluten vated temperature in the order of about 120°F'. and removing at least part of the diluent from to about 170° F. to extract zein-containing pro 25 the extract to form the aforesaid solution. teins from the gluten,.said solvent mixturecom 5. The method of preparing directly‘ from prising the aforesaid zein-oontaining protein sol gluten a solution of zein-containing proteins in a ' vents‘having boiling points above about 125° C. mixture-‘of solvents comprising as essential sol and a miscible diluent therefor ‘having a" boiling vent constituents for the zein~containing pro point below about 125° C., separating the ex 30 teins, a mixture of solvents each having a boil tract from the residual gluten and removing at ing point above about 150° C. and having a pro least part of the diluent from the extract to form _ portion of polar to non-polar radicals which lies the aforesaid solution. within a range extending between the limits of . 2. The method of preparing directly from glu the proportion of polar to non-polar radicals of ten-a solution of zein-containing proteins in a 85 methanol and the proportion’ of polar to non-polar mixture of solvents comprising as essential sol radicals of ethanol, which comprise contacting vent constituents vi’or the zein-containing pro gluten with a solvent mixture at an elevated teins, a mixture of solvents each having a boiling temperature in the order of about .120? F. to point above about 150° C. and having a propor about 170° F. to extract zein-containing pro tion of polar to non-polar radicals which lies 40 teins from the gluten, said solvent mixture com- -. withhi a range extending between the limits of. prising the aforesaid zein-containing protein the ll‘oportion of polar to non-polar radicals of solvents having boiling points above about 150° methanol and the proportion of polar to non C. and a miscible diluent therefor having a boil- _ polar radicals of ethanol, which comprises con ing point below about 100° C., said diluent being tacting gluten with a solvent mixture at an ele 45 ‘a substantially anhydrous solvent for said zein vated temperature in the order of about 120° F. containing proteins, separating the extract from toiabout 170° F. to extract zeinecontaining pro the residual gluten and removing at least part of teins from the gluten, said solvent mixture com the diluent from the extract to form the afore prising the aforesaid aein-containing protein sol said solution. vents having boiling points above about 150° C. 50 6. The method of preparing directly from and a miscible diluent therefor having a boiling gluten a solution of zein-containing proteins in is point below about 100° C., separating the extract ‘ from the residual gluten and removing at least part of the diluent from the extract to form the aforesaid solution. ' a mixture of solvents comprising as essential ' solvent constituents for the zein-containing pro teins, a mixture‘ of solvents each having a boiling 65 point above about 150° C. and having a propor '3. The method of preparing directly from tion of polar to non-polar radicals which, lies gluten a solution of zein-containing proteins in. within a range extending between the limits of a mixture of solvents comprising as essential sol vthe proportion of polar to‘non-polar radicals of vent constituents for the zein-containing pro methanol and the proportion of polar to non teins, a mixture of solvents each having a boiling 60 polar radicals of ethanol, which comprises con point above about 150° C. and having a propor tacting gluten with a solvent mixture at an tion of polar to non-polar radicals which lies within a range extending between the limits of elevated temperature in the order of about 120° F. to‘above 170° F. to extract zein-containing the proportion of polar to non-polar radicals of proteins from the gluten, said solvent mixture methanol and the proportion ofv polar to non 65 comprising the aforesaid zein-containing pro-v - polar radicals of ethanol, which comprises con tacting gluten with a solvent mixture at an ele tein solvents having boiling points above about 150° C. and a miscible diluent therefor having vated temperature ‘in the order of about 120° a boiling point below about 125° C.,- said diluent 1''. to about ‘170° F.,_to. extract zein-containing being an aqueous solvent for said zein-contain- ' proteins from the gluten, said solvent mixture 70 ing proteins, separating the extract from the comprising the aforesaid zein-ccntaining protein solvents having boiling points above about 150° C. and a miscible diluent therefor having a boil . ing point below about 125° C., separating the ex tract ‘from the residual gluten and removing residual gluten and removing at least part of the diluent from the extract to form the aforesaid solution. I ' " 7. The method of preparing directly from glu- > 75 ten a solution of zein-containing proteins in a 2,859,204 , " I 6 mixture of solvents comprising a glycoland a ' comprising a glycol, .a glycol ether and a miscible diluent therefor having a boiling point below about 125° (1.,’ said diluent being an aqueous glycol ether as essential solvent constituents for the zein-containing proteins, . which comprises contacting gluten with a solvent mixture at an solvent for said zein-containing proteins. separat i'ng'the extract from the residual gluten and re moving, at least part of the diluent from the ex elevated temperature in the order of about 120° F. to about 170° F. to extract zein-containing proteins from the gluten, said solvent mixture tract to form the aforesaid solution. ' . .10. The method oi! preparing directly from glu ten a solution of zein-con‘taining proteins in a comprising a glycol, a glycol ether and a miscible diluent therefor'having a boiling ‘point below of solvents comprising propylene glycol about 125° >CI., separating the extract from the 10 mixture and diethylene glycol monoethyl ether as essen residual gluten and removing at least part of the solventconstituents tor the zein-containing diluent from the extract to form the aforesaid _ tial proteins, which comprises contacting gluten with . a solvent mixture at an: elevated temperature in 8. The method of preparing directly from glu the order of about 120° F. to about 170° F. to ex-‘ 15 ten a solution of zein-containing proteins'inv a tract zein-containing proteins from the gluten, mixture of solvents comprising a glycol and a solvent mixture comprising propylene glycol, glycol ether as essential solvent constituents for ' said diethylene glycol monoethyl ether and 91%.iso-. the zein-containing proteins, which comprises propyl alcohol,’ separating the extract from the contacting gluten with a solvent mixture at-an gluten and removing at least parto! the elevated-temperature in the order of about 120°_ 20 residual isopropyl alcohol from the extract to form the solution. _ V ' F. to about.l70° F. to extract. zein-containing aforesaid solution- proteins from the gluten, said solvent mixture . 11. The methodoi preparing directly from glu comprising a glycol, a gylcol ether and a misci ten a solution of zein-containing proteins in a ble ‘diluent therefor having a boiling point below about 125° C., said diluent being a solvent for said mixture of solvents comprising diethylene glycol - and benzyl alcohol as essential solvent constitu forthe rein-containing proteins, which com from the residual gluten and removing at. least ents prises contacting gluten with a solvent mixture part of the diluent from the extract to form the at an elevatedtemperature in the order of about aforesaid solution. 120° F. to about 170° F. to'extract zein-contain 9. The method of preparing directly from glu-l 80 ing proteins from the gluten, said solvent mix ten a solution of zein-containing proteins in a ' zein-containing proteins, separating the'extract ture comprising diethylene glycol, benzyl alcohol, 95% ethyl alcohol and water, separating the ex tract from the residual gluten and removingat mixture of solvents comprising a 'glycol» and a glycol ether as essential solvent constituents‘ for the zein-containing proteins, which comprises contacting gluten with a solvent mixture, at an elevated temperature in the order 01' ‘about 120° it‘. about 170° F. to extract zein-containing pro-' teins from the gluten, said solvent mixture as least part of the.95% alcohol and water from the extract'to form the aforesaid solution; . ROY E. COLEMAN. '