Food historian Lois Ellen Frank calls potatoes, tomatoes, corn, beans, squash, chili, cacao, and vanilla the "magic eight" ingredients that were found and used only in the Americas before 1492 and were taken via the Columbian Exchange back to the Old World, dramatically transforming the cuisine there. According to Frank,
If we deconstruct that these foods were inherently native, then that means that the Italians didn't have the tomato, the Irish didn't have the potato, half the British National Dish—Fish and Chips—didn't exist. The Russians didn't have the potato, nor did they have vodka from the potato. There were no chiles in any Asian cuisine anywhere in the world, nor were there any chiles in any East Indian cuisine dishes, including curries. And the French had no confection using either vanilla or chocolate. So the Old World was a completely different place.
Given this paragraph, what key crops were not available in Europe before the colonization of the New World?
Potatoes, tomatoes, corn, beans, squash, chili, cacao, and vanilla were not available in the Old World prior to the European discovery of the Americas