Chocolate Pudding Lab Aim To study the effects

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: 10 - 100 um – Corn: 5 - 25 um Potato Starch

Factors That Affect Starch 1. Moist Heat → Gelatinization 2. Temperature and Time of Heating 3. Agitation and Stirring 4. p. H 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

p. H • 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