Fresh Look at Food Preservatives

by Judith E. Foulke

Unless you grow all your food in your own garden and prepare
all your meals from scratch, it's almost impossible to eat food
without preservatives added by manufacturers during processing.
Without such preservatives, food safety problems would get out of
hand, to say nothing of the grocery bills. Bread would get moldy,
and salad oil would go rancid before it's used up.
Food law says preservatives must be listed by their common or
usual names on ingredient labels of all foods that contain them--
which is most processed food. You'll see calcium propionate on most
bread labels, disodium EDTA on canned kidney beans, and BHA on
shortening, just to name a few. Even snack foods--dried fruit,
potato chips, and trail mix--contain sulfur-based preservatives.
Manufacturers add preservatives mostly to prevent spoilage
during the time it takes to transport foods over long distances to
stores and then our kitchens. It's not unusual for sourdough bread
manufactured in California to be eaten in Maine, or for olive oil
manufactured in Spain to be used on a California salad. Rapid
transport systems and ideal storage conditions help keep foods
fresh and nutritionally stable. But breads, cooking oils, and other
foods, including the complex, high-quality convenience products
consumers and food services have come to expect, usually need more
Preservatives serve as either antimicrobials or antioxidants--
or both. As antimicrobials, they prevent the growth of molds,
yeasts and bacteria. As antioxidants, they keep foods from becoming
rancid, browning, or developing black spots. Rancid foods may not
make you sick, but they smell and taste bad. Antioxidants suppress
the reaction that occurs when foods combine with oxygen in the
presence of light, heat, and some metals. Antioxidants also
minimize the damage to some essential amino acids--the building
blocks of proteins--and the loss of some vitamins.

Safety Questions
Consumers often ask the Food and Drug Administration about the
safety of preservatives, and if there's a system in place to make
sure preservatives are safe.
Many preservatives are regulated under the food additives
amendment, added to the Federal Food, Drug, and Cosmetic Act in
1958. The amendment strengthened the law to ensure the safety of
all new ingredients that manufacturers add to foods. Under these
rules, a food manufacturer must get FDA approval before using a new
preservative, or before using a previously approved preservative in
a new way or in a different amount. In its petition for approval,
the manufacturer must demonstrate to FDA that the preservative is
safe for consumers, considering:

* the probable amount of the preservative that will be consumed with the
food product, or the amount of any substance formed in or on the food
resulting from use of the preservative
* the cumulative effect of the preservative in the diet
* the potential toxicity (including cancer-causing) of the preservative
when ingested by humans or animals.

Also, a preservative may not be used to deceive a consumer by
changing the food to make it appear other than it is. For example,
preservatives that contain sulfites are prohibited on meats because
they restore the red color, giving meat a false appearance of
freshness. (The U.S. Department of Agriculture regulates meats, but
depends on the FDA regulation to prohibit sulfites in meats.)
The food additive regulations require the preservative to be
of food grade and be prepared and handled as a food ingredient.
Also, the quantity added to food must not exceed the amount needed
to achieve the manufacturer's intended effect.
Regulations about the use of nitrites demonstrate the scrutiny
given to the use of additives. Nitrites, used in combination with
salt, serve as antimicrobials in meat to inhibit the growth of
bacterial spores that cause botulism, a deadly food-borne illness.
Nitrites are also used as preservatives and for flavoring and
fixing color in a number of red meat, poultry, and fish products.
Since the original approvals were granted for specific uses of
sodium nitrite, safety concerns have arisen. Nitrite salts can
react with certain amines (derivatives of ammonia) in food to
produce nitrosamines, many of which are known to cause cancer. A
food manufacturer wanting to use sodium nitrites must show that
nitrosamines will not form in hazardous amounts in the product
under the additive's intended conditions of use. For example,
regulations specify that sodium nitrite, used as an antimicrobial
against the formation of botulinum toxin in smoked fish, must be
present in 100 to 200 parts per million. In addition, other
antioxidants, such as sodium ascorbate or sodium erythorbate, may
be added to inhibit the formation of nitrosamines.
As scientists learn more about the action of certain chemicals
in our bodies, FDA uses the new data to reevaluate the permitted
uses of preservatives. Two examples are the commonly used
preservatives butylated hydroxyanisole (BHA) and sulfites.

BHA and the related compound butylated hydroxytoluene (BHT)
have been used for years, mostly in foods that are high in fats and
oils. They slow the development of off-flavors, odors, and color
changes caused by oxidation. When the food additives amendment was
enacted, BHA and BHT were listed as common preservatives considered
generally recognized as safe (GRAS). GRAS regulations limit BHA and
BHT to 0.02 percent or 200 parts per million (ppm) of the fat or
oil content of the food product.
Lawrence Lin, Ph.D., of FDA's Center for Food Safety and
Applied Nutrition, explains, "The 0.02 percent allowed relates only
to the product's fat content. For example, if a product weighs 100
grams and one of those grams is fat, the quantity of BHA in the
product cannot exceed 0.02 percent of that one gram of fat."
BHA is also used as a preservative for dry foods, such as
cereals. But because such foods contain so little fat, the amount
of BHA allowed cannot be measured against the percentage of fat,
explains Lin. Therefore, as manufacturers petitioned FDA for
approvals for this use, the agency set limits for each type of
food. On cereals, for example, FDA limited BHA to 50 ppm of the
total product.
In 1978, under contract with FDA, the Life Sciences Research
Office of the Federation of American Societies for Experimental
Biology (FASEB) examined the health aspects of BHA as part of FDA's
comprehensive review of GRAS safety assessments. FASEB concluded
that although BHA was safe at permitted levels, additional studies
were needed.
Since that evaluation, other studies suggested that at very
high levels in the diets of laboratory animals, BHA could cause
tumors in the forestomach of rats, mice and hamsters, and liver
tumors in fish. Many experts examined the data and concluded the
tests did not establish that such problems could exist in humans,
mostly because humans do not have forestomachs. Other studies
showed that BHA was protective, inhibiting the effect of some
chemical carcinogens, depending on the conditions of the tests.
Studies on BHA were reviewed by scientists from the United
Kingdom, Canada, Japan, and the United States. Their findings were
published in 1983 in the Report of the Working Group on the
Toxicology and Metabolism of Antioxidants and reviewed in the 1990
Annual Review of Pharmacology and Toxicology. The 1983 report
stated that data from a Japanese study showed a high incidence of
cancerous tumors and papillomas (benign tumors of the skin or
mucous membranes) of the forestomach of treated rats and that the
effect was dose-related. The report also mentioned the possible
existence of a no-effect level, based on dose response, and noted
that the level which produced cancer in this study was many
thousands of times higher than the level to which humans are
In November 1990, Glenn Scott, M.D., a physician then living
in New York who has since moved to Cincinnati, filed a petition
with FDA, asking the agency to prohibit the use of BHA in food.
Scott cited animal studies to support his request. Before acting on
Scott's petition, however, FDA asked FASEB to reexamine the
scientific data on BHA. By March 1994, FASEB is scheduled to
provide FDA with a report on the most current scientific
information bearing on the relationship of BHA ingestion to cancer
in animals.

Sulfites are used primarily as antioxidants to prevent or
reduce discoloration of light-colored fruits and vegetables, such
as dried apples and dehydrated potatoes. They are also used in
wine-making because they inhibit bacterial growth but do not
interfere with the desired development of yeast.
Sulfites are also used in other ways, such as for bleaching
food starches and as preventives against rust and scale in boiler
water used in making steam that will come in contact with food.
Some sulfites are used in the production of cellophane for food
FDA prohibits the use of sulfites in foods that are important
sources of thiamin (vitamin B1), such as enriched flour, because
sulfites destroy the nutrient.
Though most people don't have a problem with sulfites, some
do. FDA's sulfite specialist, consumer safety officer Joann Ziyad,
Ph.D., points to a bookcase full of binders and says, "Those are
the case histories of adverse reactions to sulfites that have been
reported to FDA. Since 1985, when the agency started reporting on
sulfites through the Adverse Reaction Monitoring System, over 1,000
adverse reactions have been recorded."
As reports of adverse reactions mounted, FDA asked FASEB to
reexamine the use of sulfites. FASEB's report, released in 1985,
concluded that sulfites posed no hazard to most Americans, but that
they were a hazard of unpredictable severity to people who were
sensitive to the substance. Based on the FASEB study, FDA estimated
that more than 1 million asthmatics are sensitive or allergic to
the substance.
In 1986, FDA ruled that sulfites used specifically as
preservatives must be listed on the label, regardless of the amount
in the finished product. Sulfites used in food processing but not
serving as preservatives in the final food must be listed on the
label if present at levels of 10 parts per million or higher.
Regulations issued in 1990 extended these required listings to
standardized foods.
Also in 1986, FDA banned the use of sulfites on fruits and
vegetables intended to be eaten raw, such as in salad bars and
grocery store produce sections. Grocers and restaurateurs were
using them to maintain the color and crispness of fresh produce.
(Even before the FDA ban, industry trade groups had persuaded many
of their members to stop using sulfites on fresh produce.)
FDA plans to repropose a ban for sulfites on fresh, peeled
potatoes served or sold unpackaged and unlabeled, such as for
french fries in restaurants. An earlier FDA rule dealing with
sulfites on potatoes was invalidated by the court in 1990 on
procedural grounds.
In addition, sulfite-sensitive consumers are learning how to
avoid sulfites. Consumer awareness combined with FDA actions have
slowed the number of adverse reaction reports. Ziyad says that from
1990 to 1992, fewer than 40 were reported, and at press time, there
had been only three reports in 1993.
Ziyad says the only way FDA can know about sulfite-sensitivity
problems is through consumer and physician reports. Adverse
reaction reporting is totally voluntary, and FDA encourages
physicians to report patients' reactions to sulfites. But there are
times when such reactions are not medically treated because the
individual doesn't go to the doctor with the condition or the
symptoms are not recognized. Such information would help FDA
evaluate the current status of problems with foods among sulfite-
sensitive individuals.
The agency'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

Puzzling It Out
Preservatives are a puzzle for many consumers that can
sometimes raise safety concerns. Even though these concerns are
usually unfounded, some industry publications are reporting
attempts to find naturally occurring substitutes for synthetic
antioxidants. In a 1990 article, one such publication, Inform, says
alternatives to synthetics are commercially available in the United
States, although most are generally more costly or have other
drawbacks. For example, tocopherol (vitamin E), generally is not as
effective in vegetable fats and oils as it is in animal fats. Also,
some herbs and herb extracts, such as rosemary and sage, can do the
work of antioxidants, but they impart strong color or flavors. And
just because these are plant-derived doesn't necessarily mean they
are always safe. Inform points to the FDA rule that newly
identified natural antioxidants, like other new food additives,
must undergo rigorous toxicological tests before they can be
As an additional alternative to synthetic antioxidants, the
edible oil industry is increasingly using ultraviolet-barrier
packaging and filling under nitrogen to protect the product's
FDA scientists will continue to carefully evaluate all
research presented to the agency on new preservatives to ensure
that substances added to food to preserve quality and safety are
themselves safe.

Judith E. Foulke is a staff writer for FDA Consumer.

A Sulfite by Any Other Name ...
People who are sulfite-sensitive should know which foods may
possibly contain sulfites. But it's not always obvious by the
chemical names on the label which ingredients are sulfites.
Currently, there are six sulfiting agents allowed in packaged
foods. The names by which they are listed on food labels are:

* sulfur dioxide
* sodium sulfite
* sodium and potassium bisulfite
* sodium and potassium metabisulfite

They are used in the following food categories at these typical maxium
residual sulfur dioxide equivalent levels:

baked goods 30 ppm
beer 25 ppm
wine 275ppm
tea 90 ppm
& relishes 30 ppm
vinegar 75 ppm
dairy producst 200 ppm
processed seafood
products, other than
dried or frozen 25 ppm
fresh & frozen 100 ppm
lobster, frozen 100 ppm
gelatin 40 ppm
grain products 200 ppm
gravies & sauces 75 ppm
jam & jellies 30 ppm
nut products 25 ppm
plant protein
isolates 110 ppm
dried fruit 2,000 ppm
fruit juices 1,000 ppm in concentrates
300 ppm in regular-strength juice
glace fruit 150 ppm
cherries 150 ppm
vegtables 200 ppm
potatoes 500 ppm
canned vegtables 30 ppm
frozen potatoes 50 ppm
vegatable juice 100 ppm
filled crackers 75 ppm
soup mixes 20 ppm in dry mix
sugar 20 ppm
sweet sauces
and syrups 60 ppm
molasses 300 ppm

The symptom most reported by sulfite-sensitive people is
difficulty breathing. Other problems range from stomachache and
hives to anaphylactic shock. In addition to knowing which food
preservatives are sulfites and which foods are likely to contain
them, sulfite-sensitive consumers can help themselves avoid health
problems by following these suggestions:

* Read food labels and choose foods that don't contain sulfites.
* Be aware that foods served in restaurants, especially potato products
and some canned foods, could contain sulfites. Ask the waiter if
sulfites are used in what you plan to order.

For example, lemon juice in your tea or splashed on your salad
could be a source of sulfites. Fresh-squeezed lemon is OK, but
bottled lemon juice often contains sodium bisulfite.


| Back to Entrance | Back to Previous Page | Building Directory | OPM Directory | Open Season Basics | Choosing the Best Plan for You | Staying Healthy | Hungry? | Doctor's Offices | Library | Receptionist |

Openseason is a service of New Connections, Inc. Comments.
Original file name:foodpres.txt

This file was converted with TextToHTML - (c) Logic n.v.