alifah's+assigment+3

alifah's assignment 3

Agar and Carrageenan __Think about the chemical structure of carrageenan and agar - what do they have in common? __

Agar ** = ** Ø Extracted from seaweed and is used in many foods as a gelling agent. Ø Agar is a polymer of agarobiose, a disaccharide composed of D-galactose and 3,6-anhydro-L-galactose. Ø Highly refined agar is used as a medium for culturing bacteria, cellular tissues, and for DNA fingerprinting. Ø **used as ** = An ingredient in desserts in Japan and other Asian countries. The gels produced with agar have a crispier texture than the desserts made with animal gelatin.

Carrageenan **= ** Ø A generic term for several polysaccharides also extracted from seaweed. Ø Carrageenan compounds differ from agar in that they have sulfate groups (**-OSO3**-) in place of some hydroxyl groups. Ø **used as ** =  Thickening, suspending, and gelling food products.

Carrageenan consists chiefly of potassium,sodium,calcium,magnesium,and ammonium sulfate esters of galactose and 3,6-anhydrogalactose copolymers. These hexoses are alternately linked a <span style="color: black; font-family: "Arial","sans-serif"; font-size: 12.5pt; line-height: 115%;">-1,3and b <span style="color: black; font-family: "Arial","sans-serif"; font-size: 12.5pt; line-height: 115%;">-1,4in the polymer.The prevalent copolymers in the hydrocolloid are designated //<span style="color: black; font-family: "Arial","sans-serif"; font-size: 12.5pt; line-height: 115%;">kappa- // <span style="color: black; font-family: "Arial","sans-serif"; font-size: 12.5pt; line-height: 115%;">,  //<span style="color: black; font-family: "Arial","sans-serif"; font-size: 12.5pt; line-height: 115%;">iota- // <span style="color: black; font-family: "Arial","sans-serif"; font-size: 12.5pt; line-height: 115%;">,and  //<span style="color: black; font-family: "Arial","sans-serif"; font-size: 12.5pt; line-height: 115%;">lambda // <span style="color: black; font-family: "Arial","sans-serif"; font-size: 12.5pt; line-height: 115%;">-carrageenan.