Tomatoes are often considered a vegetable, though in actuality they are a citrus fruit. Tomatoes are an incredibly versatile food. They are delicious eaten raw, in salads or on sandwiches, and take on a wonderful sweetness when cooked. Their high acid content makes them a perfect food for canning. Tomatoes are such an important part of the American diet that it’s hard to believe that they were once considered toxic. It wasn’t until the mid 1800’s that they became a staple food in the U.S.