Evaluation of processes to destroy Escherichia coli O157:H7 in whole muscle home-dried beef jerky

The United States Department of Agriculture-Food Safety and Inspection Service (USDA-FSIS) recommends a 5-log reduction in Escherichia coli O157:H7 in processed fermented and semidry foods to be considered safe. Discrepancies exist as to whether current practices for home dried jerky preparation can achieve such destruction. This project was designed to investigate, in three phases, the survival of inoculated E. coli O157:H7 in dried beef jerky, methods to enhance destruction of the pathogen, and sensory properties of jerky prepared by selected procedures.; In phase one, the survival of inoculated E. coli O157:H7 cells during preparation of whole muscle beef jerky with and without marinade and followed by drying at two temperatures (62.5 or 68.3°C) was determined. Survival of bacterial cells was determined by plating on two culture media. Significant (P < 0.05) bacterial destruction occurred during the first 4 h of drying (2.1–4.1 log CFU/cm2), but little destruction occurred between 4 and 10 h of drying and a 5-log reduction was not obtained (2.2–4.6 log CFU/cm2).; In phase two, the survival of inoculated E. coli O157:H7 populations in beef jerky prepared by each of four pre-drying treatments and followed by drying at 62.5°C was evaluated. Four pre-drying treatments were developed to enhance destruction of E. coli O157:H7 before and during drying; survival of bacterial cells was evaluated using two agar media. After 10 h of drying, significant (P < 0.05) bacterial destruction (4.3–5.8 log CFU/cm2) was achieved; however, only one pre-drying treatment achieved a ≥5-log reduction (5.7–5.8 log CFU/cm2) with both media.; In phase three, consumer responses to uninoculated beef jerky prepared using the four pre-drying treatments was evaluated. A taste panel (n = 120) was conducted at three central locations to evaluate five sensory characteristics typical of beef jerky for the treatment methods, plus one commercial jerky product. Mean scores for the commercial jerky were significantly (P < 0.05) higher than mean scores for the experimental products. Consumer results indicated moderate acceptance of the experimental products.; Overall, this research provided information on survival of inoculated E. coli O157:H7 in beef jerky, and sensory characteristics typical to beef jerky.