UNIVERSIDAD NACIONAL SAN ANTONIO ABAD DEL
CUSCO
ESCUELA DE POST GRADO
MAESTRIA EN CIENCIA Y TECNOLOGIA DE ALIMENTOS
COMPOSICION Y ANÁLISIS
DE ALIMENTOS
EPA 01ACT
CARBOHIDRATOS – Polisacaridos
Dra. Celina Luízar Obregón
Polisacáridos
Polisacáridos
Clasificación de los Polisacáridos
Homopolisacáridos de glucosa:
• enlace a: almidón, glucógeno (reserva energía)
• enlace b: celulosa (fibras pared celular)
Heteropolisacáridos:
Ej., proteoglicanos de la matriz extracelular
Clasificación de los Polisacáridos
Clasificación de los Polisacáridos
Posición reductora y no reductora
Polisacáridos
Polisacáridos
Almidón

Starch is used for energy storage in plants
◦ it can be separated into two fractions; amylose and
amylopectin. Each on complete hydrolysis gives only Dglucose
◦ amylose is composed of continuous, unbranched chains of
up to 4000 D-glucose units joined by
a-1,4glycoside bonds
◦ amylopectin is a highly branched polymer of D-glucose.
Chains consist of 24-30 units of D-glucose joined by a1,4-glycoside bonds and branches created by a-1,6glycoside bonds
CH2OH
H
O
H
OH
H
H
H
1
O
OH
6CH OH
2
5
O
H
4 OH
3
H
OH
H
H
H
H 1
O
H
OH
CH2OH
CH2OH
CH2OH
H
H
H
O
H
OH
H
O
O
H
H
O
H
OH
H
O
OH
2
OH
H
OH
H
OH
H
amylose
Plants store glucose as amylose or amylopectin, glucose
polymers collectively called starch.
Glucose storage in polymeric form minimizes osmotic
effects.
Amylose is a glucose polymer with a(14) linkages.
The end of the polysaccharide with an anomeric C1 not
involved in a glycosidic bond is called the reducing end.
H
OH
Amilosa
Soluble starch, polymer of D-glucose.
 Starch-iodide complex, deep blue.

=>
Chapter 23
15
AMILOSA
Amylopectin
Branched, insoluble fraction of starch.
=>
Chapter 23
17
AMILOPECTINA
Almidón y glucógeno
CH2OH
CH2OH
O
H
H
OH
H
H
O
OH
CH2OH
H
OH
H
H
H
OH
CH2OH
O
H
OH
H
OH
OH
H
H
O
H
OH
H
H
O
O
H
OH
H
H
OH
H
O
amylopectin
H
1
O
6 CH2
H 5
H
4 OH
3
H
CH2OH
O
H 1
2
OH
H
H
O
CH2OH
O
H
4 OH
H
H
H
H
O
OH
O
H
OH
H
H
OH
H
OH
Amylopectin is a glucose polymer with mainly a(14) linkages,
but it also has branches formed by a(16) linkages. Branches are
generally longer than shown above.
The branches produce a compact structure & provide multiple chain
ends at which enzymatic cleavage can occur.
Gránulos de almidón en un embrión de judía
Gránulos de almidón en un embrión de judía
Celulosa

Cellulose is a linear polymer of D-glucose
units joined by b-1,4-glycoside bonds
◦ it has an average molecular weight of 400,000,
corresponding to approximately 2800 Dglucose units per molecule

Both rayon and acetate rayon are made
from chemically modified cellulose
CH2OH
H
O
H
OH
H
H 1
OH
O
H
H
OH
6CH OH
2
5
O
H
4 OH
3
H
H
H 1
2
OH
O
O
H
OH
CH2OH
CH2OH
CH2OH
H
H
O
O
H
OH
H
OH
O
H
O
H
OH
H
OH
OH
H
H
H
H
H
H
H
cellulose
Cellulose, a major constituent of plant cell
walls, consists of long linear chains of glucose
with b(14) linkages.
Every other glucose is flipped over, due
to b linkages.
OH
This promotes intra-chain and inter-chain H-bonds
and van der Waals interactions, that cause cellulose
chains to be straight & rigid, and pack with a
crystalline arrangement in thick bundles - microfibrils.
Schematic of arrangement of
cellulose chains in a microfibril.
Celulosa
b-Glucanos: Celulosa
n
Celulosa
O
CH2OH
O
HO
Acetato celulosa
O
OH
n
O
- CH3COOH
O
CH2O C CH3
O
CH3CO O COCH3
O
C O
CH3
O
O
C O
CH3
n
Nitro celulosa
Si de algodón y menor grado de esterificación
= algodón pólvora o piroxilina
O
O
CH2OH
CH2O NO2
HNO3- H2SO4
O
HO
O
O
O
O
NO2
OH
n
O
NO2
n
Celuloide
O
CH 2O
Celulosa
NO2
CH 3 C CH 3
O
O
O
O
NO2
O
NO2
CH 3
n
Piroxilina (Grado de nitración 2)
Alcanfor
Mezcla gelatinizada
Primer plástico moldeable de principios siglo pasado
Descubierto por John Wesley Hyattt
Sustituto del marfil para bolas de billar (explosivas)
Carboxi Metil celulosa
Carboxymethylcellulose; carmellose; E466
Se trata la celulosa con NaOH concentrada y caliente (cadenas de
menor Pm) y después tratar con un R-Cl
Espesante y cambiador de cationes
Carboxi Metil celulosa
Carboxi Metil celulosa
Carboxymethylcellulose; carmellose; E466
Carboxymethyl cellulose (CMC) or cellulose gum [1] is
cellulose derivative with carboxymethyl groups (-CH2-COOH) bound to
some of the hydroxyl groups of the glucopyranose monomers that make up
the cellulose backbone. It is often used as its sodium salt, sodium
carboxymethyl cellulose.
Dietilaminoetil celulosa
Diethylaminoethyl cellulose (DEAE or DEAE-C) is a positively charged resin
used in ion exchange chromatography, a type of column chromatography, used in
protein and nucleic acid purification/separation. Gel matrix beads are derivatized with
DEAE and lock negatively charged proteins or nucleic acids into the matrix, until
released by increasing the salt concentration of the solvent. DE52 has a pKa of 11.5.
DEAE-Dextran (DEAE-D) is also used for transfecting animal cells with foreign DNA.
It is added to solution containing DNA meant for transfection. It binds and interacts
with negatively charged DNA molecules and via a largely unknown mechanism brings
about the uptake of nucleic acids by the cell. This procedure is highly suited for
transient transfection used for various molecular biology studies.
Dietilaminoetil celulosa
Farmacia - laxante
Si R= -CH2 -CH2 –N(CH2 –CH3 )2
Espesante y cambiador de aniones
Muy utilizado como cambiador de aniones
Glycogen
Glucose polymer, similar to amylopectin, but
even more highly branched.
 Energy storage in muscle tissue and liver.
 The many branched ends provide a quick
means of putting glucose into the blood.

=>
Chapter 23
51
CH2OH
CH2OH
O
H
H
OH
H
H
OH
H
O
OH
CH2OH
H
H
OH
H
H
OH
H
H
OH
CH2OH
O
H
OH
O
H
OH
H
H
O
O
H
OH
H
H
OH
H
H
O
4
glycogen
H
1
O
6 CH2
5
H
OH
3
H
CH2OH
O
H
2
OH
H
H
1
O
CH2OH
O
H
4 OH
H
H
H
H
O
OH
O
H
OH
H
H
OH
H
OH
Glycogen, the glucose storage polymer in animals, is similar in
structure to amylopectin.
But glycogen has more a(16) branches.
The highly branched structure permits rapid glucose release from
glycogen stores, e.g., in muscle during exercise.
The ability to rapidly mobilize glucose is more essential to animals
than to plants.
Glucógeno
Glycogen is the reserve carbohydrate for
animals
 Like amylopectin, glycogen is a nonlinear
polymer of D-glucose units joined by a1,4- and a-1,6-glycoside bonds bonds
 The total amount of glycogen in the body
of a well-nourished adult is about 350 g
(about 3/4 of a pound) divided almost
equally between liver and muscle

Glucógeno
Gránulos de glucógeno en el citoplasma de un hepatocito
Almidón y glucógeno
a
Ramificación: amilopectina, 4%; glucógeno, 10%
Chitin
Polymer of N-acetylglucosamine.
 Exoskeleton of insects.

Chapter 23
57
Chitin
Chitin is a long-chain polymer of a N-acetylglucosamine, a derivative
of glucose, and is found in many places throughout the natural world. It is the
main component of the cell walls of fungi,
the exoskeletons of arthropods such
as crustaceans(e.g., crabs, lobsters and shrimps) and insects,
the radulas of mollusks, and the beaks ofcephalopods,
including squid and octopuses. In terms of structure, chitin may be compared
to the polysaccharide cellulose and, in terms of function, to the
protein keratin. Chitin has also proven useful for several medical and industrial
purposes
Chapter 23
58
Quitina
Quitina
Chitin is used in industry in many processes. It is used as an additive to
thicken and stabilize foods and pharmaceuticals. It also acts as a binder
in dyes, fabrics, and adhesives. Industrial separation
membranes and ion-exchange resins can be made from chitin.
Processes to size and strengthen paper employ chitin
Pectinas

Pectin (from Greek πηκτικός pektikos, "congealed, curdled"[1]) is
a
structural heteropolysaccharide co
ntained in the primary cell
walls of terrestrial plants. It was
first isolated and described in 1825
by Henri Braconnot.[2] It is
produced commercially as a white
to light brown powder, mainly
extracted from citrus fruits, and is
used in food as a gelling
agent particularly in jams and jellies.
It is also used in fillings, sweets, as a
stabilizer in fruit juices and milk
drinks and as a source of dietary
fiber.
Pectina

Pectins are a family of complex polysaccharides that contain 1,4-linked
α-D-galactosyluronic acid residues. Three pectic polysaccharides have
been isolated from plant primary cell walls and structurally
characterized. These are:

Homogalacturonans

Substituted galacturonans

Rhamnogalacturonans
Pectina
Pectins are the major components of most higher plant cell walls; they are
particularly prevalent in fruits and vegetables. Commercial pectins are
prepared mostly from some by-products of the food industry, such as apple
pulp, citrus peels, and sugarbeet pulp. Pectins are the most complex class of
plant cell wall polysaccharides. They comprise of two families of covalently
linked polymers, galacturonans and rhamnogalacturonans (type I)
Gomas
Exudate gums are polysaccharides produced by plants as a result of stress,
including physical injury and/or fungal attack.
Gum arabic, gum tragacanth, gum karaya, and gum ghatti have been used by
humans for many thousands of years in various food and pharmaceutical
applications.
Generally, these gums are structurally related to arabinogalactans,
galacturonans, or glucuronomannans .They all contain a high proportion of
glucuronic or galacturonic acid residues (up to 40%).
Gomas
Gomas
Goma Arábiga (goma acacia)
La goma arábiga (E-414) es
un polisacárido de origen natural que se
extrae de
a resina de árboles subsaharianos
(Acacia senegal y Acacia seyal) como
parte del proceso de cicatrización de
éstos (gummosis).
La resina de color ámbar se recolecta
normalmente a mano una vez seca.
Es un polisacárido con cantidades variables de D-galactosa, L-arabinosa, Lramnosa y algunos ácidos derivados como el ácido D-glucorónico o el 4O-metil-D-ácido glucorónico.
Se trata de una sustancia de color amarillento a pardo, inflamable aunque
con un elevado punto de inflamación (>250 ºC), buena solubilidad en agua
(aprox. 500 g/l) y con un LD50 > 16.000 mg/kg.
Goma Guar
The guar plant is an annual plant known as 'Cyamopsis Tetragonaloba'.
The important source of nutrition to human and animals is the legume, it
regenerates soil nitrogen and the endosperm of guar seed is an important
hydrocolloid widely used across a broad spectrum of industries.
Guar Gum mainly consists of
hydrocolloidal polysaccharide with
a high molecular weight, which
consists of galactopyranose- and
mannopyranose- units in glycoside
linkage which can be chemically
described as galactomannan.
Goma Guar
Goma Guar
Tragacanth Gum (Goma tragacanto)
La goma tragacanto es un polisacárido obtenido por incisión de tallos de
varias especies de Astragalus, que se encuentran en regiones montañosas
de Turquía, Siria,Irak, Irán y Rusia
It is collected by hand, then graded, milled, and sifted to remove impurities.
Tragacanth gum contains a water-soluble fraction and a water-insoluble
fraction and the water-soluble fraction is accounted for 30 to 40% of the total
gum.
Astragalus gummifer Labillardiere
Tragacanth Gum (Goma tragacanto)
La goma es de color blanco o blanco amarillento muy pálido, traslúcida y
córnea. Se rompe con fractura breve, es inodora y tiene ligero sabor.
Cuando se pone en agua, la goma tragacanto se hincha, dando una masa
gelatinosa, pero sólo se disuelve una pequeña porción.
The water soluble fraction is a highly branched neutral polysaccharide
composed of 1→6-linked D-galactosyl backbones with L-arabinose side chains
joined by 1→2-, 1→3- and/or 1→5-linkages. The water-insoluble fraction (~60
to 70%), is tragacanthic acid which is consisted of D-galacturonic acid, Dgalactose, L-fucose, D-xylose, L-arabinose and L-rhamnose. It has a (1→4)linked α-D-galacturonopyranosyl backbone chain with randomly substituted
xylosyl branches linked at the 3 position of the galacturonic acid residues.
Tragacanth Gum (Goma tragacanto)

La formación de la goma tragacanto es completamente distinta a la de
la goma arábiga, pues la goma exuda inmediatamente después de herir el
árbol y, por tanto, estará preformada en la planta, mientras que la goma
arábiga se produce lentamente después de la herida. Un corte del tallo de
la planta muestra que las membranas celulares de la médula y radios
medulares se transforman gradualmente en goma, proceso
denominado gomosis. La goma absorbe agua y da lugar a una considerable
presión dentro del tallo