Elizabeth's Gums+and+stabilizers

=**Lecture Summary**=

**Week 1- week 5**
**(Gums and stabilizers)**

__Hydrocolloid__
 * Range of polysaccharides and protein
 * Also know as water soluble gums, stabilisers

__Functions:__ primary---> Secondary--->
 * Thickening agent
 * Gelling or texturizing agents
 * Stabilisation of emulsion
 * Suspension of particulates
 * Control of cystallisation
 * Encapsulation

__Structure of hydrocolloid__

High degree of substitution, faster to hydrate Low degree of substitution,slower to hydrate

High degree of polymerization,high viscosity-->slow to hydrate Lower degree of polymerization,low viscosity-->faster to hydrate

__Factors affect gum properties__


 * Molecular weight
 * Monosaccharide composition
 * Type of side chain
 * Number of side chain
 * Distribution of side chain

List of hydrocolloid:
 * ===** (Gelling Gums) **===
 * Pectin
 * Carrageenan
 * Alginate
 * Gelatin
 * Agar
 * Gellan
 * Konjac Glucomannan
 * Methyl cellulose ( hot)
 * ====** (Thickening Gums) **====
 * Locust bean gum (LBG)
 * Tara gum
 * Gum Arabic
 * Gum karaya
 * Xantan gum
 * Guar gum
 * Tragacanth
 * Propylene glycol alginate
 * Carboxymethycellulose

__**Pectin**__
Raw material which are source of pectin: Citrus peel

Apple pomace

Sugar beet chips

Natural form is called protopectin ( where they are still in primary form and not yet extracted)

**Types of pectin** High methoxyl pectin (HMP)---> degree of esterification>50% Low methoxyl pectin (LMP)--->degree of esterification<50% DE=Galacturonic acid partially esterified as methyl esters.

__HMP__
 * To form gel, the soluble solid content must be 5-58% and PH 2.8-3.8 in jam and jellies.
 * its a rapid set(DE 77) & slow set(DE 58)
 * Rapid set- widely used in jams with whole fruits(marmalade) -->to ensure uniform distribution
 * Acidic fruit( blackcurrant) require slow set---> avoid premature gelation
 * Not heat reversible
 * Gels at high temperature and low PH
 * DE high, ability to gel high

__LMP__
 * 2 sub groups, conventional LMP, and Amidated LMP.
 * Calcium ion needed for it to form gel with low solid content and PH 1-7.
 * Thickening agent in yoghurt-because less calcium ion reactive than ALMP
 * Assist gelation in low sugar jam and jellies-because very reactive calcium ion
 * Heat reversible

**Usage of pectin in food**


 * Jams, jellies and preservatives
 * Stabilisers( in fruit juices, fruit drinks concentrated)
 * In fermented/directly acidified dairy products
 * Used in baked products-cake glazing,fruit fillings (confectioneries)
 * Soft drinks and sherbets
 * Ketchup,sauces,and chutneys

** Carrageenan **
Extracted of red algae, the Carrageenan structure composed of linear galactan polysaccharides that have sulfate(negative charge).

3 types---> kappa, Lambda, and Iota


 * Kappa and Iota Carrageenan have ability to form thermoreversible gels upon cooling of hot aqueous solution contain cation example potassium ion.
 * Lambda does not form gel

(Carrageenan versatile as food additives, because they are capable of binding water,promoting gel formation, act as thickener and stabilizing agents as well as improve the palatibility and food's appearance)

Food examples that use carrageenan



Desserts, gels, ice-cream, chocolate, milk, canned foods.