5.

SACCHARIDES

sugars
classification
according number of sugar molecules
 monosaccharides
 oligosaccharides (2-10 monosacharides)
 polysaccharides ( 10 monosacharides)
 conjugated (complex) saccharides

 free
 bound homoglycosides, heteroglycosides, aglycons (non-sugar components)

Monosaccharides
polyhydroxyalkyl substituted aldehydes a ketones and derived compounds
main nutrients, biological and sensory activites
content (book 1, tab. 4.4, 4.5)
structure and classification
according to type of carbonyl group
 aldoses
 ketoses
H
C O C O

according to number of C atoms (3-8)

 trioses
1
CH O CH O CH O CH O
H C* OH
2
H C * OH H * OH HO C* H
3
CH2OH CH2OH CH2OH CH2OH

D-(+)-glyceraldehyde (D-glycero-triose) L-(-)-glyceraldehyde

optical isomers (enantiomers) D/L, R/S d/l, +/-
CH2OH

C O

CH2OH

1,3-dihydroxyacetone (1,3-dihydroxypropane-2-one, glycerone)

 tetroses
 pentoses, hexoses
CH O CH2OH
H C* OH C O
HO C* H HO C* H
H C* OH H C* OH
H C* OH H C* OH
CH2OH CH2OH

D-glucose (D-gluko-hexosa) D-fructose (D-arabino-hex-2-ulose)

dextrose, grape sugar levulose, fruit sugar

according to chain
 linear chain
  branched chain
 according to type of lactol
2 2
R OH R OH 2
O H 1
OR
1 1
R CH O R CH R CH
OR OR 2

aldehyde semiacetal acetal

 furanose
 pyranose
CH2OH CH2OH CH2OH CH2OH
OH
O OH HO HO HO HO
O
5 OH * 1 OH * OH OH *
*
HO OH HO OH
OH OH OH OH

-D-glukopyranosa -D-glukopyranosa -D-glukofuranosa -D-glukofuranosa

HO CH2 CH2OH HO CH2 O OH

O CH2OH O OH O
5 HO * 2 HO * HO * HO *
OH OH CH2OH
HO HO CH2OH
OH OH OH
OH
-D-fruktopyranosa -D-fruktopyranosa -D-fruktofuranosa -D-fruktofuranosa

mutarotation
anomers, anomeric C, anomeric OH
-pyranosa -pyranosa

acyklická forma

-furanosa -furanosa
conformation
 furanoses (envelope E, twist T)
 pyranoses (chair 4C1, 1C4)
 acyclic forms (cik-cak)

occurrence
present in all food
less typical monosaccharides
CH2OH
CH2OH O
O HO H
CH O HO H HO H
H OH H OH H OH
HO CH2OH HO H H OH
CH2OH CH2OH CH2OH

D-apiose L-sorbose D-manno-hept-2-ulose

branched sugar ketoheptose
root vegetables rowanberries avokado

2
abbreviations
glucose Glc furanose f
fructose Fru pyranose p
mannose Man acid A
apiose Api
sorbose Sor

-D-glukopyranose -D-Glcp

derivatives of monosaccharides
formation
 oxidation (or rearrangement) sugar acids
ketoaldoses, diketoses
 reduction suger alcohols
deoxysugars
 dehydration anhydrosugars
 reaction with other compounds glycosides
ethers
esters
amino sugars

sugar acids
content in malt and chicory (book 1, tab. 4.10)

 aldonic
Ca-gluconan (medicine), -laktone (fermented salami, 0,1 %)
 alduronic
polysaccharidy: D-GlcA6 (glycoproteins), D-GalA6 (pectins), D-ManA6 a L-GulA6 (alginates)
 aldaric, for example tartaric and malic acids

ketoaldoses, diketoses
main products of Maillard reaction and oxidation
 3-deoxyglycosuloses
 1-deoxyglycodiuloses
 4-deoxyglycodiuloses
CH O CH3
C O C O
CH2 C O
H C OH H C OH
H C OH H C OH
CH2OH CH2OH
o
3-deoxy-D-erythro-hexos-2-ulosa 1-deoxy-D-erythro-hexo-2,3-diulosa

CH2OH CH O
C O C O
C O HO C H
CH2 H C OH
H C OH H C OH
CH2OH CH2OH

4-deoxy-D-glycero-hexo-2,3-diulosa D-arabino-hexos-2-ulosa
sugar alcohols
3
alditols, glycitols (homologues of glycerol)
reduction
content (book 1, tab. 4.7 a 4.8)
CH2OH CH2OH
CH2OH CH2OH H C OH HO C H
H C OH H C OH HO C H HO C H
H C OH HO C H H C OH H C OH
H C OH H C OH H C OH H C OH
CH2OH CH2OH CH2OH CH2OH

ribitol xylitol D-glucitol D-mannitol

 natural components of food

ribitol riboflavin
arabinitol mushrooms
xylitol mushrooms
D-glucitol plums, rowanberries, pears
D-mannitol mushrooms, rowanberries, celery, green coffee
galactitol mushrooms, fermented milk products

 synthetic (reduction H2/catalyst., NaHgx, sweetners)

xylitol, D-glucitol

cyclitols
content (book 1, tab. 4.9)
cyclohexane-1,2,3,4,5,6-hexols (inositols, cycloses)
OH OH OH OH
1 2
OH HO OH
6 OH 3 OH HO HO
4 OH
HO OH
HO 5
OH OH OH

myo-inositol ( meso-inositol) 1D-(+)-chiro-inositol 1L-(-)-chiro-inositol o

OH OH OH OH OH
OH OH OH
OH HO HO

HO HO HO
OH OH OH

scyllo-inositol (scyllitol) neo-inositol allo-inositol

OH OH OH OH
OH OH
HO
OH
OH HO OH HO
OH HO
HO OH OH
HO
epi-inositol muko-inositol cis-inositol
 myo-inositol widespread” phospholipids, fytates
 pseudooligosaccharides pulses
D-galaktosa myo-inositol

CH2OH OH
HO O
5
OH
6
OH 1 1 HO 4
 2 3
O
OH OH OH

galaktinol
deoxysugars
reduction of primary / secondary hydroxyl
 natural
4
  Maillard reaction
2-deoxysugars
CH2OH
O
2
H OH

OH H

2-deoxy-D-ribose (thyminose)
deoxyribonucleic acids
6-deoxysugars (6-deoxyhexose = methylpentose)
CH3
6 HO 6 6 O
O O
CH3HO OH CH3 OH OH OH
HO HO
OH OH OH OH

L-fucose L-rhamnose D-chinovose

6-deoxy-L-galactose 6-deoxy-L-mannose 6-deoxy-D-glucose
milk oligosaccharides heteroglycosides heteroglycosides

anhydrosugars
sugar anhydrides, glycosans
water elimination, mostly poloacetal and other OH

 natural components of polysaccharides

CH2
HO O
O
OH
OH

3,6-anhydro--D-galactopyranose (carageenan)
3,6-anhydro--L-galactopyranose (agar)
 products of thermal reactions
CH2 O

O
OH

HO
OH

1,6-anhydro--D-glucopyranose (-glucosan, levoglucosan) (caramel)

glykosides, ethers, esters and other derivatives

O
CH2OH CH2OH R C O CH2
O O R O OH O OH
OH OH OH

HO HO HO
OH O R OH

O-glykosid ether ester

CH2OH CH2OH CH2OH
O S R O NH R O OH
OH OH OH

HO HO HO
OH OH NH2

S-glykosid N-glykosid 2-amino-2-deoxycukr

5
O-glykosides widespread
ethers 4-O-methyl-D-GlcpA (hemiceluloses)
2-O-methyl-D-Xylp (pectins)
esters natural (phosphates, acetates, benzoates etc.), synthetic (fatty acids, emulgators)
S-glycosides glucosinolates in brassica vegetables
N-glycosides natural (ATP, NADH), Maillard reaction (glycosylamines)
aminodeoxysugars natural (chitosamine), Maillard reaction (Amadori products)
C-glycosides
OH O
HO OH
CH2OH
O CO OH
OH
OH O CH3
HO
OH karminovÿá kyselina
(anthrachinony)
carminic acid

Oligosaccharides
homoglycosides
pentoses, hexoses, sugar acids and other derivatives
furanoses, pyranoses

classification
according to number of monosaccharides (2-10)
 disaccharides (bioses) – decasacharides (decaoses)

according to semiacetal OH
 reducing (glycosides)
 non-reducing (glycosylglycosides)

according to major monosaccharids (backbone)

 glucooligosaccharides
maltose, maltooligosaccharides
 fructooligosaccharides
saccharose
 galactooligosaccharides
lactose, -galactosides

according to digestability
 digestible
 non-digestible

according to biological effects

 prebiotic effects
(stimulate growth and metabolisms of desirable microorganisms)
 probiotic effects
(with fibre influence and regulate peristaltic activity)
 symbiotic effects (simultaneously prebiotic and probiotic effects)

6
 CH2OH OH
O
1
1
OH
OH   HOH2C
HO O O OH
CH2OH CH2OH OH
O O
4
OH
1
+
4 1 -H2O  -trehalosa
OH
HO OH HO OH
CH2OH CH2OH
OH OH
O O
-D-glukopyranosa -D-glukopyranosa 4
1 OH
OH  OH
HO O
OH OH
CH2OH CH2OH
O O OH
4 1 + 4 1 - H2O maltosa
OH OH
HO OH HO OH OH
 
OH OH HO O
OH
-D-glukopyranosa -D-glukopyranosa OH 1 1
HOH2C
O O OH
CH2OH

CH2OH CH2OH
O  -trehalosa
O OH
4 1 4 1- H2O
OH + OH
HO HO OH
OH OH CH2OH OH

-D-glukopyranosa -D-glukopyranosa O O
1 4 OH
OH OH
HO O
OH CH2OH
CH2OH CH2OH
O OH O OH cellobiosa
4 1 + 4 1 - H2O
OH OH
HO HO CH2OH OH
 
OH OH O O
OH
-D-glukopyranosa -D-glukopyranosa OH
1 1
HOH2C
HO O OH
OH

  -trehalosa

terminology
maltose -D-glucopyranosyl-(14)-D-glucopyranose
4-O--D-glucopyranosyl-D-glucopyranose
-D-Glcp-(14)-D-Glcp
,-trehalose -D-glucopyranosyl--D-glucopyranoside
-D-Glcp-(11)--D-Glcp

glucooligosaccharides
maltose -D-Glcp-(14)-D-Glcp malt sugar
CH2OH CH2OH
O O
1 4
OH OH OH

HO O
OH OH

occurrance (book 1, tab.4.11 a 4.12)

product of starch hydrolysis, reversion of glucose
malt, bread (1,7-4,3 %), honey (2,7-16 %)

production
 maltose sirups (85 %), glucose sirups (acids, enzymes)
 maltose
 isomeration on maltulose, -D-Glcp-(14)-D-Fruf
 reduction on maltitol, -D-Glcp-(14)-D-glucitol

7
fructooligosaccharides
saccharose -D-Glcp-(12)--D-Fruf
CH2OH
HO CH2 O
O
OH 1 2 HO
 
HO O CH2OH
OH OH

occurrance (book 1, obr. 4.14)

fruits up to 8 %
vegetables 0,1-12 %
green coffee (roasted) 6-7 % (0,2 %)
sugar beet 15-20 % saccharose
sugar cane 12-26 % saccharose
maple sirup
date sirup

production (from sugar beet)

 extraction of sugar beet slices (diffusion)
 cleaning (epuration) of crude juice, clarification by Ca(OH)2
 saturation by CO2
 filtration, light juice
 thickening
heavy juice (61-67 % saccharose, 68-72 % dry matter)
 crude (brown) sugar
96 % saccharose, 2-3 % non-sugars, 1-2 % water
(1,0-1,2 % organic, 0,8-1,0 % inorganic matters)
 afinade
 rafinade
molasses (folder, substrat for fermentation processes)
production of invert suger, other products

galactooligosaccharides
lactose -D-Galp-(14)-D-Glcp milk sugar
HO CH2

HO CH2 O
HO  4 OH OH
O O
OH 1
OH

OH

occurrance (book 1, tab.4.15, 4.16)

cow milk 4-5 %
human milk 5,5-7 %

production (from whey)

 ultrafiltration
 thickening, crystalisation
 production of galactose, galactitol, lactulose, lactitol

other -galactooligosaccharides of milk

8
-galactooligosaccharides of pulses
content (book 1, tab.4.17)
HOCH2 sacharosa
HO O
OH 1 6

O CH2 1
O HO CH2 O
OH n 1
OH 2 HO
 
HO O CH2OH
raffinosa (n = 1)
verbaskosa (n = 2) OH OH
stachyosa (n = 3)
ajugosa (n = 4)

REACTIONS OF SACCHARIDES
complex of enzymatic and nonenzymatic reactions
carbonyl, anomers OH, primary OH, secondary OH

nonenzymatic browning reactions

 reaction of saccharides
 Maillard reaction (reaction with proteins, amino acids)
 caramelisation

Reaction of saccharides
reactants
 reducing mono- and oligosaccharides
 non-reducing oligo- and polysaccharides after hydrolysis

main reactions of monosaccharides

(acid-basic catalysed)

in acid medium in alcali medium

(futher factors: temperature, time)

mutarotation mutarotation
formation (hydrolysis) of glycosides isomeration
dehydration fragmentation
reductone formation rearrangement
oxidation

formation and hydrolysis of glycosides

reaction of poloacetals OH
CH2OH CH2OH CH2OH
O + O - H2O O
H +
OH OH OH O H OH +
HO HO H HO
OH OH OH
monosacharid karbeniový kation
CH2OH CH2OH CH2OH
O -H
+ O
O R OH +
+
OH O R OH O R
OH
HO HO
HO H
OH OH
OH
glykosid (hetero- nebo homoglykosid)

9
hydrolysis (inversion)
 production of starch hydrolysates
 invert sugar
 galactose

formation (reverse, Fischer reaction)
side products of inversion (starch sirup: 5-6 %)
side products of caramelisation
low energy products
indicaters of edulteration

dehydratation reactions
reaction of semiacetal OH and other OH
semiacetal OH / and other OH anhydrosugars (glycosans)
other OH / other OH  deoxysugars

anhydrosugars
-D-Glcp  1,6-anhydro--D-Glcp (-glucosan)
6
CH2 O

O
OH 1

HO
OH

ketoses  dimericanhydrides (tricyclic compounds)

CH2OH
O 1 O O
,
2 2
HO , HO
1
O CH2OH
OH OH

(-D-fruktofuranosa)-( -D-fruktofuranosa)-1,2´:1´,2-dianhydrid
deoxysugars
1,2-enolisation (series of isomeration and dehydratation)
H C O H C OH CH O
H C OH C OH C O
HO C H HO C H CH2
H C OH H C OH - H2O H C OH
H C OH H C OH H C OH
CH2OH CH2OH CH2OH

D-glukosa 1-en-1,2-diol 3-deoxy-D-erythro-hexos-2-ulosa

CH O
C O
CH
CH
- H2O - H2O HO CH2 O CH O
H C OH
CH2OH

3,4-dideoxy-D-glycero-hex-3-enos-2-ulosa 5-hydroxymethylfuran-2-karbaldehyd
o

10
 D-glukosa
HO CH2 O CH O

5-hydroxymethylfuran-2-karbaldehyd o

D-fruktosa CH2OH
O
O
2-hydroxyacetylfuran

pentosy, L-askorbová kyselina

O CH O

furan-2-karbaldehyd

6-deoxyhexosy (methylpentosy) CH3 O CH O

5-methylfuran-2-karbaldehyd
2,3-enolisation
CH2OH CH2 OH CH2 CH3
C O C OH C O H C O
HO C H HO C O C C O
H C OH H C OH - H2O H C OH H C OH
H C OH H C OH H C OH H C OH
CH2OH CH2OH CH2OH CH2OH

D-fruktosa 2-en-2,3-diol 1-deoxy-D-erythro-hexo-2,3-diulosa

O
OH
CH3 CH3
C O C O O CH3
C O H C O maltol
C OH - H2O C OH - H2O
OH
H C O H H C
CH2OH CH2OH
O COCH3
isomaltol
caramel aroma
reductone formation
 Antioxidants (reduction of organic substances, metal ions)
1
R1 R
C O -2H C O
C OH C O
C OH 2H C O
2 2
R R

redukton triulosa
isomerisation
aldose  ketose
aldose  aldose (epimeration)

11
 CH O CH OH CH O
H C OH C OH HO C H
HO C H HO C H HO C H
H C OH H C OH H C OH
H C OH H C OH H C OH
CH2OH CH2OH CH2OH

D-glukosa 1-en-1,2-diol D-mannosa

CH2OH
C O
HO C H
H C OH
H C OH
CH2OH D-fruktosa

disaccharides isomeration
lactose lactulose epilactose
-D-Galp-(14)-D-Glcp -D-Galp-(14)-D-Fruf -D-Galp-(14)-D-Manp

rearrangement to acids
1-en-1,2-diol, Cannizzaro reaction, benzyl rearrengement

fragmentation
formation of reactive componds
 retroaldolisation
R
R CH CH=O aldolizace R CH CH C CH=O
OH OH OH OH
retroaldolizace
 oxidadation (after isomeration, dehydration)

12
 CH O CH O CH2OH CH O
H C OH H C OH C O H C OH
CH2OH CH2OH CH2OH CH2OH

D-glyceraldehyd -glyceraldehyd
D 1,3-dihydroxyaceton D-glyceraldehyd

CH O CH OH CH2OH CH2OH
H C OH C OH C O C OH
HO C H HO C H HO C H HO C
H C OH H C OH H C OH H C OH
H C OH H C OH H C OH H C OH
CH2OH CH2OH CH2OH CH2OH
D -glukosa 1-en-1,2-diol -fruktosa
D 2-en-2,3-diol

CH O CH O
CH2OH
H CH O HO C H H C OH
CH O
H C OH H C OH
formaldehyd glykolaldehyd
H C OH CH2OH
CH2OH -arabinosa
D D -erythrosa

MAILLARD REACTION
non-enzymatic browning reaction

reactants
 sugars (carbonyl compounds)
monosaccharides and reducing oligosaccharides
(nonreducing oligosaccharides, polysaccharides, glycosides)
triose  ….  pentose  hexose (acyclic forms)
aldose  ketose
-dicarbonyls  aldehydes  ketones  saccharides

 proteins (amino compounds)

-NH2 Lys, N-ending NH2, guanidyl Arg, SH Cys
free amino acids, amines, ammonia
-NH2  ….  -NH2  -NH2
NH3  R-NH2  amino acids

reaction conditions
 water activity (aw 0,3-0,7)
 pH (9-10)
 others (temperature, time of reaction, other components)

concequences: positive, negative

 formation of aroma compounds
 formation of yelow, brown, black pigments melanoidins
 decrease of nutritive value
 formation potentially toxic products
 reaction in vivo (glykosylation of proteins)

13
mechanism of reaction
3 stages
 initial stage
formation of glykosylamines (Amadori rearrangement) and formation of aminodeoxysugars
(Amadori products)
 central stage
decomposition of saccharides, glycosylamines, aminodeoxysugars (dehydratation, fragmentation)
decomposition of amino acids (Strecker degradation)
 final stage
reaction of degradation products, formation of aroma, taste and colour products (melanoidins)

glycosylamines and aminodeoxysugars

NH R N R
CH O CHOH CH
H C OH CH2OH
H C OH H C OH
O
HO C H R NH2 HO C H - H2O HO C H
OH NH R
H C OH H C OH H C OH HO
H C OH H C OH H C OH OH
CH2OH CH2OH CH2OH

D-glukosa karbinolamin imin (Schiffova báze) D-glukosylamin

+
NH R NH R NH R
CH CH CH2
CH2OH CH2 NH R
O + H C OH + C OH C O O
H -H
OH NH R HO C H HO C H HO C H HO
HO - HO
H C OH H C OH H C OH OH
OH OH
H C OH H C OH H C OH
CH2OH CH2OH CH2OH

D-glukosylamin kation Schiffovy D-fruktosamin (1-amino-1-deoxy- D-fruktosa)

báze enolforma oxoforma cyklická forma
totally utilisable form non-utilisable form
ketose  ketosylamine  aldosamine (2-amino-2-deoxyaldose), Heyns rearrangement

mechanisms (reaction of acyclic forms)

decomposition of aminodeoxysugars
1,2-enolisation in acidic medium
2,3-enolisation in neutral and alkali medium
formation of glycosuloses and glycodiuloses (aldoketoses a diketoses)
1,2-enolisace +
CH NHR CH NHR CH NR CH O
+
C OH H C OH - H2O C OH H2O C O
produkty
HO C H H2O C H
+
C H - H + CH2
R - R NH2 R
R R
CH2 NHR
enaminol 3-deoxy-D-erythro-hexos-2-ulosa
C O
HO C H 2,3-enolisace
+
R CH NHR CH2 NH2R CH2 CH3
+
C OH H C OH C OH C O
-fruktosamin
D +
produkty o
HO C H O C -H C O C O
R R - R NH2 R R

endiol 1-deoxy-D-erythro-2,3-hexo-2,3-diulosa
analogy with reaction of sugars but:
 lower activation energy
 products contain N a S
 qualitativelly and quantitativelly more products
14
important heterocyclic products
OH HO O

CH3
O CH3 O CH3 O CH2 SH
O
isomaltol furaneol furfurylthiol
(caramel) (strawberry, pineapple) (coffee)
O
OH CH3 N

CH3 CH3
O CH3 S CH3 N N CH3
O
maltol 2,4-dimethylthiophene 2-acetyl-1-pyrroline 2,6-dimethylpyrazine
(caramel) (fried anion) (bread) (chocolate, nuts)

Maillard reaction in important food commodities

positive and negative consequences, desirable and undesirable reactions

technology (aroma, taste, colour, nutritive value)

 roasting
 boiling, frying , backing
 drying
 extrusion, microvawe heating
 milk, milk products
Lys losses: 10-30 % traditional drying, 3 % sprey drying
 cereals, vcereal products
Lys losses: 70 % bread crust, 10 % total
 meat, meat products
mutagenes
 fruits, vegetables
 coffee, cocoa, nuts
reaction during processing of milk non-utilisable (blocked) Lys (example)
NH
NH CH2 NH [CH 2 ]4 CH
NH2 [CH2]4 CH C O C O
CH2OH C O HN
HO C H 2 H2O
O + HN
CH2OH H C O OH
OH OH CH R HCl
HO O O H C OH
O C OH
OH OH
OH CH2OH HOH2C
O
OH
laktosa protein 1-lysino-1-deoxylaktulosa
-N-deoxylaktulosyllysin)

CH2 NH [CH2]4 CH COOH

C O NH2
C CH 2 NH [CH 2 ]4 CH COOH
C O O
O NH 2
CH2
furosin
H C OH
CH 3
CH2OH
O N [CH 2 ]4 CH COOH
NH 2
HO
pyridosin

15
isomeration lactose  lactulose + epilactose
lysinoalanine

inhibition of Maillard reaction

 unfavourable conditions
water content (activity), lower temperature, regulation of pH
 removal of one reaction partner
 use of inhibitors
SO2 + H2O H2SO3 H+ + HSO3-
-
SO3
CH=O HSO3
- CHOH
H C OH H C OH
o

aldehyd sulfonová kyselina

CARAMELISATION
sugars (saccharose, glucose, fructose, starch sirup, invert sugar)
temperature: 150-190oC (240oC)
reaction time: 5-10 hours
catalysts

caramel = solid product, couler = liquid product

class name of couler additives matter utilisation

I CP caustic Na2CO3, K2CO3, NaOH, KOH, alcoholic beverages
H2SO4, acetic citric acid, (high content of alcohol)
II CCS caustic sulphite SO2, H2SO4, Na2SO3, K2SO3, NaOH, vinegar, beer, alcoholic
KOH, beverages, aromatised wine
III AC ammonium NH3, (NH4)2SO4, Na2CO3, H2SO4, beer, alcoholic beverages,
NaOH, KOH acid food
IV SAC ammonium-sulphite NH3, SO2, (NH4)2SO3, Na2SO3, acid food, non-alcoholic
K2SO3, Na2CO3, K2CO3, NaOH, beverages
KOH, H2SO4,

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