a Yuzanis Samuel 8 éve
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Chocolate milk - carrageenan Salad dressing - Xanthan, Pectin Processed Fruits - Pectin
Pectin (pH< 4.6) Carrageenan (pH> 4.6)
MC HPC CMC PGA LMA Pectin
HMP & LMP Carrageenan Tragacanth, Karaya Agar, Gelatin Na alginate, Guar, Tara Xanthan, Gellan Konjac, Arabic LBG
Guar LBG CMC PGA Arabic Tara Tragacanth Karaya Xanthan
Pectin Carrageenan Gellan Agar Methyl Cellulose Na alginate Konjac Gelatin
Konjac
Swell below 90 Soluble at temp. 90?>
Agar
Not soluble below temp. 70 and swell at 70 Soluble at temp. 90/>
Gelatin
Soluble in temp. above 25 and swell at 25
Guar Arabic Xanthan CMC Pectin *85-90% soluble in temp. 25
Guar Starch LBG Xanthan Polyproplyene Alginate Konjac Microcystalline cellulose
Pectin Refined LBG
Cellulose Carrageenan Gellan Gum Arabic Gelatin Agar
Guar PGA MCC Gelatin Alginate Agar
Carrageenan Cellulose derivatives
Pectin Xanthan Gellan LBG Tragacanth
Thickening, suspending and stabilizing effects Pseudoplastic - thin with shear and recover their initial viscosity when shearing stops - important for good flavour release, mouthfeel
~Completely soluble in cold water ~Viscosity - High viscosity at low concentration ~Stable to heat and pH - Remain unchanged across temp. range 0-100, pH 1-13
Propylene glycol alginate (esterified form of alginate) stabilize emulsion e.g: mayonnaise/ low-fat mayonnaise
Thickener in beverages e.g: dry mix fruit drinks, gives fast hydration and mouthfeel
Stabilizing effect in frozen products e.g: ice cream to avoid crystallization, gives homogenous breakdown without whey separation
Properties *Ratio of M:G and MW of polymer determine the solution and gelling properties
Can form gel in cold water in the presence of Ca ions, *gel are thermoreversible
High G alginate forms strong, brittle gel with good heat stability
Type of Carrageenan
Lambda, repeating of D-Galactose-2-Sulphate and D-Galactose-2,6-Disulphate with 35% of sulphate content
Kappa, repeating unit is D-Galactose-4-Sulphate linked with 3,6-anhydrous-D-Galactose with 25% of sulphate content
Iota, repeating unit is D-Galctose-4-Sulphate linked with 6-anhydrous-D-Galactose-2-Sulphate with 32% of sulphate content
Gelation of Carrageenan
Kappa and iota carrageenan has the ability to form thermoreversible gels upon cooling of hot aqueous solution containing various cation
Lambda carrageenan do not gel because it structure does not allow double helices formation
Structure of kappa & iota allow the two molecules to form double-helices-like structure, a chain molecules in 3-D network, a gel
Cations are important. Calcium ions and potassium ions form bridges between adjacent double helices through an electrostatic binding in two adjacent sulphate groups so, it stabilize and strengthening the network.
Very stable from pH 4-10
More highly substituted than LBG *more soluble, hydrates fully in cold water giving high viscosity
Nongelling *mainly used as viscosity builder, stabilizers and water binder
Canned foods, sauces, desserts, beverages, ice cream, processed meat
Primary function: thickening, emulsion stabilizer, inhibit syneresis
Non-ionic, stable over pH range 3.5- 11.0
Does not form gel by itself *combined with xanthan gums to gel
Maximum viscosity develop when heated to 95 degree Celsius, then cooled
Insoluble in cold water *must be heated to dissolve
Galactomannan gums *made up of mannose and galactose, in ratio of 4:1
Use in fried food to: create barrier to oils absorption, retard loss of moisture, improve adhesion of batter
Methylcellulose (MC) and HPMC gel when heated. It also returns to origial liquid viscosities when cooled
Very clear solution, Stable over pH 4-10
Gelation of Pectin
HMP: gels at high solids, low pH HMP: DE increase, gelling ability increase LMP: forms gel with calcium ions, loses ability as DE increases
Type of Pectin
Low Methoxyl Pectin (LMP)
Application
Heat reversible *utilised in bakery jams, jellies for glazing purpose
Used in jams with soluble solids <55% *low calories jam, jellies preserves
Formation of Gel
"egg-box" model 1. chain segment with 14/> residues having a ribbon-like symmetry forms parallel-oriented aggregates. 2. Calcium ions fit into cavities in the structure. 3. Chelate bonds with Oxygen from both galacturonan chains formed by calcium ions are formed.
Wide pH range (1-7) *soluble solid can be up to 85%
Low solid content
Presence of Calcium ions
DE < 50%
Amidated LMP (ALMP) *very reactive calcium ions , assist gelation in low sugar food preparation; e.g: low-sugar jams and jellies
Conventional LMP *less reactive calcium ions than ALMP, used as thickening agent in yogurt fruit
High Methoxyl Pectin (HMP)
Structure
Excellent flavour release
Clear and transparent
Not heat reversible
Firm and short structure
Setting times from 1-3 mins to more than 1 hr
DE- 58-75%
Classified further into
slow set (DE as low as 58)
Suitable to very acid fruits *to avoid premature gelation
ultrarapid/ rapid set (DE as high as 77)
Used in jams with whole fruits *to ensure uniform distribution of fruits particles
Formation of gel
Effect of pH in gelation Rapid sey pectin will set at higher pH, higher temperature than slow set pectin High DE, less soluble solid, higher pH which gels can be formed
pH= About 2.8-3.8
Soluble solid content= About 55-85%
Uses
Soft drink emulsion *As emulsifier and stabilizers
Foam in beer *promote stabilization
Encapsulation agent *to encapsulate visible flavour compounds
Used in confectionery products *to retard sugar crystallization, promote emulisification
Properties
Least viscous
Easily dissolve in hot/cold water *most soluble of all hydrocolloids, 55% solid conc. can be used
Distribution
Number
Type
Degree of Polymerization (DP)
Lower DP - Low viscosity, faster to hydrate
Higher DP - High viscosity, slower to hydrate
Degree of Substitution (DS)
Lower DS - Slower to hydrate
Higher DS - Faster to hydtrate
Film formation
Encapsulation
Crystallization contoller
Suspension of particulates
Emulsion stabilizers
Gelling/ Texturizing agents
Thickening agents
