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`I
`USO05283322A
`5,283,322
`[11] Patent Number:
`[19]
`Umted States Patent
`
`Martin et al.
`[45] Date of Patent:
`Feb. 1, 1994
`
`[54] DEWATERING GLUTEN WITH NONIONIC
`SUWANTS
`Inventors: Roy W. Martin. I-aGrange; Robert J.
`Danton, Lockport, both of 111.
`
`[75]
`
`426/618
`4,411,927 10/1983 Bermudcz et al.
`».
`
`42:43::
`21:17:21 1512::
`at . ..... ......
`......
`,
`,
`
`210/593
`4,929,351
`5/1990 Polizzotti
`5,019,564 5/1991 Lowe ct 3.1. ........................... 514/75
`
`P”-man, Emm,-ne,_H°wm.d E_ Sham
`:nB1antExaminer;?. Lyxln Toxgzcalua Ri
`Dt.t%:§y‘vi Agent, or
`1m1—-
`exan er
`.
`
`' S
`cc1,
`
`teven
`
`ABSTRACT
`[571
`Methods of enhancing the dewatering of gluten are
`d‘11:cflost:nd.t zfhteh metliodls tcomp_r1sctac:id1ngta .non1on1c
`a
`, as 1n
`i.c...°1.n d£m§r5."§ .‘f;1‘I1,§,’L=‘Z1'$T”1=a‘lt1c°J1”;‘}1'§"i‘§‘rect1ve
`surfactants are oxyalkylated sorbiton R surfactants
`when R is monoolcate, trioleatc, monostearate, tristea-
`-
`me’ m°"°palm'm° and m°"°la“"“°‘
`
`4 Claims, No Drawings
`
`[73] Assignce: Betz Laboratories, Inc., Trevose, Pa.
`[21] App1_ No_; 929,543
`[22] Filed:
`Aug. 12, 1992
`[51]
`Int. Cl.5 .............................................. .. A23L 1/12
`[52] us. Cl. ....................... 530/374; 530/427
`
`[58] Field of Search ................................ 530/374, 427
`[56]
`References Cited
`‘
`U-S PATENT DOCUMENTS
`3,362,829
`1/1968 Landfried ct al.
`§.gg(1),;g§
`EYPPOIEI ------------
`,
`,
`ao ct
`.
`......
`3,958,016
`5/1976 Galle et a].
`4,108,847 4/1978 Crcinin et al.
`4,156,649
`5/1979 Quinn et al.
`
`426/61
`530/374
`
`........................ 210/749
`
`426/99
`
`
`
`(cid:0)H(cid:0)Y(cid:0)D(cid:0)R(cid:0)I(cid:0)T(cid:0)E(cid:0) (cid:0)E(cid:0)X(cid:0)H(cid:0)I(cid:0)B(cid:0)I(cid:0)T(cid:0) (cid:0)1(cid:0)0(cid:0)1(cid:0)0
`

`
`1
`
`5,283,322
`
`DEWATERING GLUTEN WITH NONIONIC
`SURFACTANTS
`
`FIELD OF THE INVENTION
`
`5
`
`The present invention is directed to a method of
`improving the dewatering of gluten in grain processing.
`More specifically, the present invention is directed to
`the use of nonionic surfactants to enhance the dewater-
`ing activity ofvacuum dewatering equipment employed 10
`in corn gluten processing.
`
`BACKGROUND OF THE INVENTION
`
`5
`
`The present invention relates to the dewatering of I
`gluten during corn processing. The wet milling process-
`ing of shelled corn is employed to obtain staple prod-
`ucts such as com oil, dextrose, corn syrup, high fructose
`corn syrup, dextrins, dry starches and feeds. The princi-
`ple steps in the wet milling of corn include steeping,
`milling, recovering and processing. During the steeping
`operation, corn kernels are softened by soaking in a hot
`dilute solution of sulfurous acid (i.e., sulfur dioxide).
`The softened kernels are then passed through grinding
`mills and separators where the germ is removed and the
`starch and gluten are separated from the coarser hull
`and fibers. The starch is then separated from the gluten
`which is added to the fibrous material and processed
`into a high protein animal feed. The starch is recovered
`as dry starch or further processed into dextrose and
`fructose. The sulfurous acid steepwater initially used to
`soften the corn contains solubles which are recovered
`for use in feeds. The steepwater solids are recovered by
`evaporation and drying. The solids recovered from
`evaporating and drying the steep water are used as ‘35
`additives to livestock feeds to enhance their nutritional
`value.
`
`20
`
`25
`
`30
`
`Processing of the gluten also involves dewatering.
`Typically, the gluten stream is held in a light gluten
`storage tank prior to pumping to a bowl type centrifuge
`where the first step of dewatering begins. The gluten
`slurry from the centrifuge, called heavy gluten, is then
`sent to a vacuum dewatering system where the second
`step in the dewatering occurs. The gluten cake from the
`vacuum dewatering system is transported by auger to a 45
`dryer for final dewatering.
`In the gluten dewatering process, the second step of
`vacuum dewatering is often the limiting factor in gluten
`recovery. The time necessary to teach the required
`gluten moisture content coupled with the potential for so
`blinding of the filter media limits the throughput of
`gluten in this area. The present invention is directed to
`a process for decreasing the dewatering time and inhib-
`iting blinding of the filter media in gluten dewatering.
`The use of surfactants in grain processing is known.
`U.S. Pat. No. 3,362,829 discloses a process for coating
`powdered vital wheat gluten with a nonionic hydro-
`philic lipid selected from the class consisting of mono-
`glycerides, salts of lactylic esters of fatty acids, poly-
`oxyethylene stearate and stearyl monoglyceridyl ci-
`trate. The coating of the powdered wheat gluten with
`such nonionic hydrophilic lipids is disclosed as control-
`ling wetting of the vital wheat gluten upon hydrogena-
`tion. The use of polyoxyethylene sorbitan monostearate
`in combination with hydrophilic lipids is also disclosed.
`The surface active agent, i.e., polyoxyethylene sorbitan
`monostearate is included as an aid for the initial disper-
`sion of the vital wheat gluten.
`
`55
`
`60
`
`65
`
`2
`U.S. Pat. No. 3,880,824 discloses a gluten/lipid com-
`plex and process for preparing a gluten/lipid complex in
`which vital wheat gluten complexes with lipids are
`prepared which are resistant to particle cohesion. A
`finely divided vital wheat gluten is reacted with ionic
`and nonionic fatty substances selected from the group
`consisting of fatty acid chlorides, fatty monoglycerides,
`lactylic esters of fatty acids, phospholipids and sorbitan
`fatty acid esters in the presence of a mild base catalyst.
`The phospholipids and lactylic esters of fatty acids yield
`comparable complexes in an acidic environment.
`U.S. Pat. No. 4,929,361 discloses a method of control-
`ling the fouling of heat transfer surfaces in evaporators
`and concentrators employed in wet corn milling which
`comprises treating the wet corn solution with a non-
`ionic surfactant such as polyoxyethylene 20 sorbitan R.
`SUMMARY OF THE INVENTION
`
`A The present invention provides a process to enhance
`the removal of water from wet gluten in a gluten dewa-
`tering operation. The present inventors discovered that
`the addition of a nonionic surfactant to a wet gluten
`stream prior to dewatering enhanced the dewatering
`ability of vacuum equipment. Particularly effective at
`enhancing vacuum dewatering are oxyalkylated sorbi-
`tan R surfactants where R is monooleate,
`trioleate,
`monostearate, tristearate, monopalmitate and monolau-
`rate.
`
`DESCRIPTION OF THE PREFERRED
`EMBODIMENT
`
`The present inventors discovered that surfactants and
`more particularly nonionic surfactants effectively en-
`hance the dewatering of gluten in vacuum dewatering
`equipment. Typically, in the processing of corn gluten
`the dewatering operation is the limiting factor in gluten
`recovery. Conventionally, the dewatering of gluten is a
`multiple step operation comprising centrifuge dewater-
`ing followed by vacuum dewatering and thereafter
`drying. The vacuum dewatering equipment limits glu-
`ten recovery due to the time consuming nature of the
`operation and possibly due to filter cloth plugging.
`Filter cloth plugging is especially a problem when poly-
`mers such as polyacrylamide type polymers have been
`added to the gluten stream.
`The preferred surfactants in the process of the pres-
`ent invention are nonionic surfactants, particularly oxy-
`alkylated sorbitan fatty esters. Representative surfac-
`tants are those surfactants marketed by ICI Americas
`Inc., under the trademark “Tween” label. The “Tween”
`label surfactants are polyoxyethylene 20 sorbitan R
`surfactants with R being a fatty acid moiety. The gen-
`eral structure of the polyoxyethylene sorbitan R is;
`
`EH2 ----------
`H<'3‘-0(C2H40)w
`'H(0C2H4)x0(l3H
`rr—c|: ---------------«'
`H-f—o<c2H4o>,H°
`CH20(CzH40)z0CR
`
`9
`
`where w+x+y+z=20. When R equals monooleate the
`material is “Tween” 80 (polysorbate 80). When R=tri-
`oleate the material is “Tween" 85. When R=monostea-
`rate the material
`is “Tween" 60 and 61. When
`
`(cid:0)H(cid:0)Y(cid:0)D(cid:0)R(cid:0)I(cid:0)T(cid:0)E(cid:0) (cid:0)E(cid:0)X(cid:0)H(cid:0)I(cid:0)B(cid:0)I(cid:0)T(cid:0) (cid:0)1(cid:0)0(cid:0)1(cid:0)0
`

`
`5,283,322
`
`3
`R=monopalmitate the material is “Tween” 40. When
`R=monolearate the material is “Tween” 20 and 21.
`For triesters, the hydrogens marked with an asterisk are
`replaced by RCO—.
`It is also believed that the sugar modified surfactants
`such as octaglycerol monooleate or polyglycerol ester
`would also be effective. Such polyglycerol esters are
`known to be an effective replacement for polysorbates.
`EXAMPLE
`
`The effectiveness of the present invention at enhanc-
`ing the vacuum dewatering in gluten processing was
`determined in filter leaf testing which employed filter
`cloth identical to that employed in a commercial gluten
`dewatering process. The filter testing was done on
`heavy gluten. 1000 milliliters samples of heavy gluten
`were treated with the material being tested and mixed
`with a gang stirrer. The treated gluten sample was then
`decanted into a large plastic container for ease in per-
`forming the filter leaf test. Vacuum readings were main-
`tained at 18 inches of mercury throughout the test per-
`iod. The testing was performed with a variety of poly-
`meric surfactants including cationic, anionic and non-
`ionic materials. The test procedures monitored: treat-
`ment type and dosage, time required to draw filtrate
`during forming, time required to observe a crack (vac-
`uum break) during drawing, milliliters of filtrate col-
`lected, filtrate appearance, ease of cake release, and
`filter cloth appearance. Table 1 summarizes the test
`results. Table 2 describes the polymeric surfactants
`tested.
`
`4
`
`TABLE 2
`Treatment
`Description
`“Tween“ 80
`Anionic acrylamide/sodium acrylate
`Emulsion Copolymer
`Cationic Emulsion Polymer
`Cationic Emulsion Polymer
`Cationic Emulsion Polymer
`Cationic Emulsion Polymer
`
`“I'll‘flUOB1)
`
`l0
`
`15
`
`20
`
`25
`
`30
`
`35
`
`45
`
`50
`
`55
`
`65
`
`During testing, it was found that the nonionic surfac-
`tant polyoxyethylene 20 sorbitan R provided significant
`improvements in filtrate recover rate. Cationic and
`anionic surfactants did not provide similar improve-
`ments. On all occasions when a blank test followed a
`nonionic surfactant test,
`the blank performed better
`than previously run blank tests. This is believed to be
`due to residual nonionic surfactant adsorbing onto the
`filter media and thereby providing a residual effect.
`When nonionic surfactant tests were performed after
`blank tests, the results are slightly lower than back to
`back nonionic surfactant tests. This again is believed to
`be due to a residual or preconditioning effect.
`The treatment range for the nonionic surfactant of
`the present invention can range from about 75 to about
`300 parts per million based upon dry solids. The pre-
`ferred treatment range is from about 75 to about 150
`parts per million based upon dry solids. No additional
`benefit was seen when the treatment rate was increased
`from 150 parts per million to 300 parts per million.
`The filtrate recovery rate will vary with changes in
`percent solids in the heavy gluten being treated. During
`testing, (Runs 1, 2 and 3) the percent solids off of the
`centrifuge varied from about 12 to 17%. However, in all
`cases treatments of 150 parts per million nonionic sur-
`factant based upon dry solids out-performed the blank
`runs.
`
`It is believed that the nonionic surfactant treatment of
`the present invention may be fed to the wet gluten prior
`to the centrifuge in order to reduce fouling of the centri-
`fuge nozzles and bowl.
`While the present invention has been described with
`respect to particular embodiments thereof, it is apparent
`that numerous other forms and modifications of the
`invention will be obvious to those skilled in the art. The
`appended claims and this invention generally should be
`construed to cover all such obvious forms and modifica-
`tions which are within the true spirit and scope of the
`present invention.
`We claim:
`1. A method of enhancing the dewatering of gluten
`which comprises adding to an aqueous gluten solution
`prior to dewatering, an effective dewatering amount of
`a nonionic surfactant.
`2. The method of claim 1, wherein said nonionic
`surfactant is a polyoxyethylene 20 sorbitan R surfactant
`wherein R is selected from the group consisting of
`monooleate, trioleate monostearate, tristearate, mono-
`laurate, and monopalmitate.
`3. A method of enhancing vacuum dewatering of wet
`corn milling gluten which comprises adding to said wet
`gluten, prior to vacuum dewatering, an effective dewa-
`tering amount of a nonionic surfactant.
`4. The method of claim 3, wherein said nonionic
`surfactant is a polyoxyethylene 20 sorbitan R surfactant
`wherein R is selected from the group consisting of
`monooleate, trioleate, monostearate, tristearate, mono-
`laurate, and monopalmitate.
`I
`t
`8
`1
`Q
`
`—
`—
`42 sec
`25 sec
`30 sec
`16sec
`24 sec
`30 sec
`27 sec
`28 sec
`28 sec
`
`33 sec
`29 sec
`33 sec
`40 sec
`45 sec
`54 sec
`47 we
`36 sec
`36 sec
`31 sec
`34 sec
`30 sec
`41 sec
`
`46 sec crack
`50 sec crack
`40 sec crack
`40 sec crack
`32 sec crack
`40secbreak
`44 sec crack
`39 sec crack
`35 sec crack
`39 sec crack
`30 sec crack
`
`60 sec crack
`44 sec crack
`41 sec crack
`40 sec crack
`43 sec crack
`5l sec crack
`42 sec crack
`37 sec crack
`45 sec crack
`42 sec crack
`35 sec crack
`41 sec crack
`44 sec crack
`
`95 ml
`92.5 ml
`95.5 ml
`108 ml
`120 ml
`113 ml
`101 ml
`101 ml
`105 ml
`102 ml
`107.5 ml
`
`96.5 ml
`102 ml
`98 ml
`93 ml
`85 ml
`87 ml
`87 ml
`94 ml
`100 ml
`102 ml
`99 ml
`105 ml
`98 ml
`
`
`TABLE 1
`Time
`Time
`Filtrate
`Volume
`(sec)
`(sec)
`to Draw
`Vacuum
`(ml)
`Recovery
`
`Treatment
`Water
`Break
`Filtrate
`Rate(ml/sec)
`1ST RUN
`Blank
`Blank
`Blank
`A 150 ppm
`A 150 ppm
`A 150 ppm
`A 75 ppm
`A 300 ppm
`A 300 ppm
`Blank
`A 150 ppm
`2ND RUN
`Blank
`A 150 ppm
`Blank
`B
`lw ppm
`200 ppm
`C l(I) ppm
`200 ppm
`D 100 ppm
`200 ppm
`E 1(1) ppm
`200 ppm
`100 ppm
`F
`100 ppm
`B
`plus FeSO4
`50 ppm
`3RD RUN
`1.27
`75 ml
`38 we crack
`59 sec
`Blank
`1.49
`79 ml
`39 sec crack
`53 sec
`A 150 ppm
`1.77‘
`78 ml
`41 sec crack
`44 sec
`Blank
`2.34
`89 ml
`58 sec crack
`38 sec
`A 150 ppm
`
`F 1.78’ 100 ppm 49 sec 53 sec crack 87 ml
`
`
`
`
`‘Test results higher than expected due to preconditioning effect of previous test.
`"Prior to this run the filter medium was flinhed with water.
`
`—
`—
`2.27
`4.32
`4.00
`7.06
`4.20
`3.36
`3.89
`3.64‘
`3.84
`
`2.92
`3.51
`2.97‘
`2.33
`1.96
`l.6l
`1.85
`2.61
`2.78
`3.29"
`2.91
`3.50
`2.39
`
`The treatment rates are ppm based on dry solids.
`
`(cid:0)H(cid:0)Y(cid:0)D(cid:0)R(cid:0)I(cid:0)T(cid:0)E(cid:0) (cid:0)E(cid:0)X(cid:0)H(cid:0)I(cid:0)B(cid:0)I(cid:0)T(cid:0) (cid:0)1(cid:0)0(cid:0)1(cid:0)0