Describe the procedures and positive results for testing starch and protein in food.

Here are the details for the food tests described: Starch Test (using Iodine solution) Procedure: To test for starch, prepare a food sample (solid, cut surface, or crushed with water). Add a few drops of iodine solution to the sample. Positive Result: The presence of starch is indicated if the straw-coloured iodine solution turns blue-black*. Protein Test (using Biuret test) Procedure: 1. Place 2 cm^3 of the food sample (crush with water if solid) in a test tube. 2. Add 2 cm^3 of dilute sodium hydroxide solution. 3. Add 1\% copper sulphate solution drop by drop. 4. Shake the mixture. Positive Result: A purple (violet)* colour indicates the presence of protein. Protein Test (using Millon's test) Procedure: 1. To a solution of the food sample (e.g., beans, egg white, or ground meat) in a test tube, add a few drops of Millon's reagent. 2. Boil the mixture for one minute. Positive Result: A deep red* colour indicates the presence of protein. That's 2 down. 3 left today — send the next one.