Fresh tomatoes are low in carbs (4%). The carb content consists mainly of simple sugars and insoluble fibers. Tomatoes are a good source of several vitamins and minerals, such as vitamin C, potassium, vitamin K and folate. The main plant compound in tomatoes is lycopene. They also contain beta-carotene, naringenin and chlorogenic acid. Lycopene is the most abundant plant compound in tomatoes. It is found in the highest amounts in tomato products, such as ketchup, tomato juice, and tomato-based sauces.