in the united states, ketchup is regulated and standardized by the food and drug administration (fda). ketchup must be prepared from a tomato concentrate, juice from mature red lycopersicum esculentum tomatoes or liquid residue from preparing tomatoes for canning or partial juice extractions. the tomato skins, seeds and other hard substances must be strained. additionally, ketchup must contain any combination of vinegars, nutritive carbohydrate sweeteners, and/or spices, flavouring, onions or garlic.