Warning: mysql_result(): Unable to jump to row 0 on MySQL result index 6 in /www/ext/pubs/html/stdheader.php on line 53
Warning: mysql_result(): Unable to jump to row 0 on MySQL result index 6 in /www/ext/pubs/html/stdheader.php on line 54
Warning: mysql_result(): Unable to jump to row 0 on MySQL result index 6 in /www/ext/pubs/html/stdheader.php on line 55
Warning: mysql_result(): Unable to jump to row 0 on MySQL result index 6 in /www/ext/pubs/html/stdheader.php on line 56
Warning: mysql_result(): Unable to jump to row 0 on MySQL result index 6 in /www/ext/pubs/html/stdheader.php on line 57
Safety of Raw Alfalfa Sprouts
Judy Harrison, Ph.D.Associate Professor and Extension Food Safety Specialist judyh@uga.edu
In recent years, eating raw sprouts on salads and sandwiches has become more popular in the U.S. Sprouts are the germinating form of seeds or beans. Sprouting requires no soil. Seeds or beans are held in warm, moist conditions, and sprouts are produced within two to seven days, depending on the variety. These same conditions are also favorable for microbial growth. Sprouting seeds contain proteins, carbohydrates, minerals and vitamins, making them a good source of nutrients for humans and microbes. This combination (available nutrients and warm, moist conditions) makes bacterial growth a safety concern.
Although most studies examining sprouts have not found bacteria which cause illness to be present, conditions are favorable to support growth if the sprouts should become contaminated during the germination process. Historically, there have been several outbreaks of foodborne illness worldwide from sprouts. One of the earlier outbreaks was attributed to sprouts contaminated with Bacillus cereus. Investigations of several outbreaks since that time have implicated various species of Salmonella.
More recent outbreaks of Salmonella and E.coli O157:H7 from raw sprouts have prompted the Centers for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA) to issue health advisories about the safety of raw alfalfa sprouts. The advisories caution people at high risk for foodborne illness to avoid eating this product. High risk groups include children, older adults and people with compromised immune systems such as those with AIDS, people on chemotherapy for cancer, etc.
The federal government and sprout growers are working together to identify ways to ensure the safety of these products. Since even a few bacterial cells can multiply to high levels during the sprouting process, it is important for growers to find ways to eliminate the bacteria from the surfaces of the seeds. To date, various treatments with hypochlorite solutions, chlorine, hydrogen peroxide and ethanol have been examined. Although these treatments reduced the number of bacteria present, they did not completely eliminate bacteria. In addition, seeds treated with ethanol did not germinate or "sprout." One explanation that has been offered as to why these chemical treatments failed to eliminate the contamination completely is that perhaps bacterial cells become trapped in cracks and crevices on the seed making them inaccessible to the chemicals.
Another technique that is being investigated is the application of heat to destroy disease-causing organisms (pasteurization). Currently, no data are available on the effectiveness of pasteurization methods for sprouts. Even if seeds can be effectively pasteurized prior to germination, pasteurization will not control or eliminate bacteria introduced during the sprouting process. In addition, there is a fine line between the heat treatment required to eliminate disease-causing bacteria and temperatures that will prevent the seed from germinating. Irradiation is a technique that has shown promise in eliminating contaminating organisms on sprout seeds. Food and Drug Administration approval, however, would be required for irradiation to be used in the sprouting process. Irradiation of seeds, like pasteurization, would not control or eliminate bacteria introduced at later steps in the sprouting process or marketing stages. Until an effective treatment is found, consumers in at-risk groups (such as children, older adults and people whose immune systems are not functioning properly) are advised to avoid eating raw alfalfa sprouts or to cook sprouts before consumption. If you are a healthy adult and choose to eat raw sprouts, follow these tips to help minimize your risk:
- Purchase sprouts only if they are at refrigerator temperature.
- Choose only sprouts that look crisp or fresh; avoid those that have a musty odor or appear dark or slimy.
- Keep sprouts refrigerated at 40°F or below at home.
- Wash hands for at least 20 seconds with soap and water before and after handling raw foods.
- Rinse sprouts thoroughly under clean, running water before use to remove surface dirt. Do not use soaps or detergents.
- Feng, Peter. 1997. A Summary of Background Information and Foodborne Illness Associated With the Consumption of Sprouts. Center For Food Safety and Applied Nutrition - FDA.
- FDA. 1998. Sprout Safety - High Risk Groups Warned: Don't Eat Alfalfa Sprouts. FDA Consumer 32 (6): 2.
- FDA. 1999. Questions Keep Sprouting About Sprouts. FDA Consumer 33 (1): 18.
