Oxidation is a natural process that causes fruits and vegetables to turn brown when exposed to air. This reaction occurs due to enzymes in the produce reacting with oxygen in the air. Fruits like apples and avocados are particularly prone to oxidation, leading to browning on their surfaces. To prevent this discoloration, acidic substances like lemon juice or vinegar can be used to slow down the oxidation process by inhibiting enzyme activity. Proper storage techniques such as wrapping cut produce tightly or storing them in an airtight container can also help minimize oxidation effects on various fruits and vegetables beyond just potatoes.