General Mills is dropping artificial colors and flavors from its cereals, the latest company to respond to a growing desire for food made with ingredients people see as natural.

A range of food companies including Subway, Pizza Hut, Panera, Hershey and Nestle have said in recent months that they're removing artificial ingredients from some or all products. Companies say the changes are a response to a demand for food made with ingredients people can recognize.

This cereal makeover is more difficult than it may sound.

Red 40, Yellow 6, Blue 1 sounds more like an NFL play, but these synthetic dyes have been used for decades.

Ted Labuza, professor of food science at the University of Minnesota, says natural food dyes typically don't work as well.

"The compound has to be a stable compound and not have something that could react to other things," said Labuza. "Most of them are very rare compounds, so the chances of them not reacting to other things are pretty small."

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