Colorado State University Extension
SafeFood Rapid Response Network
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SUSHI: MINIMIZING THE FOOD SAFETY RISK
Edited by: Stephanie Wallner, M.S., Mary Schroeder, M.S., R.D, Pat Kendall, Ph.D., R.D., Colorado State - Fall 2006
Sushi has long been known as a traditional Japanese food, mainly available in specialty markets and not widely consumed in the United States. However, in recent years sushi has become more popular among Americans, with sushi restaurants becoming common and more and more people trying this trendy food for its taste, novelty, and healthfulness.
Sushi is made with vinegared rice, seaweed, vegetables, and often raw fish. Some types of sushi are prepared with cooked seafood, although many popular menu items are served raw. Sashimi is a type of sushi defined as raw fish served alone, without vinegared rice or other ingredients. With raw seafood prepared in any way, however, there are risks of foodborne illness.
Outbreaks of foodborne illness linked to sushi have most often been caused by Vibrio parahaemolyticus, Staphylococcus aureus, Salmonella species and Listeria monocytogenes (1). For example, in February 2006, an outbreak of salmonellosis was linked to a sushi restaurant, Sushi King, in Bentonville, Arkansas (2). The Arkansas Department of Health and Human Services reported that 123 individuals became ill after eating at the restaurant; 30 cases of salmonellosis were confirmed. Following the outbreak, Sushi King was voluntarily closed to sanitize the restaurant and implement employee classes on safe food handling. As sushi has become more popular, outbreaks such as this serve as a reminder of the food safety risks of consuming raw seafood - especially for those with compromised immunity.
The Boulder County (Colorado) Public Health Department website provides guidelines for consumers who eat sushi at restaurants or prepare it at home (3). According to Section 3-102B of the Colorado Retail Food Establishment Rules and Regulations (4), "raw, raw-marinated, lightly cooked-marinated, marinated, or partially cooked fish other than molluscan shellfish shall be frozen throughout to a temperature of -4ºF (-20ºC) or below for 168 hours (7 days) in a freezer, or to a temperature of -31ºF (-35ºC) or below for 15 hours in a blast freezer" prior to preparation for use. The only exceptions are certain species of tuna: Thunnus alalunga, Thunnus albacares (Yellowfin), Thunnus atlanticus, Thunnus maccoyii (Southern Bluefin), Thunnus obesus, and Thunnus thynnus (Northern Bluefin) (3, 4). These may be served or sold in a raw, raw-marinated or partially cooked ready-to-eat form without prior freezing.
When purchasing raw seafood in grocery stores or ordering from a restaurant menu, the Boulder County Health Department recommends looking for the words "sushi-grade" or "sashimi-grade," indicating that the seafood has been commercially frozen according to state the regulations. In addition, proper handling and preparation habits are crucial to ensure the safety of sushi made with raw fish. After purchase, raw seafood and fish and sushi rice should be refrigerated below 41ºF until served. Preparing rice with vinegar, as is often done for sushi, lowers the pH of the product, which help slow the rate of bacterial growth (3).
Once sushi rolls and sashimi are prepared, they should be immediately refrigerated until serving. Cross-contamination is also a concern since sushi can be made with both raw and cooked fish. To prevent cross-contamination, raw and cooked fish must be physically separated during preparation, and different utensils, cutting boards, and surfaces should ideally be used.
Finally, individuals with compromised immunity (young children, the elderly, pregnant women, and persons with disease or chronic illness) should entirely avoid consuming sushi made with raw fish or seafood.
By paying attention to these guidelines, sushi lovers can enjoy the new trend as more specialty sushi restaurants pop up around the country. More information on sushi safety is available at the following websites:
- http://www.cfsan.fda.gov/~comm/ift4-4.html
- http://www.co.boulder.co.us/health/environ/foodsafety/factsheets/safeSushi.htm
- http://hgic.clemson.edu/factsheets/HGIC3482.htm
- http://hgic.clemson.edu/factsheets/HGIC3660.htm
Sources:
- Government of the Hong Kong Special Administrative Region Food and Environmental Hygiene Department (FEHD). Safe Food and Public Health: An Evaluation of Sushi and Sashimi 1997-1999. Available at: http://www.fehd.gov.hk/safefood/report/sashimi/ss_ras2.html. Accessed March 29, 2006.
- Number of People Sickened in Sushi Food Poisoning Case Rises. Available at: http://fsrio.nal.usda.gov/news_article.php?article_id=3166. Accessed March 29, 2006.
- Boulder County Public Health Department. Food Safety Fact Sheets: Sushi Safety. Available at: http://www.co.boulder.co.us/health/environ/foodsafety/factsheets/safeSushi.htm. Accessed March 29, 2006.
- Colorado Retail Food Establishment Rules and Regulations. Section 3-102B. Available at: http://www.cdphe.state.co.us/op/regs/consumer/101019retailfood.pdf. Accessed March 29, 2006.
