THY+Carrageenan+and+Agar


 * Carrageenan and Agar **

1. Think about the chemical structure of carrageenan and agar - what do they have in common?

The common characteristic of carrageenan and agar include they are both polysaccharides extracted from marine algae. They are both composed of alternating α (1,3) and β(1,4) linked galactopyranose residues. Besides that, they are both work as gelling agent in food system.

 2. What are the differences between kappa, iota and lambda carrageenan? Why? The primary differences which influence the properties of kappa, iota and lambda carrageenan are the number and position of the ester sulfate groups on the repeating galactose units. Higher levels of ester sulfate lower the solubility temperature of the carrageenan and produce lower strength gels, or contribute to gel inhibition (lambda carrageenan).
 * ** Kappa ** || ** Iota ** || ** Lambda ** ||
 * Strong. Rigid gels || Soft gels || Does not gel ||
 * Gels with potassium ions || Gels with calcium ions || used to thicken dairy products ||
 * Mainly from //Eucheuma cottonii// || Produced mainly from //Eucheuma spinosum// || common source is //Gigartina// from South America ||