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Monthly
Feature:
The
tumble of fresh green peas looks so tempting. They're fat,
crisp, and break with a snap. Sure signs of freshness. As
you search for the youngest and most tender, gently wiggle
your hand inside the pile. You'll likely be surprised at the
amount of warmth near its center as even after harvesting,
cell activities continue and energy is released in the form
of heat.
That
heat is a reminder that even after picking, vegetables are
still living things. But once harvested, they can no longer
renew their food and energy supplies, thus most fresh produce
moves quickly past prime condition.
Sweet
fresh flavors are fleeting, especially in corn, peas and beans.
Corn
stored for just one day at room temperature can lose over
25 per cent of its total sugars. Peas and beans lose even
more. As sugar provides the energy for the continuing life
processes in all vegetables, it's quickly depleted once vegetables
are picked. When vegetables are left on the vine to mature,
sugar gradually changes to starch - a form of carbohydrate,
which vegetables can store.
 Thus,
tiny peas are tender and sweet, while mature ones are starchy
- perfect for drying, to use later in the year in thick nutritious
winter soups.
As soon as vegetables are harvested, they also begin to lose
moisture. Celery shrivels. Beans flop. Even tiny carrots soon
sag.
Their
cut stems also provide a perfect escape route for moisture,
so vegetables wilt even faster once sliced. When plant tissues
lose water, their nutrients, sugars, and plant acids become
more concentrated in the remaining cell sap. Consider the
garden-ripe tomato and how quickly it deteriorates. Produce
high in plant acids spoil more quickly, because their own
acids sabotage cell membranes already weakened by the processes
of picking and standing.
In
addition, bruised or damaged tissues offer an ideal refuge
for bacteria to initiate spoiling. So there's good reason
to buy vegetables in the best condition possible, particularly
when you don't intend to use them immediately.
.
Keeping 'em crisp.
Refrigerator "crispers"
reduce moisture loss by keeping the immediate surroundings
more humid, reducing moisture loss. Lightly sealed storage
bags serve the same purpose. Unless bags are permeable to
air, however, vegetables can't breathe properly and water
released by the tissues accumulates. And while too little
moisture encourages shriveling, too much moisture encourages
spoiling. To remedy storing difficulties, perforated produce
packages allow the air to circulate freely and excess moisture
to escape.
Temperature also affects keeping qualities.
In
most vegetables, refrigerator temperatures just above freezing
(34-40° F) retard enzyme action and delay the loss in
quality. While deterioration slows, it doesn't stop. Very
low temperatures and freezing places vegetables in a state
of suspended animation. As most of their water turns to crystals,
and the respiratory process halts, chemical activities also
slow greatly. Thus, freezing dramatically retards (but does
not completely stop) their decline.
In
contrast, vegetables of tropical or subtropical origin don't
breathe properly when they're stored below 50°F. Thus
peppers, eggplant, snap beans, potatoes and sweet potatoes,
tomatoes, cucumbers, and squash prefer being stored in a cool,
rather than a cold, place.
While
new varieties of vegetables suffer less from the rigors of
commercial transport and handling than many traditional varieties,
there's still validity to the old instruction - "Set
the cooking pot to boil, and then run to the garden to pick
fresh corn." Most summer vegetables don't take kindly
to waiting!
Pick
and choose.
So go ahead and be a fussy shopper! Select the
freshest produce you can find. Store it with care. And enjoy
it as soon as you can.
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