According to ScienceDaily, researchers in Illinois have devised a method for detecting adulterated coffee supplies: ScienceDaily: Fingerprinting Fake Coffee. Along the coffee supply chain, unscrupulous profiteers regularly short-change customers by cutting the coffee with cereal grains (particularly corn), coffee twigs, and even brown sugar.

Roasted corn has particularly high concentrations of vitamin E, and the researchers have made this the basis for their fingerprinting technique. Brazilian coffee supplies have been particularly targeted by this form of fraud, and in lab tests they found one brand of Brazilian coffee contained almost 9 percent corn.