Chemistry Reference
In-Depth Information
contributingtothebread'scolorandlavor.Theyarecalledhardwheatproducts,inwhichagluten
structureisdevelopedbykneadingthewheatlourproteinsinthepresenceofwater.Theseinclude
yeast-raisedbreads,rolls,bagels,andsweetrolls.Thetypicalconcentrationoftraditionalsweeten-
ersvariesbetween0%-15%,dependingonhowsweettheproductis.Nutritivesweetenersactasa
fermentablecarbohydratefortheyeast.Fermentationproducesgas,causingtheproducttoriseand
formanaircellstructure.Fermentationalsocreatesreducingsugars,whichparticipateinMaillard
browningandcaramelization,givingtheproductitsbrowncrustcolor.
Alternativesweetenersarenotusedtoreplacetraditionalsweetenersinbreadsandrollsbecause
nutritivesweetenersareusedatlowconcentrations.Caloriesarereducedbyusinglessfat,replac-
ing lour with a iber source, adding emulsiiers and vital wheat gluten, and increasing moisture
(Altschul1993).
Yeastsutilizestarchbutpreferentiallyutilizeglucoseorsucrose.Sugaralcoholsinhibityeast
activity,andtheproductmaynotfullyprooforriseadequately(Nelson2000a,b).
Itmaybenecessarytoaddsucroseorenzymestoaidinstarchbreakdowntoprovideferment-
ablecarbohydrates.Thiswillaidthebrowningprocess.
Insweetdoughproducts,alternativesweetenerscouldbeadded,replacingnutritivesweeteners.
Theseproductsaremoistandsoftbecauseoftheirhighsugarlevels,whichinhibitglutendevelop-
ment.Hence,partialreplacementofsugarscanresultinadrierproduct.Hygroscopicagents,suchas
sugaralcohols,canbeaddedtoincreasemoistness.Gums,cellulose,orstarchescanalsobeadded
tohelpbindthemoisture.Toreducetoughness,plasticizingagentscanbeadded,eitherbyincreas-
ingthefatcontentorbyaddingemulsiiersifcaloriesareofconcern.
8.9.11 Shortened and Unshortened Cakes
Inshortenedcakes,sugaraidscreamingtoincorporateairintotheshorteningofthesecakes.
Duringmixing,sugartenderizescakesbyabsorbingliquidandpreventingcompletehydrationof
glutenstrands.Duringbaking,sugartenderizesshortenedcakesbyabsorbingwateranddelaying
gelatinization(Ponte1990).
Unshortenedcakes,suchasspongeandangelfoodcakes,containnofatbutincludealargepro-
portionofeggsoreggwhites.Muchofthecellularstructureofthecakeisderivedfromeggprotein.
Theleaveningagentistheairthathasbeenbeatenintotheeggs.Sugarservesasawhippingaidto
stabilizethebeatenfoam.Partofthesugarisalsocombinedwithlourbeforebeingfoldedintothe
foammixture(Ponte1990).
Nutritivesweetenersprovidebulk,batterviscosity,andpropersettingofthecrumbbydelay-
ingstarchgelatinizationandproteindenaturation.Theyinluencecrumbcharacteristics(moistness
andtenderness)andshelflife.Sucroseisusedincakeformulationsat25%-30%andhigh-intensity
sweetenersat0.1%-2%.
Maltodextrinsandgranularsugaralcoholscanbeusedduringcreamingtoaddbulk,andemulsi-
iershelpintheincorporationandretentionofair.PolydextrosecanaffectthepHoftheformulation;
hence,theleaveningsystemisadjustedbychangingthesodiumbicarbonatelevels.Polydextroseis
addedincakesat7%-15%byweight.Iftoomuchisused,aheavycakewithasyrupymouthfeeland
bitteraftertastecanresult(Khan1993).Shrinkageoftheinalproductcanalsooccur.
Powderedcellulose,aninsolublebulkingagent,hasalsoshowngoodresults(AngandMiller
1991). Sugar alcohols could also be used to provide bulk and viscosity. Frye and Setser (1992)
have reported the use of polydextrose, maltodextrin, sorbitol, lactitol, isomalt, and hydrogenated
starchhydrolysates(HSH)incakeformulations,showingthat,whentheirsttwoareused,apuffed
appearanceandairpocketformationdonotoccur.
Finally,sugaralcoholsmaintain crumb tenderness and moistness. Otherhumectants, such as
water-bindingstarchesandgums,areused.
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