Lipid Test - Brown Paper Place one drop of vegetable oil on the brown paper. Place one drop of your test liquid two to three inches away on the same brown paper. Allow the paper to dry for 15 minutes. Turn the paper over. Note any stains left by each sample.
Protein test – Biuret solution Add 40 drops of test liquid to a test tube. Add 40 drops of protein solution to a different test tube. Add 3 drops of Biuret solution to each test tube. Shake gently to mix. Note color change.
Glucose test – Benedict’s solution Add 40 drops of test liquid to a test tube. Add 40 drops of glucose solution to a different test tube. Add 10 drops of Benedict’s solution into each test tube. Carefully heat the test tubes by suspending in a hot water bath for 5 minutes. Note any color change (see the color change chart on the board).
Starch test – Lugol’s iodine Place a sample of your positive test food in one of the well’s of your test plate. Add about 10 drops of water to the food. Add 10 drops of the test liquid to a different well. Add 3 drops of Lugol’s iodine to each well. Use a toothpick to mix the sample thoroughly. Observe color change (use white paper as a backdrop for your test plate to better observe color differences)