The watermelon, Citrullus lanatus, is a beloved summer fruit known for its refreshing sweetness and bright interior. Consumers often wonder if a purple variety of this fruit exists, given the wide range of colors found in nature. This article will provide a definitive answer and explore the genetics and chemistry that determine why watermelons appear red, yellow, or white, but not the deep violet hue many imagine.
The Reality of Purple Watermelon
The direct answer is no; there is no naturally occurring variety of Citrullus lanatus with purple flesh. The specific genetic makeup required to produce a true violet pigment in the edible part is absent. Some cultivated varieties, such as “scarlet red,” exhibit a deep, intense crimson color that may appear darker than typical pink flesh. However, this deep red is not true purple. Photos and claims of purple watermelons circulating online are consistently proven to be digital fabrications or hoaxes.
Exploring the True Range of Watermelon Colors
While purple is not a natural option, watermelon flesh showcases a surprising array of colors beyond the standard pink and red. Genetic variations within the species lead to several distinct flesh colors, each determined by a different expression of plant compounds. These naturally occurring colors include yellow, orange, and even white.
Yellow watermelons, such as ‘Yellow Doll,’ result from a genetic expression that prevents the accumulation of red coloration compounds. Their flesh ranges from pale yellow to a vibrant, buttery hue. Orange-fleshed varieties, like ‘Orange Glo,’ are also available, presenting a salmon-colored interior distinct from both yellow and red types.
The lightest color is found in white-fleshed watermelons, which still exist in heirloom varieties. These melons contain only trace amounts of pigments, resulting in an interior that is pale green or nearly colorless.
The Chemistry Behind Watermelon Pigments
The color of watermelon flesh is primarily determined by a class of compounds called carotenoids. In the most common red and pink varieties, the dominant pigment is lycopene, a powerful antioxidant that accounts for 84% to 97% of the total carotenoids present. The intensity of the red color directly correlates with the concentration of lycopene that accumulates as the fruit matures.
Yellow and orange watermelons are colored by different carotenoids expressed when the lycopene pathway is blocked. For example, the orange color often results from the accumulation of beta-carotene, the same pigment found in carrots. White-fleshed varieties produce very low levels of any carotenoids, which is why their interior appears pale.
The specific purple color is achieved in nature by a separate class of compounds known as anthocyanins, which are responsible for the blue, purple, and red hues in berries and eggplants. Watermelon fruit flesh does not produce or accumulate these anthocyanin compounds. This lack of the necessary genetic mechanism to synthesize anthocyanins provides the scientific explanation for why a true purple watermelon cannot exist.
Why Does the Idea of Purple Watermelon Persist?
The persistent belief in a purple watermelon is largely fueled by digital misinformation and viral hoaxes spread across social media platforms. Images of sliced purple watermelons are often created using photo editing software to manipulate the color of a standard red fruit. These fraudulent images capture public attention and are shared widely, leading many to believe a rare cultivar exists.
Deceptive online sellers have capitalized on this curiosity by offering “purple watermelon seeds” for sale. Buyers who plant these seeds inevitably grow a standard red-fleshed watermelon, confirming the product’s fraudulent nature. Confusion may also arise from certain watermelon rind varieties, like ‘Moon and Stars,’ which can have a very dark, almost black-purple exterior. However, the edible flesh inside remains the standard red or pink color.