With a few exceptions — the tenderizing of
meat by its own internal enzymes, the firming
of some vegetables before further cooking,
and fermentations in general — the cook
wants to prevent enzymatic activity in food.
Storing foods at low temperatures delays
spoilage in part because it slows the growth of
spoilage microbes, but also because it slows
the activity of the food’s own enzymes.
Cooking Accelerates Enzyme Action Before
Stopping It Because the activity of an
enzyme depends on its structure, any change
in that structure will destroy its effectiveness.
So cooking foods sufficiently will denature
and inactivate any enzymes they may contain.
One vivid example of this principle is the
behavior of raw and cooked pineapple in
gelatin. Pineapples and certain other fruits
contain an enzyme that breaks proteins down
into small fragments. If raw pineapple is
combined with gelatin to make a jelly, the