carbohydrates lecture 5

Question 1

How to distinguish between glucose, mannose and galactose?

Answer 1

mannose contains a carbon atom with an oh atom pointed upwards on the first carbon of glucose while galactose contains an oh atom pointed upwards on the 6th carbon for glucose

Question 2

Galactomannos: structure

Answer 2

mannose bonded to a galactose monomer

Question 3

characteristics of locus bean gum

Answer 3

Long hydrodynamic molecule which has a large amount of sweeping space creating intense viscosity. It’s psuedoplastic meaning that by pushing against it with great force will cause decreases in viscosity, it’s a neutral polymer (no charge»doesn’t form bonds with charged proteins and create gels), not impacted by salt due to it’s lack of charge. can’t crystallize allowing it to dissolve in water and reacts with other HC’s to increase viscosity.

Bonds with other starch molecules to modify texture and viscosity. It binds water very readily preventing crystallization in ice cream and synerisis. Resistant to heat and uses as a mouthfeel thickener in various alternative milks.

Question 4

characteristics of guar gum

Answer 4

Long hydrodynamic molecule which is thixotrphic, produces a weak gel structure
Neutral polymer:
-does not bind to salt and protein
-used to thicken ice cream and does not dissolve in water

Question 5

structure of locus bean gum

Answer 5

beta linked chains of mannose with galactose bonded to 56 percent of mannose units

Question 6

structure of guar bean gum

Answer 6

beta linked chains with galacotse bonded to the all manose units at the hairy side and no mannose units at the smooth side.