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

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

Starch Gradules Stored in plant cells Come in different sizes and shapes depending on the type of starch –Potato: um –Corn: um Potato Starch

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

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

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

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

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

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

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