The Browning of Guacamole

The focus of our video was to help explain the browning of avocados in a simple, scientific way. We tried to draw connections between science and everyday life; we have all seen fruit and vegetables turn brown. The reason why the avocados are turning brown is due to an enzyme reacting with oxygen. The enzyme polyphenol oxidase changes the compounds and the chemical structure in the avocado. As a result, the avocado turns brown. To prevent this from happening, we must change the environment in which the enzyme is working. Every enzyme works most efficiently under particular environmental conditions. Therefore, if we change the environment, the enzyme will not be able to work efficiently. Refrigeration and the addition of acidic juice (in our video it was lime juice) will delay the effects of the enzyme reaction. The enzyme is denatured, meaning it loses its structure and is unable to perform its function because of the acid in the lime juice. This is simply, yet elegantly, shown in our video on the comparison between guacamole with lime juice (which did not turn brown) and guacamole without lime juice (which turned brown).