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Why is lycopene red in ripe tomatoes?

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Isoprenoid Camphor, an isoprenoid compound classified as a terpenoid ketone, is used in incense and certain medicinal compounds. It is a natural substance obtained from the camphor laurel (*Cinnamomum camphora*), a species of evergreen.

Lycopene is responsible for the red color of ripe tomatoes due to its specific chemical structure as an isoprenoid compound.12

Specifically, lycopene is a polyene, meaning it contains a long chain of alternating single and double carbon-to-carbon bonds known as a conjugated system. This structural feature dictates the compound's light-absorption properties; as the number of conjugated double bonds increases, the molecule absorbs light at longer wavelengths. Because of this extended conjugation, lycopene absorbs visible light in a way that causes it to appear red to the human eye.32

During the ripening process, the chlorophyll that gives immature tomatoes their green color breaks down, and the plant synthesizes lycopene. This transition serves a biological purpose: the vibrant red color acts as a signal to animals that the fruit is mature and ready to eat, which facilitates the plant's seed-dispersal strategy.4