This product is known by a few different names within the beef industry including partially defatted beef fatty tissue and lean finely textured beef (LFTB). The product is a high-protein, low-fat beef made from trim (the meat and fat leftover from trimming other beef cuts - steak, roasts, etc). The trim, which might also contain some connective tissue, is spun in a centrifuge and protein is separated out. The product has been approved for use in ground beef products since the early 1990s. Beef containing LFTB must meet federal food safety requirements and undergo food safety inspections. LFTB was developed as a way to reduce waste within the beef industry (and its production/sale subsidizes the cost of ground beef products).
According to the School Nutrition Association (a national, nonprofit professional organization representing more than 55,000 members who provide high-quality, low-cost meals to students across the country). This product has also been used in the National School Lunch Program (NSLP) since the 1990s as well (The maximum allowable percentage of LFTB that may be formulated into single servings of the ground beef purchased for the NSLP is 15 percent, which is similar to the composition found in many commercially available ground beef products). Of the ground beef purchased by USDA in 2011 for the NSLP, LFTB comprised approximately 6.5 percent of the total volume.
Pink slime/LFTB precursor, beef trim, is edible on its own, and has been linked to higher concentrations of E. coli O157 than primal cuts/ground beef. Because of this, the beef industry treats it with compounds to change the pH of the spun down beef to reduce pathogen levels . Two processes are common - organic acids (lactic, citric, acetic) or the more controversial ammonium hydroxide. The U.S. Food and Drug Administration as well as the Food Safety and Inspection Service (FSIS) considers ammonium hydroxide as “generally recognized as safe”(see http://www.fda.gov/Food/FoodIngredientsPackaging/GenerallyRecognizedasSafeGRAS/default.htm). In 2005, the USDA limited the amount of ammonia-treated Lean Beef Trimmings in a serving of ground beef to 15 percent. The prime control measures for pathogens in ground beef don't change with the addition of LFTB - temperature control (cooking especially, and refrigeration of raw product) as well as reducing cross-contamination risks. The safe end-point temperature for beef products containing LFTB is no different than those without it (160F for instant kill, or 155F for 15 seconds).
Manufacturers are not required to list LFTB as an ingredient currently - it is estimated that about 70% of commercially available ground beef contains some LFTB. In response to recent requests, USDA announced last week that they will create a system that will allow for schools/districts to choose beef with or without LFTB. Some fast food outlets, like McDonalds, have recently announced that they do not use ammonium hydroxide treated LFTB.
Links of interest:Recent coverage that has raised this issue:
Story with McDonald's statement:
USDA's choice statement:
2009 NY Times article on this issue:
Iowa State paper describing protein content of LFTB:
Benjamin Chapman, Ph.D.Assistant Professor,
Food Safety Specialist Department of 4-H Youth Development and Family & Consumer Sciences
North Carolina State University, NC Cooperative Extension