On Food and Cooking

reduce enzymatic and other chemical activity,
some reactions are actually enhanced by the
concentrating effects of ice formation,
including enzymatic breakdown of vitamins
and pigments. The solution to this problem is
blanching. In this process the food is
immersed in rapidly boiling water for a
minute or two, just enough time to inactivate
the enzymes, and then just as rapidly
immersed in cold water to stop further
cooking and softening of the cell walls. If
vegetables are to be frozen for more than a
few days, they should be blanched first. Fruits
are less commonly blanched because their
cooked flavor and texture are less appealing.
Enzymatic browning in frozen fruit can be
prevented by packing it in a sugar syrup
supplemented with ascorbic acid (between ¼
and ¾ teaspoon per quart, 750–2,250 mg per
liter, depending on the fruit’s susceptibility to
browning). Sugar syrup (usually around 40%,
or 1.5 lb sugar per quart water, 680 gm per