
Why Does Lettuce Turn Pink When You Cut It? (And Is it Safe to Eat?)
Lettuce leaves turn pink due to a reaction between an enzyme called polyphenol oxidase (PPO) and compounds called polyphenols, which are present in the plant. When lettuce is cut or bruised, the PPO enzyme is activated and reacts with the polyphenols to produce a reddish-brown pigment called o-quinones. These o-quinones then polymerize, resulting in the pink color.
It’s commonly believed that pink lettuce is a sign of spoilage, but this is usually not the case. The pink coloration caused by PPO is harmless and does not affect the safety or nutritional value of the lettuce.
However, if the lettuce shows other signs of spoilage, such as wilting, sliminess, or an off-odor, it’s best to discard it for safety reasons.
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