We need a Talmudic scholar here...
"Corn" is a generic English term for grain, but in North America the term is reserved for maize, which is native to the New World. I've never heard of there being a rabbinical proscription on corn, but if there is, how could it refer to the grain that ethanol is derived from here in the Americas. The Old Testament God was an Old World God, he would not have included in the dietary laws a grain that did not even exist in the middle east until relatively recent times.