Ground Beef: Safe Handling and Cooking

Sandra McCurdy, Ph.D. — Mon, 31 Aug 2009 09:00:17 +0000

Ground Beef: the Most Popular Meat Ground beef patties are the most popular beef item for United States consumers; nearly 12 billion hamburgers were consumed by Americans in 2007 (3). Ground beef patties are the most frequently grilled meat (1). Ground beef is also popular in other forms such as meat loaf, meat balls, sloppy joes, and tacos. How To Handle and Cook Ground Beef As explained below (see Why is Raw Ground Beef Singled Out by Food Safety Experts?), the unique character of ground beef warrants careful handling. Avoid Contaminating Other Foods with Raw Meat or Raw Meat Juice

Thaw raw ground beef on a plate on the lowest shelf of the refrigerator, to avoid drip onto other foods.
Keep raw and ready-to-eat meats separate. Make it a household rule to use the refrigerator meat drawer for ready-to-eat foods, like cheese and deli meats, and do not store raw foods here. (Or, if you use the meat drawer for raw meats, store ready-to-eat foods in another location in the refrigerator.)
Wash hands thoroughly before and after handling raw ground beef. Wash cutting boards, bowls, and utensils used to prepare raw ground beef with hot soapy water and rinse well. As an extra precaution, a solution made from one teaspoon of unscented chlorine bleach in one quart of water can be used to sanitize the clean kitchen tools.
Use separate plates to carry raw ground beef patties to the cooking area and cooked patties to the serving area.

Use a Thermometer to Insure Ground Beef Reaches the Safely Cooked Internal Temperature of 160°F Destruction of the pathogens that may be present in raw ground beef, particularly E. coli, requires a cooking procedure that heats the beef to an internal temperature of 160°F (20). Use of a food thermometer is the only way to determine that the internal temperature of ground beef patties has reached 160°F (13, 19). (Unfortunately, only 13% of consumers always or often use a thermometer when cooking or grilling hamburgers (9).) Learn how to use a food thermometers when cooking ground beef: The University of Idaho Extension website, “All About Food Thermometers” provides information about cooking with food thermometers, including information about how to choose a food thermometer and how to use one. The USDA’s Food Safety and Inspection Service Thermometers and Food Safety page also provides information about thermometers and how to use them. Ground beef patties should be tested for the safely cooked temperature of 160°F in several locations because the entire patty does not reach one temperature at the same time. Additionally, the lowest temperature is not always in the center of the patty (16). Why is Raw Ground Beef Singled Out by Food Safety Experts? Although other meats have caused foodborne illness, there are several attributes of ground beef which suggest that more careful handling–particularly use of a thermometer to cook to 160°F– is required. Ground Beef May Contain Pathogens Throughout Retail ground beef may contain pathogens (disease-causing microorganisms), most notably Escherichia coli O157:H7 and Salmonella enterica. These pathogens are frequently associated with food animals, and E. coli O157:H7 is particularly associated with ruminant animals.

Ground beef is made from ‘beef trimmings’ (10) which often include trim from the exterior of carcasses and may more frequently carry pathogens.
Although the presence of E. coli O157:H7 in ground beef was declared an adulterant in 1994 (21), 0.46% of ground beef samples tested in 2008 by the Food Safety and Inspection Service were positive for this pathogen. In the same period, 2% of ground beef samples were positive for Salmonella (pdf).
The process of grinding distributes any pathogens present throughout the meat. In contrast, whole muscle cuts of meat that have not been tenderized or injected with an enhancement fluid, are considered ‘pathogen free’ in the interior portion of the meat.

Illnesses Have Been Associated with Ground Beef Consumers have developed E. coli O157:H7 infections from consumption of undercooked ground beef.

The most well known case is that in which over 500 consumers became ill and four died in 1993 as a result of consuming undercooked ground beef patties at a fast food chain (4). In another case in 2002, home preparation of E. coli O157:H7-contaminated ground beef sickened 28 consumers and caused a nationwide recall of 18.6 million lbs of fresh and frozen ground beef and beef trimmings (17).
In 2007, there were 19 recalls of ground beef totaling over 30 million pounds, of which less than 3 million pounds was recovered. Outbreaks from E. coli O157:H7 are most commonly linked to beef; during the period 1990 to 2005 56% of E. coli O157:H7 outbreaks were attributed to beef (5).
Cases of consumer illness from ground beef consumption continue to be reported. See the FSIS Recall Announcements Website.
E. coli O157:H7 causes about 62,000 human infections from food sources annually. Contracting an E. coli O157:H7 infection causes hospitalization in about 17% of cases, usually due to extreme diarrhea or kidney failure and results in death in an estimated 0.5% of cases (15). E. coli O157:H7 infections are the leading cause of hemolytic uremic syndrome in children (18).

Previous Advice to Consumers to Use Cooked Meat Color as an Indicator of Safe Ground Beef was Wrong Prior to 1997, consumers were encouraged to cook ground beef until “brown” in the middle to assure a safe temperature had been reached (11). However, research conducted in the 1990s determined that cooked ground beef color does not correlate to safe endpoint temperature (2, 6, 7, 11). Ground beef can turn brown before it reaches 160°F or it may retain a pink color at temperatures above 160°F–cooked color change in ground beef depends on a number of factors, including pH, meat source, packaging, freezing history and added ingredients (8).

These photos illustrate the color-temperature disconnect for ground beef patties:

The only way to determine that ground beef patties, or other products formed from ground beef, such as meat loaf or large meat balls, are safely cooked is to use a thermometer to determine the safe temperature of 160°F has been reached. (Normal cooking practice for small ground beef products such as crumbles means they are generally cooked to well above 160°F.)

Labels on Packages of Frozen Ground Beef Patties Do Not Always Provide Cooking Instructions That Result in Safely Cooked Patties

A recent survey of labels on packages of frozen ground beef patties (4 oz. size) revealed some packages suggest cooking times of 1.5 to 2 min/side. Research on consumer cooking procedures indicates that cooking times of less than 3 min/side could not produce a safely cooked product, thus some packages provided unsafe instructions. Frozen ground beef patties generally required 7 to 9 min total cooking time and starting with a room temperature pan (not preheated) extends the cooking time by about 4 min. Furthermore, cook times on a propane grill are more variable in than a fry pan on the electric stove. Bottom line: The variability of cooking times for patties makes it Packaging also gave conflicting information about the use of cooked color to predict doneness and about avoiding both overcooking and undercooking, provided an array of confusing instructions for consumers (12).

Since 1994, federal regulations require a Safe Handling Label, which includes information about storing, cooking, and avoiding cross contamination, on all consumer packages of ground beef (and other raw meat) (14).

Conclusion

Until ground beef is assured to be a pathogen-free product, consumers can best protect themselves and their loved ones by using a food thermometer to make sure cooked ground beef reaches a safe temperature of 160°F.

References

1. American Meat Institute. 2007. Grills to Sizzle Over Holiday Weekend, May 26. http://www.meatami.com/ht/d/ReleaseDetails/i/3023.

2. Berry, B. W. and M.E. Bigner-George. 2000. Factors affecting color properties of beef patties cooked on an outdoor gas grill. J. Muscle Foods 11:213-226.

3. Cattleman’s Beef Board. 2008. “I’ll take a burger with a side of burger,” CBB Checkoff News, http://www.beefboard.org. Accessed July 11, 2008.

4. Davis, M. plus 34 others. 1993. Update: Multistate outbreak of Escherichia coli O157:H7 infections from hamburgers — Western United States, 1992-1993, Morb. Mort. Weekly Rep. 42(14):258-263.

5. DeWaal, C. S. and F. Bhuiya. 2007. Outbreak Alert! Center for Science in the Public Interest, page 12, http://www.cspinet.org/foodsafety/outbreak_alert.pdf.

6. Hague, M.A.; K.E. Warren; M.C. Hunt; D.H. Kropf; C.L. Kastner; S.L. Stroda; and D.E. Johnson. 1994. Endpoint temperature, internal cooked color, and expressible juice color relationships in ground beef patties. J. Food Sci. 59(3): 465-470.

7. Killinger, K.M., M.C. Hunt, R.E. Campbell and D.H. Kropf. 2000. Factors affecting premature browning during cooking of store-purchased ground beef. J. Food Sci. 65(4):585-587.

8. King, N.J. and Whyte, R. 2006. “Does It Look Cooked? A Review of Factors that Influence Cooked Meat Color,” J. Food Sci. 71(4):R31-R40.

9. Lando, A. and L. Verrill. 2008. 2006 FDA/FSIS Food Safety Survey, http://www.fda.gov/Food/ScienceResearch/ResearchAreas/ConsumerResearch/ucm080374.htm.

10. Lange, L. 2008. Beef trim baseline results and how FSIS will use, Presentation at E. coli Public Meeting, April 9, Washington, D.C., http://www.fsis.usda.gov/PPT/Beef_Trim_Baseline_040908.ppt. Accessed October 8, 2008.

11. Lyon, B. G., B. W. Berry, D. Soderberg, and N. Clinch. 2000. Visual color and doneness indicators and the incidence of premature brown color in beef patties cooked to four end point temperatures. J. Food Prot. 63(10):1389-1398.

12. McCurdy, S.M., M.T. Takeuchi, Z. Edwards, M. Edlefsen, D-H. Kang, V.E. Mayes, and V. N. Hillers. 2006. Food safety education initiative to increase consumer use of food thermometers in the United States. Br. Food J. 108:775-794.

13. McCurdy, S.M., Finley, K., and Zemmer, T. 2009. Label instructions and cooking times for retail frozen ground beef patties. Food Prot. Trends 29(6):335-341.

14. Ralston, K. L. and Lin, C. T. J. 2001. U.S. Safe Handling Labels for Meat and Poultry: A Case Study in Information Policy. Consumer Interests Annual, Volume 47.

15. Rangel, J.M., P.H. Sparling, C. Crowe, P.M. Griffin, and D.L. Swerdlow. 2005. Epidemiology of Escherichia coli O157:H7 outbreaks, United States, 1982-2002. Emerging Infect. Dis. 11(4):603-609.

16. Rhee, M.S., S.Y. Lee, V.N. Hillers, S.M. McCurdy, and D-H. Kang. 2003. Evaluation of consumer -style cooking methods for reduction of Escherichia coli O157:H7 in ground beef. J Food Prot. 66:1030-1034.

17. Shillamplus, P. plus 12 others. 2002. Multistate outbreak of Escherichia coli O157:H7 infections associated with eating ground beef — United States, June–July 2002, Morb. Mortal. Weekly Rep. 51(29):637-639.

18. Slutsker, L., A.A. Ries, K. Maloney, J.G. Wells, K.D. Greene, and P.M. Griffin. 1998. A nationwide case-control study of Escherichia coli O157:H7 infection in the United States, J. Infect. Dis. 177:962-966.

19. U.S. Department of Agriculture, Food Safety and Inspection Service. 2008a. Food Safety Education: Thermy™, http://www.fsis.usda.gov/food_safety_education/thermy/index.asp, accessed June 30, 2008. http://www.fsis.usda.gov/News_&_Events/R01-2008_release/index.asp, accessed June 30, 2008.

20. U.S. Department of Agriculture, Food Safety and Inspection Service. 2003a. Color of cooked ground beef as it relates to doneness, http://www.fsis.usda.gov/FactSheets/Color_of_Cooked_Ground_Beef/index.asp.

21. U.S. Department of Agriculture, Food Safety and Inspection Service. 2002. Backgrounder: New measures to address E. coli O157:H7 contamination. http://www.fsis.usda.gov/OA/background/ec0902.pdf, accessed June 30, 2008.

Sandra McCurdy, Ph.D. | Food Safety News

Ground Beef: Safe Handling and Cooking