I’ve heard that some fruits and vegetables are actually healthier for you when you cook them, (for instance the Lycopene in tomatoes becomes more accessible). What things may be better for a person when they are cooked? Also how much degradation does the nutrients of fruits and vegetables experience through cooking or other processes like pureeing?
Lycopene does become more accessible when cooked, and there is some evidence that other phytochemicals, including beta carotene and anthocyanins are also better absorbed when cooked. Cooking and pureeing break down the cellulose, or fiber, (which we don’t digest), and may “free” the nutrients within the fruit or vegetable, making them more accessible. Cooking destroys some vitamins, especially vitamin C and some of the B vitamins, but how much is destroyed depends on several factors. Generally speaking, long cooking times, higher temperatures, cutting food into smaller pieces and discarding the cooking water all increase nutrient loss. Cooking vegetables only until wilted, tender crisp (as in a stir fry) or quickly steamed all help nutrient retention.