Functional polysaccharides

Question 1

What are the 3 solvent and solute interactions?

Answer 1

Solvent-solute
Solute-solute
Solvent-solvent

Question 2

What does viscous ideal mean?

Answer 2

Material changes shape

Question 3

What does elastic ideal mean?

Answer 3

Material retains shape

Question 4

What is viscoelastic?

Answer 4

Mix between viscous and elastic

Question 5

Examples of viscoelastic materials

Answer 5

Ketchup (fluid) and jelly (solid)

Question 6

What do thickening agents increase?

Answer 6

Solution viscosity
Resistance to external force
Internal friction
Solvent-solute interactions

Question 7

How do thickening agents work?

Answer 7

Formation of polymers which capture water molecules

Question 8

What are gelling agents?

Answer 8

Macromolecules that cause liquids to have solid-like consistency (jelly)

Question 9

How do gelling agents work?

Answer 9

Formation of cross-linked polymers to increase solute-solute interactions

Question 10

What are anomeric effects?

Answer 10

Differences between alpha and beta polysaccharides (alpha right carbon is on the bottom whereas beta is on top)

Question 11

What effects polysaccharides secondary structure?

Answer 11

Anomeric effects
Bond positions
Number of units

Question 12

What effects polysaccharide tertiary structure?

Answer 12

Hydrogen bonding
Other molecules
Geometry

Question 13

Differences between amylose and cellulose

Answer 13

Amylose= alpha-D-Glucose
Cellulose= beta-D-Glucose
Amylose has helix structure, cellulose has chained structure

Question 14

What occurs when flour is added to water then heated?

Answer 14

Dry grain becomes dispersed and swollen
Swollen grain becomes a dissolution
Dissolution becomes thickening or gelling structure

Question 15

Chains in gels are formed by what?

Answer 15

Electrostatic interactions
Hydrogen bonding
Hydrophobic bonding
Entropic interactions

Question 16

Are gel chains stronger or weaker than solution chains?

Answer 16

Stronger

Question 17

What is gelling point dependent on?

Answer 17

Temperature
Ions
pH
Co-solutes

Question 18

What are the 2 areas of cellulose?

Answer 18

Amorphous and crystalline

Question 19

How do modifications in the amorphous area effect cellulose?

Answer 19

Changes structure and functionality

Question 20

What is the structure of galactomannans (thickener)?

Answer 20

(1-4)-beta-D-Mannose backbone with (1-6)-alpha-D-Galactose side group

Question 21

What is the structure of alginates (gelling)?

Answer 21

(1-4)-beta-D-mannuronic and alpha-L-guluronic acid

Question 22

Structure of pectin

Answer 22

(1-4)-alpha-D-galacturonate backbone with galacturonic acid and methyl-esterified side chains

Question 23

What does high esterification (>50%) cause in pectin?

Answer 23

High methoxy (HM) pectin which causes gelation through hydrophobic bonding

Question 24

What does low esterification (<50%) cause in pectin?

Answer 24

Low methoxy (LM) pectin which forms gels with calcium ions through cross linking

Question 25

What is degree of blockiness?

Answer 25

Measure of distribution of ester groups in pectin chains

Question 26

What does degree of blockiness effect?

Answer 26

Cross-linking

Question 27

What is xanthan gum?

Answer 27

Exocellular polysaccharide of bacterial fermentation

Question 28

Structure of xanthan gum

Answer 28

(1-4)-beta-D-glucose backbone with side chains of 2 mannose units

Question 29

What does xanthan gum form?

Answer 29

Weak gels