Buying This Food
Look for: Broccoli with tightly closed buds. The stalk, leaves, and florets should be fresh,
firm, and brightly colored. Broccoli is usually green; some varieties are tinged with purple.
Avoid: Broccoli with woody stalk or florets that are open or turning yellow. When the green
chlorophyll pigments fade enough to let the yellow carotenoids underneath show through,
the buds are about to bloom and the broccoli is past its prime.
Storing This Food
Pack broccoli in a plastic bag and store it in the refrigerator or in the vegetable crisper to
protect its vitamin C. At 32°F, fresh broccoli can hold onto its vitamin C for as long as two
weeks.
Keep broccoli out of the light; like heat, light destroys vitamin C.
Preparing This Food
First, rinse the broccoli under cool running water to wash off any dirt and debris clinging to
the florets. Then put the broccoli, florets down, into a pan of salt water (1 tsp. salt to 1 qt.
water) and soak for 15 to 30 minutes to drive out insects hiding in the florets. Then cut off
the leaves and trim away woody section of stalks. For fast cooking, divide the broccoli up
into small florets and cut the stalk into thin slices.
What Happens When You Cook This Food
The broccoli stem contains a lot of cellulose and will stay firm for a long time even through
the most vigorous cooking, but the cell walls of the florets are not so strongly fortified and
will soften, eventually turning to mush if you cook the broccoli long enough.
Like other cruciferous vegetables, broccoli contains mustard oils (isothiocyanates),
natural chemicals that break down into a variety of smelly sulfur compounds (including
hydrogen sulfide and ammonia) when the broccoli is heated. The reaction is more intense
in aluminum pots. The longer you cook broccoli, the more smelly compounds there will be,
although broccoli will never be as odorous as cabbage or cauliflower.
Keeping a lid on the pot will stop the smelly molecules from floating off into the air but
will also accelerate the chemical reaction that turns green broccoli olive-drab.
Chlorophyll, the pigment that makes green vegetables green, is sensitive to acids.
When you heat broccoli, the chlorophyll in its florets and stalk reacts chemically with acids
in the broccoli or in the cooking water to form pheophytin, which is brown. The pheophytin
turns cooked broccoli olive-drab or (since broccoli contains some yellow carotenes) bronze.
Broccoli