Quality Control of Sweeteners: Production, Handling, and Storage - Sweeteners: Nutritional Aspects, Applications, and Production Technology

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Mostapplicationsofthisapproachinvolveusinglameatomicabsorptionspectrometry(FAAS).

Severalcontinuousautomaticprecipitationsystemscoupledonlinetoaconventionalatomicabsorp-

tioninstrumenthavebeenusedforindirectdeterminationsofinorganicanions.

9.18.10 Nuclear Magnetic resonance

Rebaudioside A is a natural sweetener from S. rebaudiana in which fourβ-d-glucopyranose

unitsareattachedtotheaglyconesteviol.Its 1 Hand 13 CNMRspectrainpyridine-d 5 wereassigned

using one- and two-dimensional methods. Constrained molecular dynamics of solvated rebau-

dioside using nuclear magnetic resonance (NMR) constraints derived from ROESY cross peaks

yieldedtheorientationoftheb-d-glucopyranoseunits(SteinmetzandLin2009).Hydrogenbonding

wasexaminedusingthetemperaturecoeficientsofthehydroxylchemicalshifts,ROESYandlong-

rangeCOSYspectra,andproton-protoncouplingconstants.

Onlypartial 13 CNMRassignmentsareavailable(Dacomeetal.2005).

9.18.11 Inductively Coupled plasma Optical emission Spectrometry

Forliquidcyclamate-saccharinesweeteners,cadmiumwasfoundinoneof15analyzedsam-

ples,employingtheinductivelycoupledplasmaopticalemissionspectrometry(ICPOES)technique

(Sousa,Baccan,andCadore2006),arsenicandleadwerefoundintwooffoursamplesofliquid

aspartamesweeteners,analyzedbyICP-MS(Sousaetal.2007),andseleniumwasfoundinmany

samplesofliquidsweeteners,containingcyclamate-saccharineandstevioside,analyzedbygraph-

itefurnaceatomicabsorptionspectrometry(Sousaetal.2006,2007,2011).ICPOEShasbeenused

byPedro,Oliveira,andCadore(2006)forthedeterminationofmajorandminorelementsinfoods.

Inorganic species (calcium, cadmium, copper, cobalt, iron, magnesium, manganese, sodium,

nickel, lead, selenium, and zinc) were determined by Sousa, Baccan, and Cadore (2011) in solid

sweetenersbyICPOESwithoutemployingamineralizationstep.Robustconditionswereusedin

theICPequipment,andthesampleswereanalyzedasaqueoussuspensions.Theanalysisofdiffer-

entkindsofsweetenersshoweddifferentconcentrationproiles.Somesamplespresentedcontami-

nationbycadmium,butingeneral,thesampleswerefoundtocontaincalcium,iron,magnesium,

manganese,sodium,andseleniumintolerableamounts.Themethod'saccuracywasevaluated,and

recoveryvaluesbetween90%and110%wereattainedfortherecoveryexperiments;theRSDval-

ueswerelowerthan5%inmostcases.

9.18.12 titrimetric and Other Methods

Titrationwithacopper(II)salt(Lane-Eynontitration)isthestandardmethodforthedetermina-

tionofreducingsugars(glucoseandfructose)inbulkrawandwhitesugars.Moistureinsolidsugars

isdeterminedgenerallybyovendrying;inliquidproducts,byKarlFischertitration(Yebra-Biurrun,

Cancela-Perez, and Moreno-Cid-Barinaga 2005; Yebra-Biurrun, Moreno-Cid, and Cancela-Perez

2005).Inorganiccontentisdeterminedbyeitherconductivityinsolutionorsulfatedashgravimetric

procedures.

In syrups, the solids content, degrees Brix, or refractometric dry solids, is determined by RI

measurement.TablescorrelatingRIwithsucroseandinvertcontentarepublishedintheICUMSA

andAOACmethods topics.

Physicochemicalanalysisofvarioussweetenersandanalyticaltechniquesusedinthedetermi-

nationofartiicialsweetenersinfoodproductsaredescribedinTable9.9.

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