NON STARCH POLYSACCHARIDES.ppt

non-starch polysaccharides (NSP) commonly referred to as dietary fibre.
Food polysaccharides also include exudates gums, seed gums, microbial
polysaccharides, algal polysaccharides.
carbohydrates that are not digested
or absorbed, pass through the colon where bacteria ferment them for energy,
thereby stimulating their growth.The major
polysaccharides in the plant cell wall are cellulose, carboxymethyl cellulose,
hemicellulose and pectin.

1. NON STARCH POLYSACCHARIDES
Mrs. R.Subha, M.Sc., M.Phil., D.C.T.,
Assistant Professor of Home Science

2. Introduction
•Plantscontaintwomaintypesof
polysaccharides.Theyarethestarchandnon-
starchpolysaccharides(NSP).
•Non-starchpolysaccharides(NSPs)isa
categoryofchemicalsfoundnaturallyin
plants.
•Collectivelynon-starchpolysaccharidesare
alsoknownas:dietaryfibre/roughage
•Inadditionfoodpolysaccharidesalsoinclude
exudatesgums,seedgums,microbial
polysaccharides,algalpolysaccharides.

3. Dietary Fibre
•Alsoknownasnon-starchpolysaccharides(NSP).
•Itisthenamegiventoagroupofmaterialsfoundinthe
cellwallsofplantswhichgivetheplantitsstructureand
form.
•Itincludesthosecarbohydratesthatarenotdigestedor
absorbed,butpassthroughtothecolonwherebacteria
fermentthemforenergy,therebystimulatingtheir
growth.
•Becausetheterm‘dietaryfibre’describesanutritional
conceptratherthanacomponentofdiet,ithasbeen
suggestedthatthetermbephasedoutandreplaced
withtheterm‘NSP’butthishasbeendifficultbecause
thewordfibreissowidelyused.
•ExamplesofNSPincludecellulose,pectin,gums,beta-
glucansetc.

4. 1.Cellulose
•Cellulose is found in plants as microfibrils (2-20 nm diameter and
100–40,000 nm long). These form the structurally strong framework
in the cell walls. Cellulose is mostly prepared from wood pulp.
•Structurally, cellulose is a β1→4 linked glucan.
•The cellulose chains are unbranched, and may contain as many as
5000 glucose units.
•Because of the β-1,4 linkage, the glucose units in the chain
alternate, and the molecule is effectively a rigid and straight chain.
•As a result, cellulose molecules can readily align themselves side-by-
side in an arrangement which is stabilized by intermolecular
hydrogen bonding and form crystalline regions.
•Intermolecular bonding is so strong that cellulose is insoluble in
water, and even in strong sodium hydroxide solution.
•The cellulose is responsible for the form and gross texture in all
foodstuffs prepared from plants.

5. •Beinginsoluble,itislittleaffectedbyanycookingprocessanddoesnot
disperse.
•Oningestion,itisunaffectedbyenzymesinthedigestivetractanddoes
nothydrate
Functionality:Cellulosehasmanyusesasananticakingagent,emulsifier,
stabilizer,dispersingagent,thickenerandgellingagent,buttheseare
generallysubsidiarytoitsmostimportantuseofholdingwater.
•Dryamorphouscelluloseabsorbswaterbecomingsoftandflexible.
•Someofthiswaterisnon-freezingbutmostissimplytrapped.
•Lesswaterisboundbydirecthydrogenbondingifthecellulosehashigh
crystallinitybutsomefibrouscelluloseproductscanholdonto
considerablewaterinporesanditstypicallystraw-likecavities.
•Assuchwaterissupercoolable,thiseffectmayprotectagainstice
damage.
•Cellulosecangiveimprovedvolumeandtexture,particularlyasafat
replacerinsaucesanddressingsbutitsinsolubilitymeansthatall
productswillbecloudy.

6. 2. Hemicellulose
•Hemicelluloses are present in many plant tissues.
•They are structural components of the cell wall.
•They are water-insoluble, non-starchy
polysaccharides.
•They are heteropolysaccharides.
•Monosaccharide units present in hemicelluloses
are xylose, arabinose, galactose, glucose,
glucuronicacid.
•Hemicelluloses are nonfibrouswhile celluloses are
fibrous.
•They are more soluble in alkali and more readily
hydrolyzed by dilute acids than celluloses.

7. •Hemicelluloseisdefinedasalarge
polysaccharide,whichhelpsgivestructureto
plantcells.
•Hemicellulosegivesfruitsandvegetablescrisp,
chewy,fibrouscharacteristicsthatpartially
remainaftercooking.
•Alongwithpectin,itformsanamorphousmatrix
inwhichcellulosefibrilsfromtheplantcellwalls
areembedded.
•Importantsourcesofhemmicelluloseinclude
seedcoatsofcorn,cerealbrans,wheatoats,
barleyandrice.
•Otherpossiblesourcesareskinsofsugarbeets,
potatoesandtomatoes

8. Hemicellulose –Nutritional effects
•Hemicelluloses are classified under the category of
soluble dietary fibers.
•Hemicelluloseis an indigestible complex carbohydrate
that absorbs water.
•It is good for promoting weight loss, relieving
constipation and controlling carcinogens in the intestinal
tract.
•A commercial product (β-glucansbased) possess the
ability to reduce serum cholesterol.
•Oat and barley β-glucanswhen taken in foods reduce
postprandial serum glucose levels; reduce insulin
response and serum cholesterol levels.
•Hemicellulosecan be converted to a number of value-
added fermentation products such as fuel ethanol,
xylitol, butanediol, and lactic acid.

9. Hemicellulose –Food Applications
•Thehemicellulosesfindtheirapplicationinfood
systemsasemulsifer,stabilizerandbinderin
flavorbases,dressingsandpuddingmixes.
•Thesemayalsobeusedasapotentialbulking
agent.Thesearegoodsourceofdietaryfiberand
stimulatetheimmunesystem.
•Itspropertiessuggestusefulnessasalow-
viscositythickenerand/oremulsionstabilizer,
foreg.cornoil/wateremulsionsarestabilizedby
cornfibergum.
•Italsofindspotentialusefulnessinpourable
dressings.Itmayalsoactasafatreplacer/
mimetic.

10. 3. Pectin
•ThewordpectinisderivedfromaGreekword
whichmeansto“congealorsolidify”.
•Pectinisanacidicstructuralpolysaccharide,found
infruitandvegetablesandmainlypreparedfrom
'waste'citruspeelandapplepomace(skin).
•Pectinispresentasastructuralpolysaccharidein
themiddlelamellaandprimarycellwallofhigher
plants.
•Pectinisapolygalacturonicacidesteralongwith
rhamnose,arabinoseandgalactose.
•Pectinisalsoindustriallyextractedfromappleand
citruspomaceandtradedinternationallyin
purifiedandstandardizedforms.

11. Pectin
•Themajorfunctionofpectinisincementing
thecelluloseandhemicellulosesnetwork,cell-
celladhesionandplantdefense.
•Pectinisgenerallysolubleinwaterand
insolubleinmostorganicsolvents.
•Pectinsolutionsshowrelativelylowviscosities
thanotherplanthydrocolloidsand
consequentlyhaslimiteduseasathickener.
•Low-esterpectinformsgelsinthepresenceof
calciumandotherdivalentmetalions.

12. Pectin -Functionality

13. REFERENCES
•https://egyankosh.ac.in/bitstream/123456789
/33579/1/Unit-2.pdf