1. Chocolate Pudding Lab Aim: To study the effects of cornstarch in the preparation of a simple pudding

2. Pudding A starch thickened desert –A starch is a polysaccharide made up of 2 fractions: amylose and amylopectin Amylose – linear molecule and gives gelling characteristics to cooked and cooled starch mixers Amylopection – highly branched and bushy; no gelling properties

3. Starch Gradules Stored in plant cells Come in different sizes and shapes depending on the type of starch –Potato: 10 - 100 um –Corn: 5 - 25 um Potato Starch

4. Factors That Affect Starch 1.Moist Heat → Gelatinization 2.Temperature and Time of Heating 3.Agitation and Stirring 4.pH 5.Addition of Other Ingredients

5. Gelatinization As you heat the starch its granules absorb water and swell → increased viscosity and thickness After a period of time the granules gelatinize – gets rigid and takes shape

6. Temperature and Time of Heating Starch paste is quickly prepared by boiling it for 1 minute –granules swell at high temperatures

7. Agitation and Stirring Stir in the early stages of cooking with uniform consistency for a smooth product If agitation is too intense → rupture of granules and decreased viscosity

8. Other Ingredients Sugar –raises temperature at which a starch gelatinizes → delays swelling of starch granules decreasing thickness of paste –It competes with the starch for water

9. pH High acidity causes fragmentation of granules –Decreases the thickening power

10. Other Ingredients Protein and Fat: –coat the starch which delays swelling and lowers rate of viscosity development