0The New Complete Book of Food
they also have a shorter shelf life. And they also have less sugar than truly fresh mushrooms.
By the fourth day after mushrooms are picked, about half their sugar and starch will have
turned to chitin, a polymer (a compound with many molecules) similar to cellulose. That is
why older mushrooms are “crisper” than fresh ones.
Look for dried mushrooms in tightly sealed packages.Avoid: Any wild mushrooms. Stick to commercially grown mushrooms from reputable
growers.Storing This Food
Refrigerate fresh mushrooms in containers that allow air to circulate among the mushrooms.
The aim is to prevent moisture from collecting on the mushrooms; damp mushrooms dete-
riorate quickly. Mushrooms should never be stored in plastic bags.Preparing This Food
Rinse the mushrooms under cold running water and rub them dry with a soft paper towel
or scrub them with a soft mushroom brush to remove dirt on the cap.
You can clean mushrooms quickly simply by peeling the cap, but that will make them
less tasty. The mushroom’s flavor comes from an unusually large amount of glutamic acid
in the skin. Glutamic acid is the natural version of the flavor enhancer we know as MSG
(monosodium glutamate).
Slicing mushrooms hastens the loss of riboflavin. According to the United Fresh Fruit
and Vegetable Association, boiled whole mushrooms may retain as much as 82 percent of
their riboflavin, sliced mushrooms only 66 percent. Slicing also changes the color of mush-
rooms. When you cut the mushroom, you tear its cells, releasing polyphenoloxidase, an
enzyme that hastens the oxidation of phenols in the mushroom, producing brownish par-
ticles that make the white mushroom dark. You can slow this natural reaction (but not stop
it entirely) by coating the mushrooms with an acid—lemon juice, vinegar, or a salad dressing
that contains one or the other.
Button mushrooms lose moisture and shrink when you cook them. If you choose to cut
off their stems before you cook them, leave a small stub to help the mushroom hold its shape.
Dried mushrooms must be soaked and rinsed as directed on the package.What Happens When You Cook This Food
The B vitamins in mushrooms are all water-soluble. They will leach out into the cooking
water, which should be added to your recipe along with the mushrooms.
Cooking toughens the stem of button mushrooms but does not affect their nutritional
value since riboflavin is not destroyed by heat and remains stable in a neutral solution or an
acid one such as a tomato sauce or a stew with tomatoes and bell peppers.