Photograph by Rebecca Hale, National Geographic

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Cochineal insects (shown crushed) are responsible for creating the red dye found in many products.

Photograph by Rebecca Hale, National Geographic

Scientists Make Red Food Dye From Potatoes, Not Bugs

Purple sweet potatoes could be an alternative to bug-based cochineal or carmine.

Would you rather eat bugs or plants?

If you picked the latter, you're in luck: Researchers are developing better vegetable-based alternatives to cochineal, a commonly used red food coloring made from crushed insects. One of the most promising candidates is the purple sweet potato.

Purple sweet potatoes can be used to produce a range of colors, from light pink to deep purple, says Stephen Talcott, an associate professor of food chemistry at Texas A&M University.

Demand for natural food colorings has risen in recent years, as consumers are shying away from artificial food dyes, which have been linked to allergies and behavioral problems such as hyperactivity in children.

The pigments in purple sweet potato, called anthocyanins, are "among the most desirable for their superior color and stability," says Talcott, who presented his work at the American Chemical Society's annual meeting in Indianapolis earlier this month.

While colorings made from purple sweet potatoes are already on the market, extracting the pigments is difficult and inefficient, and much of the color can be lost to oxidation during processing, says Talcott.