Steaming.
Plastic wrap is good to use to retain steam and nutrients in microwave cooking. There are also lids specially made for this purpose.
Steaming
This will vary based upon the vegetable and cooking method. Generally, steaming vegetables is thought to retain the most nutrients. ----
so that it stops them from going mushy, to retain nutrients and to retain colour
Steaming food is a method of cooking. You can use a food steamer or a pan of boiling water with a rack of some kind over the pan. You place the food directly over the steam and allow it to cook. Steamed foods retain their flavor and nutrients and are usually cooked until it is just done; not until it's so done it's soft or mushy.
Steaming as a method of cooking is one of the most healthiest ways to serve food. There is very little effect on the nutritional value of steamed foods. Steaming helps food retain their natural goodness.
Cooking vegetables makes nutrients more available for the body to absorb, but overcooking can mean losing nutrients. Plant cell walls are broken down in cooking, which means the food can be more completely digested and used by the body. While potato should be well cooked, overcooking less starchy vegetables will result in loss of nutrients, so steaming or microwaving vegetables (so they are still crunchy) helps retain most nutrition. Meat should always be well cooked to destroy bacteria and make nutrients available for the body to absorb
Adding other preservation agents for foods.
As the corn grows older, it loses nutrients and goes through flavor changes. It will retain them longer if it is refrigerated.
Fruits do not retain their shape when stewed, because the cooking process breaks down the cellular structure. Lemon juice is often added to stewed fruit to retain their color, but that does not effect their shape. ... starrskitchen.com
No, if you did, then your body wouldn't retain any nutrients from the food you eat and you would die.
filtration, reabsorbtion, and secretion