Cut Apples and Avocados Brown From Oxygen

Photo by marlene_charlotte on Pixabay

Slicing into an apple, avocado, or potato ruptures cells and exposes an enzyme (polyphenol oxidase) that reacts with oxygen to produce brown pigments — it's a genuine chemical reaction, not spoilage, and it's harmless to eat. Acid (lemon or lime juice) slows the enzyme down directly, while submerging cut fruit in water or pressing plastic wrap directly onto the surface works by limiting its access to oxygen instead — either approach buys time before the browning becomes visible.