 In this lab experiment you are going to play the role of a chemical detective to decide which chemicals are present in common food substances.  Certain reagents act as chemical indicators in the presence of specific chemicals.  The knowledge of how these reagents react will allow us to test for these chemicals in familiar foods.

 Today we will be using various chemical indicators on different foods to test for the presence of 4 specific chemicals within them.  The chemicals we will be testing for are: - Starch - Protein - Vitamin C - Glucose

FOOD Reagents  Apples  Egg  Potato Chips  Popcorn  Potato  Orange  Cheese  Cooked Rice

Apples Egg White Potato chips Popcorn Potato Orange Cheese Cooked Rice L B I 1) Place a small sample in the respective well as seen in the diagram. 2) Add the respective reagents to each sample. (Lugol’s, Biuret, Indolphenol). Each Individual will be responsible for one reagent. 3) Benedicts reagent will be tested on the side benches with the additions of heat.

 One person from each table will be responsible for completing the Benedicts test on the side counters.  Here, you will put the food samples in a test tube and place them into a beaker of hot water on the hot plates on the side benches and add the Benedicts reagent and wait for a color change.  Please be very careful not to touch the hot plate, for obvious reasons, or to knock over the beaker.