Separator's Digest 2004/1 - GEA Westfalia Separator Group

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IndustryIsolatedSoy Protein➤ Food source ofthe futureAp Apart from soy oil recovery,the glycine from the family oflegumes is also a very efficientand inexpensive supplier of protein.This is because the soy beans containapprox. 20 % oil and around 50 %protein. This is a virtually ideal compositionfor human nutrition. However,raw soy beans are inedible – they containnatural substances such as trypsininhibitors which inhibit the digestionof protein.The potential applications of soyprotein are extremely varied. It is estimatedthat up to 30,000 food productscontain soy components in some form,e.g. sports drinks, confectionery, dietfoods, bakers’ additives and baby food.In addition, soy protein is often usedfor technical products, for instancewater-soluble dyes, in textiles and plastics,in cosmetics and packaging film.Isolate recoverywith centrifugalseparating technologySoy is nowadays anessential componentof many foods. Half acup of soy beans forinstance supplies asmuch protein as a150g steak. Soy alsocontains the aminoacids which manrequires but is notable to make himself.Soy is the global protein and oil plant.More than half of vegetable oil producedthroughout the world is derived from thesoy bean. The inconceivable quantity of184 million tonnes was harvested in 2002,90 % of this figure in the USA, Brazil,Argentina and China.The raw material for all these applications,namely isolated soy protein, issupplied by a process in which separatorsand decanters from WestfaliaSeparator play a major role.Roughly speaking, the soy bean isinitially cleaned, broken, peeled andprocessed into flakes. To enable theprotein to be recovered, the soy oilmust first be removed, so that the oilcontainingphase and the aqueousphase, in which the proteins are contained,do not result in an emulsionsimilar to mayonnaise.The oil is extracted by means of solvent,in general hexane, which is subsequentlyremoved. This process producesso-called “white flakes” whichderive their name from their whitecolour – all originally yellow pigmentsof the glycine are combined with theseparated oil. This is the point atwhich centrifugal separating technologycomes into action. In a two- ormulti-stage extraction phase, the pHvalue is increased by adding, for example,caustic soda.24Separator´s Digest 1/2004Separator´s World
The proteins are dissolved, and canideally be separated with decantertechnology into an aqueous proteinphase and solid fibre material. Thetwo-gear drive of, for example, adecanter CB 505, achieves optimumdewatering of the solids and excellentclarification.“As the protein tobe recovered is usedfor food, the decantershave hygienic designand are CIP-capable.”Two-stage extraction can be usedconsistently in the counters-currentmode, i.e. most of the protein ispumped into the second stage andthen returned to the first stage to enablefurther protein potential to be released.Stringent requirementsregarding regulating accuracyThe next step is to precipitate theproteins from the aqueous solution byadjusting the solution to its isoelectricpoint. The solids that are obtained inthis way are also recovered by decanters.Because the protein is in the formof a very fine solids suspension, therequirements regarding the decanterdrive are extremely stringent as far asregulating accuracy is concerned. Thisis because the decanter is operated ina very low differential speed range.Westfalia Separator machines areaccordingly equipped with specialfeatures such as a gentle feed througha rotating inlet tube, special conicalangle, measures for avoiding foamingand immersion discs for optimumdewatering. An important requirementfor sanitary operation is a facilityfor efficiently cleaning the machines.The machines have special features toachieve this. Under certain circumstances,the low density differencemight not allow the extremely finesuspended solids to be removed entirely.An additional separator of theHSB series can be used for clarifyingthe overflow to assure product safety;this solution of course meets the samehygiene criteria as the decanter.High value and strong growthIsolated soy protein has to feature aprotein content of more than 90%.After initial precipitation, the figuresare normally below this level. A seconddecanter is therefore used for proteinwashing. The soy isolate protein,obtained in this way, can be processedspecifically into functional protein as araw material by physical or chemicalmeans. Depending on the specificnature and application, these proteinsare extremely valuable and are sold forprices of up to EUR 5,000 per tonne.“Soy protein is clearlya growth market.China alone will tripleproduction during thenext five years.”Westfalia Separator recently installeda protein recovery process withfive decanters in Israel; the developmentis ongoing. In parallel with isolate,the process also enables proteinconcentrate to be recovered in highervolumes and with correspondinglylower margins.More new ideas are already maturingat Westfalia Separator. ■Markus SeilerHead of Starch Technology, Business UnitStarch Technology/Industrial BiotechnologyWestfalia Separator Food Tec, OeldeTel.: + 49 25 22/77-18 34seiler.markus@gea-westfalia.deSeparator´s World25Separator´s Digest 1/2004
Page 2 and 3: CONTENTS3 PrefaceTopical4 ➤ Separ
Page 4 and 5: Separator’s NewsSuccess Model Wes
Page 6 and 7: Separator’s NewsAbsolute Separati
Page 8 and 9: Separator’s NewsNew Generationof
Page 10 and 11: MilestonesA new generation in creat
Page 12 and 13: Food TecHow Does it Work?➤ How a
Page 14 and 15: Food TecWestfalia SeparatorClarifie
Page 16 and 17: multaneously to reduce the costs of
Page 18 and 19: Kwas has been known since 1056 and,
Page 20 and 21: Food TecDry Fractionationwith STEP
Page 22 and 23: IndustryKaolin for thepaper industr
Page 26 and 27: Mineraloil SystemsSMS insteadof SOS
Page 28 and 29: Mineraloil SystemsProper exposure
Page 30 and 31: Environmental TechnologyMega-Size C
Page 32 and 33: Environmental TechnologyHops and Ma
Page 34 and 35: ServiceAct local➤ Clear focus on
Page 36 and 37: Separation Technology + Beverage Te

Separator's Digest 2004/1 - GEA Westfalia Separator Group

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