CA1087611A - Process for the treatment of comminuted oats - Google Patents
Process for the treatment of comminuted oatsInfo
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- CA1087611A CA1087611A CA267,784A CA267784A CA1087611A CA 1087611 A CA1087611 A CA 1087611A CA 267784 A CA267784 A CA 267784A CA 1087611 A CA1087611 A CA 1087611A
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Abstract
ABSTRACT OF THE DISCLOSURE
A process for the treatment of comminuted oats so as to effect separation of the comminuted oats into fractions differing in composition is disclosed. The process comprises admixing comminuted oats, or fractions derived therefrom, with an organic solvent for oat oil and subjecting the admixture, in the form of a slurry, to the influence of centrifugal force in, for example, a centrifuge, including continuous or semi-con-tinuous centrifuges, and/or a hydrocyclone. In an embodiment the oats are oats that have not been subjected to heat treatment.
Examples of suitable solvents are pentane, hexane, heptane, cyclohexane and alcohols of 1-4 carbon atoms. The products obtainable include bran, oat oil, flour and protein-enriched or protein deficient flours. In particular embodiments flours having greater than 80% or less than 2% protein are obtainable.
The products have a variety of uses in the food industry.
A process for the treatment of comminuted oats so as to effect separation of the comminuted oats into fractions differing in composition is disclosed. The process comprises admixing comminuted oats, or fractions derived therefrom, with an organic solvent for oat oil and subjecting the admixture, in the form of a slurry, to the influence of centrifugal force in, for example, a centrifuge, including continuous or semi-con-tinuous centrifuges, and/or a hydrocyclone. In an embodiment the oats are oats that have not been subjected to heat treatment.
Examples of suitable solvents are pentane, hexane, heptane, cyclohexane and alcohols of 1-4 carbon atoms. The products obtainable include bran, oat oil, flour and protein-enriched or protein deficient flours. In particular embodiments flours having greater than 80% or less than 2% protein are obtainable.
The products have a variety of uses in the food industry.
Description
1087611.
The present invention relates to an improved process for the treatment of comminuted oats so as to effect separation of the comminuted oats into fractions differing in composition.
In particular, the present invention relates to the treatment of comminuted oats so as to separate the comminuted oats into a so-called "flour" fraction, a so-called "bran" fraction and an oil, and into products derived therefrom, in which the flour - is essentially free of gum. The present invention also r~lates to the treatment of comminuted oats, or flour or bran fractions derived therefrom, so as to obtain fractions having a range of protein contents, especially fractions of high and low protein contents.
As used herein the expresslon "groats" refers to the kernel oi the oat, the expression "flour" refers to the endosperm of the oat and the expression "bran" refers to the bran of the oat; such bran msy have endosperm attached thereto as i3 ex-emplified hereinafter. The expression t~gum~ refers-in particular to water-soluble gum.
Oats are a potential source of a wide variety of useiul products. Examples of such products are flour, starch, protein isolate, protein-enriched flour, bran, gum and oil. Trad-ltional techniques used in the cereal grain processing industry are frequently dif~lcult to use with oats. For example, milli~g techniques are difficult to use with oats because of process problems relating to the presence of oll in the oats. Moreover, unless the oats are de-oiled prior to milling, such milling tech-niques would result in the formation of flour and bran fractions containing oil w~lch may result in rancldity problems on storage of the flour and bran.
3o Gum, together with some protein and starch, may be removed in part by treatment of oats with water, the resultant -dilute aqueous solution of gum then requiring treatment prior to disposal or for recovery o~ the gum. Protein may be extracted from commirluted oats with aqueous solutions, especially alkaline solutions. Howe~er gum present in the oat~ may also be extracted into solutlon and the resultant solutions may be ~iscous and cause process problems, especially in the separation of 301idæ
from the aqueous solutions.
The composltion and properties of water-soluble gums obtained from cereal grains are discussed by BoL~ D'Appolonia in a paper presented at the sym~osium on "Industrial Use~ of Cerealsl' held ~ conJunction with the ~8th Annual Meetirlg o~ the American ~ssociation of Cereal Chemists, ~ovember 1973.
A process for the separation of acid-soluble protein from com~inuted oats, a~d techniques for the reco~ery o~
starch, gum and the like in related processes, is described in Canadian Application No. 245,163 of A. BeLl, J.R. B. Boocock and R.N. O~ghton, f~ed Febr~r 4, 1976. Tec~niqueæ for the separation o~ oil ~rom commlDuted oats are ~mo~n; such tech~que3 are discussed ln the a~orementioned applicatio~ o~ A. Bell et al.
A process ~or i~olating protein ~rom a pulverlzad oil seed w~ing liqlsid f`luorocarbons is disclosed in U.S. Patent 3,869,438 o~ J.W. Finley et al, which issued March 4, 1975.
A process for the separation of a flour fraction, a bran fraction and oil ~rom commi~uted oats in which ~um does not cause signi~ic~t process problems and in which the flour is ess~ntially free of gam ~s Lisclosed i~ Ca~adian Application 254,864 of R.W. Oughton, f~led June 15, 1976. However, the pro-ces~ disclosed by R.W. Oughton is capable of impro~ement.
Processes for the sol~rent-extractiire n~ g of maize or corn, whea~, rye ana the sorghum grains to remove the brs~
coat fro~hole kernels of such grains followe~ by commi~utio~
of the whole mllled kernel3 and for the separation o~ so-caLl.ed 10876i1 fibrous, proteinaceous, endosperm and/or starch ~ractions derived from such grains are disclosed by T.B. W~yne in Canadian Patents 86~,538, which issued February 23, 1971, and 905,509 and 905,910, both o~ which issued July 25, 1972.
A need exists for the discovery of a process for the treatment Or comm~nuted oats, especially for the productlon of flour and/or protein, that is less susceptible to process pro-blems relating to the presence of oil snd gum in the oats.
An improved process ~or the separation of a flour frsctlon, a bran ~ractlon and oil, especially protein-enriched flours and protei~-de~icient flours, from comm~nuted oats has now been found.
Accord~ngly the present invention provides a process for the ~paration of comminu~ed oats into fractions differing in compo8itlo~, said proce~s comprising:
(a) admi~lng comminuted oats with a~ organic sol~ent, said solvent being capable of extracting oat oil from sa~d oats;
(b) forming a slurry Or said admixture of comm~nuted oats a~d solveat; and (c) Qub~ecting the 51urry to the influence of c-ea-trifugPl force and thereby separating the commi~uted oats in said slurr~ lnto at least two fraction~, said fractions d~fering i~
compositlon.
me present invention also provid~s a process ~or the separation of com~nuted oat~ into ~ractions dif~ering in com- -positio~ Qaid process co~prising:
(a) ad~ixing an oat fr~ction, derived from said com-mi~uted oats, with an organic solvent, said ~olvent b~ing a sol-vent capsble o~ extractl~g oat oil from oats.
(b) ~orming a slurry of said admixture of oat fraction . and organic ~olvent; and _3_ .. . . . .... .
108761~
(c) sub~ecting the slurry to the influence of centri~ugal force and thereby sep~ating said oat fraction lnto at least tw~ fractlons, said fractions differing in protein content.
In addition the present in~ention provides a process for the separation of comminuted oats into ~ractions differing in composition, said process comprising:
(a) a~m~ing an oat fraction, der~ved ~rom comminuted oats, with an organic solvent, said sol~ent being a solvent capable o~ e~tracting oat oil from oats;
(b) sub~ect~ng said admixture to the in~luence of centrirugal force in a centrifuge and thereby forming a centrifuge cake o$ said oat fraction;
(c) separating said cake in the substantial absence of said solYent i~to at lea~t two layers, the protein content of at leaQt one of said layers being different ~rom the protein con-tent of at least one o~ said other layers.
Furthermore the present invention prov~des a process for the ~eparation Or comminuted oats, or fraction~ derived therefrom, into ~ractions dif~er~ng in composltion, said ~ep-~-- aration being carried out in the presen~e of an organic ~olvent, the impro~ement comprisi~g utllizing oats which ha~e not been subJected to heat treatmRnt.
The comminuted oats ~sed ln the process of the present invention are pre~erably obtained from dehulled oats. Techniques ~or dehulllng oat~ are known in the art. me dehulled oats, herei~ generally referred to as groats, are commlnuted ln order to facilitate e~traction o~ oil and to ~acilitate separation of the sub~equentl~ ~ormed slurry o~ comminuted groats and organic solvent into a ~lour fractio~ and a bran ~raction. Ihe re~uired , 1~87611.
partlcle size o~ the comminuted gxoats will depend in particular on the techni~ue to be used to separate the comminuted groats in the slurry into fractions di~fering in composition. For example, if a hydrocyclone is used to separate the comminuted groats into fractions the particle size of the comminuted grQats must be sufficiently small to allow the hydrocyclone to operate smoothly and e~iciently and without clogging or plugglng of the hydrocyclone. Conventional techniques, ror example, pin-m~lling, hamm~r milling and other shearing technlques ~ould appear to produce acceptable comminuted groats.
In the process of the present in~ention the com~inuted groats are admixed with a solvent for the oil i~ the oats in order to fac~litate extraction of the oil from the commi~uted groats i.e. to de-oil the comminuted grosts. The solvents u~ed m~st be acceptable ~or u~e with foodstu~s, e.g. be non-toxic at the le~els remaining in the products subsequently produced, not cause the ~ormation o~ toxic materials ln the pxoduct and not ha~e a significant deleterious effect on the nutritional ~alue o~ the product, and must be capable of permitting separa-tion o~ the ~lour and bran fractlons. ~he amount snd type of sol~ent remaini~g in products offered ~or ~ale must be acceptable to the appropriate health authorities, as will be under~tood by thoæe skllled in the art. Examples o~ solvent~ are pentane, hexane, heptane, cyclohexa~e and alcohQls o~ 1 1! carbon atoms, a~d mixtures thereo~; as used herein the solvents hexane and hepta~e include those solvents re~erred to ln the ~ood industr~
as hexane and heptane. The pre~erred solvent is hexane. The present inventlon will generally be described here~nafter with re~erence to hexane as the solvent.
me admlxing of the comm$nuted groats and hexane is pre~erabl~ carried out with agitation, e.g., stirring. I~ a , 1~87611preferred embodiment of the process o~ the present invention the commi~uted groats a~d heæane axe admixed and then agitated so as to form a ~lurry of the comminuted grosts and hexane. The time between admixing the comminuted groats and hexane snd forming the slurry of comminuted groats and hexane may be very short or alternati~ely the admixture may be mai~tained as ~uch for a sig~i~icant perioq of time before the slurry is ~ormed.
me period of time during which the comminuted ~roat~ and heæane are in contact, i.e., the time as an admixture and as a slurry, should be such that the desired degree o~ e~traction of oil from the comminuted groats ls achieved, the period of time being depe~den~ in part on the actual technique o~ e~traction. Gen-era ~ a slurry o~ comminuted groats and hexane will be formed essentially on ad ~ .
me comminuted groat~ and heza~e m~y be a~m~Yed and/or formed into a 31urry under conditions that result in ~urther - comminution o~ the groats. Thus, the comminuted groats a~mi~ed with the he~ane may be o~ a paricle size that is not s~itable for the ~ubseguent separatlon step and the necessary additional comminution prior to separation of the slurry lnto at least two fractions ma~ occur while the commlnuted ~roat~ and hexzne are admixed or i~ the form of a slurry. In such embodiments it may be pre~erable to incorparate means ~or separation o~ o~ersize particles ~rom the admixture and/or slurry, especiall~ ~ust prior to the separation o~ the comminuted groats i~ the slurry i~to fractions, and to sub~ect such particles to further com-minution. me utilization o~ the admixture and/or the slurry for additional comminution o~ the comminuted groats may be a factor in the determinatlon of the period o~ time between the admi~ng of the comminuted groats and hexane and the subseguent separation o~ the comminuted groats into at least two ~ractions.
1~3187611 In order to effect separation of the comminuted groats into ~ractions, the slurry is sub~ected to centri~ugal ~orce. me means used to sub~ect the slurry to centri~ugal ~orce is a centrifugal separator, pre~erably a centri~ugal separator capable of being operated on a continuous or semi-continuous basis. Egamples of centrifugal separator~ are con-tinuous centrifuges including semi-continuous centrifuges, and, - in partlcular, hydrocyclones.
In order to effect separation of the comminuted groatæ
into ~ractlons in a hydrocyclone, the slurr~ o~ comminuted groats asd he~ane is ~ed to the hydrocyclone whereupon the slurry i~
sub~ected to centrlfugal force. Under such conditions, fraction-ation of the comminuted groats in the slurry tends to occur.
The operation o~ the hydrocyclone so as to obtain a desired fractionation of the comminuted groats in the slurry wlll depend o~ a number o~ process variables. Examples Or such varlables are the degree of comminution of the comm~nuted groats, the amount o~ sol~d material in the slurry, the pressure drop across the h~drocyclone, the ratio o~ the ~lows through the so-called '~nderflow" and "over~low" outlets, the dif~erence in density between the sol~ent and the particles of the comminuted groat~, the viscosity of the solvent and the like, as will be understood by those skilled in th~ art. The operatlon of the hydrocyclo~e is ad~usted so that a desired fractionation o~ the comm~nuted groats in the slurry ~ed to the hydrocyclone is obtained. In particular, the hydrocyclone is operated so that a bran fraction, in hexane, flows ou~ the underflow outlet and a ~lour fractlon, ~n hexane, flows out the ~erflow outlet. Preferably one f~ac-tion contain~ at least 20% and in particular at least 40% of the comminuted oats.
10876~.1 The ~lour ~raction may be separated from the flour fraction~hex&ne mixture by known techniques ~or sep~rating a solid ~rom a solution. For eæample, the flour ~raction may be separated ~rom the ~lour ~raction/hexane mixture by centri-fuging techniques. As the hexane contains dissolved oil, it may be desirable to wash the flour ~raction after separation so as to remo~e any oil adsorbed on the flour. The oil may be recovered from the oil-containing hexane solution by removal of the hexane. Similarly the bran fraction may be recovered from the bran ~raction~hexane mix~ure by removal o~ the hex2ne. In these operations the hexa~e is pre~erably reco~ered and re-used in the separation of the ~lour and bran ~ractions from the com-minuted groats. Alternatively, the oil-containing hexane solution may at least in part, be used in the separation o~ the ~lour and bran fractions ~rom the comminuted groats.
Depending on the desired products, the flour and bran fractions may, either before or after separation ~rom the he~ane, be subJected to ~urther comminution and~or further separatlon uslng, ~or example, a hydrocyclone. Thus the separation o~
the comminuted groats into ~ractions ma~ involve the multiple use o~, for e2ample, h~drocyclones, such multiple use may be in a sequential m~nner and may ~nclude recycle of ~ractions. Other - methods of separation may be used in con~unction with ~ep-aratlo~s in~olv~ng the use of hydrocyclones, e.g., a ~lo~r fraction containing a small amount of bxan may advantageo~sly be treated with a ~creen or cla~sifier. The procesæ of the pre-sent inYention can therefore be u~ed for the separation of com-minuted groat~ into ~lour fraction~ conta~n~ng flour o~ varying propertlos, especially varying protein contents, a~d into bran fractions of var~ing properties. Such may be zdvantageous for ~ome end use3.
~0876~1 me bran fraction in the process o~ the present ln-vention may be comprised of br&n particles having endosperm adhered thereto. The bran fraction may be sub~ected to further comminution in the pre~ence or absence of hexane and either returned to the admixture of commi~uted groats and hexane for further separation into flour and bran fractions or independently separated into further flour and bra~ fractions. Bran fractions of varying endo~perm content are obtainable.
The oil obtained in the proces3 of the present in-vention may be turbid and it may be desirable to clari~y theoil. me oil may be clairi~ied by techniques known in the art or by mixing with ~sopropanol especially isopropanol containi~g h~drogen peroxide, agitating and then removing any ~olld material, e.g. by centri~uging. A clear brown oil is obtainable. ~he solids remo~ed o~ centrifuging ar~ believed to contain signi-flcant ~mounts of phospholipids and may be suitable for use, for exsmple, as emNlsifiers.
The ~lour ~raction that is separated by the proce~s of the prese~t invention i~ essenti~lly ~ree of gum. In addi-tion the flour fraction is essentially free of oil~ me water-soluble gu~s, which are in the bran fraction, are recoverable.
The product3 of the process of the present in~ention are believed to be use~ul in the food ~ndustry either 8S such or as a source of other products.
~ he ~a~or componentæ o~ the flour fraction are stsrch and proteln. In addition to separation under the in~luence o~
centri~ugal force, the flour fraction is capable of being sep-arated into fractions o~ ~arying starch and protein contents using air classification techniques. Protein and stsrch con-centrates may be also obtained from the flour fraction by _g_ 1087611extracting the flour with aqueous acidic or alkaline solutions.
A high proportion of the protein in the flour fraction may be extracted by slurrying the ~lour fraction in such aqueous solutions. The pH o~ the aqueous solution is pre~erably at least 9.O and especially about 11.0 if the solution is alkaline and about 2.0 ir the solution is acidic. Examples of suitable alkalis ~or the ad~ustment of pH are sodium hydroxide and potassium hydroxide. Examples of suitable acids are phosphoric acid, hydrochloric acid and citric acid. As discussed herein gums, especially water-soluble gums in the oats, are separated in the bran ~raction in the process described above and the flour fraction obtalned is essentially free of gum. Thus processes for the extractlon o~ protein from the flour fraction of the process of the present inYention may be operated at low solution Yiscosities, which is most advantageous ~rom a processing and especially a product separation point o~ ~iew. The solid mat-erial in the protein extraction solution may be separated from the solution u~ing, ~or example, centrifuging techniques. It i8 l~kely desirable to wash or re-slurry the solids with water to separate absor~ed solubilized protein and to re-separate the solids. The solid material is comprised primarily of starch. If the starch contai~s a m~nor amount of bran or the like it may be des~rable to subJect it to, for e~ample, sieYing3 washlng or air classi~ication to puri~y the starch.
The solubilized protein obtained on extraction of the rlour ~raction may be reco~ered by, for example, isoelectric precipitation. me pH of the solubilized protein solution is ad~usted to about 3.5-4.5 with alkali, e.g., sodium hydroxide, ; or acid, e.g., phosphoric acid~ as required. me precipitate Or protein obtained may be separated by, for example, centri-~uging the solution. Protein may also be obtained by freeze drying the solutlon o~ solubulized protein. This may be especially useful for recovery o~ acid-soluble protein especially 10~376~L1 from solutions at the pH at ~hich it is desired that the pro-tein be soluble. The properties of the protein, including the colour of the protein may depend on the technique o~ extracting and separating the protein. Protein obtained by alkali or acid extractio~ is believed to be stable in hot aqueous acidic sol-utions. Acid^soluble protein obtainable from the flour fraction, as de~cribed herei~ may be preferable to that obtainable dir-ectly ~rom de-oiled groats. If the protein is to be blended with another substance, e.g., flour, it may be preferable to extract the protein from the flour fraction with an acidic solution and ~reeze dry the protein as the protein so obtained may b~ whiter than that obtained by isoelectric precipitation.
Protein may also be extracted from the ~lour ~raction~
u~ing aqueous solutions of substantially neutral pH. Such pro-tein is capable of being precipitated in hot water.
While the present invention has been desc~ibed herein-be~ore with particular re~erence to the separation o~ comminuted æroats into ~raction using in particular a hydrocyclone, the present invention is not l~m~ted thereto. In a pre~erred em~odi-ment o~ the in~entlon the material which is subJected to thein~luence o~ centrifugal force is an oat fraction that ha~ been obtained ~rom comminuted groats by means other than the use of centrifugal force. For a~ample the oat fraction, which may be ~or example a bran fraction or a flour ~raction, may be ob-tained by clas~i~ying admi~tures o~ comminuted groats and a 801-vent, for example, hcxane. The classifying of admixture~ of comminuted groats and ~ lvents and other tech~iques for the separatlon of oat ~ractions are di~closed in the a~orem~ntioned Canadian patent application ~o. 254,864.
3761~
The use of the influence of centrifugal force on fractions derived from comminuted groats, rather than on commi-nuted groats per se, may be advantageous in that process prob-lems associated with large particles e.g. the clogging of hydrocyclones, may be reduced or avoided. The treatment of bran fractions is less preferred than the treatment of flour - fractions because of the greater likelihood of large particles, and the consequent possibility of process problems resulting therefrom, in bran fractions. Oat fractions, especially flour fractions, may be subjected to single or multiple treatments under the influence of centrifugal forces to produce a variety of products as has been disclosed hereinbefore for fractions derived from comminuted groats. The centrifugal force may be applied by means of for example hydrocyclones or continuous centrifuges.
In a particular embodiment of the processes of the present invention, a flour fraction is subjected to the influence of centrifugal force in a centrifuge. After sepa-ration of the solvent, e.g. hexane, the cake of solid material obtained may be selectively split into fractions of widely varying protein content, as is exemplified hereinafter. For example by single or multiple use of centrifuges, or the use of hydrocyclones followed by the use of centrifuge, and selective separation of the centrifuge cake thus obtained into fractions, fractions having protein contents of greater than 50%, espe-cially greater than 80~, and/or less than 5%, especially less than 2.0%, are obtainable. Techniques for the selective split-ting of a centrifuge cake into fractions are known. For example a basket centrifuge may be used as the centrifuge and the fractions may be split out of the basket using a knife , : .-: ~ . - .. - - . . , : :
1~7611 blade, as is known for basket centrifuges. Flour fractions derived from oats and having high or low protein contents are believed to be particularly viable articles of commerce.
The products of the embodiments of the process of the present invention include fractions, derived from flour frac-tions, which are protein-enriched flour or protein-deficient flour. The protein-enriched flour may have a protein content of greater than 50% and especially greater than 80%. The protein-deficient flour may have a protein content of less than 5% and especially less than 2.0%. The embodiments used to obtain such protein-enriched flour or protein-deficient flour may involve the multiple use, at least in part, of centrifuges and hydrocyclones. -In general in the embodiments of the process of the present invention, at least one fraction obtained will comprise at least 20% of the comminuted groats or of an oat fraction derived therefrom.
In the separation of oats into a variety of fractions using the influence of centrifugal forces, whether on commi-nuted groats per se or on fractions derived from comminutedgroats, it is preferable, at least in so far as the separation of fractions of high protein content is concerned, that the oats, comminuted groats or fractions derived therefrom not be subjected to heat treatment. Thus in a preferred embodiment of the present invention it is preferable not to subject oats to heat treatment for drying purposes or to subject oat fractions to heated solvents. Such heating processes have been used to for example prevent subsequent oil rancidity in processes known heretofore. The absence of heat treatments in the processes of the present invention is belived to facilitate separation of products of differing protein content. `
~ ' : ' ~87611 In the processes of the present invention it is pre-~erred that water not be added to the admixtures of comminuted groats, or ~ractions derived therefrom, and solvent. As ex-empli~ied hereinafter, the addition of water may adversely af~ect the separation of the fractlons. Although water is pre~erably not added to admixtures o~ comminuted oats~ and fractions derived therefrom, and solvent, it is not neces~ry to remove water - naturally present in the oats. In fact removal o~ such ~ater by the use of a heat treatment ad~ersely a~fects the separatlon of ~ractions, as discussed hereinabove.
The products obtained in the process described herein are belie~ed to be commercially viable products. The bran fraction, with or without added prote~n9 may be useful, ~or ~xample, ~n breakrast cerealæ, as a filler for meat products or pet roods or in th~ manuracture Or textured ~egetable protein.
The flour is capable o~ being used as ~uch or when enrlched with protein, ror example, in breakfast cereals, mea~ products, baby ~oods, c~kes, pastries and cookies, as a nutritional fortirler for ~heat ~lour and as 3 sub~titute for skim m~lk powder in ~ce c~eam and other dairy products. The gum is capable o~ being e~tracted from the bra~ ~ith, for example, hot water and recovered for use as a binder or thickener in the food industry, ~or example, in lce cream, cheese and meat products.
me oil i8 capable of being used as, ~or example, a vegetable o~l.
The present inventlon i~ illu~trated by the ~ollowing examples.
EXAMPIE I
Dehulled Einoat oats, obtained ~rom Agrlculture Canada, Ottawa, O~tario, were comm~nuted on an ALPINE CO~TR~P1E~* pin-mill operating at appro~mPtely 19000 rpm. 1000 ~rams o~ the -* denote~ trade mark 1(~87611 comminuted groats were admlxed with 6.o6 litres o~ hexane and maintained in the ~orm of a sl~rry for 15 minutes. ~he slurry was then passed through a hydrocyclone (DORR-OLIVER DOXIE 'l'Y~
A IMPURITY EL~INATOR*). me inlet pressure on the hydrocyclone was varied. For each inlet pressure samples o~ so-called flour fractlon were obtained from the over~low of the hydrocyclone over a period of 20 seconds. The samples were ce~trifuged so as to separate the solids and the solids 80 obtained were dried in a ~acuum oven. In all cases the dried solids, which may be classi~ied as protein-enriched flour, were white; in comparison the comminuted groats ~ere buff coloured. me dried solids were analyzed ~or protein content (nitrogen x 6.25) using macro E~eldahl analysis.
The results were as ~ollows:
Materi~ Hydrocyclone Weight o~ Protein Inlet Pressure Solids (%) ( kg/cm2 ) ( g) Commlnuted Groats - 1000 24.1 O~er~low Solids #1 0.7 5.65 66.4 Overflow Solids #2 1.4 6.69 68.o O~erflow Solids ~ 2.1 8.39 71.1 ; Thi~ example l~lustrates the separation of protein-enriched flours from comminuted groats and the e~ect o~ di~fer-ent pressure8at the inlet of the hydrocyclone on such separation.
~ II
1000 Grams of comminuted groats obtained by pinmilling dehulled ~inoat oats using the procedure of Example I were admi~ed with 6.o6 litres o~ he~ane and maintained ~n the form of a ~lurry ~or 15 mlnutes. me slurry was then passed through the hydrocyclo~e o~ Example I using an inlet pressure o~ 1.4 kg/cm2, the slurry being separated into an o~er~low or so-called flour * denotes trade mar~
- ' - ' '~ ' 1~87~
fractlon and an underflow or so-called bran fraction. An addi-tional l~tre of hexane was then passed through the hydrocyclone so as to remove any residual amounts of the slurry. The over-flow and under flow were each centrifuged so as to separate the solids. The solids from the o~er~low were re-admixed with 0.5 litres of hexane, to remove any residual oilJ and then re-cen-tri~uged. The resultant overflow solids a~d the under flow - solids were dried ln a vacuum oven and analyzed for protein content. me results were as follows:
Materlal ~eight of Protein Colour Solids (~) (O
Comminuted Groats 1000 24.1 buff Overflow ~olids 92 65.5 white Underflow Solids 849 20.5 buf~
EXAMPLE III
2500 Grams of comm~nuted groats obtained by pinmilllng dehulled ~inoat oats using the procedure of Eæample I were ad-mi~ed with 15 litres o~ hexane and malntained in the form of a slurry for 15 minutes. me slurry was then passed through the hydrocyclone of Example I using an 1nlet pressure o~ 1.4 kg/cm2;
0.1 litres o~ hexane was subsequently passed through the hydro-cyclone 80 as to remove residual slurry from the hydrocyclone.
The overflow ~rom the ~ydrocyclone was passed through a 325 TYLER* me~h screen to remove any large particles in the over~low ~ ;
and then centri~uged to separate the solid materi~l f~om the hexane. The solid material ~as re-admixed with hexane, to remove residual oil, and then re-centri~uged. me solid materlal so obtained was dried in a vacuum oven to give the product re~erred to hereinbelow as Product ~1.
* denotes trade mark - . ~
1~876~
Two litres o~ hexane were added to the underflow from the h~drocyclone and the resultant solution was passed through a 20 TYLER mesh screen and then through a 30 TYLER mesh screen.
The solid matter retained on the two screens were dried separ-ately in a vacuum oven. ~he products obtained ~re rererred to hereinbelow as Product ~2 and Product ~3 respectively.
A further 2 litres of hexane were added to the under-- ~low solution that had passed throu~h the 30 TYLER mesh screen.
me resultant solution was pa~sed through the hydrocyclone again using an inlet pres~ure of 1.4 kg/cm2. The resultant over~low was passed thxough a 325 ~YLER mesh screen, centri~uged and the solids obtained were admixed ~ith he~ane and re-centrifuged.
The solid materlal thus obtained was dried. This product is referred to hereinbelow as Product ~ . The under~low ~as passed through a 325 TYLER mesh screen. me material (bra~) retained on the scxeen was dried and iæ referred to hereinbelow as Product ~5. ~he ~olutio~ that passed through ths ~creen Wa8 centri~uged, and the sol~ds obtained were admixed with hexane and re-cen-tri~uged. ~he solid material thus obtained was dried. T,his product i~ rererred to herein below as Product #6.
All the products were analyzed for protein conte~t.
~he res~t~ obta~ned were a~ follow~:
Material Wei~ht Protein Colour (g~ (o ~:
Commlnuted Groat~ 2500 17.1 buf~
Product ~1 191 50.9 white Product ~2 276 16.8 buff Product ~3 137 16.9 buf~
Product #4 104 55.6 white Product #5 295 14.7 buff Product ~6 989 8.4 white 1 ~ ~76 11 Products #l, ~4 and ~6 may be generally clasæi~ied as flour fractions and are of differing protein contentg. The remaining products ~ay be general~y classifed as bran fractions.
E~AMPl:E IV
2500 Grams of comminuted groats obtained by hammer-m~lling and then p~n~illing dehulled ~lnoat oats were admixed with 15 litres of hexane and main~ained in the form o~ a slurry for 15 minutes. me slurry ~nas then passed through the hydro-cyclone of E~ample I using an lnlet pressure Or 1.4 kg/cm~.
The overflow rrom the hydrocyclone was centri~uged to separate the ~ollds. ~he solids were re-admixed with hexa~eJ re-cen-tri~uged and the solid~ thus obtalned ~protein concentrate) were dried ln a vacuum oven. The underflow from the hydrocyclone waæ passed through a 20~ TYLE~ mesh and then a 325 TYLER mesh sieve. The material (bran) retalned on the two sieves uaæ com-bined and dried in a vacuum oven. The underrlow, after the sieving, was centri~uged and the solids obtained were re-admi~ed wlth hcsane and re-centrifuged. m e solids thus obtained (~lour? were driod in a vacuum oven. All the hesane solutions were combined and the oil was recovered there~rom b~ removal o~ hesane in a single stage evaporator operated at 100C and at atmospherlc pressure.
~he results were as follows:
Materlal Weight Protein Colour , (gl, ~%) Comminuted Groats 2500 17.5 bur~
Protein Concentrates 103 61.3 white Bran 750 21.0 bu~f Flour 1265 12.1 white 3o 0~ 169 - green ~-1 ~ ~ 76 E~ PLE V
Heat-treated (dried) dehulled Hinoat groats were com-minuted using a commercial hammer mill. Using a batch procesæ
samples of the comminuted groats obtained were admixed, in the form of a slurry, with hexane for approximately 15 minutes and then pas~ed through a SWEC0* ~ibro Energy Separator equipped with a 200 mesh TYLER screen. ~he so-ca~led ~lour ~raction, which passed through the screen, was centrifuged to separate the flour ~rom the hexane miscella. me flour was then dried over-night in a rotary vacuum drier.
Approximately 2 kg of the ~lour were admixed, in the ~orm of a slurry, with lO litres o~ a solvent ~or a period of 15 ~tnutes. The slurry was then passed through a lO mm DORR-OLIVER DO~IE TYPE A hydrocyclone at an inlet pre~sure of 2.8 ke/cm2. The solid material in the over~low, high protein flour, and the solid material in the underflow, low protei~ flour, from the hydrocyclone were separately centrifuged ~rom the solvent, washed with fresh solv0nt and dried in a rotary vacuum drier.
~he high a~d low protein flours were analyzed for protein using a E~el-Foss ~utomatic 16210 protein analyzer.
Details of the sol~ents u~ed and the results obtained were as ~ollow8:
Solvent Ei~h Protein Flour** Low Protein Flour ~t~g)Prote~n(~) W~(gJProtein(70) Methanol 110 41.4 1665 13.9 Ethanol*** 314 24.6 1473 15-3
The present invention relates to an improved process for the treatment of comminuted oats so as to effect separation of the comminuted oats into fractions differing in composition.
In particular, the present invention relates to the treatment of comminuted oats so as to separate the comminuted oats into a so-called "flour" fraction, a so-called "bran" fraction and an oil, and into products derived therefrom, in which the flour - is essentially free of gum. The present invention also r~lates to the treatment of comminuted oats, or flour or bran fractions derived therefrom, so as to obtain fractions having a range of protein contents, especially fractions of high and low protein contents.
As used herein the expresslon "groats" refers to the kernel oi the oat, the expression "flour" refers to the endosperm of the oat and the expression "bran" refers to the bran of the oat; such bran msy have endosperm attached thereto as i3 ex-emplified hereinafter. The expression t~gum~ refers-in particular to water-soluble gum.
Oats are a potential source of a wide variety of useiul products. Examples of such products are flour, starch, protein isolate, protein-enriched flour, bran, gum and oil. Trad-ltional techniques used in the cereal grain processing industry are frequently dif~lcult to use with oats. For example, milli~g techniques are difficult to use with oats because of process problems relating to the presence of oll in the oats. Moreover, unless the oats are de-oiled prior to milling, such milling tech-niques would result in the formation of flour and bran fractions containing oil w~lch may result in rancldity problems on storage of the flour and bran.
3o Gum, together with some protein and starch, may be removed in part by treatment of oats with water, the resultant -dilute aqueous solution of gum then requiring treatment prior to disposal or for recovery o~ the gum. Protein may be extracted from commirluted oats with aqueous solutions, especially alkaline solutions. Howe~er gum present in the oat~ may also be extracted into solutlon and the resultant solutions may be ~iscous and cause process problems, especially in the separation of 301idæ
from the aqueous solutions.
The composltion and properties of water-soluble gums obtained from cereal grains are discussed by BoL~ D'Appolonia in a paper presented at the sym~osium on "Industrial Use~ of Cerealsl' held ~ conJunction with the ~8th Annual Meetirlg o~ the American ~ssociation of Cereal Chemists, ~ovember 1973.
A process for the separation of acid-soluble protein from com~inuted oats, a~d techniques for the reco~ery o~
starch, gum and the like in related processes, is described in Canadian Application No. 245,163 of A. BeLl, J.R. B. Boocock and R.N. O~ghton, f~ed Febr~r 4, 1976. Tec~niqueæ for the separation o~ oil ~rom commlDuted oats are ~mo~n; such tech~que3 are discussed ln the a~orementioned applicatio~ o~ A. Bell et al.
A process ~or i~olating protein ~rom a pulverlzad oil seed w~ing liqlsid f`luorocarbons is disclosed in U.S. Patent 3,869,438 o~ J.W. Finley et al, which issued March 4, 1975.
A process for the separation of a flour fraction, a bran fraction and oil ~rom commi~uted oats in which ~um does not cause signi~ic~t process problems and in which the flour is ess~ntially free of gam ~s Lisclosed i~ Ca~adian Application 254,864 of R.W. Oughton, f~led June 15, 1976. However, the pro-ces~ disclosed by R.W. Oughton is capable of impro~ement.
Processes for the sol~rent-extractiire n~ g of maize or corn, whea~, rye ana the sorghum grains to remove the brs~
coat fro~hole kernels of such grains followe~ by commi~utio~
of the whole mllled kernel3 and for the separation o~ so-caLl.ed 10876i1 fibrous, proteinaceous, endosperm and/or starch ~ractions derived from such grains are disclosed by T.B. W~yne in Canadian Patents 86~,538, which issued February 23, 1971, and 905,509 and 905,910, both o~ which issued July 25, 1972.
A need exists for the discovery of a process for the treatment Or comm~nuted oats, especially for the productlon of flour and/or protein, that is less susceptible to process pro-blems relating to the presence of oil snd gum in the oats.
An improved process ~or the separation of a flour frsctlon, a bran ~ractlon and oil, especially protein-enriched flours and protei~-de~icient flours, from comm~nuted oats has now been found.
Accord~ngly the present invention provides a process for the ~paration of comminu~ed oats into fractions differing in compo8itlo~, said proce~s comprising:
(a) admi~lng comminuted oats with a~ organic sol~ent, said solvent being capable of extracting oat oil from sa~d oats;
(b) forming a slurry Or said admixture of comm~nuted oats a~d solveat; and (c) Qub~ecting the 51urry to the influence of c-ea-trifugPl force and thereby separating the commi~uted oats in said slurr~ lnto at least two fraction~, said fractions d~fering i~
compositlon.
me present invention also provid~s a process ~or the separation of com~nuted oat~ into ~ractions dif~ering in com- -positio~ Qaid process co~prising:
(a) ad~ixing an oat fr~ction, derived from said com-mi~uted oats, with an organic solvent, said ~olvent b~ing a sol-vent capsble o~ extractl~g oat oil from oats.
(b) ~orming a slurry of said admixture of oat fraction . and organic ~olvent; and _3_ .. . . . .... .
108761~
(c) sub~ecting the slurry to the influence of centri~ugal force and thereby sep~ating said oat fraction lnto at least tw~ fractlons, said fractions differing in protein content.
In addition the present in~ention provides a process for the separation of comminuted oats into ~ractions differing in composition, said process comprising:
(a) a~m~ing an oat fraction, der~ved ~rom comminuted oats, with an organic solvent, said sol~ent being a solvent capable o~ e~tracting oat oil from oats;
(b) sub~ect~ng said admixture to the in~luence of centrirugal force in a centrifuge and thereby forming a centrifuge cake o$ said oat fraction;
(c) separating said cake in the substantial absence of said solYent i~to at lea~t two layers, the protein content of at leaQt one of said layers being different ~rom the protein con-tent of at least one o~ said other layers.
Furthermore the present invention prov~des a process for the ~eparation Or comminuted oats, or fraction~ derived therefrom, into ~ractions dif~er~ng in composltion, said ~ep-~-- aration being carried out in the presen~e of an organic ~olvent, the impro~ement comprisi~g utllizing oats which ha~e not been subJected to heat treatmRnt.
The comminuted oats ~sed ln the process of the present invention are pre~erably obtained from dehulled oats. Techniques ~or dehulllng oat~ are known in the art. me dehulled oats, herei~ generally referred to as groats, are commlnuted ln order to facilitate e~traction o~ oil and to ~acilitate separation of the sub~equentl~ ~ormed slurry o~ comminuted groats and organic solvent into a ~lour fractio~ and a bran ~raction. Ihe re~uired , 1~87611.
partlcle size o~ the comminuted gxoats will depend in particular on the techni~ue to be used to separate the comminuted groats in the slurry into fractions di~fering in composition. For example, if a hydrocyclone is used to separate the comminuted groats into fractions the particle size of the comminuted grQats must be sufficiently small to allow the hydrocyclone to operate smoothly and e~iciently and without clogging or plugglng of the hydrocyclone. Conventional techniques, ror example, pin-m~lling, hamm~r milling and other shearing technlques ~ould appear to produce acceptable comminuted groats.
In the process of the present in~ention the com~inuted groats are admixed with a solvent for the oil i~ the oats in order to fac~litate extraction of the oil from the commi~uted groats i.e. to de-oil the comminuted grosts. The solvents u~ed m~st be acceptable ~or u~e with foodstu~s, e.g. be non-toxic at the le~els remaining in the products subsequently produced, not cause the ~ormation o~ toxic materials ln the pxoduct and not ha~e a significant deleterious effect on the nutritional ~alue o~ the product, and must be capable of permitting separa-tion o~ the ~lour and bran fractlons. ~he amount snd type of sol~ent remaini~g in products offered ~or ~ale must be acceptable to the appropriate health authorities, as will be under~tood by thoæe skllled in the art. Examples o~ solvent~ are pentane, hexane, heptane, cyclohexa~e and alcohQls o~ 1 1! carbon atoms, a~d mixtures thereo~; as used herein the solvents hexane and hepta~e include those solvents re~erred to ln the ~ood industr~
as hexane and heptane. The pre~erred solvent is hexane. The present inventlon will generally be described here~nafter with re~erence to hexane as the solvent.
me admlxing of the comm$nuted groats and hexane is pre~erabl~ carried out with agitation, e.g., stirring. I~ a , 1~87611preferred embodiment of the process o~ the present invention the commi~uted groats a~d heæane axe admixed and then agitated so as to form a ~lurry of the comminuted grosts and hexane. The time between admixing the comminuted groats and hexane snd forming the slurry of comminuted groats and hexane may be very short or alternati~ely the admixture may be mai~tained as ~uch for a sig~i~icant perioq of time before the slurry is ~ormed.
me period of time during which the comminuted ~roat~ and heæane are in contact, i.e., the time as an admixture and as a slurry, should be such that the desired degree o~ e~traction of oil from the comminuted groats ls achieved, the period of time being depe~den~ in part on the actual technique o~ e~traction. Gen-era ~ a slurry o~ comminuted groats and hexane will be formed essentially on ad ~ .
me comminuted groat~ and heza~e m~y be a~m~Yed and/or formed into a 31urry under conditions that result in ~urther - comminution o~ the groats. Thus, the comminuted groats a~mi~ed with the he~ane may be o~ a paricle size that is not s~itable for the ~ubseguent separatlon step and the necessary additional comminution prior to separation of the slurry lnto at least two fractions ma~ occur while the commlnuted ~roat~ and hexzne are admixed or i~ the form of a slurry. In such embodiments it may be pre~erable to incorparate means ~or separation o~ o~ersize particles ~rom the admixture and/or slurry, especiall~ ~ust prior to the separation o~ the comminuted groats i~ the slurry i~to fractions, and to sub~ect such particles to further com-minution. me utilization o~ the admixture and/or the slurry for additional comminution o~ the comminuted groats may be a factor in the determinatlon of the period o~ time between the admi~ng of the comminuted groats and hexane and the subseguent separation o~ the comminuted groats into at least two ~ractions.
1~3187611 In order to effect separation of the comminuted groats into ~ractions, the slurry is sub~ected to centri~ugal ~orce. me means used to sub~ect the slurry to centri~ugal ~orce is a centrifugal separator, pre~erably a centri~ugal separator capable of being operated on a continuous or semi-continuous basis. Egamples of centrifugal separator~ are con-tinuous centrifuges including semi-continuous centrifuges, and, - in partlcular, hydrocyclones.
In order to effect separation of the comminuted groatæ
into ~ractlons in a hydrocyclone, the slurr~ o~ comminuted groats asd he~ane is ~ed to the hydrocyclone whereupon the slurry i~
sub~ected to centrlfugal force. Under such conditions, fraction-ation of the comminuted groats in the slurry tends to occur.
The operation o~ the hydrocyclone so as to obtain a desired fractionation of the comminuted groats in the slurry wlll depend o~ a number o~ process variables. Examples Or such varlables are the degree of comminution of the comm~nuted groats, the amount o~ sol~d material in the slurry, the pressure drop across the h~drocyclone, the ratio o~ the ~lows through the so-called '~nderflow" and "over~low" outlets, the dif~erence in density between the sol~ent and the particles of the comminuted groat~, the viscosity of the solvent and the like, as will be understood by those skilled in th~ art. The operatlon of the hydrocyclo~e is ad~usted so that a desired fractionation o~ the comm~nuted groats in the slurry ~ed to the hydrocyclone is obtained. In particular, the hydrocyclone is operated so that a bran fraction, in hexane, flows ou~ the underflow outlet and a ~lour fractlon, ~n hexane, flows out the ~erflow outlet. Preferably one f~ac-tion contain~ at least 20% and in particular at least 40% of the comminuted oats.
10876~.1 The ~lour ~raction may be separated from the flour fraction~hex&ne mixture by known techniques ~or sep~rating a solid ~rom a solution. For eæample, the flour ~raction may be separated ~rom the ~lour ~raction/hexane mixture by centri-fuging techniques. As the hexane contains dissolved oil, it may be desirable to wash the flour ~raction after separation so as to remo~e any oil adsorbed on the flour. The oil may be recovered from the oil-containing hexane solution by removal of the hexane. Similarly the bran fraction may be recovered from the bran ~raction~hexane mix~ure by removal o~ the hex2ne. In these operations the hexa~e is pre~erably reco~ered and re-used in the separation of the ~lour and bran ~ractions from the com-minuted groats. Alternatively, the oil-containing hexane solution may at least in part, be used in the separation o~ the ~lour and bran fractions ~rom the comminuted groats.
Depending on the desired products, the flour and bran fractions may, either before or after separation ~rom the he~ane, be subJected to ~urther comminution and~or further separatlon uslng, ~or example, a hydrocyclone. Thus the separation o~
the comminuted groats into ~ractions ma~ involve the multiple use o~, for e2ample, h~drocyclones, such multiple use may be in a sequential m~nner and may ~nclude recycle of ~ractions. Other - methods of separation may be used in con~unction with ~ep-aratlo~s in~olv~ng the use of hydrocyclones, e.g., a ~lo~r fraction containing a small amount of bxan may advantageo~sly be treated with a ~creen or cla~sifier. The procesæ of the pre-sent inYention can therefore be u~ed for the separation of com-minuted groat~ into ~lour fraction~ conta~n~ng flour o~ varying propertlos, especially varying protein contents, a~d into bran fractions of var~ing properties. Such may be zdvantageous for ~ome end use3.
~0876~1 me bran fraction in the process o~ the present ln-vention may be comprised of br&n particles having endosperm adhered thereto. The bran fraction may be sub~ected to further comminution in the pre~ence or absence of hexane and either returned to the admixture of commi~uted groats and hexane for further separation into flour and bran fractions or independently separated into further flour and bra~ fractions. Bran fractions of varying endo~perm content are obtainable.
The oil obtained in the proces3 of the present in-vention may be turbid and it may be desirable to clari~y theoil. me oil may be clairi~ied by techniques known in the art or by mixing with ~sopropanol especially isopropanol containi~g h~drogen peroxide, agitating and then removing any ~olld material, e.g. by centri~uging. A clear brown oil is obtainable. ~he solids remo~ed o~ centrifuging ar~ believed to contain signi-flcant ~mounts of phospholipids and may be suitable for use, for exsmple, as emNlsifiers.
The ~lour ~raction that is separated by the proce~s of the prese~t invention i~ essenti~lly ~ree of gum. In addi-tion the flour fraction is essentially free of oil~ me water-soluble gu~s, which are in the bran fraction, are recoverable.
The product3 of the process of the present in~ention are believed to be use~ul in the food ~ndustry either 8S such or as a source of other products.
~ he ~a~or componentæ o~ the flour fraction are stsrch and proteln. In addition to separation under the in~luence o~
centri~ugal force, the flour fraction is capable of being sep-arated into fractions o~ ~arying starch and protein contents using air classification techniques. Protein and stsrch con-centrates may be also obtained from the flour fraction by _g_ 1087611extracting the flour with aqueous acidic or alkaline solutions.
A high proportion of the protein in the flour fraction may be extracted by slurrying the ~lour fraction in such aqueous solutions. The pH o~ the aqueous solution is pre~erably at least 9.O and especially about 11.0 if the solution is alkaline and about 2.0 ir the solution is acidic. Examples of suitable alkalis ~or the ad~ustment of pH are sodium hydroxide and potassium hydroxide. Examples of suitable acids are phosphoric acid, hydrochloric acid and citric acid. As discussed herein gums, especially water-soluble gums in the oats, are separated in the bran ~raction in the process described above and the flour fraction obtalned is essentially free of gum. Thus processes for the extractlon o~ protein from the flour fraction of the process of the present inYention may be operated at low solution Yiscosities, which is most advantageous ~rom a processing and especially a product separation point o~ ~iew. The solid mat-erial in the protein extraction solution may be separated from the solution u~ing, ~or example, centrifuging techniques. It i8 l~kely desirable to wash or re-slurry the solids with water to separate absor~ed solubilized protein and to re-separate the solids. The solid material is comprised primarily of starch. If the starch contai~s a m~nor amount of bran or the like it may be des~rable to subJect it to, for e~ample, sieYing3 washlng or air classi~ication to puri~y the starch.
The solubilized protein obtained on extraction of the rlour ~raction may be reco~ered by, for example, isoelectric precipitation. me pH of the solubilized protein solution is ad~usted to about 3.5-4.5 with alkali, e.g., sodium hydroxide, ; or acid, e.g., phosphoric acid~ as required. me precipitate Or protein obtained may be separated by, for example, centri-~uging the solution. Protein may also be obtained by freeze drying the solutlon o~ solubulized protein. This may be especially useful for recovery o~ acid-soluble protein especially 10~376~L1 from solutions at the pH at ~hich it is desired that the pro-tein be soluble. The properties of the protein, including the colour of the protein may depend on the technique o~ extracting and separating the protein. Protein obtained by alkali or acid extractio~ is believed to be stable in hot aqueous acidic sol-utions. Acid^soluble protein obtainable from the flour fraction, as de~cribed herei~ may be preferable to that obtainable dir-ectly ~rom de-oiled groats. If the protein is to be blended with another substance, e.g., flour, it may be preferable to extract the protein from the flour fraction with an acidic solution and ~reeze dry the protein as the protein so obtained may b~ whiter than that obtained by isoelectric precipitation.
Protein may also be extracted from the ~lour ~raction~
u~ing aqueous solutions of substantially neutral pH. Such pro-tein is capable of being precipitated in hot water.
While the present invention has been desc~ibed herein-be~ore with particular re~erence to the separation o~ comminuted æroats into ~raction using in particular a hydrocyclone, the present invention is not l~m~ted thereto. In a pre~erred em~odi-ment o~ the in~entlon the material which is subJected to thein~luence o~ centrifugal force is an oat fraction that ha~ been obtained ~rom comminuted groats by means other than the use of centrifugal force. For a~ample the oat fraction, which may be ~or example a bran fraction or a flour ~raction, may be ob-tained by clas~i~ying admi~tures o~ comminuted groats and a 801-vent, for example, hcxane. The classifying of admixture~ of comminuted groats and ~ lvents and other tech~iques for the separatlon of oat ~ractions are di~closed in the a~orem~ntioned Canadian patent application ~o. 254,864.
3761~
The use of the influence of centrifugal force on fractions derived from comminuted groats, rather than on commi-nuted groats per se, may be advantageous in that process prob-lems associated with large particles e.g. the clogging of hydrocyclones, may be reduced or avoided. The treatment of bran fractions is less preferred than the treatment of flour - fractions because of the greater likelihood of large particles, and the consequent possibility of process problems resulting therefrom, in bran fractions. Oat fractions, especially flour fractions, may be subjected to single or multiple treatments under the influence of centrifugal forces to produce a variety of products as has been disclosed hereinbefore for fractions derived from comminuted groats. The centrifugal force may be applied by means of for example hydrocyclones or continuous centrifuges.
In a particular embodiment of the processes of the present invention, a flour fraction is subjected to the influence of centrifugal force in a centrifuge. After sepa-ration of the solvent, e.g. hexane, the cake of solid material obtained may be selectively split into fractions of widely varying protein content, as is exemplified hereinafter. For example by single or multiple use of centrifuges, or the use of hydrocyclones followed by the use of centrifuge, and selective separation of the centrifuge cake thus obtained into fractions, fractions having protein contents of greater than 50%, espe-cially greater than 80~, and/or less than 5%, especially less than 2.0%, are obtainable. Techniques for the selective split-ting of a centrifuge cake into fractions are known. For example a basket centrifuge may be used as the centrifuge and the fractions may be split out of the basket using a knife , : .-: ~ . - .. - - . . , : :
1~7611 blade, as is known for basket centrifuges. Flour fractions derived from oats and having high or low protein contents are believed to be particularly viable articles of commerce.
The products of the embodiments of the process of the present invention include fractions, derived from flour frac-tions, which are protein-enriched flour or protein-deficient flour. The protein-enriched flour may have a protein content of greater than 50% and especially greater than 80%. The protein-deficient flour may have a protein content of less than 5% and especially less than 2.0%. The embodiments used to obtain such protein-enriched flour or protein-deficient flour may involve the multiple use, at least in part, of centrifuges and hydrocyclones. -In general in the embodiments of the process of the present invention, at least one fraction obtained will comprise at least 20% of the comminuted groats or of an oat fraction derived therefrom.
In the separation of oats into a variety of fractions using the influence of centrifugal forces, whether on commi-nuted groats per se or on fractions derived from comminutedgroats, it is preferable, at least in so far as the separation of fractions of high protein content is concerned, that the oats, comminuted groats or fractions derived therefrom not be subjected to heat treatment. Thus in a preferred embodiment of the present invention it is preferable not to subject oats to heat treatment for drying purposes or to subject oat fractions to heated solvents. Such heating processes have been used to for example prevent subsequent oil rancidity in processes known heretofore. The absence of heat treatments in the processes of the present invention is belived to facilitate separation of products of differing protein content. `
~ ' : ' ~87611 In the processes of the present invention it is pre-~erred that water not be added to the admixtures of comminuted groats, or ~ractions derived therefrom, and solvent. As ex-empli~ied hereinafter, the addition of water may adversely af~ect the separation of the fractlons. Although water is pre~erably not added to admixtures o~ comminuted oats~ and fractions derived therefrom, and solvent, it is not neces~ry to remove water - naturally present in the oats. In fact removal o~ such ~ater by the use of a heat treatment ad~ersely a~fects the separatlon of ~ractions, as discussed hereinabove.
The products obtained in the process described herein are belie~ed to be commercially viable products. The bran fraction, with or without added prote~n9 may be useful, ~or ~xample, ~n breakrast cerealæ, as a filler for meat products or pet roods or in th~ manuracture Or textured ~egetable protein.
The flour is capable o~ being used as ~uch or when enrlched with protein, ror example, in breakfast cereals, mea~ products, baby ~oods, c~kes, pastries and cookies, as a nutritional fortirler for ~heat ~lour and as 3 sub~titute for skim m~lk powder in ~ce c~eam and other dairy products. The gum is capable o~ being e~tracted from the bra~ ~ith, for example, hot water and recovered for use as a binder or thickener in the food industry, ~or example, in lce cream, cheese and meat products.
me oil i8 capable of being used as, ~or example, a vegetable o~l.
The present inventlon i~ illu~trated by the ~ollowing examples.
EXAMPIE I
Dehulled Einoat oats, obtained ~rom Agrlculture Canada, Ottawa, O~tario, were comm~nuted on an ALPINE CO~TR~P1E~* pin-mill operating at appro~mPtely 19000 rpm. 1000 ~rams o~ the -* denote~ trade mark 1(~87611 comminuted groats were admlxed with 6.o6 litres o~ hexane and maintained in the ~orm of a sl~rry for 15 minutes. ~he slurry was then passed through a hydrocyclone (DORR-OLIVER DOXIE 'l'Y~
A IMPURITY EL~INATOR*). me inlet pressure on the hydrocyclone was varied. For each inlet pressure samples o~ so-called flour fractlon were obtained from the over~low of the hydrocyclone over a period of 20 seconds. The samples were ce~trifuged so as to separate the solids and the solids 80 obtained were dried in a ~acuum oven. In all cases the dried solids, which may be classi~ied as protein-enriched flour, were white; in comparison the comminuted groats ~ere buff coloured. me dried solids were analyzed ~or protein content (nitrogen x 6.25) using macro E~eldahl analysis.
The results were as ~ollows:
Materi~ Hydrocyclone Weight o~ Protein Inlet Pressure Solids (%) ( kg/cm2 ) ( g) Commlnuted Groats - 1000 24.1 O~er~low Solids #1 0.7 5.65 66.4 Overflow Solids #2 1.4 6.69 68.o O~erflow Solids ~ 2.1 8.39 71.1 ; Thi~ example l~lustrates the separation of protein-enriched flours from comminuted groats and the e~ect o~ di~fer-ent pressure8at the inlet of the hydrocyclone on such separation.
~ II
1000 Grams of comminuted groats obtained by pinmilling dehulled ~inoat oats using the procedure of Example I were admi~ed with 6.o6 litres o~ he~ane and maintained ~n the form of a ~lurry ~or 15 mlnutes. me slurry was then passed through the hydrocyclo~e o~ Example I using an inlet pressure o~ 1.4 kg/cm2, the slurry being separated into an o~er~low or so-called flour * denotes trade mar~
- ' - ' '~ ' 1~87~
fractlon and an underflow or so-called bran fraction. An addi-tional l~tre of hexane was then passed through the hydrocyclone so as to remove any residual amounts of the slurry. The over-flow and under flow were each centrifuged so as to separate the solids. The solids from the o~er~low were re-admixed with 0.5 litres of hexane, to remove any residual oilJ and then re-cen-tri~uged. The resultant overflow solids a~d the under flow - solids were dried ln a vacuum oven and analyzed for protein content. me results were as follows:
Materlal ~eight of Protein Colour Solids (~) (O
Comminuted Groats 1000 24.1 buff Overflow ~olids 92 65.5 white Underflow Solids 849 20.5 buf~
EXAMPLE III
2500 Grams of comm~nuted groats obtained by pinmilllng dehulled ~inoat oats using the procedure of Eæample I were ad-mi~ed with 15 litres o~ hexane and malntained in the form of a slurry for 15 minutes. me slurry was then passed through the hydrocyclone of Example I using an 1nlet pressure o~ 1.4 kg/cm2;
0.1 litres o~ hexane was subsequently passed through the hydro-cyclone 80 as to remove residual slurry from the hydrocyclone.
The overflow ~rom the ~ydrocyclone was passed through a 325 TYLER* me~h screen to remove any large particles in the over~low ~ ;
and then centri~uged to separate the solid materi~l f~om the hexane. The solid material ~as re-admixed with hexane, to remove residual oil, and then re-centri~uged. me solid materlal so obtained was dried in a vacuum oven to give the product re~erred to hereinbelow as Product ~1.
* denotes trade mark - . ~
1~876~
Two litres o~ hexane were added to the underflow from the h~drocyclone and the resultant solution was passed through a 20 TYLER mesh screen and then through a 30 TYLER mesh screen.
The solid matter retained on the two screens were dried separ-ately in a vacuum oven. ~he products obtained ~re rererred to hereinbelow as Product ~2 and Product ~3 respectively.
A further 2 litres of hexane were added to the under-- ~low solution that had passed throu~h the 30 TYLER mesh screen.
me resultant solution was pa~sed through the hydrocyclone again using an inlet pres~ure of 1.4 kg/cm2. The resultant over~low was passed thxough a 325 ~YLER mesh screen, centri~uged and the solids obtained were admixed ~ith he~ane and re-centrifuged.
The solid materlal thus obtained was dried. This product is referred to hereinbelow as Product ~ . The under~low ~as passed through a 325 TYLER mesh screen. me material (bra~) retained on the scxeen was dried and iæ referred to hereinbelow as Product ~5. ~he ~olutio~ that passed through ths ~creen Wa8 centri~uged, and the sol~ds obtained were admixed with hexane and re-cen-tri~uged. ~he solid material thus obtained was dried. T,his product i~ rererred to herein below as Product #6.
All the products were analyzed for protein conte~t.
~he res~t~ obta~ned were a~ follow~:
Material Wei~ht Protein Colour (g~ (o ~:
Commlnuted Groat~ 2500 17.1 buf~
Product ~1 191 50.9 white Product ~2 276 16.8 buff Product ~3 137 16.9 buf~
Product #4 104 55.6 white Product #5 295 14.7 buff Product ~6 989 8.4 white 1 ~ ~76 11 Products #l, ~4 and ~6 may be generally clasæi~ied as flour fractions and are of differing protein contentg. The remaining products ~ay be general~y classifed as bran fractions.
E~AMPl:E IV
2500 Grams of comminuted groats obtained by hammer-m~lling and then p~n~illing dehulled ~lnoat oats were admixed with 15 litres of hexane and main~ained in the form o~ a slurry for 15 minutes. me slurry ~nas then passed through the hydro-cyclone of E~ample I using an lnlet pressure Or 1.4 kg/cm~.
The overflow rrom the hydrocyclone was centri~uged to separate the ~ollds. ~he solids were re-admixed with hexa~eJ re-cen-tri~uged and the solid~ thus obtalned ~protein concentrate) were dried ln a vacuum oven. The underflow from the hydrocyclone waæ passed through a 20~ TYLE~ mesh and then a 325 TYLER mesh sieve. The material (bran) retalned on the two sieves uaæ com-bined and dried in a vacuum oven. The underrlow, after the sieving, was centri~uged and the solids obtained were re-admi~ed wlth hcsane and re-centrifuged. m e solids thus obtained (~lour? were driod in a vacuum oven. All the hesane solutions were combined and the oil was recovered there~rom b~ removal o~ hesane in a single stage evaporator operated at 100C and at atmospherlc pressure.
~he results were as follows:
Materlal Weight Protein Colour , (gl, ~%) Comminuted Groats 2500 17.5 bur~
Protein Concentrates 103 61.3 white Bran 750 21.0 bu~f Flour 1265 12.1 white 3o 0~ 169 - green ~-1 ~ ~ 76 E~ PLE V
Heat-treated (dried) dehulled Hinoat groats were com-minuted using a commercial hammer mill. Using a batch procesæ
samples of the comminuted groats obtained were admixed, in the form of a slurry, with hexane for approximately 15 minutes and then pas~ed through a SWEC0* ~ibro Energy Separator equipped with a 200 mesh TYLER screen. ~he so-ca~led ~lour ~raction, which passed through the screen, was centrifuged to separate the flour ~rom the hexane miscella. me flour was then dried over-night in a rotary vacuum drier.
Approximately 2 kg of the ~lour were admixed, in the ~orm of a slurry, with lO litres o~ a solvent ~or a period of 15 ~tnutes. The slurry was then passed through a lO mm DORR-OLIVER DO~IE TYPE A hydrocyclone at an inlet pre~sure of 2.8 ke/cm2. The solid material in the over~low, high protein flour, and the solid material in the underflow, low protei~ flour, from the hydrocyclone were separately centrifuged ~rom the solvent, washed with fresh solv0nt and dried in a rotary vacuum drier.
~he high a~d low protein flours were analyzed for protein using a E~el-Foss ~utomatic 16210 protein analyzer.
Details of the sol~ents u~ed and the results obtained were as ~ollow8:
Solvent Ei~h Protein Flour** Low Protein Flour ~t~g)Prote~n(~) W~(gJProtein(70) Methanol 110 41.4 1665 13.9 Ethanol*** 314 24.6 1473 15-3
2-Propanol280 22.5 1466 14.2 ie~tane 25 51.9 1836 15.7 ~eptsne 50 55.9 1750 16.9 Cyclohe~ane 140 38.2 1670 14.6 * denotes trade mark 1~87611 ** The starting material, flour, contained 17.6~ protein *** Denatured alcohol containing 85~ ethanol and 15~ methanol was used.
EX~LE Vl Approximately 2 kg o~ dehulled Hinoat groats that had been comminuted on a commercial hammer m~ll were admixed, in the form of a slurry, with solvent for 15 minutes. me slurry was then passed through a SI~ECO Vibro Energy Beparator equipped with a 200 me h TYLER screen. me oversize material, bran, retained on the screen was dried ln a rotary vacuum drier. The slurry of ~lour in solvent miscella was passed through a 10 mm ~ORR-OLIVER DOXIE TYPE A hydrocyclone at an ~nlet pressure Or 2.8 kg/cm . me orerflow ~rom the hydrocyclone was collected.
The underflow was passed through the hydrocyclone again and the overflow obtained was combined with that obtained previously.
The underflow thus obtained, which contained low protein ~lour, was centrifuged, r~n~ed with fresh solvent and dried in a rotary racuum drier. The combined orerrlows, which contained high pro-tein flour were s~m~arIy centrifuged, rinsed and dried. me solvent miscella obtained was passed through a rotary evaporstor to recover the o~l~ The oil obtained was dried in a racuum oren. me flour and bra~ fractions obtained were analyzed for protein using a B~el-Foss Automatic 16210 protein analyzer.
Details o~ the solvents used and the results obtained were a~ followg:
Run A* B*
Solrent Methanol ~yclohexane -` Bran welght(g) 755 692 protein(%) 23.2 21.1 , . ,, ~ . - . -, ,:
, . , . :.
.
Run A* B*
High Protein Flour weight(~) 47 128 protein(~) 39.7 42.7 Low Protein Flour weight(g) 1213 600 protein(%) 1~.5 13.8 Oil we*ght(g) 52 166 * the startlng material, comminuted groats, contained 19.3$
- protein.
EXAMPIE VII `
Approximately 250 g of pinmilled dehulled Hinoat groats were stirred, as a SlurrY~ with 400 g of hex~ne at ambient temp-erature for five minutes and then passed through a 200 mesh TYLER screen. The oversized material, bran, retained on the screen was admi2ed, in the form of a slurry, with 200 g o~ hexane and re-screened. The undersized mater~al, flour, ~rom both screenings were comblned, centrifuged and the hexane miscella was decanted of~. The flour so obtai~ed was admised, in the ~orm o~ a slurry with 125 ml of hexane, poured into two extraction thimbles, each measuring 43 x 123 mm, located in separate 250 ml centri~uge cups and centrifuged at 1000 G for 10 minutes. me hexane was decanted o~. me th~mbles were cut open and analytical-size samples (First Centrifuge samples) were taken from the top, middle and bottom ~ections of the cake of solid mater~al in the thimLble. Each o~ the cakes were then separated into ntop-hal~l' and nbottom-hal~" ~ractions. One "top-hal~l' fractlon and one "bottom-half" ~raction were separately admixed, in the ~orm o~ a slurry, with 30 ml o~ hexane and re-centri~uged at 1000 G. Analytical sample~ (Second Centrifuge Top-~al~ and Bottom-Eal~ samples) were again taken from the top, middle and bottom sections of the cake of solid material obtained. The second "top-half" and "bottom-halr" ~ractions were separately admlxed wlth 30 ml Or hexane in a WARI~G* Blender ~or 5 m~nute3 * denotes trade mark -21-1~ ~7 6 11 and then re-centrifuged at lOOO G. Once again analytical samples (Blender-Centrifuge Top-Hal~ and Bottom-~alf samples) were taken from the top, middle and bottom sections of the cake of solid materlal obtained.
All samples were dried in a vacuum oven and analyzed ~or protein with a Kjel-Foss Automatic 16210 Analyzer.
The results were as folLows:
Location ofProtein in Analyzed SampleSample (~) LO First Centrifuge Samples Top 83.o Middle 6.2 Bottom 10.2 Second Centri~uge Samples (a) Top-Half Top 56.~
Middle 6.4 Bottom 7.6 (b) Bottom-~alf Top 15.4 MiddLe 2.2 Bottom 2.8 Blender Centrifuge Samples - (a) Top-Half Top 88.6 Mlddle 7.7 Bottom 7.6 (b) Bottom-Hal~ Top 21.4 Middle 2.2 Bottom 2.7 The anay~ses Or the "top" fractions of the Second Centrifuge and Blender centrifuge samples indicate the ef~ect of the high shear in the Waring blender on protein content of fractions. The eæample sl~o 3hows that fr~ction3 of hlgh and low proteln content are obtainable.
EXAMPLE VIII
Approximately 200 g of pinmilled Hinoat groats which had not been subJected to any heat treatment, were ad~ixed, in the form of a ~lurry, with 500 g of hexane for five minutes and then passed through a 200 mesh TYLER screen. The oversized 1~7611 particles, bran, retained on the screen were admixed, in the form of a slurry, with a further 200 g of hexane for ~lY~ minutes and re-screened. The undersized material, flour, and hexane miscella from both screenings were combined and centrifuged. The hexane miscella was decanted off and the solid material admixed, in the form of a slurry, wlth a further 130 g of hexane. Portions of the slurry were poured into 43 x 123 mm extractlon thimbles located in 250 ml centrifuge cups and centrifuged for 10 minutes at specific centrifugal forces. The hexane was decanted off and the thimbles were permitted to air-dry for ten minutes.
Analytlcal-size samples were then taken from the top, middle and bottom 3ections of the cake o~ solid material in the thimble.
m ese samples were dried and analyzed for protein conbent using a K~el-Foss Automatic 16210 proteln analyzer.
e above procedure was repeated uslng plnmilled groats that had been heat-treated at 95C in a forced-air oven for one hour prior to the initial admixing with hexane.
Using a different s~mple of pinmilled groats, the above procedure was repeated on pinmilled groats that had not been sup~ected to heat treatment and on pi~milled groats that, after the initial admixing with hexane, were heated ror one hour ln the hexane under reflux conditions (68C).
m e above procedure was also repeated using a flour fraction that had been obtained from hammer milled groats by screening a slurry of the hammer milled groats in hexane, sep-arating and drying the flour fraction in an oven.
The results obtained were as follows:
~{~876~1 Run A B C D E
Starting Material Protein(~ 20.2 20.2 17.2 17.2 17.1 Heat Treatment none 95C none 68C d~ied Products (a) Centrifugal Force 300 G
Protein(~) (i ~P 60.2 49.4 62.9 53.3 24.7 (iii Middle 9.011.1! 6.510.0 14.8 10(iv Bottom 5.1 7.9 4.0 4.8 13~5 (b) Centrifugal Force 1000 G
Protein(~) (1 Top 64.6 42.3 80.6 47.2 24.5 (ii ~iddle 8.315.1 6.3 6.6 1~.9 (iii Bottom 7.1 8.8 4.1 4.8 15.7 The above example indicates that heat treatment affects the separation of, in particular, fractions of high protein con-tent.
,EXA~PIE IX
Approximately 500 g of ~inoat groatæ that had been obtained u~ing a commercial hammer mill were admixed in the form of a slurry with one litre of hexane for fi~e ~tnutes. The resultant admixture was then passed through a 200 mesh T~LER
screen. The o~ersized material, i.e. that retained on the screen, wa~ re-zdmixed with one litre of hexane for five minutes and re-screened. The flour fraction and hexane miscella from both screenings were combined and then centrifuged at 1000 G for 10 minutes. The hexane miscella was decanted off. The solid material was admlxed, as a slurry, with 175 g of hexane, poured into four 43 x 123 mm extraction thimbles supported in 250 ml centrifuge cup~ and centri~uged at 1000 G for lD minutes. The hexane was decanted off and the thimbles were cut open.
Analy~ical-size samples (First centrifuge samples) were taken from the top, middle and bottom ~ections of the cake of solid material in the thimbles. The cakes were then split into "top-half" and "bottom-half" samples, me combined bottom-h&lf samples were admixed, in the form of a slurry, with 90 g of ~. .
.. . .
l~S7611 hexane and centrifuged using the extraction thimbles as described above. Analytical-size samples (First ~plit Cen-trifuge samples) were taken from the top, middle and bottom sections o~ the cake of solid material obtained. Once again the cakes were split into "top-half" and "bottom-hal~" samples.
The combined bottom-half samples were admixed with 45 g of hexane and the procedure was repeated using on~y one thimble.
Analytical-size samples (Second Split Centrifuge samples) were again taken from the top, middle and bottom sections o~ the cake of solid material obtained. Yet again the cakes were split into "top-h~l~" and "bottom-half" samples. The bottom hal~ sample was admlxed with 25 g of hexane and the above procedure repeated u8ing a 33 x 94 mm extraction th~mble. Analytical-size samples (Third Split Centri~uge samples) were agaln taken ~rom the top, middle and bottom sections of the cake o~ solid material obtained. All samples were analyzed ~or protein using a K~el-Foss Automatic 16210 Protein Analyzer.
The results ~ere as ~ollows:
Sample Protein Ana ~ sis (~)_ ~rop M1~ e~Qitom - F~rst Centrifuge* 80.9 7.7 4-9 First Spllt Centri~uge 16.8 2.4 3.1 Second Split Centrifuge 4.1 2.0 2.1 Third Split Centrifuge 2.5 1.6 1.7 * ~lour ~ract~on contained 17.3% protein.
Ihis example shows that flour fractions having protein contents o~ less than 3.0% and in particular less than 2.0 are obtainable.
EXA~ X ~, A sample of dehulled Scott gr~ats was comminuted in a CASEILA* grain mill using a 2.5 mm diameter circular hol~ screen.
* denotes trade mark -....: , , . - . . . -. . . ~. . .
1~87611 The comminuted groat was then reground on the CASELLA grain mill using a 1.0 mm diameter circular hole screen. 150 g o~
the finely comminuted groats~hus obtained were admixedJ in the form of a slurry, with 300 g of hexane for 5 minutes. me slurry was then sleved with a 200 TYLER mesh screen. The material retained on the screen was re-admixed with 150 g o~ hexane for 5 minutes and re-sieved through the 200 TYLER mesh screen. me oversized material thus obtained i.e. that retained on the screen, was dried in a vacuum oven and analyzed ~or protein.
The undersized materlal i.e. that passing through the screen in each instance, was combined and centrifuged for 10 minutes at 1000 G. The hexane miscella was decanted off and a composite sample of the solid material was analyzed for protein.
me remaining solid material was re-admixed, as a slurry, with 75 g o~ hexane, poured into a 43 x 123 mm extraction thimble supported in a 250 ml centri~uge cup and centri~uged at 1000 G
for 10 minutes. me he~ane was decanted off. me thimble was cut open, the length of the centri~uge cake was measured and a~alytical samples, ~or protein analysis, were taken from the top, middle and bottom sections o~ the cake. All protein a~algæes were carried out OR dried samples using a KJel-Foss Automatlc 16210 protein analyzer.
me oil ~rom the he~ane miscella was recovered using a rotar~ e~aporator.
- Details of the results obtained are gi~e~ below. me centrifuge cake o~ uadersized material (flour) was white in colour thc o~er~ized material (~ran) was bu~f-coloured and the oil ~as turbid greea.
.
~ -26-Protein Content of Scott groats16.5 ~eight of Oil 7.3 g Oversized Material (bran) Weight 64.4 g Protein Content 21.4 Undersized Material (flour) Composite Protein Content 13.4 Cake Depth 48 mm Protein Content ~ Top 75.4 Middle 6.1 Bottom 4.1 EXAMPLE XI
Approximately 300 g o~ pinmilled Hinoat groat was admixed, in the form of a slurry, with 600 g of hexane for 5 mlnutes. m e slurry was then sieved with a 200 T~LER mesh screen. The material retained on the screen was re-admixed with 300 g of hexane for 5 minutes and re-sieved through the 200 TYLER megh screen. The oversized material thus obtained, ; i.e. that retained on the screen, was dried in a vacuum oven and analyzed for protein.
m e undersized material i.e. that passing through the screen in each instance, was combined and centrifuged for 10 minutes at 1000 G. The hexane miscella was decanted off and a composite sample of the solid material was analyzed for protein. The remaining solid material was re-admixed, as a slurry, with 150 g of hexane and then divlded into three por-tions.
One portion was poured into a 43 x 123 mm extrac-tion thimble supported in a 250 ml centrifuge cup and centri-fuged at 1000 G ~or 10 minutes. The hexane was decanted off.
The thimble was cut open a~d analytical samples, for protein analysis, were taken from the top, middle and bottom sections of the cake.
1()~76~1 ... - : .. , . . : ~
EX~LE Vl Approximately 2 kg o~ dehulled Hinoat groats that had been comminuted on a commercial hammer m~ll were admixed, in the form of a slurry, with solvent for 15 minutes. me slurry was then passed through a SI~ECO Vibro Energy Beparator equipped with a 200 me h TYLER screen. me oversize material, bran, retained on the screen was dried ln a rotary vacuum drier. The slurry of ~lour in solvent miscella was passed through a 10 mm ~ORR-OLIVER DOXIE TYPE A hydrocyclone at an ~nlet pressure Or 2.8 kg/cm . me orerflow ~rom the hydrocyclone was collected.
The underflow was passed through the hydrocyclone again and the overflow obtained was combined with that obtained previously.
The underflow thus obtained, which contained low protein ~lour, was centrifuged, r~n~ed with fresh solvent and dried in a rotary racuum drier. The combined orerrlows, which contained high pro-tein flour were s~m~arIy centrifuged, rinsed and dried. me solvent miscella obtained was passed through a rotary evaporstor to recover the o~l~ The oil obtained was dried in a racuum oren. me flour and bra~ fractions obtained were analyzed for protein using a B~el-Foss Automatic 16210 protein analyzer.
Details o~ the solvents used and the results obtained were a~ followg:
Run A* B*
Solrent Methanol ~yclohexane -` Bran welght(g) 755 692 protein(%) 23.2 21.1 , . ,, ~ . - . -, ,:
, . , . :.
.
Run A* B*
High Protein Flour weight(~) 47 128 protein(~) 39.7 42.7 Low Protein Flour weight(g) 1213 600 protein(%) 1~.5 13.8 Oil we*ght(g) 52 166 * the startlng material, comminuted groats, contained 19.3$
- protein.
EXAMPIE VII `
Approximately 250 g of pinmilled dehulled Hinoat groats were stirred, as a SlurrY~ with 400 g of hex~ne at ambient temp-erature for five minutes and then passed through a 200 mesh TYLER screen. The oversized material, bran, retained on the screen was admi2ed, in the form of a slurry, with 200 g o~ hexane and re-screened. The undersized mater~al, flour, ~rom both screenings were comblned, centrifuged and the hexane miscella was decanted of~. The flour so obtai~ed was admised, in the ~orm o~ a slurry with 125 ml of hexane, poured into two extraction thimbles, each measuring 43 x 123 mm, located in separate 250 ml centri~uge cups and centrifuged at 1000 G for 10 minutes. me hexane was decanted o~. me th~mbles were cut open and analytical-size samples (First Centrifuge samples) were taken from the top, middle and bottom ~ections of the cake of solid mater~al in the thimLble. Each o~ the cakes were then separated into ntop-hal~l' and nbottom-hal~" ~ractions. One "top-hal~l' fractlon and one "bottom-half" ~raction were separately admixed, in the ~orm o~ a slurry, with 30 ml o~ hexane and re-centri~uged at 1000 G. Analytical sample~ (Second Centrifuge Top-~al~ and Bottom-Eal~ samples) were again taken from the top, middle and bottom sections of the cake of solid material obtained. The second "top-half" and "bottom-halr" ~ractions were separately admlxed wlth 30 ml Or hexane in a WARI~G* Blender ~or 5 m~nute3 * denotes trade mark -21-1~ ~7 6 11 and then re-centrifuged at lOOO G. Once again analytical samples (Blender-Centrifuge Top-Hal~ and Bottom-~alf samples) were taken from the top, middle and bottom sections of the cake of solid materlal obtained.
All samples were dried in a vacuum oven and analyzed ~or protein with a Kjel-Foss Automatic 16210 Analyzer.
The results were as folLows:
Location ofProtein in Analyzed SampleSample (~) LO First Centrifuge Samples Top 83.o Middle 6.2 Bottom 10.2 Second Centri~uge Samples (a) Top-Half Top 56.~
Middle 6.4 Bottom 7.6 (b) Bottom-~alf Top 15.4 MiddLe 2.2 Bottom 2.8 Blender Centrifuge Samples - (a) Top-Half Top 88.6 Mlddle 7.7 Bottom 7.6 (b) Bottom-Hal~ Top 21.4 Middle 2.2 Bottom 2.7 The anay~ses Or the "top" fractions of the Second Centrifuge and Blender centrifuge samples indicate the ef~ect of the high shear in the Waring blender on protein content of fractions. The eæample sl~o 3hows that fr~ction3 of hlgh and low proteln content are obtainable.
EXAMPLE VIII
Approximately 200 g of pinmilled Hinoat groats which had not been subJected to any heat treatment, were ad~ixed, in the form of a ~lurry, with 500 g of hexane for five minutes and then passed through a 200 mesh TYLER screen. The oversized 1~7611 particles, bran, retained on the screen were admixed, in the form of a slurry, with a further 200 g of hexane for ~lY~ minutes and re-screened. The undersized material, flour, and hexane miscella from both screenings were combined and centrifuged. The hexane miscella was decanted off and the solid material admixed, in the form of a slurry, wlth a further 130 g of hexane. Portions of the slurry were poured into 43 x 123 mm extractlon thimbles located in 250 ml centrifuge cups and centrifuged for 10 minutes at specific centrifugal forces. The hexane was decanted off and the thimbles were permitted to air-dry for ten minutes.
Analytlcal-size samples were then taken from the top, middle and bottom 3ections of the cake o~ solid material in the thimble.
m ese samples were dried and analyzed for protein conbent using a K~el-Foss Automatic 16210 proteln analyzer.
e above procedure was repeated uslng plnmilled groats that had been heat-treated at 95C in a forced-air oven for one hour prior to the initial admixing with hexane.
Using a different s~mple of pinmilled groats, the above procedure was repeated on pinmilled groats that had not been sup~ected to heat treatment and on pi~milled groats that, after the initial admixing with hexane, were heated ror one hour ln the hexane under reflux conditions (68C).
m e above procedure was also repeated using a flour fraction that had been obtained from hammer milled groats by screening a slurry of the hammer milled groats in hexane, sep-arating and drying the flour fraction in an oven.
The results obtained were as follows:
~{~876~1 Run A B C D E
Starting Material Protein(~ 20.2 20.2 17.2 17.2 17.1 Heat Treatment none 95C none 68C d~ied Products (a) Centrifugal Force 300 G
Protein(~) (i ~P 60.2 49.4 62.9 53.3 24.7 (iii Middle 9.011.1! 6.510.0 14.8 10(iv Bottom 5.1 7.9 4.0 4.8 13~5 (b) Centrifugal Force 1000 G
Protein(~) (1 Top 64.6 42.3 80.6 47.2 24.5 (ii ~iddle 8.315.1 6.3 6.6 1~.9 (iii Bottom 7.1 8.8 4.1 4.8 15.7 The above example indicates that heat treatment affects the separation of, in particular, fractions of high protein con-tent.
,EXA~PIE IX
Approximately 500 g of ~inoat groatæ that had been obtained u~ing a commercial hammer mill were admixed in the form of a slurry with one litre of hexane for fi~e ~tnutes. The resultant admixture was then passed through a 200 mesh T~LER
screen. The o~ersized material, i.e. that retained on the screen, wa~ re-zdmixed with one litre of hexane for five minutes and re-screened. The flour fraction and hexane miscella from both screenings were combined and then centrifuged at 1000 G for 10 minutes. The hexane miscella was decanted off. The solid material was admlxed, as a slurry, with 175 g of hexane, poured into four 43 x 123 mm extraction thimbles supported in 250 ml centrifuge cup~ and centri~uged at 1000 G for lD minutes. The hexane was decanted off and the thimbles were cut open.
Analy~ical-size samples (First centrifuge samples) were taken from the top, middle and bottom ~ections of the cake of solid material in the thimbles. The cakes were then split into "top-half" and "bottom-half" samples, me combined bottom-h&lf samples were admixed, in the form of a slurry, with 90 g of ~. .
.. . .
l~S7611 hexane and centrifuged using the extraction thimbles as described above. Analytical-size samples (First ~plit Cen-trifuge samples) were taken from the top, middle and bottom sections o~ the cake of solid material obtained. Once again the cakes were split into "top-half" and "bottom-hal~" samples.
The combined bottom-half samples were admixed with 45 g of hexane and the procedure was repeated using on~y one thimble.
Analytical-size samples (Second Split Centrifuge samples) were again taken from the top, middle and bottom sections o~ the cake of solid material obtained. Yet again the cakes were split into "top-h~l~" and "bottom-half" samples. The bottom hal~ sample was admlxed with 25 g of hexane and the above procedure repeated u8ing a 33 x 94 mm extraction th~mble. Analytical-size samples (Third Split Centri~uge samples) were agaln taken ~rom the top, middle and bottom sections of the cake o~ solid material obtained. All samples were analyzed ~or protein using a K~el-Foss Automatic 16210 Protein Analyzer.
The results ~ere as ~ollows:
Sample Protein Ana ~ sis (~)_ ~rop M1~ e~Qitom - F~rst Centrifuge* 80.9 7.7 4-9 First Spllt Centri~uge 16.8 2.4 3.1 Second Split Centrifuge 4.1 2.0 2.1 Third Split Centrifuge 2.5 1.6 1.7 * ~lour ~ract~on contained 17.3% protein.
Ihis example shows that flour fractions having protein contents o~ less than 3.0% and in particular less than 2.0 are obtainable.
EXA~ X ~, A sample of dehulled Scott gr~ats was comminuted in a CASEILA* grain mill using a 2.5 mm diameter circular hol~ screen.
* denotes trade mark -....: , , . - . . . -. . . ~. . .
1~87611 The comminuted groat was then reground on the CASELLA grain mill using a 1.0 mm diameter circular hole screen. 150 g o~
the finely comminuted groats~hus obtained were admixedJ in the form of a slurry, with 300 g of hexane for 5 minutes. me slurry was then sleved with a 200 TYLER mesh screen. The material retained on the screen was re-admixed with 150 g o~ hexane for 5 minutes and re-sieved through the 200 TYLER mesh screen. me oversized material thus obtained i.e. that retained on the screen, was dried in a vacuum oven and analyzed ~or protein.
The undersized materlal i.e. that passing through the screen in each instance, was combined and centrifuged for 10 minutes at 1000 G. The hexane miscella was decanted off and a composite sample of the solid material was analyzed for protein.
me remaining solid material was re-admixed, as a slurry, with 75 g o~ hexane, poured into a 43 x 123 mm extraction thimble supported in a 250 ml centri~uge cup and centri~uged at 1000 G
for 10 minutes. me he~ane was decanted off. me thimble was cut open, the length of the centri~uge cake was measured and a~alytical samples, ~or protein analysis, were taken from the top, middle and bottom sections o~ the cake. All protein a~algæes were carried out OR dried samples using a KJel-Foss Automatlc 16210 protein analyzer.
me oil ~rom the he~ane miscella was recovered using a rotar~ e~aporator.
- Details of the results obtained are gi~e~ below. me centrifuge cake o~ uadersized material (flour) was white in colour thc o~er~ized material (~ran) was bu~f-coloured and the oil ~as turbid greea.
.
~ -26-Protein Content of Scott groats16.5 ~eight of Oil 7.3 g Oversized Material (bran) Weight 64.4 g Protein Content 21.4 Undersized Material (flour) Composite Protein Content 13.4 Cake Depth 48 mm Protein Content ~ Top 75.4 Middle 6.1 Bottom 4.1 EXAMPLE XI
Approximately 300 g o~ pinmilled Hinoat groat was admixed, in the form of a slurry, with 600 g of hexane for 5 mlnutes. m e slurry was then sieved with a 200 T~LER mesh screen. The material retained on the screen was re-admixed with 300 g of hexane for 5 minutes and re-sieved through the 200 TYLER megh screen. The oversized material thus obtained, ; i.e. that retained on the screen, was dried in a vacuum oven and analyzed for protein.
m e undersized material i.e. that passing through the screen in each instance, was combined and centrifuged for 10 minutes at 1000 G. The hexane miscella was decanted off and a composite sample of the solid material was analyzed for protein. The remaining solid material was re-admixed, as a slurry, with 150 g of hexane and then divlded into three por-tions.
One portion was poured into a 43 x 123 mm extrac-tion thimble supported in a 250 ml centrifuge cup and centri-fuged at 1000 G ~or 10 minutes. The hexane was decanted off.
The thimble was cut open a~d analytical samples, for protein analysis, were taken from the top, middle and bottom sections of the cake.
1()~76~1 ... - : .. , . . : ~
3.4 g of water (30~ by weight on a protein basis) were added to a second portion of the above slurry. m e pro-cedure used for the first portion was then repeated for the second portion.
The procedure for the second portion was repeated on the third portion of the slurry except that 11.25 g (100 by weight on a protein basis) o~ water were added.
All protein analyses were carried out on dried sam-ples using a K~el-Foss Automatic 16210 protein ~nalyzer.
m e oil from the hexane miscella wa~ recovered using a rotary evaporator.
Details of the results obtained were as follows:
Protein Content of Groats 17.3 %
Weight of 011 l9.Z g Oversized Material (bran) Weight 118 g Proteln Content 20.9 %
Underslzed Material (flour) ~ Composite Protein Content 14.1 ~
; 20 Portlon 1 2 3*
Water Content (%) O 30 100 Protein Content - Top 66.160.2 80.
- Middle 7.1 7.i 6.~
- Bottom 4.4 4.4 4.0 .. ...
* Portion 3 showed indications of becoming gelatinous. The centri~uge cake obtained showed indications of a plurality of layers differing slightly in colour.
.
; .
, 28 ~761~
SUPPLEMENTARY DISCLOSURE
As stated hereinabove, in an embodiment of the process of the present ~nvention comminuted oats may be separated lnto ~ractions using a continuous centrifuge.
A preferred embodiment of a continuous centrifuge is a so-called solld bowl centrifuge equipped with a screw conveyer.
A number o~ variables may be important in the control of the operation of such a centrifuge according to the process of the in~ention, including for example the rate o~ flow of the slurry of commlnuted oats to the centrifuge, the depth of the liquid pool in the bowl of the centrifuge, the placement of the inlet to the bowl and the rotational speed of the bowl and of the screw.
The preæent in~ention is further illustrated by the , following example.
EXAMPLE XII
A sample of H~noat groats was passed two times through ~ -a COMOMIL* comm~nution mill equipped with a punched hole screen having 1.9 mm diameter holes. Approximately 36 kg of the com~
minuted groats thus obtained were fed to a mixing tank at 225 g/mln together with hexane at 600 cm3/min. The resultant admix-ture was paRsed through a SWECO Vibro Ener~y separator equipped with a 200 mesh TYLER screenO The oversized material retained on the screen was comminuted further and fed to the SWECO sepa-rator again. The combined materlal passing through the separator contained 1605%, by weight, of solids. The solids contalned 21.2~ protein.
The combined material was fed, as a slurry, to the r'liquid discharge" end of a six inch BIRD* centrifuge, a solid -bowl centrifuge equipped with a screw conveyer, at a rate of * denotes trade mark - ,~
;
761~
25 litres/min. The centrifuge was operated at 5000 rpm with a liquid pool depth of 0.37 cm.
Two streams were dlscharged from the BIRD centrifuge, centrifuged to separate solids from liquid and analyzed. The liquor discharge stream was a 4.0~ solids stream in which the solids contained 77.3~ protein. The solids discharge stream was a 77.2% solids stream in which the solids contained 804% protein.
The example shows the use of a relatively large scale centrifuge in the separation of comminuted oats into fractions dif~crl~8 ln proteln contcnt.
' ~ ~
., .
. :
The procedure for the second portion was repeated on the third portion of the slurry except that 11.25 g (100 by weight on a protein basis) o~ water were added.
All protein analyses were carried out on dried sam-ples using a K~el-Foss Automatic 16210 protein ~nalyzer.
m e oil from the hexane miscella wa~ recovered using a rotary evaporator.
Details of the results obtained were as follows:
Protein Content of Groats 17.3 %
Weight of 011 l9.Z g Oversized Material (bran) Weight 118 g Proteln Content 20.9 %
Underslzed Material (flour) ~ Composite Protein Content 14.1 ~
; 20 Portlon 1 2 3*
Water Content (%) O 30 100 Protein Content - Top 66.160.2 80.
- Middle 7.1 7.i 6.~
- Bottom 4.4 4.4 4.0 .. ...
* Portion 3 showed indications of becoming gelatinous. The centri~uge cake obtained showed indications of a plurality of layers differing slightly in colour.
.
; .
, 28 ~761~
SUPPLEMENTARY DISCLOSURE
As stated hereinabove, in an embodiment of the process of the present ~nvention comminuted oats may be separated lnto ~ractions using a continuous centrifuge.
A preferred embodiment of a continuous centrifuge is a so-called solld bowl centrifuge equipped with a screw conveyer.
A number o~ variables may be important in the control of the operation of such a centrifuge according to the process of the in~ention, including for example the rate o~ flow of the slurry of commlnuted oats to the centrifuge, the depth of the liquid pool in the bowl of the centrifuge, the placement of the inlet to the bowl and the rotational speed of the bowl and of the screw.
The preæent in~ention is further illustrated by the , following example.
EXAMPLE XII
A sample of H~noat groats was passed two times through ~ -a COMOMIL* comm~nution mill equipped with a punched hole screen having 1.9 mm diameter holes. Approximately 36 kg of the com~
minuted groats thus obtained were fed to a mixing tank at 225 g/mln together with hexane at 600 cm3/min. The resultant admix-ture was paRsed through a SWECO Vibro Ener~y separator equipped with a 200 mesh TYLER screenO The oversized material retained on the screen was comminuted further and fed to the SWECO sepa-rator again. The combined materlal passing through the separator contained 1605%, by weight, of solids. The solids contalned 21.2~ protein.
The combined material was fed, as a slurry, to the r'liquid discharge" end of a six inch BIRD* centrifuge, a solid -bowl centrifuge equipped with a screw conveyer, at a rate of * denotes trade mark - ,~
;
761~
25 litres/min. The centrifuge was operated at 5000 rpm with a liquid pool depth of 0.37 cm.
Two streams were dlscharged from the BIRD centrifuge, centrifuged to separate solids from liquid and analyzed. The liquor discharge stream was a 4.0~ solids stream in which the solids contained 77.3~ protein. The solids discharge stream was a 77.2% solids stream in which the solids contained 804% protein.
The example shows the use of a relatively large scale centrifuge in the separation of comminuted oats into fractions dif~crl~8 ln proteln contcnt.
' ~ ~
., .
. :
Claims (52)
1. A process for the separation of comminuted oats into fractions differing in composition, said process com-prising:
(a) admixing comminuted oats with an organic sol-vent, said solvent being selected from the group consisting of pentane, hexane, heptane, cyclohexane and alcohols having 1-4 carbon atoms, and mixtures thereof, (b) forming a slurry of said admixture of comminuted oats and solvent; and (c) subjecting the slurry to the influence of cen-trifugal force whereby the comminuted oats in said slurry are separated into at least two fractions, said fractions dif-fering in composition.
(a) admixing comminuted oats with an organic sol-vent, said solvent being selected from the group consisting of pentane, hexane, heptane, cyclohexane and alcohols having 1-4 carbon atoms, and mixtures thereof, (b) forming a slurry of said admixture of comminuted oats and solvent; and (c) subjecting the slurry to the influence of cen-trifugal force whereby the comminuted oats in said slurry are separated into at least two fractions, said fractions dif-fering in composition.
2. The process of Claim 1 in which one of said fractions contains at least 20% of the comminuted oats.
3. The process of Claim 2 in which the comminuted oats are dehulled oats.
4. The process of Claim 3 in which the oats are de-oiled in steps (a) and (b).
5. The process of Claim 4 in which one fraction is flour, said flour being essentially free of bran.
6. The process of Claim 4 in which one fraction is flour and the other fraction is comprised of bran.
7. The process of Claim 6 in which said oats have not been subjected to a heat treatment.
8. The process of Claim 7 in which the fraction comprised of bran is subjected to further comminution, ad-mixed with said organic solvent in the form of a slurry and subjected to the influence of centrifugal force to separate the bran into two additional fractions, one of said addi-tional fractions consisting essentially of flour.
9. The process of Claim 7 in which the organic solvent is selected from the group consisting of pentane, hexane, heptane and cyclohexane, and mixtures thereof.
10. The process of any one of Claim 2, Claim 6 and Claim 7 in which the slurry is subjected to the in-fluence of centrifugal force in a hydrocyclone.
11. The process of any one of Claim 2, Claim 6 and Claim 7 in which the slurry is subjected to the influence of centrifugal force in a continuous centrifuge.
12. The process of Claim 5 in which a slurry of said flour and said organic solvent is subsequently subjected to the influence of centrifugal force to separate the flour into at least two additional fractions, said additional frac-tions differing in protein content.
13. The process of any one of Claim 6, Claim 7 and Claim 12 in which the solvent is hexane.
14. A process for the separation of comminuted oats into fractions differing in composition, said process comprising:
(a) admixing an oat fraction, derived from said comminuted oats, with an organic solvent, said solvent being selected from the group consisting of pentane, hexane, heptane, cyclohexane and alcohols having 1-4 carbon atoms, and mixtures thereof;
(b) forming a slurry of said admixture of oat fraction and organic solvent; and (c) subjecting the slurry to the influence of centrifugal force whereby the said oat fraction is separated into at least two fractions, said fractions differing in protein content.
(a) admixing an oat fraction, derived from said comminuted oats, with an organic solvent, said solvent being selected from the group consisting of pentane, hexane, heptane, cyclohexane and alcohols having 1-4 carbon atoms, and mixtures thereof;
(b) forming a slurry of said admixture of oat fraction and organic solvent; and (c) subjecting the slurry to the influence of centrifugal force whereby the said oat fraction is separated into at least two fractions, said fractions differing in protein content.
15. The process of Claim 14 in which the oat frac-tion is comprised of bran and endosperm.
16. The process of Claim 14 in which the oat frac-tion is comprised of flour.
17. The process of Claim 14 in which the oat frac-tion consists essentially of flour.
18. The process of Claim 17 in which the oats of the oat fraction have not been subjected to a heat treatment.
19. The process of Claim 18 in which a slurry of one of said fractions with said organic solvent is subsequently subjected to the influence of centrifugal force to separate aid one fraction into at least two additional fractions, said additional fractions differing in protein content.
20. The process of Claim 17 in which the organic solvent is selected from the group consisting of pentane, hexane, heptane, and cyclohexane, and mixtures thereof.
21. The process of any one of Claim 14, Claim 16 and Claim 18 in which the slurry is subjected to the influence of centrifugal force in a hydrocyclone.
22. The process of any one of Claim 14, Claim 16 and Claim 18 in which the slurry is subjected to the influence of centrifugal force in a continuous centrifuge.
23. The process of Claim 19 in which a slurry of one of said additional fractions with said organic solvent is subsequently subjected to the influence of centrifugal force to separate said additional fraction into at least two further fractions, said further fractions differing in protein content.
24. The process of Claim 17 in which the protein content of a fraction so obtained is greater than 50%.
25. The process of Claim 19 in which the protein content of a fraction so obtained is greater than 50%.
26. The process of Claim 20 in which the protein content of a fraction so obtained is greater than 50%.
27. The process of Claim 23 in which the protein content of a fraction so obtained is greater than 50%.
28. The process of Claim 17 in which the protein content of a fraction so obtained is greater than 80%.
29. The process of Claim 19 in which the protein content of a fraction so obtained is greater than 80%.
30. The process of Claim 20 in which the protein content of a fraction so obtained is greater than 80%.
31. The process of Claim 23 in which the protein content of a fraction so obtained is greater than 80%.
32. The process of Claim 17 in which the protein content of a fraction so obtained is less than 5%.
33. The process of Claim 19 in which the protein content of a fraction so obtained is less than 5%.
34. The process of Claim 20 in which the protein content of a fraction so obtained is less than 5%.
35. The process of Claim 23 in which the protein content of a fraction so obtained is less than 5%.
36. The process of Claim 17 in which the protein content of a fraction so obtained is less than 2%.
37. The process of Claim 19 in which the protein content of a fraction so obtained is less than 2%.
38. The process of Claim 20 in which the protein content of a fraction so obtained is less than 2%.
39. The process of Claim 23 in which the protein content of a fraction so obtained is less than 2%.
40. The process of any one of Claim 17, Claim 19 and Claim 23 in which the solvent is hexane.
41. A process for the separation of comminuted oats into fractions differing in composition, said process comprising:
(a) admixing an oat fraction, derived from com-minuted oats, with an organic solvent, said solvent being selected from the group consisting of pentane, hexane, heptane, cyclohexane and alcohols having 1-4 carbon atoms, and mixtures thereof;
(b) subjecting said admixture to the influence of centrifugal force in a centrifuge and thereby forming a centri-fuge cake of said oat fraction; and (c) separating said cake in the substantial absence of said solvent into at least two layers, the protein content of at least one of said layers being different from the pro-tein content of at least one of said other layers.
(a) admixing an oat fraction, derived from com-minuted oats, with an organic solvent, said solvent being selected from the group consisting of pentane, hexane, heptane, cyclohexane and alcohols having 1-4 carbon atoms, and mixtures thereof;
(b) subjecting said admixture to the influence of centrifugal force in a centrifuge and thereby forming a centri-fuge cake of said oat fraction; and (c) separating said cake in the substantial absence of said solvent into at least two layers, the protein content of at least one of said layers being different from the pro-tein content of at least one of said other layers.
42. The process of Claim 41 in which the oat frac-tion is comprised of flour.
43. The process of Claim 42 in which the flour is substantially free of bran.
44. The process of Claim 43 in which said oats have not been subjected to a heat treatment.
45. The process of Claim 44 in which the organic solvent is selected from the group consisting of pentane, hexane, heptane and cyclohexane, and mixtures thereof.
46. The process of Claim 45 in which the protein content of said one layer is greater than 50%.
47. The process of Claim 45 in which the protein content of said one layer is greater than 80%.
48. The process of Claim 45 in which the protein content of one of said other layers is less than 5%.
49. The process of Claim 45 in which the protein content of one of said other layers is less than 2%.
50. The process of any one of Claim 41, Claim 47 and Claim 49 in which the solvent is hexane.
CLAIMS SUPPORTED UNDER THE SUPPLEMENTARY DISCLOSURE
CLAIMS SUPPORTED UNDER THE SUPPLEMENTARY DISCLOSURE
51. The process of any one of Claim 1, Claim 2 and Claim 4 in which the slurry is subjected to the influence of centrifugal force in a continuous centrifuge, said continuous centrifuge being a solid bowl centrifuge equipped with a screw conveyer.
52. The process of any one of Claim 14, Claim 15 and Claim 16 in which the slurry is subjected to the influence of centrifugal force in a continuous centrifuge, said con-tinuous centrifuge being a solid bowl centrifuge equipped with a screw conveyer.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB51498/75 | 1975-12-16 | ||
| GB51498/75A GB1552012A (en) | 1975-12-16 | 1975-12-16 | Process for the treatment of comminuted oats |
| US006766 | 1979-01-26 | ||
| US06/006,766 US4211695A (en) | 1975-12-16 | 1979-01-26 | Process for the treatment of comminuted oats |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1087611A true CA1087611A (en) | 1980-10-14 |
Family
ID=26266886
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA267,784A Expired CA1087611A (en) | 1975-12-16 | 1976-12-14 | Process for the treatment of comminuted oats |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1087611A (en) |
-
1976
- 1976-12-14 CA CA267,784A patent/CA1087611A/en not_active Expired
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