What temperature do apples brown in?

Apples begin to brown when exposed to oxygen, a process known as enzymatic browning, which can occur at any temperature, but it typically happens more rapidly at warmer temperatures. This reaction is facilitated by the enzyme polyphenol oxidase, which is most active around room temperature. To slow down browning, it's best to store cut Apples in a cool environment or use acidic solutions like lemon juice.