Why are pumpkins orange?
Carotenoids! Naturally-occurring coloring pigments called carotenoids help give pumpkins that festive orange color. With more than 70 carotenoids already identified, these pigments are responsible for not just pumpkins, but a whole lot of beautiful color in the produce aisle – reds, yellows, and oranges.
Why are pumpkins orange all the way through? Apples only have colored skin.
In pumpkins, the carotenoids are dispersed throughout the skin and flesh. This is different from a red apple which has color localized in the skin, or a mango with brightly colored flesh.
But pumpkins don’t start out orange…do they?
Pumpkins start out green due to the chlorophyll levels in the plant. The chlorophylls reduce because of oxidation, an enzyme called chlorophyllases, and a decrease in pH. As pumpkins mature, chlorophylls are replaced with carotenoids, and that signature orange color develops, indicating ripeness.
There are different types of pumpkins. Are all carotenoids the same?
In fruits with yellow/orange flesh, β-carotene and α-carotene are the dominant carotenoids. And, β-carotene can undergo a conversion to vitamin A (retinol). The benefits of vitamin A have been linked to improved vision and healthy immune function. (Mmm hmm….now I feel better about having a second pumpkin treat.)