Destruction of Escherichia coli O157:H7, Salmonella, Listeria monocytogenes, and Staphylococcus aureus Achieved during Manufacture of Whole-Muscle Beef Jerky in Home-Style Dehydrators

Abstract

Adequate lethality in jerky manufacture destroys appropriate levels of Escherichia coli O157:H7, Salmonella, Listeria monocytogenes, and Staphylococcus aureus. Our goal was to evaluate the lethality of four home-style dehydrator processes against these pathogens. Whole-muscle beef strips were inoculated with L. monocytogenes (five strains), S. aureus (five strains), or a mixed inoculum of E. coli O157:H7 (five strains) and Salmonella (eight strains). After allowing for attachment, strips were marinated in Colorado-, Original-, or Teriyaki-seasoned marinade for 22 to 24 h and dried in three home-style dehydrators (Garden Master, Excalibur, and Jerky Xpress) at 57.2 to 68.3°C. Samples were taken postmarination; after 4, 6, and 8 h of drying; and after drying, followed by heating for 10 min in a 135°C oven. Surviving inocula were enumerated. With a criterion of ≥ 5.0-log CFU/cm² reduction as the standard for adequate process lethality, none of the samples achieved the target lethality for any pathogen after 4 h of drying, even though all samples appeared "done" (water activity of less than 0.85). A postdehydration oven-heating step increased the proportion of samples meeting the target lethality after 4 h of drying to 71.9, 88.9, 55.6, and 77.8% for L. monocytogenes-, S. aureus-, E. coli O157:H7-, and Salmonella-inoculated samples, respectively, and after an 8-h drying to 90.6, 94.4, 83.3, and 91.7% of samples, respectively. Significantly greater lethality was seen with higher dehydrator temperature and significantly lower with Teriyaki-marinated samples. Heating jerky dried in a home-style dehydrator for 10 min in a 135°C oven would be an effective way to help ensure safety of this product.

Thermal Tolerance of O157 and non-O157 Shiga Toxigenic Strains of Escherichia coli, Salmonella, and Potential Pathogen Surrogates, in Frankfurter Batter and Ground Beef of Varying Fat Levels

“…The strain of P. acidilactici used in these experiments has been shown to function as an effective pathogen surrogate in the manufacture of whole-muscle and ground-and-formed beef jerky under commercial and homestyle processing conditions (5,6,11,12). For a bacterial strain to function as a pathogen surrogate in a thermal processing operation, the stain should be nonpathogenic and admissible in a processing facility and should have equal or slightly enhanced thermal tolerance compared with the pathogen under identical testing conditions (7).…”

Infrared drying as a potential alternative to convective drying for biltong production

“…This indicates that the conventional process is not able to eliminate potential pathogens carried through from contaminated meat quantitatively. In addition to using materials of proper hygiene quality to avoid carry through of faecal contamination via the processing, the high temperature regime established using the SW infrared heater would be able to eliminate E. coli effectively if present, as temperatures that exceed 70°C are known to eliminate this microorganism (Dierschke et al , 2010). These results demonstrate that the SW heater employed in the drying process of biltong production sufficiently controlled microbial growth in the meat and reduced the microbial burden.…”

The Study of Marination Time on the Quality of Traditional Dried Meat Ready to Eat

“…Nilai pH dendeng dengan perlakuan perendaman berkisar antara 5,42-5,69. Nilai pH maksimum perlakuan tersebut mendekati nilai pH dendeng industri rumah tangga yang dilakukan oleh Dierschke et al (2010) yang berkisar antara 5,61-5,80 dan hasil studi Lonnecker et al (2010) Hasil penelitian memperlihatkan bahwa nilai pH dendeng dengan berbagai lama perendaman menunjukkan pola menurun dengan semakin lamanya perendaman. Hal ini kemungkinan disebabkan karena sel daging cukup memperoleh waktu untuk masuknya asap cair yang juga mengandung asamasam yang akan menurunkan pH dalam bahan.…”