Restructured beef requires attention for risk.

Anyone who consumes restructured or mechanically tenderized beef probably doesn't know it. These processes yield meat products that generally appear to be whole muscle cuts. However, they offer the advantages of being uniform in shape and tenderness. But do these products pose a different level of risk compared to intact, whole-muscle counterparts? Research at Kansas State University (Department of Animal Sciences and Industry, Manhattan, KS 66506) is addressing this question in order to make processing and cooking recommendations designed to improve the products' safe preparation.

Restructuring is a procedure often used to produce meat products for restaurants and food service operations. Pieces of meats from different cuts are bound together using enzymes or other binding technologies to create a more usable product. The process can be used to make a more high-end product and cause it to appear more uniform, an important characteristic for food service applications. But the resulting meat isn't intact muscle, so the risk of microbial contamination can be higher, unless appropriate processing and cooking guidelines are followed.

With whole muscle meat products, bacteria are confined at or near the surface of the meat and are easily killed during even minimal cooking, thus ensuring the product's safety. But the restructuring process carries formerly exterior surfaces into the interior of the product. If those surfaces are contaminated with pathogenic bacteria, these harmful bacteria could be distributed throughout the interior of the product in fairly high concentrations. The center of the cut--the slowest heating area--must reach lethal temperatures to acceptably control the risk. This is similar to cooking ground beef patties. A rare to medium-rare restructured steak may pose a risk to the consumer.

Blade tenderization is more widely utilized. In this process, narrow blades are passed through the meat subprimal to break connective tissue and provide more uniform tenderness of the final products. This process results in a non-intact muscle. However, the final product does not appear different from an intact counterpart to an average consumer. The penetration of the blades through the exterior surface of the meat could carry bacterial contamination into the interior of the product. Kansas State University studies examined the resulting distribution of bacteria throughout the products and identified cooking protocols that would effectively eliminate that level of bacteria present in the center of resulting meat cuts.

By artificially inoculating the meat surfaces with E. coli O157:H7, researchers found that approximately 3% to 5% of the external contamination is typically carried to the center of the product. Oven-broiling the steaks cut from these blade-tenderized subprimals indicated that this level of potential contamination is effectively controlled by cooking the product to an internal temperature of 60 C.

The most important finding from these studies, according to investigators, is that it is not scientifically valid to classify as non-intact all meat products produced through restructuring, mechanical tenderization, marination and injection technologies. Studies with both beef and pork products clearly demonstrate that the bacteriological risks associated with different product types that are lumped into the non-intact category are very different. Food service cooking recommendations and regulatory considerations for production of these products must consider these risk differences. Blanket statements and recommendations should not be made with regard to their safety.

Studies document that restructured beef and pork products appear to pose a higher level of risk in terms of pathogenic contamination compared with other products that are considered non-intact. These risks can be minimized if processors operate within a well-designed, scientifically validated HACCP system. If this approach is not taken, we're told, then restructured steaks should be cooked according to USDA ground beef recommendations--to an internal temperature of 71 C. If an effective HACCP plan is in operation, lower and more desirable end-point temperatures may be safely utilized for restructured products.

Further information. Randy Phebus; phone: [phone]; fax: [phone].