Final Lab Project

Apples/Enzymatic Browning

Materials:

-Apple Slices

-test tube with 0.1% Ascorbic

-test tube with 0.1% Citric acid test tube

-test tube with 0.1% Acetic acid test tube

-test tube with 1.0% Acetic acid test tube

-Beaker with water

-tongs

-experiment mat

This experiment will monitor the amount of enzymatic browning of apple slices. In apples there is an enzyme called phenolase. When an apple is touched by oxygen, the phenolase catalyses the formation of brown pigments. If we treat the apples with acids such as ascorbic, citric or acetic acids this will reduce the level of browning. When fruits and vegetables are cut the enzymes are released in the presence of oxygen and produces brown pigments known as melanins.

First we will label a paper towel “Control” and place an untreated apple slice on the control towel. Using the tongs, dip each apple slice into the solutions (.1% ascorbic, .1% citric, .1% acetic, 1.0% acetic) and lay each slice tested with the different solutions onto a towel labeled with that solution. Take one slice and soak it in the beaker with water for 30 seconds and again place it on a paper labeled “Water”. Begin to observe the apple slices every ten minutes for 1 hour.