Round, red fruit with a lot ofseeds, eaten cooked or uncooked as avegetable, for example in salads orsauces. Tomatoes are the major dietary source of the antioxidant lycopene, which has been linked to many health benefits, including reduced risk of heart disease and cancer. They are also a great source of vitamin C, potassium, folate and vitamin K.They are usually red when mature, but can come in a variety of colors, including yellow, orange, green and purple.