'Meat Glue' Is No 'Pink Slime'

After the ‘pink slime’ media hype, food safety risks of meat binding agents are overblown.

Published on: May 31, 2012

Since “pink slime” has chilled out as a hot media dish, “meat glue” has been the most recent food risk feasted upon, due to zealous and uninformed food industry critics. But while cross-linking meat enzymes have been tagged by critics with an unappetizing name, the only food issue concern might be over labeling, suggests Edward Mills, a Penn State University meats expert.

HOT TOPIC: Meat cuts, such as these melded together products pose no food safety risk from the “glue”. But interior temperatures should reach at least 140 degrees, says meats expert.  Photo courtesy of Penn State University
HOT TOPIC: Meat cuts, such as these melded together products pose no food safety risk from the “glue”. But interior temperatures should reach at least 140 degrees, says meats expert. Photo courtesy of Penn State University

And he claims it’s a labeling controversy, not a food safety issue. American Meat Institute officials point out that there’s absolutely no evidence of food safety risks associated with the enzymes. Mark Dopp, AMI’s top lawyer, called allegations the glue is being used to make chuck steak look like filet mignon “unfounded.”

“Meat glues” go by the trade names Activa and Fibrimex. Activa, Mills explains, is a powder form of transglutaminase enzyme made by bacterial fermentation. Fibrimex also is a natural protein cross-linking system derived from pig or beef blood.

Added to meat, it forms a nearly invisible and permanent bond to any other meat you stick it to. While critics contend there might be an E. coli food safety risk involved in melding meat tissues together, the risks would be due to improper meat handling, not the glue itself.

USDA reports that the enzymes are also used in imitation crabmeat and some pasta and dairy products. But they must be listed on the ingredient label of anything containing them.

Most meat products containing these enzymes are sold in the restaurant, food-service and institutional markets, where uniformity of shape is very important, adds Mills. The enzymes are listed on package labels. But the actual consumers will rarely see them.

The enzymes are used to make portion-controlled, fresh-meat cuts such as beef or pork tenderloins. “These pieces of meat have irregular shapes, so connecting two together results in cuts yield slices that are more uniform and attractive,” he explains.

A similar process is used with turkey breasts, notoriously irregular in shape. But the enzymes aren’t used in boneless hams or most cold cuts, Mills stresses. And he charges that reports that meat glue is found in up to a third of products such as bologna and luncheon meats are wildly inaccurate.

Many restructured meat products are on the grocer’s meat section. But most are formed using the natural tendency of the muscle to re-adhere due to protein coagulation during cooking, he points out. In boneless hams, for instance, a salt-soluble protein is extracted from the meat surface during a process called massaging, or tumbling.

Mills sees one aspect of the debate about meat glue and restructured meats as important for consumers to understand. Restructured meats should be thoroughly cooked. Cooks and chefs need to read the labels and know the difference.

“When a meat such as filet mignon is reassembled or reformed – when part of the surface becomes the center – microorganisms are trapped inside,” he says. “So it’s really important that you be aware of what you’re cooking and cook it appropriately.”

Mills advises against cooking restructured meats to a very rare degree of doneness. Such products should be cooked to medium-rare (defined by USDA as 145 degrees F). But they must be held at that temperature for four minutes before serving.