arabera nurul husna bt che saad 8 years ago
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Honelako gehiago
What is Gum?
-Is a polysaccharides chains contain hydroxyl group which can bind to water.
- Also have side chains such as ester, sulfates and acetyl.
- Some gums are react strongly in presence of other ingredients. Example : sodium alginate does react actively with calcium.
Functions & Applications
1- Adhesive - Bakery glaze
2- Crystallization - Ice- cream
3- Cloud Agent - Fruit juice
4- Emulsifier - Salad Dressing
5- Film former - Sausage casing
6- Foam stabilizers - Beer, Whipped topping
7- Geling agent -Puddings
8-Suspending agent - Chocolate milk
9-Syneresis in inhibitor - Cheese, frozen foods
10- Thickening agent- sauces and gravies
CELLULOSE:
-Derived using alkaline treatment which convert cellulose into an ether (e.g: CMC - sodium carboxythylcellulose and HPMC-Hydroxypropylmethylcellulose.
CMC:
:Monovalent salts, soluble
:Divalent salt, hazy
:Trivalent salts, gel or precipitate
:React with proteins to increase viscosity of dispersions
CMC PROPERTIES
:Water soluble
:Pseudoplastic dispersions
:Stable at pH 5-10, best pH 7-9
CMC USAGE
: Pie filling-to prevent synersis
: Breads- Has an anti-staling effect
: Dietatic food- to provide bulk and body replacer that normally given by sucrose
*MC and HPMC formed gel when heated and return to it original liquid viscosity when cooled.
PECTIN derived from peel of citrus fruits
STRUCTURE:
-Chain of polygalacturonic acid units
Molecular weight up to 150,000
TYPES:
-HMP (High methoxyl pectin)- DE>50%
:To form gels, soluble solid content : 55-58%, pH 2.8-3.8
:Used in jams
:Not heat reversible
: Gels at high solids and low pH
-LMP(Low methoxyl pectin)-DE<50%
:DE < 50 %
:LM are heat reversible
:-Conventional low methoxyl pectin (LMP)
-Amidiate low methoxyl pectin (ALMP)
: The presence of Ca2+ needed to form gels with low solid content and wide pH range 1-7
:ALMP is very reactive than Conventional low methoxyl pectin
USES:
-Jams
-Jellies
XANTHAN GUM
-polysaccharides produced from fermentation of CHO substrate with Xanthomonas Campestris
STRUCTURE:
-Basically a derivative cellulose
XANTHAN PROPERTIES:
-Xanthan is soluble in hot or cold water to produce dispersion of high viscosity at low concentration
-The dispersion are highly pseudo-plastic (shear-thickening)
USES:
1)Beverages
-good flavor release ( due to shear-thickening)
-Cloud stabilizers
2) Frozen food
-Pie filling-Increase freeze-thaw stability
3) Relishes
-Good acids stability
4) Xanthan -LBG gels and puddings
-Instant gels and pudding
ALGINATE ( Source = brown seaweed, Macrocystis pyrifera)
STRUCTURE:
- D- mannuric acid, L- guluronic acid
-Poly M blocks
-Poly G blocks
-Alternating M-G blocks
PROPERTIES:
-Low molecular weight fractions
-Non-newtonian behavior increase with:
-Increasing degree of polymerizations (DP)
- Increasing concentrations
- Presence of Ca+ instead of Na+
-As temperature increase, viscosity decrease
-Good stability in the pH range 5-10
-maximum viscosity occur between pH 6-8
-Degradation occurs at low pH 1-4
-Alginate is fairy resistant to microorganism
ALGINATE GELATION:
-Ca+ gels
-Acid gels
-Combination gels
*can form heat stable gel
*Sodium alginate react strong with calcium produce alginate thick when mixed in water, but if calcium was added it will form a cold water gel.
USES:
1) Ice-cream
2) Bakery icing
3) Bakery jelly
4) Meringues
5) Salad dressing
6) Pimento stuffe olives
7) Frozen reformed onion rings
GUAR GUM
(SOURCE: cyamopsis tetragonolobus)
- hydrates rapidly in cold water to give highly viscous dispersion.
-Totally soluble in cold and hot water, and gives slimy solutions.
-Good synergism with xanthan gum for extra high viscosity solutions.
STRUCTURE:
- Galactomannans which containing mannose and galactose monomers (ratio= 2:1)
- Molecular weight : 1,000,000 to 2,000,000 daltons.
Uses:
-Processed cheese
-Ice-cream
-Baked goods
-Meat
- Dressing and sauce
-Beverages
LOCUS BEAN GUM (SOURCE : CAROB TREE (ceretonia siliqua)
STRUCTURE:
- A galactomannan ( man : gal = 4:1)
- Molecular weight = 300,000 to 360,000
*contain long stretches of bare mannose backbone which responsible for synergism
SOLUBILITY:
-Partially soluble in cold water but only under strong agitations. Totally soluble in hot water.
SYNERGIES:
- Good synergism with xanthan gum for every elastic chewy gum. Can built up quite strong gels. Useful in mayonnaise which required strong gels.
APPLICATION:
- Used in ice-cream, cheese productions and meat product
ADVANTAGE:
- Have strong interaction with K-caraggenan
-Good flavor release
GUM ARABIC - from Acacia senegal L
STRUCTURE:
- D-galactose, L-arabinose, L- rhamnose, D- glucurunic acid
- Molecular weight : 250,000 to 1,000,000
- Very complex structure
ADVANTAGES:
- High water solubility
- Flavor encapsulations
APPLICATION:
- Emulsification (w/o or o/w) in salad dressing
- Flavor fixation in powder drinks milk
- Crystallization control in ice-cream
