CA1097980A - Process for separating and recovering vital wheat gluten from wheat flour and the like - Google Patents

Abstract

ABSTRACT

A mixture of vital wheat gluten and starch containing at least 25% protein, e.g. a protein-rich fraction of wheat flour, is treated with a bacterial alpha-amylase (preferably substantially free of protease) under conditions which solubilize the starch but do not unduly solubilize, or denature, the vital gluten.
Specifically, the temperature should be not above about 60°C and the time of treatment should not exceed about 6 hours. After the enzymatic treatment the gluten, which still retains its vital pro-perties, is separated out, and the solubilized starch fraction is recovered or subjected to further processing.

Description

)979~

This in~en~ion relates to a process ~or treati.ng ~. ~ixture of ~ital ~heat gluten and ~heat starch, e.~. whe&t flour, in order to obtain the wheat gluten i.n ~ital, undenatu2ed f~rm and as a second produ~t, a solubilized starch wnich may be used as is or further t~eated by saccharificati~n~

: It is known that wheat gluten will lose its"vit~l't propertie~
if subjected to high te~peratures, and it i~ alsn known that wheat gluten has a tendency to solubiliæe i~ it is in contact with warm water for an extended period of time.
For these reasons~ the application l~o whea~ ~lour of a conventional enz~Jmatic solubilizati.on prvcess 9 (i ~ e~
gel~tinizi~g, li~uefying, and solubili~ing the .
.

sLarch l~or~ n of the :~lour with heat and a llclu~yirlg ~n~ylrle ~ ch as al.ph~a~y:l.ase~ 111 r esult iT~ denatu ~tlon~
well as sub~tantla:l ~solllbi:Lizati on~ of t}-le glutenO
Furtherlnore, i i:he solubillæ.~d s~;a~ch is saccilari~-`ied ~ltr a sacchari~yiTl~, erlæyrne to prvduc a starch hy(lf oLyz~:e, the resul ~ing hydrolyæat:e Will conkain a large am0urlt.
o s~lubi.lizecl gluten~ and chls ~;7ill make u:Lt:imat:e ~ e~i.ning (and paxticularly decoloriæ;.n~) di1.cult an~l i~npractlc~l .
1~) Corl~r;~ ional proces9~.s i~GX' en2:~la~1ca~'1y solubili.zi.ng starch or starch~cor~aitalllg materl~l~s such as f10urs~ meals~ ~Igrits~ or the 1il~.e Lrlvo1ve go1atir~i.3at10n of the starch~ by heating an ~queous slurry o~ s~me, either be~ore ~dditj.on of the enzyllle or~
1~ a the~.nc~sta~,1e a1pha am~l.ase i5 USed9 in the pr~sence o the enzyrne. These processes employ high temperatures, alid if applied to ~t mater.ia1 co~ta1nin~
vital ~ eat gluten, wL11 denature the gluten. It:has long been kI~own that a1pha amy1ases are capab1e o~
so1ubi1izing starch un~r non~1atill.izing conditi.ons, but the early ~;ior art processes ha~e never been practiced commercia11y~ W~11erstein et al, in UaS~
~te~t 2,583,451, d:isc10se ~ process or converting pure ~tarch to dext.rose with al.pha-amy1ase und2r non ge1ati.niæill~ conditiorls; in t'o-;s process the teMperatUre does nr,t exceed 45C, the treatmen~- ~i.mes are 4S-72 hours, and th~ yi~lcls are very lo~; t~le prc,ces~
wou1d be unsuitab1.e for use with ct glt~ten-cpn~ctinillg starch produc,~.

' 3L~7 Rece~ltl~ processes have been devel.oped Eor ~ f f ec t i~f ~ ly hydro lyz i ll~; gran:uï a .r s tarc h wi 1:;ho u'c ~ e conventional gelLa' 1ni.za-~on Step9 Whei~e.~.~ydUrill~; the hydrol~sis the residua1 ~tarch reta.lns its gra^~llar form~ See; or exarnp1e, U ~ S, pate~ s 3 ~ 942, 196 e,nd 3, ~22 ,197 to Leach et al ~, 3~ 922 ,1~8 to l~lske et al ., 3,9g2;1~(3 co He~eda et a1., and 3,92~,200 ~co Walon et al. These processes are extrem21y efect1ve in hydro1yæing ~tarch and star:ch con~aining material.s, 10 but t,he conditlons are s.uch that 9 lf applied t,o wheat ~lo~lr, exc.essive solubi.li~ation and denaturation of the vltal g1ul:en will take place.
It , s an ob~ect of the invent~.on to devis~
a process or treating wheal: 1.our or similar procluc.ts in order to obta~n therefrom starch, vital glu~cen~and a starch nydroly~ate. A further ~bjecG of the inventior is to devi~e a pr~cess for th.e enzymati.c soluklliæatioll, plu3 enzymatlc ~acchariica'cion lf desired, o~ the starch portion of a gluten-rich :~ract:ion of wheat flo-~:~r~
20 or other ~nixture o vital wheat gluten and ~tar~h~ in such a way tharc t'ne glut:en can be recove.red in undenatured, vital form9 and the solubi3.ized (~r saccha~ified~ starch wi.ll contaill virtuall~ LlO solublli2ed ten, and therefore c~in be rç~.firled by con~reTLtlonal and ~col~omic means, In accordance wil;h l;he process of thg inve~lti OLl~
a mixture of ~i.tal wheat ~luten and starch is ~.reated, in aqUeC)U3 ~;usr)ensi~n~ wlth a bact:eri.al al.ph~ amylase ~m~er conditiorls ~where~by the starch is sol.ubliize~

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without g~latîtli2ation. That ,is ~o say, during the solu~illza~ioll the resldual .starGh is malnta-3ned in granular~ i~e. ung21atitlized for~rl. Ater sollt~ili,Jation o the ~tarch the ~luterl, whlch îs ~till in vi.tal and undenatured ~orm~ can readily be r2covered by convention~l means s-uch a~ 11tration; decantatio~7 centrlfug~t:i.on or usin~g hydroclones. The solu~ilized starch solutlon c~n then b~ concentratPd and~or dried, f~lrther treated wich addi.tional. enzymes to for~ sacGharifled pro.~ucts, or, as wll.l ~e described ~ater, used as a sllbstrate or - hydrolysls of addit-Lonal starch. The specific condltlons will now b~ described.
~lthou&h the invention can be pr~ctLced with any : mlxtllre o starch and vital wheat gluten the most obvious, and practical, starting material is wheat 10ur, therefore the invention will be described he~inafte-,-as ~pplîed to wheat flour. The materlal tc. be subjected to the en~mAtic solubilizatio~ sh~ul.d contai.n at l~ast about 25% protein (by weight, ~y b~ , a ~an~e o~
from 25% to 80,' prote-Ln beitlg sultable. If the starting material contains less than 25% protei~, with the balance b~ing princlpally starh~ unacceptable solubilization of the proteln wi.ll occur due to the conditions of the reacti.on b~ing etnployed, i~eO the ratio of water to -,rotein and the ti.me nnd temperature of the reac.tion. Therefore, the wheat flour should ~irst be scparated into two fractions~ one bein~
substantially pure whea'c starch (Y~hich is, of course, c~ valunble prod1.lct) 5 the secortd fraction cont.lining at .

,Q_ : `

lea9t 2-)/. (prefQrably 30% ' 4(~,) glu~;en, 'I`he proceris o~ the in~JeTItioll is then app3.ie~ t o c!~le secor~ racti.on.
T'lle initie:l frarti.or~ation o the :~lour can be per~orlned in a~ily way7 tEIe only reclulrement be}ng t:ha~ t.he gluten is not det~atured. Cerl~li.u~,al decanta~-iGn ~ onQ
example of the process ~ha~ cln b~ used for the fract-ioII~bi on, T~ all aque.ous slurry oE the second, glllten~rirr f~actic~n (solids concentratioTI preferably 10% _ 35 %
10 by weight) is added a bacteri.al alpha mylase~ ~hich is preferab~ly subs~cantially free of protease~ and tlie enz~ne ls permited to react wit'n t--le sta-ich for a short - period o time ~not to exceed ab~tlt 6 ~our.~) at a tempera~ure of llot greater than abou~ 60~C (the preerred temperature bein~ in the range of 45C and 60~C~ and at a pH wh7ch is ~he optimurn for the ~ l '`' .

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enzyme to attach the starch (preferably the p~l is about 5 to abolt 7). By means of this process substantially all (or as much as desiredl of the starch is completely solubilized, the gluten is not denatured, and substantially no solu-bilization of the gluten occurs. Therefore one can easily recover the still vital gluten, plus the solubilized starch which contains a minimum amount of solubilized protein. The solubilized starch may be concentrated and/or dried and used "as is'`, or subjected to any conventional saccharification process The bacterial alpha-amylase preferably is one which is active within the pH range of from about 4.0 to about 7.0 and which possesses appreciable activity at relatively low temperatures, i.e. 60C and below. Preferred sources of such alpha-amylases include certain species of the Bacillus microorganisms, viz., B. Subtilis, B.Licheni-formis, B. Coagulans and B. Amyloliquefaciens. Suitable alpha-amylases are described in Austrian Patent 300,699 and in U.S. 3,697,378. Especially suitable amylases are those derived from B. Licheniformis, as described in the Austrian patent specificatio~. Particularly preferred is that alpha-am~lase derived from B. Licheniformis strain NCIB ~C61, ; NCIB 8059, ATCC 6598, ATCC 6634, ATCC 8480, ATCC 9945A and ATCC 11945. They are unusualLy effective in the lique-faction of granular starch. One such enzyme is identified by the trade mark "Thermamyl", available from NOVO Enzyme Corporation, Mamaroneck, New York. Thermamyl is characterised by the followin~ properties:
E~

. .

~ ~7~
~ ' - Sa -- (a) it is thermally stable;
(b) it is active through a wide range of pH;
and (c) its activity and heat stability are less : dependent than other alpha-amylases on the p.resence of added calcium ion.
Typical analyses of three different Thermamyl*
preparations are as follows:

* trade mark " ~

7~

I
~D O ~ ~ ~
1~ . . . . ., a) ,~ , , .. ~
rl ~ O ~- ~ O ~ ~ 0 U~ O
1~ 1` ~ d~ ~1 ~ ~ ~ ~ u~ o CO .-- o ~ ~ ~
o ~ ~ ~
,~ r~
I oD o ~ ~ ~ ~ ~ ~ , . ~ . . . . ~
~C C~ U~ ~ ~ o ~ o ,~ ~ o ~ ~ ,~ ~
'~ ~!J
,~
a) ~
~ a) ~ ,~ rl a) rl ~ rl ~ rl E~ ~ ~1 0 3 3 t~ 3 tP 3 ~ 3 U ~ O O rl rl O rl O rl O rl r~
o a) ~D r~l ~n o ~n ~ o . . . . .
u: ~ O o <~
~ ~ ~n ~ ~ H

E~ 1) h ~4 U
-r~
~ ~:
rn ~ ,1 ~n a) Q ~ a ~r~ 0 0 ~
c~ ,~ a~ rn In u $ ~ ~ ~ o u~
m ~n ~ a {~ ~ a) ~ o o 3 3 ~rl ~
P~ O r~ O O ~ ~ O rl ., .,.1 ~
o U ~ o u~ ~o -rl o rl ~n o ~ I ~ ~ o Q o? (o I rl~ I I o I ~ ~ Q U~ X
- o x ,~ -rl ~ a) a) ~ k .IC ~ . tn ~n ~ x o ~ ~ x u~n ,~
a) 5-J ~ -rl (1) 0 ~n ~ :~ ~ (n ~ -x -k ~n u~
O -rl r~ N ~ I O O r~ rl rl O ,~ r~ r~S -rl N (I) O X 1~ X ~ I> Il) ai Ql X
5 1 rq (1~ 0 ~ ~ (d ~D C) O O r-l r~
a ~ ~ a ~ Z
E~
.

..

- -~a-The alpha-amylase should be substantially free of protease activity, in order to avoid excessive solu-bilization of the gluten, because virtually all commercially available alpha-amylase pr~parations contain protease activity, it is necessary first to treat the preparation to render it substantially protease-free~ This can readily be accompli.shed with the Thermamyl* preparations by heating an aqueous * trade mark : E3' ~79~
.
~7 s~.urry o~ the er~.yr~le prc~parcltion a~ 70~C to ~0C for :Erom 30 t~ L~5 mlnute.s.
Th~ alnoun~ o~ ~lpha-amylase emp:loyed rmlst, of course 9 ~C~ su ~ c1ent at least l:o so1ubi:liz~
subs~:an~-.ial.:l y all o the st.arch p~esent, ..~ eO at :least ~bou~ 0.1 act.i~i~y unlt per gram oE st~rch. (the alpha~
amylase activ1ty ~s used helein i.s det:er~ined ~y the method se~ ort~ in UOS. patent 399~3~196 to Le~c.h et al. ) It :i s p~e~erred5 however, tc, emp`loy more thall 10 the minimum ~mount; o f al ph.~-amylase 9 for ~wo reasons !
F~rst of .~ 9 ~ln e.xcess amoLm~ of ~nz~rne w111 ~ccelerate the solubilizatinn prs~cess, thereby minimiziIIg the time durlng wh:Lch the ~;I.u~:en is subjected to the process condit:ions ~it~l attendant minimal gluten solubiljzation.
A second, and extremely important advanta~e from the econoniic standpoint, is that a~ter separation of the gluten fraction, the solubilized st2rch, which i~ present ln the ~orm of a ~ilute solution ~.~hich contains still active alpha-am~ase, may ~e used ~irectly a~ a medi.um

2~ for solu~ ing additional starch merely by addin~
fresh raw starch to it and a~ justing the condition~, i~ necessary, for optim~l solubill~,ation of the fresh starch. A~-er solu~ atloI- of the addi~io~a`l starch the procIuct may, o~ course~ be subject ~o sacchari~
ic~i.on with th~ appropriate enzyme, e.g. gluco~
amylas~ to produce d~xtrose ~r dextrose-cont~i~ing hydrolyzates~ beS~. amylase (~i.th or without a d~branc~ rlzyme ak any .st~~e of ~he process, it i~
advant~ o-lls to adcl i~, ox ~t ~ !S t ~ E)ort:it>n o i~ i l;, .,~ .

, ~iretct].y to the i.nitial ~-lou.^ ~ract;on along witll the bac.teri~l alpha~clmyl~cr-Lse. The l~resence of a sacchariying e~ n conjullclion wi.th ~he a1ph~
~mylase acts to accele~ate ft~ her the soll1bi~ aA~ion step, with a31 .lttendant ad~antages o such acoelerat1cn.
As will ~e shown in the examples 7 an ex~realely practic~ system can be deve1oped, based on ~he process oi the inventior,9 frJr obtaining from wheat flour both vital gluten and starch hydrolyzates o ~n~ desi.red -10 composLtio~l b~ first separa~i~g the flou~, a~ ~or IllstarlGe by c~ntrifllg~l decantation9 tc, obtain a starch fra~tion. ~nd a gluten~rich fract:ion~ then adding to th glutenrich fraction bac~er1al a1pha.mamylase in an amoun~ suiLiclent ~o solubilizc not onl~ the starlh port on o-f ~hat raction but .qlso the starch obt~ifled in the sep~ration step, aiso ~dding one or more saccharifying e.næ~mes if de~sired, then subjectirl~ the gluten~rich frac~ion to th~ process of the inven~1O~I, : re~over~ng t~le vita1 glut~n, a~d then adding the starch from the ~se.paration step to t.he soluhilized staxch~
which ~s in the or,~ o.~ a dilu~e aqueous solution cont~irling ac~i~e al.pha-amyl~.se, so].ubili~,ing th~
~resh st~rch9 sacchar1ying if desirecl~ and fina1ly refining the hydrolyæate by corlver.ti~ona1 means. Thi.~
sy_~em c~n be ~signed ~o as tc, be comp12tely "bot~led ~` up"9 virtu~lly e11~inati.ng waste water disposa1 pro~].en)s.
The pH o~ the solubil;zA~ior.l proce~s ls $overried~
of cour~e, by t~le operab1e range ~f the a1pha-amyl.~1se used9 2nd tne ~se o che optiinl.lm pH of the enzy-,ne is 7~
...~

preerred. Mo~t alpha~alnyla.se6 exhibi~ the.i.r optimum activity a~ about pH6 (the opti.mum for Ther~amy'L ) is pH 5 ~ 7, for RapLdase, pH 6 9 etC.). Sacchaeifyi.n~
enzymes usually exhiblt op~i.mum activi~g a~ low~r pHs (pH k.0 - ~.5 ~r gluco amylclses, e.~). Th~ fore, if saccharifying enæyme is employed ~n conjunction~ with the alpha-~mylase during the solubiliæation, it may be desirabl~. ~o em~loy a "compromise pH"; the skllled operator ^.an readlly detennine ~he preerl~d pH for his par~iGular ope~ation, The t,ime of ~he solubilizat.ion rnust, o course9 be suicl.enk to reach the desi.red degree of sta.rch solubili~,ation but should be as s'nort aS possi.ble in order ~o avoid excessive solubilization o~ the glu~enO
The t,ime necessary will depend upon ~arious factors, e.g. amount.~ st,arch to be solubil.i.~ed, amount and type of al.pha-amylase employed, presenc2 or absenoe o~' a saccharifying enzyme, soli.ds concentration! and temperatur~. A time period grea~er than 6 hour~ shoul~
be a~oi.ded, because this results ill an ~naccepta~le amo~mt of gluten solubili7.ation, which reduces the yi.eld of vit~-l gluten and 1ntroduces 50 much color ~ into the s~lubil~zed starch solution to render ultimate refi.ning dlfficult and costly. Under most corld~t-lon~s the ~olubilizatioll can be cornpl.ete~ with ~ hour ~o 3 hours, and this i5 the preerred t:irne pe~iod~
The preferred ternperature of the scl.u~ .;zcltlon ~` i5 ab~ut 60C, but can be as lo~ as ~.5~C~ Lower ; * Trade Mark .

- - , 9~G!

-:10-tempe,.atures prolong the time and should be avoid~d;
a terilperAtule much ~bove 60~C causes denaturlæation o the gluten.
The Mlph~amylase-cont.alning slurr~ can be bro~lgh~ to solu~:illza~ion temperature in any conventional manner~ hut a toc~ rapid rise. from ~0 to fillal temperature may cause some denaturization o~
the gluten and ~hould be ~voided. A temperature rise from 50C to 60~C over a pe.r-lod of ~0 m:;n~tes i.s ~uite satisfa~tory.
The ~ollowing exarn~les wlll ~erve to i~lu~strat.e the pract-Lce o~ the inven~.ion. In the e~;ample~ the Thermamyl 60 alpha-amylase prepar~sltlon was rende~ed subs~antiall.y protease~free by heatlng the liqu-Ld prcparati.on, as del~e.red, for 30 to 4.5 minutes at 80C.
This treatment resulted in complete lnactivation of the protease without substantial loss of alpha-.slmylase act:~vity~ The Maxa~yl LX6000 was trea~ed by irst dissolYing the liqu~d enzyme ~reparation, as delivered, ill ~ low D.~, starch hydrolyzate soluti.on (30% dry substance~ which contained added calcium, and lleating lor 30 r~linutes at 75C. This tr~atrQent `~ destroyed substantially all ~ the prote~se arld le~t 90% o~ the alpha-amylase activi~y.
All percen'ages in ~he e~amples and in the - appended claims ar~ by ~elght; unless o~her~71se stat~d.

* Trade Mark 7~

EX~MPI.I' X
._ .

This exarnple ll'.ustrates the solubilizat;ion o a glute~rlch fract.ion o~ ~heat flour with both alpha~
amylase ~nd a sa~charlying enzyme (beta æmylase), and ` the ~ïtlmate p-reparation of ~ high~mal~ose syrup in add~tion to the recovel:y of a vi~al gluten prodllct.
1000 k~o of sQft wlleat flour (88 . 6% dry substanc,e Imd contain:ln~s 10 . 2%protei.ll, 76, 5 % starch; 1. 8% at and about 0 . 4% each ash an~ ~ber) was suspended in 2000 k$. water and the suspensi.on ~ieved r.o ellminate 10 50~e oE the coarse flberO The suspension was agital:ed to ma~n~alll the prote:~.n and s~arch component.s :In atl homogeneous s~ate, i . e . to prevent the gluten rom agglQmeratln~. The suspension was then sent ~o ~n Alfa~Laval centrifug~l decanter, operating at 2000 r.p.m. ~otary ~peed, and the overflo~ (protein~rich fractiQn) and the under1Ow (starch fraction) w~re collec~ed. The underflow~ whi~h contaif~ed abou~ 2..5n/o pro'.ein and so~le ~lber and ash in addition to star&h, w~s tlle~ pu~fied arld concen~rated by firs~ passing it ~, 2~ through a 3eries of super centri.fu~al clecantPrs ~2000 r.p.m.) ~nd then a dewatering centrifugal. The ri.iter cake ~as flash dried to a moisture conte~t of ~bout.
13~o~ The product contained 98.7% wheat 3tarch, 0.6%
protein and 0.1"'. ash.
The overfl OW raction had a dry substance cont~nt of ~2% and rontained 29.7% proteirl ~total -K~eld3hl), d-ry ba~is. The ptl was adjusted ~o 5~5 -* Tr~cle Marlc ~9 ~12~
:`
and 0.4~/~ PrOteP~Se-~ree ~e~ Pr~ 1Pha ~nl'jr~.AS~
(ThermamY1 6V~ and 0,06V,~O~Deta-arnY1aSe (B1rJr~Yrne M.
frOm ~manO Chem.iCa1S) ~ere ad.ded ~perCeQta~es ~-y We1.ght~
dr~r baS~ aSed OL1 the dr~ ai ~J~i,gh~.~) ZOO P.P~m~
CaC12 WaS a1SO a~ded9 and the tem~eratUr2 WaS rai~ed 'S:O
57C and hal for tWo hOUr5. At ~he erld o that ~ia~e 9~.3% o~ the starch was solubilized.
The procluct was passed th~-oll~h a Sharples cent.rifugal, opera~ing at l~,OOO r.p.m~ an~ the tln~erf~.o~
l~) (gluten fractiorl) and the o~er-flow (solu~le starch fracti.on) ~ere CO11eCted~
~: The underflow had a dry S~bS~anCe Of 35.6% and COI1tailled ~8.2% Pr3tein dry basisO I~ w~s spray~dried to a m~istu.re content o~ 5.3% under the foLlowir con~itions: .
concen~ration eed: 35.6%
t~mP~rat~lre eed : 45G
~ in1et temPeratUre ~ 161G
: outlet temperature: ~8~C
The glute.~ portio~l (68%) o~ the resulting dry : product had retained its original insolubility.
The overflow consisted of a dilu~e (7.6C/o d.s~) ~oolubllized starch solutloll containing alph~ amylase;
the c~.lpha-amylS~se still ~etairl~d 90% o i.ts ori$irlal ~ctivity~ This s~lution was enriched with~-e previ.ously recovered arld dried whea~ s~c-rcll to a dry substanc~ of 30%. The pEl W~19 adjuste~ to 6.0, the tem.p~ratu~e Wc?.S ~al~ed ~o 95 ~, a~d ~vhe slur~-y was held u~til the st~rch was l.lque~ied~

~ Trad~ Ma~-k ~7~

The temperature ~ax then lowered ~.o S~ C, the pH adiust2~ to 5~0~ ancl beta-amy].ase w~s added in an.
amount oi~ 0.05% ',~y wei.~ t ~ased on clrv substallce~..
The starch ~as s!cchariiPd under those eol:ldi ti.on~ for 12 hou~s~ ater wh1ch the product: ~7as rec~.~ned with (a) O. 5% spent carbon, (b) a stron~g ca~ion e~change resin, ~c) su1LConateci coa~ 'Dusar1t" from Imacti), and (d) a ~,~eak an:lon e~ccllange re~in. The product w~s con&entrated allcl pas~ed o.n O . 5% vi.rgin car~.~nn. The c1ear . water~
lQ white prodllct had a D . E . o ~3 . 7, a :lex~rose conterl~
o ~ D~ a Qla1tc?se conteTlt o 55%, ~nd 4~% tri~and higher saccharicles.
_,M PLE_ An aqueous s1urry o.~ soft wheat flour ~7as prel?ared as in E~camp1e I, arld sent to an Al. ';au l~a~,al centriEuga3. decanter, The centrifuga1 decanter was operated in such ~ msnner as to produce an ovf~-rf1.ow o~ 12.8% dry subst&.nce c.ontaining 32.6% prote1n, dry basis.
~Q The urlderflow (starch fraction) was col1ected ~d processe~d as in Example I.
The ove.~low was collected and di~ided in~o thLee portion9 desi~nated as A,B~and C9 which were then tr~at2d as o11Ows.
~.
P-roducti.on of a ~saJto-~extri.r~ se f.~f Alp'nSa-AIllyla9 Alone for So1ul~i].i~ation~
The ~empeLat'Ul-e ~7~S brought to ~0 C, ch~ p~l wa.;
adjusted ~o 6~09 ~nd Ther,~ ril~l. 60 all~hs~nlyls..se

3-0 (protes~se free~was adde~ in an amo~mt o ~.3% by wei.g~t -'~Trade ~l~rk based o~ h~- dry tota1 weigllt. ~ter a reacti on tlme oi~ 2 hour.s ~7. ~ o.~ the s~arch hac~. bf en solllhi1i~ed.
The pro~uct. was cen~rifugecl i.n a Sharples centriut,a1 ~1~,000 X~.p.rD, ) and t:he underflow9 ~.~hich had a dry ~ubskance o 3C~. 7% and which con~;a~hed 72%
v1t~1 gluten (dry bas:L3) was spra~ clr1ed as i.n Exam.p1e I.
The o~er1c,w~ which had a d~ ~ of 7. 6% alld which ~tl:Ll ~ontained go'r~ ao~ive a~ pha~amy-ïase wa5 ellriChed with resh starch tG a dry .~^.Lbst:aLlice cont~-snt o~ 30%.
10 The pl-l W15 adjusted to 6.0 and th~ ~emper~ure brollght to 94C. Ater 2 IIOUrS reaction time th~ tem;perature was raised to 125C to i.nactlvate the enzyme, after which the product, which wa~ a starch~free soll7.ll1e malto~
dextrln having a ~Eo or l~.G 9 was reined and spray~
dried by conventional means.
~0 Prodl1ction o Dext~:ose IJ~e of Al~ha~m~ se and Glucoa~y~se for Solubili.zation.
__ *
The pH was adjusted to 5~5 and Thermamyl 60 (.25%~ ~nd glucoamylase (.06%) en~ymes (percentages on totlql dry welght) were added. The temperatu~e was brought to 6()C and held fcr 90 minutesO
The product was centrifuged a~ i.n A1 a~ter whlch the underflow was centrifu~ed a second time in order ~o ell~.5 nate addltio1.lal solubl.e. starch and obtai.n a ~raction higher in vi~al ~lUteII. The underrlow ~rotn the ~econd centrifuge, which con~ained 78% ~ital gluten, was spray dried a~ ln Example I.
The overlows fro~l both centrifu~ls wer2 ~m~i~Sed. The ~lph~ )ylas..-~ actlv-i.~y :in thi~ ra.cti.on ~';Trade Mark was 907~ o~ tne ori.~:i.naL 5 b~ very l ~tt:Le glucoamylase activi.~.y remained~ Fresh st.ar~h wa~ added to a dry substance content of 28 c 6%~ the pH ~as ad just.ed to 6,û~ and the ~elr,pera~cure was ~rou~h~;. to 95C and held unl il ttle starch was fu].ly ].: quefied.
The ~emperature was ' ~wered to 55 '', the pH
adjustec~ to 4r 2 and , O~uJ~ gluc,oamy:l.ase was added ~ ~~er 33 l~ours sacchari.isatiorl t.ime thfA prcduct had ~ D . F 0 o~ 97 . G and cont~ained 94. 8/~ dexLrose . It ~as refi.ned, 10 crysta1lized and dri.e~ i.n ~ conver~i.orlal man~er l:o a 99 . 6~/o dextrose product.
C.
Prod~cl:lon of Dextrose~Use o~
Solubili~r~tlcsn This por~ion was treated with alpha-amylase as was portion ~, includi.ng centrifuging and treating of the ullderflo~ containing 72% vital gIuten.
To the overflow (which stLll retained 90% alpha~
amy7ase3 wa5 added resh starch to a dry substance of 2~ 28.6%, and the temperature ~as raised to 95C ~rl~ held until the st~rch wa~ liquefied, It was ihen cooled to 55C~ and t~e pl~ adju~ted to 4.8~ glucoamylase was added in an amount o~ 0~7~0, ~nd th.e product was saccharified to dextrose as ln B.
XAMPL~ III
In this~exam?le tllree xeparat.e tri~L~. were conducted, designcltecl as AlB and C. In each triaJ wheat:
~lour containing 11% prote:in was sllspended i.n water ~md fractionc~ted as iTl t~)e previous exclmples hy means or c~n 30 h~a-Lavcll. cen~r~ruga3. cleoanter to obtai.n (13 an *Trade ~ark '~..

~1~

under~lo~1 (st.~lr, h) rae.t~Lon which ~as recovered as in tlle previ.o~ls e~;lmples and ~2) an overl.ow (protelTl-rlch fra~t:i.on) llas~ $ the follc~ composi tion:
Tot:al wei.gh~ ~ 777 . 5 kg.
% dry suostance 15 Welgllt~ dry substance ~84.4 kg~
% protei.n, d~b. 33. 65 l~eight, prot:eirl 95~ 7 kg Each ~)r~ein rioh fraot-l.on was treatecl wi`'~ a ~aoter:ial 1~ alpha-am~lase at p~l 6 and 60C for 4 ho~s J the differenc~ between the runs be1.ng in the en~.yme preparations empl.oye~d as ~ollow.s. A: Maxamyl LX 6000, deri.ve~ from P~aGillus su~tillus, treated to render lt ~ubst mti.aïly ~re~ o pro~ease, was added i.~ a~ amount o O~5% ~ased o~l total dry weight. B: Ther.~m-y1. 60 (protea~e-fre~ was added in~an amount o ~5~/b~ C:
Thermamyl 607 not treated to render it substantial1.y pro~ease~free, was added in an amount o .5%~
~ fter treatment e~ch proc1uct was separated ~-?~0 means o a Tonlatti centri.gugal operatlng a~ 25fO00 r.p.m. The res~ective underflow ~vi~.al gluten~ and overflow (soluble sta.ch) ractions had the compositioll3 set ~orth in Table II.

- * Trade Mark ..

~ 7~ 79~

TABI~r~

~nder10w (vital gl~ten f.ra~ti.on)~
A B
Tctal weight 57~.3 1~g 561~5 k~ ;,67~3 ko % dry subst.ance 26s8% 23~4a/~ 27,6%
Weigh~ d.s. ~55 k~ 13~ kg 12~ k~ ~`
% prote:in d.~. 55% 65% 53~7Cfo Weight protel.n 85.25 ~g 85015 kg ~9027 Icg ~.;

Over10w (soluble St~rGh. ~action):

Tot~l w~ hl: 1431.7 kg 144~.5 l.c~ 154~o7 l~g % dry su~stance 8.9 % 10.5 /~ lOol % 1~:
Weight dr~ substan~e129.4 k~ 15~ rg 155~8 kg i~
% proteir. 8.1 ~0 ~.8 ~f~ 16.9 '~/0 Weight protein 10.3 kg 10.3 kg 260~ kg The foregoino values ill.ustr~te the clesir~ility o employing ~n alpha~amylase ~hich is s~bstallti.ally ,`
protease-~ree~ in orde~ to mln-lmiæe solubili.zation of the gluten.

, : ~ .
-

Claims (24)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A process for treating a mixture of vital wheat gluten and wheat starch, containing at least about 25%
protein, in order to separate out the vital gluten and obtain as a second product a solubilized starch, comprising subjecting the mixture, in aqueous medium, to the action of a bacterial alpha-amylase under conditions whereby a substantial amount of the starch is solubilized without undergoing gelatinization, the temperature during the solubilization being within the range of from about 45°C to about 60°C, the pH being within the range of from about 5 to about 7 and the time of treatment not exceeding about 6 hours, and thereafter separating the vital gluten form the solubilized starch.

2. The process of claim 1 wherein the alpha-amylase is substantially free of protease.

3. The process of claim 1 wherein the mixture of vital wheat gluten and wheat starch comprises a protein-rich fraction obtained from wheat flour.

4. The process of claim 3, wherein the protein-rich fraction contains from about 25% to about 80%
protein.

5. The process of claim 4, wherein said fraction contains from about 30% to about 40% protein.

6. The process of claim 3 wherein said fraction has been obtained by subjecting an aqueous slurry of wheat flour to centrifugal decantation and thereby separating said flour into the protein-rich fraction and a second fraction comprising substantially protein-free wheat starch.

7. The process of claim 1 wherein the bacterial alpha-amylase is substantially free of protease and has been derived from a Bacillus microorganism.

8. The process of claim 7 wherein the alpha-amylase is one derived from a microorganism selected from the group consisting of Bacillus licheniformis and Bacillus subtilis

9. The process of claim 1 wherein the bacterial alpha-amylase is added in the amount in excess of the minimum amount necessary to solubilize all of the starch present, and wherein the time of the solubilization does not exceed about 3 hours.

10. The process of claim 9 wherein following the separation of the vital gluten, the solubilized starch solution, which contains still active enzymes, is combined with fresh, raw starch, and the resulting mixture is subjected to a solubilization process.

11. The process of claim 10, including the additional step of saccharifying the resulting solubilized starch with a saccharifying enzyme.

12. The process of claim 11, wherein the saccharifying enzyme is glucoamylase.

13. The process of claim 11 wherein the saccharifying enzyme is a maltogenic enzyme.

14. The process of claim 9 wherein a saccharifying enzyme is also added to the initial mixture, and wherein, after the vital gluten has separated out, the solubilized starch solution, which contains still active enzyme, is combined with fresh, raw starch, the resulting mixture is subjected to a solubilization process, and the thus solubilized starch is subsequently saccharifyied with a saccharifying enzyme.

15. The process of claim 14 wherein the saccharifying enzyme is glucoamylase.

16. The process of claim 14 wherein the saccharifying enzyme is a maltogenic enzyme.

17. The process for treating wheat flour comprising the following steps:
A. fractionating the wheat flour into a first fraction comprising substantially pure wheat starch and a second protein-rich fraction containing at least 25% protein;
B. solubilizing the starch protein of the second fraction by (1) adding to an aqueous slurry of same, a protease-free bacterial alpha-amylase in an amount sufficient to solubilize not only the starch present in that fraction but also at least a substantial portion of the wheat starch obtained as the first fraction if step A, and (2) subjecting the mixture to the action of the enzyme at a temperature within the range of from about 45°C to about 60°C, and a pH
within the range of about 5 to about 7 for a period of time not exceeding about 3 hours;
C. separating out and recovering the vital gluten from the resulting solubilized starch solution;

D. adding at least a substantial portion of the wheat starch obtained as the first fraction of step A to said solubilized starch solution, which solution contains active enzymes; and E. solubilizing the resulting mixture by means of the active enzymes contained in the solubilized starch solution.

18. The process of claim 17 including the additional step of enzymatically saccharifying the solubilized starch obtained in step E.

19. The process of claim 18 wherein the enzymatic saccharification is effected by means of a enzymatic enzyme.

20. The process of claim 18 wherein the enzymatic saccharification is effected by means of a maltogenic enzyme.

21. The process of claim 17, wherein step B, a saccharifying enzyme is added to the aqueous slurry in addition to the bacterial alpha-amylase.

22. The process of claim 17, wherein the bacterial alpha-amylase is derived from a microorganism selected from the group consisting of Bacillus licheniformis and Bacillus subtilis.

23. The process of claim 17, wherein the wheat flour is fractionated by means of centrifugal decantation.

24. The process of claim 17, wherein the wheat flour is fractionated into a first fraction comprising substantially pure wheat starch and a second protein-rich fraction containing from about 30% to about 40%
protein.