The USDA has an outstanding program you can use online or download at:
http://www.nal.usda.gov/fnic/foodcomp/The program will let you check the nutrient levels in most foods. Remember though that organic almost always has masses more nutrition in it (sadly you won't find a comparison of organic vs. conventional at this site).
Piers even did a comparison of raw vs. uncooked tomato using this program and found:
That while cooked tomatoes are higher in lycopene than raw (by around 18%) the same cooked tomato (by the same USDA figures) loses nearly half of it’s vitamin A, 65% of vitamin K, 35% of beta carotene and a whopping 100% of it’s alpha carotene . That’s just on the nutrients measured!
In health,
Sheryl