New tests reveal “Taco Bell” taco shells on sale in your grocery store may contain corn that’s not approved for human consumption. The tests were performed by a Fairfield, Iowa-based company known as “Genetic I-D.” Jeffrey Smith of “Genetic I-D” says the genetically modified “Starlink” corn found in the taco shells is only approved by the government for animal feed. Smith says they ran the tests three times because of the controversial nature of the tests. .Critics say that particular variety of corn is hard to digest and could trigger allergies in humans. Kraft Foods distributes the “Taco Bell” taco shells and will perform its own tests. The tests in Fairfield were done for members of the “Genetically Engineered Food Alert” network.