You Ask, I Answer: Frozen/Cooked Vegetables

If I microwave my vegetables instead of steaming/boiling them, will this prevent some of the vitamin loss (to water)?

Also, I know a lot of vitamins are heat-sensitive. To save time, I've started preparing a lot of foods beforehand, and then storing them in the refrigerator for a few days.

I'm wondering if, in doing so, I'm losing out on a lot of nutrients through heating, cooling, and reheating, as well as having them exposed to air (and, thus, oxidation) through my dicing/cutting.

Similarly, are frozen vegetables less nutritious than fresh ones?

-- Anonymous
Via the blog

Steaming and boiling provide very different nutritional profiles.

Since steaming does not place vegetables in direct contact with water, water-soluble nutrients (like vitamin C and the B vitamins) do not leech out.

Boil potatoes for 20 minutes, though, and you are kissing a lot of vitamin C goodbye (unless, of course, you end up using that water for soup, which not many people do.)

Microwaving is one great way to steam foods, but it ultimately comes down to how much water you are using.

Cooking broccoli in the microwave by dunking it in a big bowl of water is just as nutrient-leeching as boiling!

Although vegetables offer the most nutrition when they are cut and diced right before consumption (some nutrients are sensitive to air), keeping chopped pieces in an airtight container for a day or two in the refrigerator isn't anything worth worrying about (they key there being airtight.)

As far as frozen vegetables -- they can often be MORE nutritious than fresh vegetables.

The reason? They are, for the most part, flash frozen and packaged at their peak (when they contain the highest amount of nutrition), thereby retaining all these nutrients until you eat them at home.

Fresh vegetables -- particularly if they are not local -- can take a few days to be shipped long distances, and often sit for days at the supermarket, exposed to UV lights that can leach out certain light-sensitive nutrients (including B vitamins, vitamin C, as well as certain antioxidants).

As long as you are getting plain frozen vegetables (as opposed to the varieties that come drenched in sodium and saturated fat laden sauces), you are getting plenty of nutrition.