Potatoes turn brown after peeling

[chamois]

How come potatoes left out of water after peeling slowly turn brown. Is this an enzyme reaction of some sort? Does anyone know the name of the enzyme involved becaus I'd like to know more about it. A link would be great.

Thanks.

[Clanad]

There are physical as well as chemical changes that occur when certain vegetables and fruits are peeled or cut. One of the physical changes leading to discoloration is the loss of turgor or the hydraulic pressure within the fruit or vegetable that causes the circulatory process, not unlike blood pressure in animals. Hormel Foods says "When fresh fruits and vegetables are peeled or cut open, the enzyme called polyphenol oxidase (also called tyrosinase) contained in the cells is exposed to and reacts with the oxygen in the air. The reaction that occurs, which is called oxidation, is what turns the fruits and vegetables brown. The bruising seen on some fruit, such as apples and pears, is caused by the same type of reaction. If an apple is damaged by being hit or dropped, the apple's cells in that area are damaged and the enzymes are exposed to the air inside the apple, causing them to turn brown. When preparing fruits and vegetables for use, an anti-browning solution should be used to prevent them from turning brown."

[Clanad]

Oh... and the link is http://www.hormel.com/templates/template.asp?c atitemid=113&id=945

[chamois]

Thank you Clanad. You're answer and the link were just what I was looking for.

Much appreciated. Thanks again.