Tomatoes are actually berries, and thus belong to the category of fruit. In tomatoes, the size is as important as the color. Small, dark red tomatoes contain the most lycopene and vitamin C and are sweeter and tastier. Tomatoes are best not stored in the refrigerator. When the tomato is colder than 10 °C, the production of flavor stops. The peel and seeds deliver about half of the vitamin C, the lycopene and the other anti-oxidizing effects of the tomato. Like some other fruits cooked tomatoes are more healthier than raw ones. In fact, the longer you heat them, the healthier they become. The heat increases the nutritional value in two ways. In the first place, the cell walls will be broken down so that more nutrients can be released. In the second place the lycopene molecule transform from translycopene into the more easily recordable cislycopene. When cooking with tomatoes, choose steaming or cooking in the oven so the vitamin C content remains as high as possible.