Gums and Stabilizers
(Hydrocolloids)

Functions

Primary function:
1) as thickening agent
2) as gelling/ texturizing agent

Secondary function:
1) Stabilisation of emulsions
2) Suspensions of particulate
3) Control of Crystallisation
4)Encapsulation
5) Formation of Film

Structure

- high MW polymers consisting long chain sugar unit with substituent potruding from the main chain

1) Degree of saturation(DS)
~higher DS faster to hydrate
~lower DS slower to hydrate
2) Degree of polymerization
~higher DP=high viscocity, slower to hydrate
~lower DP=low viscocity, faster to hydrate

Gelation of Hydrocolloids
-some form gel upon heating/cooling
-some required the presence of cation
-Others will form under acidic pH with high sugar concentration and some required alkaline pH to form gel

Thermoreversible gelling agent
-gel formed on heating and cooling(reversible process)
-eg: ->Gelatin, agar, k-carrageenan, LM pectin, gellan gum, methyl cellulose, HPMC

Gelation of carrageenan(kappa and iota)
~ at concentration as low as 0.5%, kappa and iota forms thermoreversible gel

Gelation of Alginate
~ can form gel in cold water in the presence of Ca ion

Thermally-irreversible gelling agent
-eg: -> Alginate, starch, konjac & HMP

Gelation of Lambda carrageenan
~has structure that do not aloow double helix formation.

Gelation of Alginate
~Forms gel in cold water with the presence of Ca ion.

Class

1) From sap of tree (Gum Arabia)
2) Extract from seed (Locust Bean Gum)
3) Extract from seaweed (Carrageenan)
4) Microbial gums( Xanthan gum)
5) Extract from tubers( Konjac glucomannan)
6) Extract from plant parts (Pectin-from citrus fruit)

PECTIN
- Derived from citrus fruit(Lemon,Lime & Orange)
-Natural formed is called Propectin(insoluble)

Types of Pectin

High Methoxy Pectin(HMP)
-DE 58% to 75%

~ To form gel, soluble solid content must range (55%-85%), with pH(2.8-3.8)
~ e.g: jam & jellies
~classified to: ultrarapid set(DE=77%) and rapid set(DE=58%)
~Rapid set pectin : used in jams with whole fruit to ensure uniform distribution of fruit particles

Low Methoxy Pectin(LMP)

Conventional LMP(LMP)
~less Ca2+ reactive
~used as thickening agent in yoghurt fruit

Amidated LMP(ALMP)
~Very Ca2+ reactive
~Assist in Low sugar fruit gelation

Types of carrageenan

kappa carrageenan

Lambda carrageenan

iota carrageenan

ALGINATE
-Derived from brown seaweed(Laminaria hyperborea)

Application:
~excellent stabilizing agent in frozen products( avoid crystallization in ice cream)
~as Thickener and stabilizer in beverages(gives fast hydration & mouthfeel)
~has emulsification properties which used as stabilizers in emulsion like mayonnaise(Propylene glycol alginate)

GUM ARABIC(GUM ACACIA)
- extract from tree sap

Application:
~ as encapsulation agent:encapsulate volatile compound
~promote stabilization of foam in beer
~as emulsifier and stabilizer in soft drink

XANTHAN GUM
-polysaccharide produce from Xanthamonas campestris
-excellent stability to heat and pH

Application:
~thickening
~suspending
~stabilizing effect

LOCUST BEAN GUM
-from leguminose Ceratonia siliqua seed
-Only form gel when combined with Xanthan gum

Application:
~ thickening
~stabilize emulsion
~inhibit syneresis

GUAR GUM
-linear chain of mannose with single galactose unit attached as side chain

Application:
-Non gelling gum
-used as viscocity builder
-stabilizer
-water binder

CELLULOSE
-Chemically modified cellulose
-with alkaline treatment, it converts cellulose into ether

Application:
~thickening
~suspending
~stabilizing and modify flow characteristic