Cooperative Extension Service
College of Agriculture
Department 3354
1000 E. University Avenue
Laramie, Wyoming 82071
(307) 766-5124 • fax (307) 766-3998 • ces.uwyo.edu
July 1, 2010
Contact: Name, Title, Contact
Safety with Sprouts
Enjoying fresh, raw sprouts on sandwiches and salads throughout the year, especially
during the summer month, can be enticing. However, there can be serious risks involved in
enjoying these seemingly harmless, healthy additions. Within the past fifteen years, the
consumption of raw sprouts has been linked to a number of cases of foodborne illness and
infection. The majority of these cases have been caused by the bacteria Salmonella and
Escherichia coli (E. coli) 0157:H7.
When most of us think of foodborne illness we immediately think of raw chicken,
undercooked ground beef and unpasteurized milk products. So why would sprouts be in the
foreground of food safety? The source of the contamination often comes from the seeds
themselves. Depending on the sanitization of the seed source, bacteria can reside on the outside
of dry seeds. The conditions that bacteria thrive in are warm, moist environments with a food or
protein source. As seeds are sprouted these exact conditions are created. Over time, the
presence of only a few bacteria increases rapidly in this ideal environment and by the time the
seeds have sprouted and are ready for consumption (a few days later), the sprouts may be
contaminated with a harmful quantity of bacteria. Most sprouts are consumed raw, and this
presents the problem. Sprouts most often associated with foodborne illness include alfalfa,
clover, radish and mung bean.
Those who are most at risk for consuming raw sprouts are young
children, elderly persons and those with weakened or compromised
immune systems. Symptoms of infection with E. coli 0157:H7 may
include stomach cramping, vomiting, fever and bloody diarrhea and can
be present within two to 10 days of eating the contaminated food.
The University of Wyoming and the United States Department of Agriculture cooperate.
The University is an equal opportunity/affirmative action institution.
Symptoms of infection with Salmonella may include fever, headache, stomach cramps,
diarrhea, nausea and vomiting and can be present within 12 to 36 hours after eating contaminated
food. In either illness, cases of severe infection can lead to death. If any of these symptoms
occur it is recommended to contact a doctor immediately.
So why is there not more incidence of foodborne illness with commercially produced
sprouts? Commercial sprout producers have implemented many safety measures to help
decrease the incidence of foodborne illness in raw sprouts. Seeds are used from sources that use
testing methods and certification programs to decrease contamination probability. Sprouting is
done in sanitary conditions and seeds are treated prior to sprouting with high concentrations of
calcium hypochlorite or other disinfectants. Testing of irrigation water is also used to test for
Salmonella and E. coli 0157:H7. Though these methods help decrease the probability of
foodborne illness in connection with raw sprouts, people who fall in the high risk category are
still advised not to consume them.
To minimize your risk of infection, purchase sprouts that have been refrigerated and
appear fresh and crisp. Avoid sprouts that look dark or slimy, or smell musty. Always keep
purchased sprouts in a refrigerator below 40®F. It is also advisable to cook sprouts such as
mung bean or bean sprout to sufficient temperatures before consumption (165®F).
Though not commonly thought of as a high risk food in regards to foodborne illness, sprouts
should be on your radar, especially when eaten by people in high risk populations.
The Wyoming Food Safety Coalition (WFSC) is dedicated to preventing food borne illness.
This collaborative program is sponsored by the University of Wyoming Cooperative Extension
Service, Wyoming Beef Council, Department of Agriculture (WDA), Department of Health,
Environmental Health Association, and Lodging and Restaurant Association. For information
about food safety or the WFSC, please contact your local county Extension office; WDA
Consumer Health Specialist; or City-County Health Department.
Sources:
- Jennifer Jacobsen, University of Wyoming Extension Educator, Nutrition and Food
Safety, Western Area
- University of California Division of Agriculture and Natural Resources Publication
8151, 2004
- Health Canada- It’s Your Health ‘Risks Associated with Sprouts, January 2007
- FoodSafety.gov- US Department of Health & Human Services ‘Sprouts: What You
Should Know’, 2009
Safety with Sprouts Extension Column - Page 2 of 2