Purple corn

Purple corn (Spanish: maíz morado) or purple maize is another name for Blue corn, a variety of flint maize (Zea mays indurata) originating from Mesoamerica.

The kernels of purple corn are soaked in hot water by people of the Andes to yield a deep purple color for foods and beverages, a practice now recognized for its industrial uses as a colorant. Common in Bolivia, Ecuador and Peru, purple corn is used in chicha morada, a drink made by boiling ground purple corn kernels with pineapple, cinnamon, clove, and sugar, and in mazamorra, a type of pudding. One of the most popular purple corn food uses is the "Api", a smoothie served hot and sometimes called "Inca's dessert".

The pigment giving purple corn its vivid color derives from an exceptional content of a class of polyphenols called anthocyanins. Cyanidin 3-O-glucoside, also called chrysanthemin, is the major anthocyanin in purple corn kernels, comprising about 73% of all anthocyanins present. Other anthocyanins identified are pelargonidin 3-O-β-D-glucoside, peonidin 3-O-β-D-glucoside, cyanidin 3-O-β-D-(6-malonyl-glucoside), pelargonidin 3-O-β-D-(6-malonyl-glucoside) and peonidin 3-O-β-D-(6-malonyl-glucoside). Similar results for anthocyanin content were found from a variety of purple corn grown in China.

Evaluating growing conditions for anthocyanin and total polyphenol content, one research group found that field location was an important determinant, whereas seedling density and soil potassium content were not.

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