Low Calorie Nonnutritive Sweeteners - Sweeteners: Nutritional Aspects, Applications, and Production Technology - page 84

CH 2 COOH
HC NH 2

O

NH
HC C

H 2

O O CH 3

(I)

Figure 4.3 Chemical structure of ASP.

4.4 aSpartaMe

ASP (N-L-a-aspartyl-L-phenylalanine-1-methylester) is a dipeptide (Figure 4.3). It is 200 times
sweeterthansugar,anditssweettasteisalmostidenticaltothatofsucrosebutlacksinaftertaste.This
sweetenerwasdiscoveredaccidentallyin1965byJamesM.SchlatteratG.D.SearleCo.Thisnutritive
sweetenerprovides4caloriespergram,buttheamountrequiredtogivethesamesweetnessassugaris
only0.5%ofthecalories(SardesaiandWaldshan1991).Itisawhitecrystallinepowderwithamolar
massof294.31andacalorievalueof17kJ/g.Becauseofitshighlevelofsweetness,theamountsthat
canbeusedaresmall.Althoughitisrelativelystableinadryform,thecompoundcanundergopHand
temperature-dependentdegradation;forthisreason,ASPisundesirableasabakingsweeteningagent.
BelowpH3,ASPisunstableandhydrolyzestoproduceaspartylphenylalanine,andabovepH6,itchanges
toform5-benzyl-3,6-dioxo-2-piperazineaceticacid(Zygleretal.2009).ASPwasapprovedin1981and
producedforthemarketas“Nutra-Sweet.”Fortheirsttime,dairyproducts(icecream,yogurt,etc.)were
calorie-reducedandcouldbesoldwiththepreixes“diet”or“light”(WeihrauchandDiehl2004).
The metabolism of ASP was extensively studied. The major point that was concluded from
metabolismstudiesisthatASPisbrokendowninthegastrointestinaltracttoitsconstituents(i.e.,
asparticacid,phenylalanine,andmethanol;SardesaiandWaldshan1991).
ASPisprobablythemostcontroversialartiicialhigh-intensitysweeteneronthemarket.Ithas
beenreportedthatASPcancausemedicaleffectstoconsumers,suchasmultiplesclerosis,systemic
lupus,braintumors,andmethanoltoxicity(Zygleretal.2009).RecentreportssuggestthatASPcan
berelatedwithcancer,lymphomas,andleukemiasafterinvestigationsusingrats.In2006and2007,
these indings were published by the European Ramazzini Foundation (ERF) of Oncology and
EnvironmentalSciences(Soffrittietal.2007).TheseallegationsregardingASPanditseffectsin
humanshavebeencarefullyevaluatedbyscientistsatregulatoryagenciesaroundtheworldinclud-
ing the EU and the United States. The conclusion was that ASP does not cause anything of the
effects mentioned. In March 2009, EFSA investigated the results of these studies and found no
indicationsofanygenotoxicorcarcinogenicpotentialofASP(EFSA2009).Theonlydisadvantage
of ASP is that it cannot be used by individuals suffering from phenylketonuria (PKU). For this
reason,foodstuffinwhichASPisaconstituentmustbelabeledthatitcannotbeusedbyphenyl-
ketonurics as it contains phenylalanine. The intake of ASP must be limited in these individuals
(MacKinnon2003).ASPisapprovedinmorethan90countries(theEU,theUnitedStates,Canada,
SouthAmerica,Australia,Japan,etc.)foruseinnumerousfoodstuffs. (III)

4.5 aSpartaMe-aCeSULFaMe SaLt

ACS-KandASParecharacterizedasartiicialhigh-intensitysweeteners.Theyarealsocalled
nonnutritive sweeteners. These two are commonly used in foods, beverages, and confectionery