STUDENT ACTIVITY GUIDE
Enzymatic Browning of Apple
ACTIVITY OBJECT
The purpose of this experiment is to monitor the level of enzymatic browning of apple slices. The experiment will illustrate that apple contain an enzyme caked polyphenol oxidase or phenolase. In the presence of oxygen from the air, this enzyme catalyzes the formation of brown pigment called melanins. Treatment of the apple slices with organic substances such as ascorbic acid, critric acid, or acetic acid will reduce the level of browning. The reduction in browning is dependent on the type of substance and its concentration. Soaking in water alone will temporarily reduce the level of browning by restricting the amount of oxygen in contact with apple tissue.