Cooked tomato has more lycopene than raw tomato ( Eat cooked tomato with digestive enzymes )
Dr Rui Hai Liu and colleagues heated tomato samples to 88 degrees Celsius for 2 minutes, 15 minutes and 30 minutes. Levels of healthy lycopenes, which give tomatoes their red colour, increased in each case as did antioxidant levels. Trans-lycopene rose by 54%, 171% and 164% during the three treatments. Cis-lycopene levels rose by 6%, 17% and 35% and antioxidants increased by 28%, 34% and 62%. ( The heat breaks down the plants' thick cell walls and aids the body's uptake of some nutrients that are bound to those cell walls.)
Thermal Processing Enhances the Nutritional Value of Tomatoes by Increasing Total Antioxidant Activity
Tomato puree protects skin against aging
Cooked carrots, spinach, mushrooms, asparagus, cabbage, peppers and many other vegetables also supply more antioxidants, such as carotenoids and ferulic acid, to the body than they do when raw, Liu says. At least, that is, if they're boiled or steamed. A January 2008 report in the Journal of Agriculture and Food Chemistry said that boiling and steaming better preserves antioxidants, particularly carotenoid, in carrots, zucchini and broccoli, than frying, though boiling was deemed the best.
