CARBOHYDRATE - STARCHGROUP 2

ANISSA MUNIRA BINTI ABDUL AZIZ 166664

NURUL WAHIDAH BINTI GHAZALI 168678

IKMAL SAADAH BINTI JONAIDI 170087

EPF4602: BIO-MATERIAL

POLYMER

TECHNOLOGY

• Carbohydrate : molecular compounds made from three

elements (carbon, oxygen, hydrogen).

• Starch : carbohydrate that consist of large number

of glucose units joined by glycosidic bond.

FORMS OF STARCH

• AMYLOSE : unbranched chains of glucose connected by α (1→4) glycosidic

bond.

• AMYLOPECTIN : branched chains of glucose . At the main chain, glucose connected by

α (1→4) glycosidic bond and connected by α (1→6) glycosidic bond

at the branch point.

STRUCTURE

AMYLOSE AMYLOPECTIN

PHYSICAL PROPERTIES

• Starch molecules arrange themselves in the plant in semi-crystalline

granules.

• Insoluble in water because of the high molecular weight.

• Because they contain large numbers of OH groups, some starches can form thick

colloidal dispersions when heated in water.

• For example: flour or starch used as a thickening agent in gravies or sauces.

• High density

• Possible to separate from other soluble and less dense

materials.

• During cooking, the starch becomes a paste and increases

further in viscosity, holding water.

• During cooling or prolonged storage of the paste, the semi-

crystalline structure partially recovers and the starch paste

thickens, expelling water.

STARCH APPLICATION

• In Food

* Modified starch used in cooking to thicken foods : sauces and

puddings.

* Uses as emulsifier, stabilizer, fat replace , and as glazing agent.

* As edible coatings.

* As a mold in the preparation of confectionary.

• Others

* Use as glue

* As a lubricant in oil drilling

* In paper industry : to make the paper stronger

* In pharmaceutical : filling agent

*In baby diapers : to increase moisture absorption