Antimicrobials
Antimicrobial preservatives are added to food to
destroy bacteria or to inhibit the growth of mold on
foods.
BENZOATES.Benzoates are salts of benzoic acid, a
weak acid that was at one time derived from benzoin
resin, a gum obtained from the bark of trees native to
Thailand and Indonesia. The benzoates used as food
preservatives are potassium benzoate andsodiumben-
zoate. Potassium benzoate works best in products with
a low pH (below 4.5); it is used to inhibit the growth ofmolds, yeasts, and bacteria in acidic drinks and
liquids, including fruit juice, vinegar, sparkling drinks,
and soft drinks.
Sodium benzoate can be produced commercially
by reacting sodium hydroxide with benzoic acid. It is
used as an antimicrobial agent in foods with a pH
below 3.6, including salad dressings, carbonated
drinks, fruit juices, and such Oriental food sauces as
soysauce and duck sauce. It is also used as a preser-
vative in some mouthwashes. Sodium benzoate occurs
naturally in cranberries, prunes, greengage plums,KEY TERMS
Anaphylaxis—A severe and potentially fatal sys-
temic allergic reaction characterized by itching,
hives, fainting, and respiratory symptoms. Sulfites
may trigger anaphylaxis in a small number of people
who are unusually sensitive to them.
Antimicrobial—A type of food preservative that
works by preventing the growth of bacteria, fungi,
molds, or yeast in foods.
Antioxidant—A type of food preservative that pre-
vents rancidity in oils and fatty foods.
Botulism—A potentially deadly disease character-
ized by respiratory and musculoskeletal paralysis
caused by a bacterium calledClostridium botuli-
num. Botulism is a medical emergency. Nitrites are
sometimes used to prevent the growth ofC. botuli-
numspores in meat and smoked fish.
Carcinogen—A substance or other agent that causes
cancer. Some artificial preservatives have been
banned in the United States on the grounds that
they may be carcinogens or produce carcinogenic
substances when added to food.
Chelating agent—A type of food preservative that
works by binding (or sequestering) metal ions (usu-
ally iron or copper) in certain foods in order to pre-
vent the metals from oxidizing and speeding up
spoilage. The name comes from the Greek word for
a crab’s claw, because chelating agents have two
groups of atoms that encircle the metal ion like the
claws of a crab. Chelating agents are also known as
sequestrants.
Desiccation—Drying or dehydrating food as a
method of preservation,
Food additive—Defined by the Federal Food, Drug,
and Cosmetic Act (FD&C) of 1938 as ‘‘any sub-
stance, the intended use of which results directly orindirectly, in its becoming a component or otherwise
affecting the characteristics of food.’’ Food additives
include flavoring and coloring agents as well as arti-
ficial preservatives.
Generally recognized as safe (GRAS)—A phrase
used by the federal government to refer to exceptions
to the FD&C Act of 1938 as modified by the Food
Additives Amendment of 1958. Artificial food pres-
ervatives that have a scientific consensus on their
safety based on either their use prior to 1958 or to
well-known scientific information may be given
GRAS status.
Nitrosamine—Any of various organic compounds
produced by the interaction of nitrites in food with
the breakdown products of amino acids. Nitros-
amines are also found in tobacco smoke. Some nitros-
amines are powerful carcinogens.
Oxidation—In food chemistry, the process that takes
place in some foods when they combine with the
oxygen in the atmosphere in the presence of heat,
light, or such metals as iron or copper.
pH—A measure of the acidity or alkalinity of a sol-
ution. Solutions with a pH below 7 are considered
acidic while those above 7 are alkaline. A pH of
exactly 7 (pure water) is neutral.
Rancid—Having a bad or ‘‘off’’ smell or taste as a
result of oxidation.
Salt—In chemistry, an ionic crystalline compound of
positively charged ions and negatively charged ions
such that the product is neutral (without a net
charge).
Topical—Referring to a type of medication that is
applied to the surface of the body or instilled into
the eye or ear. Some topical medications contain
artificial preservatives.Artificial preservatives