Application of Sweeteners in Food and Drinks - Sweeteners: Nutritional Aspects, Applications, and Production Technology - page 232

8.22 YOGUrt FOrMULatION aND prOCeSS
Thefruitphaseusuallyconsistsoftheadditionofthawedfruitorfreshfruit,sweetenersinstead
ofsugar,water,glucose,pectin,citricacid,lavor,potassiumsorbate,andantifoamingagents.The
yogurtphaseconsistsofskimmilk,milksolids,andculture.
Theinishedyogurtshouldcontainaratioof80to20,yogurttofruitphase,respectively.
Theprocessisbasedonheatingskimmilkto43°CfollowedbytheadditionofMSNF-gelatinor
otherstabilizer.Heatingto82°Cfor30ministhencarriedouttopasteurizetheproductfollowedby
coolingto45°CheldconstantuntilpHis4.3-4.5.
Coolingat35°Cisthencarriedoutandsweetenersaddedalongwithcoloring,lavoringagents,
andfruit.
Fillingintocupsinishestheprocesswithsubsequentcoolingto4°C.
TheU.S.FDAapprovedtheuseofaspartameinyogurtsin1988(VanderVen1988;Kelleretal.
1991).Whenusedinyogurtmaking,a52%reductioninthecalorieswasachievedpercupofproduct.
Keller et al. (1991) evaluated the degradation of aspartame in yogurt in relation to microbial
growthintheproduct.Threecommercialyogurtstartercultures(i.e.,singlestrainsandmixed)con-
tainingthe Lactobacillusdelbrueckii ssp. bulgaricus and Streptococcusthermophilus wereused.
Theproportionofdegradedaspartamewasrelatedtothegrowthandactivityofthestarterculture
withnosigniicantdifferencesbetweensingleormixedstrains.Theresultsshowedthatonly10%of
theaspartamewasdegraded,anditremainedstableinyogurtover6weeksofstorageatrefrigera-
tiontemperature(Pinheiroetal.2005).
However,Fellows,ChangandShazer(1991b)evaluatedthestabilityofaspartameduringmilk
fermentationtoproduceasundae-styleyogurt,containingfruitandusingdifferentincubationperi-
odsandtemperatures.Aspartame'sstability,determinedbyHPLC,was95%inyogurtmadein6
handincubatedat43°C,andaparallelproductthatwasfermentedat32°Cfor13hshoweda90%
stabilityofthesweetener.Thestudydemonstratedthataspartamehasexcellentstabilityduringthe
preparationofyogurtswithfruit.
Brandão,Silva,andReis(1995)reportedtheeffectofaddingdifferentamountsofDairy-Lo™
(PizerInc.,NewYork,U.S.A.)(0,1,2,3,and4g/100g;thisisamicroparticulatedwheyprotein
usedasafatsubstitute)onthequalityofyogurtmadefromskimmilkandaspartame.Itwasrec-
ommendedthatsmalleramountsofaspartameshouldbeusedduringthemanufactureofayogurt
containing Dairy-Lo™. However, Monneuse, Bellisle, and Louis-Sylvestre (1991) concluded that
aspartameusedatarateof0.028g/100gofyogurtwaspreferredbyatastepanel.
Decourcelle et al. (2004) concluded that the presence of pectin and starch in low-fat stirred
yogurtreducedthereleaseofaromacompoundsintheheadspaceofthesample,andyogurtprepared
with locust bean gum signiicantly increased the lavor release. Furthermore, yogurts made with
guargumandsweeteners(fructose,fructooligosaccharides,aspartame,oracesulfame)appearedto
havenoeffectonlavorrelease.
HyvonenandSlotte(1983)studiedtheeffectofdifferentsweeteners(e.g.,xylitol,sorbitol,fructose,
cyclamate,andsaccharin—sucrosewasusedasareference)onthequalityofyogurt,andtheywere
addedtothemilkbasebeforetheincubationperiodortothefermentate.Allthesweetenersusedwere
satisfactorytosweetentheyogurt,especiallyafterincubation,exceptsaccharin.Nevertheless,saccha-
rincouldbeusedwhenmixedwithxylitoltomaskitsbitteraftertaste.Inaddition,sorbitolreducedthe
growthrateofthestarterculturewhenaddedbeforefermentingthemilk,anditseffectwasonlysatis-
factorywhenusedinconjunctionwithsucrose.Theyalsoreportedthefollowingblendsofsweeteners
shouldbeused:8%xylitol,7%fructose,and0.07%cyclamate;or4%xylitoland0.007%saccharinas
analternativereplacementofsucroseequivalentto8g/100gconcentration.
Regardingcyclamate,a10:1ratioofcyclamatetosacchariniscommonlyusedandprovidesthe
intensesweetnessofsaccharincombinedwiththeabilityofcyclamatetolessenthebitteraftertaste
ofsaccharin(Wilkes1992).