Project Summary

Escherichia coli O157:H7 Risk Assessment for the Production and Cooking of Blade Tenderized Steaks: Determination of Lethality Requirements for Blade Tenderized Steaks

Principle Investigator(s):
J. L. Marsden, R. K. Phebus, H. Thippareddi and C. L. Kastner
Kansas State University
Completion Date:
August 1999
Layman’s Summary 

Many of today’s beef steak items have gone through a blade tenderizing process, which uses multiple needles to physically disrupt the muscle system and create a more uniformly tender product. However, this results in a non-intact muscle system that could potentially transfer surface microbial contamination to the interior of the product. 

The objectives of this study were to determine the effectiveness of cooking procedures for destroying E. coli O157:H7 in both tenderized and non-tenderized muscle and to establish safe heating protocols for these types of products. Beef steaks were intentionally contaminated with E. coli O157:H7 and subjected to needling, the most common commercial method of tenderizing. The needling process transferred 3-4% of the pathogens to the interior of the steaks. It should also be noted that much higher levels of E. coli O157:H7 were used than would typically be found on the surface of a steak item. Steaks were then heated to varying degrees of doneness in an oven broiler. 

At internal temperatures ranging from 130°F (rare) to 170°F (well done), the steaks were virtually free of E. coli O157:H7. This was true on needled and non-needled steaks. There was also an additional margin of error noted in the cooking process. When steaks were removed from the cooking process, there was an additional 11°F rise in internal temperature. This study concluded that intact and non-intact steaks are safe for consumers when cooked to the endpoint temperatures evaluated in this study by the oven broiling method.