INGREDIENT FUNCTIONALITY EXAM
QUESTIONS AND ANSWERS
Describe a starch granule - Correct Answers -Crystaline amylose and amorphous
amylopectin concentric rings.
More amylose, higher the hydration temperature. Smaller granule, Higher the hydration
temeprature
Retrogradation - Correct Answers -The crystalising of starch, usually amylose, with the
result of the loss of water.
What happens if you over heat a starch thickened liquid? - Correct Answers --Bursting
of the starch granule
-Pasting of the starch granule
Four types of modified starches and their uses - Correct Answers -1. Crosslinked - Less
rupture chance
2. Lipophilic addition - Emulsifying properties
3. Converted - Depolymerised, quicker gelation
4 Stabilised - Impedes retrogradation
Collagen - Correct Answers -An insoluable exo-protein used by animals to give
structure to their cells.
Tropocollagen - Correct Answers -A triple helix of polypeptides, usually ~1000 amino
acids long. Genesis to gelatin
Gelatin - Correct Answers -A water soluable protein that will dissolve in water above
55C and melt at body temperature when set to a gel.
How is gel strength measured? - Correct Answers -Measured in bloom: The amount of
force required to depress a solution of 6.67% gelatin by 4mm. Measured in grams.
Describe the mechanism for gelatine - Correct Answers -Gelatine is dispressed in a
water based system. Hydrates at above 55C. When it sets, it attempts to return to a
triple helix conformation causing triple junction points which impede the movement of
water.
Stability factors - Correct Answers -pH 3 - 10
Thermoreversible gel
Sensitive to proteases
, Tolerates alcohol up to 40%
Applications of gelatine (name 3) - Correct Answers -Thermoreversible gels
Emulsification
Viscosififcation
Foams
H2O Binding
Describe the structure of xanthan gum - Correct Answers -Xanthan gum has a helical
conformation with 2 repeating glucose units. Every 2nd unit has a mannose and
glucoronic acid moiety.
Describe the mechanism for xanthan gum - Correct Answers -When heated, xanthan
gum loses it's local order and disasciates to random coils. As it cools, it'll form a long
range ordered network that'll complex water.
Properties of xanthan gum (name 3) - Correct Answers -High elastic modulus
High psuedoplasticity
Good enzyme stablity
High alcohol tolerance
Guar and xanthan gum have a synergy: why? - Correct Answers -Smooth
galactomannan regions in guar gum complex with the ordered regions of xanthan gum,
forming a stronger gel.
Name the xanthan synergies: - Correct Answers -Guar
Locust bean gum
Benefits of xanthan gum (name 4) - Correct Answers -Heat not needed to hydrate
Sugar not required to disperse
High viscosity at low concentrations
Low use levels
Acid stable (pH 2.5 - 10)
Salt stable
Heat stable
Emulsion stability
Carrageenan: name the origins - Correct Answers -Red seaweeds, provides flexibility to
it's cell walls.
Kappa: Amount of sulphate groups, Gel salt, Gel type? - Correct Answers -One
sulphate group
Potassium gel salt
Brittle gel
QUESTIONS AND ANSWERS
Describe a starch granule - Correct Answers -Crystaline amylose and amorphous
amylopectin concentric rings.
More amylose, higher the hydration temperature. Smaller granule, Higher the hydration
temeprature
Retrogradation - Correct Answers -The crystalising of starch, usually amylose, with the
result of the loss of water.
What happens if you over heat a starch thickened liquid? - Correct Answers --Bursting
of the starch granule
-Pasting of the starch granule
Four types of modified starches and their uses - Correct Answers -1. Crosslinked - Less
rupture chance
2. Lipophilic addition - Emulsifying properties
3. Converted - Depolymerised, quicker gelation
4 Stabilised - Impedes retrogradation
Collagen - Correct Answers -An insoluable exo-protein used by animals to give
structure to their cells.
Tropocollagen - Correct Answers -A triple helix of polypeptides, usually ~1000 amino
acids long. Genesis to gelatin
Gelatin - Correct Answers -A water soluable protein that will dissolve in water above
55C and melt at body temperature when set to a gel.
How is gel strength measured? - Correct Answers -Measured in bloom: The amount of
force required to depress a solution of 6.67% gelatin by 4mm. Measured in grams.
Describe the mechanism for gelatine - Correct Answers -Gelatine is dispressed in a
water based system. Hydrates at above 55C. When it sets, it attempts to return to a
triple helix conformation causing triple junction points which impede the movement of
water.
Stability factors - Correct Answers -pH 3 - 10
Thermoreversible gel
Sensitive to proteases
, Tolerates alcohol up to 40%
Applications of gelatine (name 3) - Correct Answers -Thermoreversible gels
Emulsification
Viscosififcation
Foams
H2O Binding
Describe the structure of xanthan gum - Correct Answers -Xanthan gum has a helical
conformation with 2 repeating glucose units. Every 2nd unit has a mannose and
glucoronic acid moiety.
Describe the mechanism for xanthan gum - Correct Answers -When heated, xanthan
gum loses it's local order and disasciates to random coils. As it cools, it'll form a long
range ordered network that'll complex water.
Properties of xanthan gum (name 3) - Correct Answers -High elastic modulus
High psuedoplasticity
Good enzyme stablity
High alcohol tolerance
Guar and xanthan gum have a synergy: why? - Correct Answers -Smooth
galactomannan regions in guar gum complex with the ordered regions of xanthan gum,
forming a stronger gel.
Name the xanthan synergies: - Correct Answers -Guar
Locust bean gum
Benefits of xanthan gum (name 4) - Correct Answers -Heat not needed to hydrate
Sugar not required to disperse
High viscosity at low concentrations
Low use levels
Acid stable (pH 2.5 - 10)
Salt stable
Heat stable
Emulsion stability
Carrageenan: name the origins - Correct Answers -Red seaweeds, provides flexibility to
it's cell walls.
Kappa: Amount of sulphate groups, Gel salt, Gel type? - Correct Answers -One
sulphate group
Potassium gel salt
Brittle gel
