How Natural Is Your Cola?

ScienceShot: How Natural Is Your Cola?

by Catherine Meyers 

Credit: Fotosearch; (cola plant) Illustrations by Walther Müller and C.F. Schmid (1887)

Water, sugar, and caramel coloring are the main ingredients in most soft drinks, but some "natural" beverage makers add cola nut extract to the recipe—and extra cents to the price tag. Now, researchers in Italy have developed a method to test whether these premium colas live up to their billing. The team took 1 liter of a particular naturally flavored soda brand and dumped in millions of tiny beads, each coated with a different sequence of amino acids. Some of the amino acid combinations latched onto the cola nut proteins in the soft drink. The researchers then separated out the captured proteins and identified them. When the team followed the same procedure with a liter of Coca-Cola, which does not claim to use cola nuts in its recipe, they found no protein signature. The technique, published today in the Journal of Proteome Research, could help consumer groups test the authenticity of naturally flavored sodas or other beverages, the researchers write.