Validating E. coli 0157:H7 in Direct Acidified Beef and Venison Semi-Dry Sausages (2001-02502)

It is estimated there are 73,480 cases of Escherichia coli O157:H7 and the infectious dose is low, ranging from 2 to 2,000 cells. In 1994 an E. coli O157:H7 outbreak was linked to a dry, fermented, presliced pork and beef salami product from delicatessen counters. Due to an E. coli O157:H7 outbreak being linked to a dry fermented sausage product for the first time, USDA's Food Safety and Inspection Service developed guidelines requiring sausage manufacturers to validate that their processes achieve a five-log reduction of E. coli O157:H7. Various validation studies have shown that E. coli O157:H7 is able to survive in sausages that are fermented and then dried to various moisture levels. Meat processors of small operations produce both beef and venison summer sausage and shelf-stable snack sticks using encapsulated citric acid instead of lactic acid starter cultures. These products may be a potential source of E. coli O157:H7 due to their low temperature processing procedures and product properties. The overall goal is to determine processing parameters for direct acidified beef and venison summer sausage and snack sticks that will achieve a five-log reduction of E. coli O157:H7. The effectiveness of McConkey sorbitol agar (MSA), trypticase soy agar with MSA overlay, phenol red agar with 1% sorbitol, and modified eosin methylene blue agar will be evaluated for detecting acid and heat-injured E. coli O157:H7 in direct acidified summer sausage and snack sticks. In addition, two fat level percentages will be processed to determine the effect of fat content on lethality of thermal processes.