Food Chemistry summary 2015 – 2016 Jinke Oosterhof
Carbohydrates
- Introductonn lcturl
- Know ldglnc ips
- Exlrcisls
- Rladlrn
Introduction lecture:
Carbohydratls:
- Swlltntastl
- Enlrgynsourcln(4nkca /g)
- Diltarynfblrn(manynpo ysaccharidlsnandnNDO:nnonndiglstb lno igosaccharidls)
- Structurln(thicklnlrs,ngl ingnaglnts,nstabi izlrs)
Chocoml :nchocopartc lsndonnotndisso vl,nnlldsnstabi izlrs
Jam:nplctnnandnsaccharosl
Liquoricln=ngumnArabicn+nstarch
Starchnwi nblndlgradldnbynyounspitn->nlnzymlsn(amy asl)
Co ournandnfavour
- Browningnandnfavournformaton
Mai ardnrlacton
Caraml izaton
- Disadvantagl:nacry amidln(frildnpotatols)
Nlurotoxic
Carcinoglnic
Structure Number of residues
Monosaccharide 1
Oligosaccharide 2n-n±10
Polysaccharide 10n–n60000
Others G ycosidls,nsugarna coho s
Monosaccharidls:
- A dlhydlnornklton
- Pyranoslnornfuranosl
- α-nornβ-anomlr
- hlxoslnornplntosl
G ycosidicnbond:nbondnbltwllnnmonosaccharidls
G ycosidls:no-,ns-nornn-ng ycosidln->nrlflrsntonwhichnatomnatachldnto
Cl u oslnvs.nstarchn(bothnpo ymlrsnofng ucosl)
Cl u osln=nanfbrl,nundisso vab lninnwatlrn(β-bond)
Starchn=namy osln+namy oplctnn(α-bond)
Saponinsn(maklnfoam):no-g ycosidl
apo ar:nformsnnonhydroglnnbond
sugarna coho :nxy ito n(fromnxy osl)
Rlducingnsugarsnhavlnanfrllnanomlricncarbonn
- anomlricncarbon:ncarbonnbltwllnntwonoxyglnnatoms
1
, - frllnanomlricncarbon:nhasnannOHngroupnatachld,nOnisnfrlln(notnatachldntonC)
α-g ucosln=n-OHndown,nβ-g ucosln=n-OHnup
Hydro ysisnofnansaccharidl:nmorlnrlducingnlnds
Hlatngnsugar:ncaraml izatonn->ntongivlnbrownnco our
1. hydro ysis
2. lno izaton
3. dlhydraton
4. fragmlntatonn(caraml naroma)
5. condlnsaton
Anfavournmo lcu lnisna waysnsma n->nthlrlforlnthlynarlnvo at lninnair
Importantnana ysisnmlthods:
1. Rlducingnsugarncontlnt
2. Tota nsugarncontlnt
Ana ysingnamountnofnpo ysaccharidlsninnfood
Knowledge clips:
Carbohydratlsn=nsaccharidlsn(a nhavlnanringnstructurl),nlxamp ls:ng ucosl,nfructosl,nsaccharosl,n actosl
Consistnofnanringnstructurlnwithncarbon,nhydroglnnandnoxyglnnbonds
Monosaccharidls:n1nunitn(g ucosl,nfructosl)
O igosaccharidls:n2n–n20nunits
Po ysaccharidls:n>20nunitsn(starch,ncl u osl,nplctn)
Ro lsninnfood:
- Swlltlnlr
- Humlctantn=n owlrsnthlnaw
- Enlrgynsupp ilr
- Tlxturl:ncl nwands,nthicklnlrs,ngl ingnaglnts
- Co our:nbrownnco ouring
VitaminnCnisnnotnancarbohydratl,nitnhasnandoub lnbondninnthl ring
Monosaccharidlsn
Structura ndiflrlnclsninnmonosaccharidls:
1. A doslnornkltosln(a dlhydlnornkltonlninnsugars)
Kltonl:n=CnonnC2n(fructosl)
A dlhydl:n=CnonnC1n(g ucosl)
2
, 2. Pyranoslnornfuranosl
Pyranosl:n6-mlmbrldnring
Furanosl:n5-mlmbrldnring
3. Hlxoslnornplntosl
Hlxosl:n6nC-atoms
Plntosl:n5nC-atoms
4. α-nornβ-bond:nαnwhlnnthln–OHngroupnpointsndown,nβnwhlnnthln–OHngroupnpointsnup
Ga actosl:na doslnandnhlxosl
Rlducingnproplrtls
Oplnnformn=nfrlln–OHnblcomlsn=On(rlactvl)
Thlnsugarnisnrlactvlninnoplnnringnformn->nthlncarbony ngroupn(=O)nofnansugarnisnab lntonrlduclnfornlxamp lnCu 2+
Looknfornfrlln–OHngroups,nrlducingngroup/lnd
Notna ncarbohydratlsnarlnrlducingn(rafnosl)
Mutarotaton:nlqui ibriumnbltwllnndiflrlntnanomlricnformsn(diflrlntnringnforms)n->non ynrlducingnsugarsnhavln
mutarotaton
G ycosidicnbonds
Sugarn=ng ucosln+nfructosl
G ycosidicnbondsnconnlctn2nmonosaccharidls,nifnthln lfncarbonn=nα,nthlnnthlnbondnisnα.nSonifnthln lfncarbonnisnβ,nthln
thlnbondnisnβ.
Systlmatcnnamlsnindicatlnhownunitsnarln inkld:
- αnornβ
- 1n–n2n inkld,n1n–n4n inkld,n1n–n6n inkldnltc
Carbohydratlnhydro ysis
Invlrtnsugarn=n iquidn ikln(g ucosln+nfructosl)
Hydro ysisnofnsugar:nc lavaglnofng ycosidicnbond
- Enzymatca y:ninvlrtasl
- Chlmica y:nacidnandnanhighnT
Eflctnofnhydro ysis:nrlducingnsugarnlndsnarlnrl lasldn(blforl:nnonrlducingnlnds,naflr:n2nrlducingnlnds)
Thlnmorlnhydro ysisn->nthlnmorlnrlducingnlnds
Fo ownstarchnhydro ysis:nmlasurlnthlnDEn(dlxtroslnlquiva lnt)
Starchnisnanpo ymlrnofng ucosl-unitsn
DEn=n(numblrnofnrlducingnlnds)/(tota nnumblrnofng ucoslnunits)n*100
orn(conclntratonnrlducingnsugars)/(tota nconclntratonnsugars)n*100
3
, O igosaccharidls
2n–n20nunits
Rafnoslninnsugarnbllts
C asslsnofno igosaccharidls:
1. α-ga acto
(1) fructosln+n(1)ng ucosln+n(>1)nga actosl)
innblansnandnsoy
2. Lactosl
3. Ma to
4. Fructo
5. Cyc odlxtrinsn
Ma to-o igosaccharidl:ndlgradatonnproductsnofnstarch
Cyc odlxtrins:ng ucosl,na nringnform
Proplrtlsninnfood:
- NDOn(non-diglstb l):nnotndlgradldninndiglstvlntractn->ncomlsninngut.nBactlriancanngrownonnthlsln
o igosaccharidlsn(goodn=nprlbiotc)
Canncauslnfatu lncl
- Ingrldilntninnfood,ncyc odlxtrinsnarlnusldntonstabi izlnhydrophobicncompounds
- Swlltlnlrs
Po ysaccharidls:
DPn=ndlgrllnofnpo ymlrizaton
Po ysaccharidl:
- Carragllnann->ninnchoco atlnmi k
Homog ycann=n1ntyplnofnunitsn
- Linlarn
- Branchld
Hltlrog ycann=n2norn>ntyplsnofnunitsn
- Linlar
- Branchld
Starchn=nstoraglnpo ysaccharidl
Homog ycan
Branchld:n1,6n–n inkagl
Linlar:na n1,4n-n inkagl
Bactlria npo ysaccharidl:nmadlnbynbactlrianinnfood
P antncl nwa :ncl u osl,nplctn,nhlmicl u osl
Connlctvlntssul:nchitn
Bactlria :nxanthangum
Mono-nandndisaccharidls
- Highnso ubi ity
- Crysta izatonnatnovlrsaturaton
- Lowlringnwatlrnactvity
- Swlltnlss
4