Food Preservatives and Dyes
Carl Schroedl
Preservatives
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Preservation aims to prevent the development
of rancid, moldy or otherwise unconsumable
food.
Preservatives allow people to safely consume
food products that are not in season or locally
available.
Methods of food preservation are many and
varied.
Curing


Salt, spices, sugar, vinegar or sodium nitrite are
added, sometimes used in combination with
smoking
End products usually very salty
Drying
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Lack of water inhibits microbial activity
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Methods
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Sun drying
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Hot air drying
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Freeze drying
Canning

Used for a wide variety of foods.

Cans are vacuum-pumped, heated and cooled
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Affects color, texture, flavor and nutrient content
Refrigeration

Low-temperature storage slows many of the
enzymatic reactions and the growth of
microorganisms
Controlled Atmosphere Storage


Chemical composition of surrounding gasses is
changed.
Controls the process of ripening
Aseptic Packaging
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Package and food sterilized separately.

Hydrogen peroxide used instead of heat
Irradiation


Food is exposed to gamma or X rays
Only a limited amount of irradiated food has
been sold
Fermentation
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Microorganisms added to facilitate process
Pasteurization
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Invented by Louis Pasteur
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Involves the heating of foods to kill microbes
Additives


Chemicals are added during processing to
improve the looks, taste, nutritive content, and
apparent freshness.
Categories

Anti-caking agents
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Humectants
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Emulsifiers
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Stabilizers / Thickeners
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Dyes
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Preservatives
BHA/BHT
butylated hydroxyanisole


Used to preserve fatty foods, chewing gum,
baked goods, dry breakfast cereals and
cosmetic products. BHA content may not
exceed 0.02% of the total fat content of foods.
In clinical studies, BHA caused cancer in the
forestomach of certain animals.
BHA
butylated hydroxyanisole
Nitrates/Nitrite
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Some epidemiological studies have linked
nitrate-contaminated drinking water and
stomach cancer.
Nitrate or nitrite exposure during pregnancy
may adversely effect the unborn child.
Sodium nitrite may promote the growth of
nitrosamines
Types

Sodium nitrate
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Potassium nitrate
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Ammonium nitrate
Sulfites

Prevents discoloration

Destroys B vitamins

Allergenic substance
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Types

sodium sulfite

sodium and potassium bisulfite

sodium and potassium metabisulfite
Dyes

Chemicals that affect the color of foods with
negligible effects on taste, texture or other
aspects
Name
Common name
Color
FD&C Blue No. 1
Brilliant Blue FCF
bright blue
FD&C Blue No. 2
Indigotine
royal blue
FD&C Green No. 3 Fast Green FCF
sea green
FD&C Red No. 3
Erythrosine
cherry red
FD&C Red No. 40
Allura Red AC
orange-red
FD&C Yellow No. 5 Tartrazine
lemon yellow
FD&C Yellow No. 6 Sunset Yellow FCF orange
Reporting Adverse Reactions
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The FDA’s Adverse Reaction Monitoring System
collects and acts on complaints concerning all food
ingredients including preservatives. If you experience
an adverse reaction from eating a food that contains
sulfites, describe the circumstances and your reaction
to the FDA district office in your area (see local phone
directory) and send your report in writing to:
Adverse Reaction Monitoring System (HFS-636)
200 C St., S.W.
Washington, DC 20204