berries under cool running water, then drain them and pick them over
carefully to remove all stems and leaves.
Happens When You Cook Blackberries
destroys some of the vitamin C in fresh blackberries and lets
water-soluble B vitamins leach out. Cooked berries are likely to be
mushy because the heat and water dissolve their pectin and the skin of
the berry collapses. Cooking may also change the color of blackberries,
which contain soluble red anthocyanin pigments that stain cooking water
and turn blue in basic (alkaline) solutions. Adding lemon juice to a
blackberry pie stabilizes these pigments; it is a practical way to keep
the berries a deep, dark reddish blue.
Other Kinds of Processing Affect Blackberries
The intense heat used in canning fruits reduces the vitamin C content of
blackberries. Berries packed in juice have more nutrients, ounce for
ounce, than berries packed in either water or syrup.
Effects Associated with Blackberries
reactions. Hives and angioedema (swelling of the face, lips, and eyes)
are common allergic responses to berries, virtually all of which have
been known to trigger allergic reactions. According to the Merck Manual,
berries are one of the 12 foods most likely to trigger classic food
allergy symptoms. The others are chocolate, corn, eggs, fish, legumes
(peas, lima beans, peanuts, soybeans), milk, nuts, peaches, pork,
shellfish, and wheat.