The fruit known for its ability to oxidize and turn brown when cut is the apple. This browning occurs due to a chemical reaction called enzymatic browning, where the enzyme polyphenol oxidase reacts with oxygen in the air, leading to the formation of brown pigments. This process not only affects the visual appeal of the fruit but can also alter its flavor and texture. To slow down this reaction, various methods can be employed, such as applying lemon juice or other acidic substances, which help to inhibit the enzyme. Despite this, apples remain popular for their taste and nutritional benefits.