1. PECTIN
1.1. * Derived from the peel of citrus fruits * Natural form : protopectin (insoluble) * Chain of polygalacturonic acid- partially esterified as methyl esters
1.1.1. High Methoxy Pectin (HMP)
1.1.1.1. * DE---58% to 75%
1.1.1.2. * to form gel, soluble solid content 55-85%, pH 2.8-3.8. (e.g. jam and jellies)
1.1.1.3. * ultrarapid/rapid set (DE as high as 77)---used in jam with whole fruits, to ensure uniform distribution of fruits particles.
1.1.1.4. * slow set (DE~58) ---used in very acid fruits such as blackcurrant to avoid premature gelation.
1.1.2. Low Methoxy Pectin (LMP)
1.1.2.1. DE < 50% — two sub-groups: Conventional low methoxyl pectin (LMP) and Amidated low methoxyl pectin (ALMP)
1.1.2.2. Form gels in the presence of Ca2+, with a low solids content & wide pH range (1-7) [but soluble solids can be up to 85%]
1.1.2.3. LMP – less Ca2+ reactive than ALMP ⇒ used as a thickening agent in yoghurt fruit
1.1.2.4. ALMP – very Ca2+ reactive ⇒ assist gelation in low sugar fruit preparations, e.g. low-sugar jams & jellies
2. GUAR GUM
2.1. Derived from guar (Cyamopsis tetragonolobus) seeds, this long, rigid, linear molecule of beta-1,4-D-galactomannans with alpha-1,6-linked D-galactose.
2.2. This galactomannan is soluble in cold water, hydrating quickly to produce viscous pseudoplastic solutions that, although shear-thinning, generally have greater low-shear viscosity than other hydrocolloids.
2.3. It is stable over a wide pH range, but will degrade at pH extremes at high temperature. The molecules’ interfacial binding allows guar to act as an emulsifier
2.4. Guar gum binds water and retards ice-crystal growth.
3. XANTHAN GUM
3.1. Polysaccharides produced from fermentation of CHO substrate with Xanthomonas campestris
3.2. Completely soluble in cold water & produce high viscosity at low conc.
3.3. Excellent stability to heat & pH
3.4. pseudoplastic (shear-reversible) over broad shear rate and concentration ranges, but imparts a stringy texture.
3.5. used to thicken and stabilize emulsions, foams and suspensions in applications including sauces and dressings
4. CELLULOSE DERIVATIVES
4.1. Alkaline treatment convert cellulose into an ether
4.2. Clear solution & stable over pH4-10
4.3. Use for thickening, suspending, stabilizing & modify flow characteristics
4.4. Examples: carboxymethylcellulose (CMC) , hydroxypropylmethylcellulose (HPMC)
4.5. Methylcellulose (MC) & HPMC gel when heated & return to their original liquid viscosities when cooled.
4.6. Use in fried foods- barrier to oil absorption, stop loss of moisture & improve adhesion of batter
5. CARRAGEENAN
5.1. - Carrageenan is a highly refined extract of seaweed from the rhodophyta family. - Chemically its composition is a long chain of galactose residues linked, resulting in a long chain of high molecular weight.
5.1.1. Kappa (K-carrageenan)
5.1.1.1. thermoreversible gel
5.1.2. Lambda (ɻ-carrageenan)
5.1.2.1. does not form gel
5.1.3. Lota (ɩ-carrageenan)
5.1.3.1. thermoreversible gel
6. ALGINATE
6.1. Derived brown seaweed (Laminaria hyperborea)
6.2. Made up of blocks of Dmannuronic acid (M-blocks) & Lguluronic acid (G-block)
6.3. heat- and freeze/thaw-stable
6.4. can be prepared at very low solids and low temperatures with moderate shear
6.5. Provide stabilizing effect in frozen products
6.6. particularly useful in the formulation of restructured fruits and vegetables
6.7. Act as thickener & stabilizer in beverage
6.8. Propylene glycol alginate esterified form of alginate has emulsification property commonly used as stabilizer in emulsions
7. GUM ARABIC
7.1. Sap exuded from various species of Acacia trees
7.2. Polysaccharide contain galactose, rhamnose, arabinopyranose, arabinofuranose, glucoronic acid
7.3. least viscous and most soluble of all hydrocollods-up to 55%solid concentration can be used
7.4. promote stabilisation in beer foam
7.5. Encapsulation agent
7.6. Emulsifier and stabilizer in soft drink emulsion
7.7. Confectionery products – to retard sugar crystallization and promote emulsification
8. LOCUST BEAN GUM
8.1. Come from seed of the leguminose Ceratonia siliqua
8.2. Galactomannan gums
8.3. Insoluble in cold water & must be heated to dissolve
8.4. Does not form a gel by itself- gel when combined with xanthan gum
8.5. Primary functions: thickening, stabilization of emulsions, inhibition of syneresis
8.6. used in canned foods, sauces, desserts, ice-cream, processed meat
9. STRUTURES
9.1. high MW polymers
9.1.1. long sugar chain
9.1.2. substituent protruding from main chain
9.1.2.1. carboxy COOH,COO-
9.1.2.1.1. pectin, alginate, xanthan, arabic
9.1.2.2. methyl ester COOCH3
9.1.2.2.1. pectin
9.1.2.3. sulfate OSO3-
9.1.2.3.1. carragenenan
9.1.2.4. acetyl
9.1.2.4.1. gellan,pectin, konjac, chitosan
9.1.2.5. mannose C6H12O6
9.1.2.5.1. guar, LBG, tara
9.1.2.6. carboxymethyl OCH2COOH
9.1.2.6.1. cellulose gum
9.1.2.7. methyl ether OCH3
9.1.2.7.1. methylcellulose
9.2. Degree of substitution DS
9.2.1. Higher DS - faster to hydrate
9.2.2. Lower DS - slower to hydrate
9.3. Degree of polymerization DP
9.3.1. Higher DP - higher viscosity, slower to hydrate
9.3.2. Lower DP - lower viscosity,faster to hydrate
10. FUNCTIONS
10.1. Thickening agents
10.2. Gelling or texturizing agents
10.3. Stabilisation of emulsion
10.4. Suspension of particulants
10.5. Control of crystallisation
10.6. Encapsulation
10.7. Formation of film
11. FACTORS AFFECT GUM PROPERTIES
11.1. Molecular weight
11.2. Monosaccharide composition
11.3. side chains
11.3.1. type
11.3.2. number
11.3.3. distribution
12. GELATION OF HYDROCOLLOIDS
12.1. gelling on
12.1.1. heating
12.1.2. cooling
12.1.3. presence of cations
12.1.4. acidic pH + high sugar conc.
12.1.5. alkaline pH
12.2. thermoreversible (gel formed on heating or cooling and the process is reversiblle)
12.2.1. gelatin, agar,kappa carrageenan,LM pectin, gellan gum, methyl cellulose, HPMC
12.3. thermally irreversible
12.3.1. alginates, strach, konjac, HM pectin
13. MAIN CLASSES OF HYDROCOLLOIDS
13.1. derivatives from exudation or sap of trees
13.1.1. cellulose, gum arabic, gum karaya, gum ghatti, gum tragacanth
13.2. extract from seed
13.2.1. guar gum, LBG, tara gum, tamarind gum
13.3. extract from seaweeds
13.3.1. agar, carrageenan
13.4. microbial gums
13.4.1. xanthan, dextrun,curdlan
13.5. extract from tubers
13.5.1. konjac
13.6. extract from plant parts
13.6.1. starch, pectin, cellulose
14. GELATIN
14.1. edible natural foodstuff
14.2. raw material used---skin (pigskin and hide split) and bone taken from slaughtered animals
14.3. collagen contained in raw materials is starting material for manufacture of gelatin
14.4. type A---derived from acid processed materials (porkskin)
14.5. type B---derived from alkaline or lime processed materials (calf hides,ossein)
14.6. forms thermally eversible gel wit water
14.7. melting temperature <35 degree celcius---give the melt-in-mouth properties, rapid release of aroma
14.8. used in gelled jelly, yogurt, fruit iuices, top quality ice-cream and frozen produts, gummy bears, etc.
14.9. FUNCTIONS
14.9.1. gel formation
14.9.2. water binding
14.9.3. texturizing
14.9.4. thickening
14.9.5. emulsion formation and stabilisation
14.9.6. foam formation and stabilisation
14.9.7. film formation
14.9.8. adhesion/cohesion
14.9.9. protective colloidal function