A segment from the USDA on making Safe Jerky...JJ
Why is temperature important when making jerky? Illnesses due to
Salmonella and
E. coli O157:H7 from homemade jerky raise questions about the safety of traditional drying methods for making beef and venison jerky. The USDA Meat and Poultry Hotline's current recommendation for making jerky safely is to heat meat to 160 °F and poultry to 165 °F before the dehydrating process. This step assures that any bacteria present will be destroyed by wet heat. But most
dehydrator instructions do not include this step, and a
dehydrator may not reach temperatures high enough to heat meat to 160 °F or 165 °F.
After heating to 160 °F or 165 °F, maintaining a constant
dehydrator temperature of 130 to 140 °F during the drying process is important because:
- the process must be fast enough to dry food before it spoils; and
- it must remove enough water that microorganisms are unable to grow.
Why is it a food safety concern to dry meat without first heating it to 160 °F?
The danger in dehydrating meat and poultry without cooking it to a safe temperature first is that the appliance will not heat the meat to 160 °F and poultry to 165 °F — temperatures at which bacteria are destroyed — before the dehydrating process. After drying, bacteria become much more heat resistant.
Within a
dehydrator or low-temperature oven, evaporating moisture absorbs most of the heat. Thus, the meat itself does not begin to rise in temperature until most of the moisture has evaporated. Therefore, when the dried meat temperature finally begins to rise, the bacteria have become more heat resistant and are more likely to survive. If these surviving bacteria are pathogenic, they can cause foodborne illness to those consuming the jerky.
What research findings exist on the safety of jerky?
"Effects of Preparation Methods on the Microbiological Safety of Home-Dried Meat Jerky" was published in the
Journal of Food Protection, Vol. 67, No. 10, 2004, Pages 2337-2341. The authors are from the University of Georgia (Brian A. Nummer, Judy A. Harrison, and Elizabeth L. Andress, Department of Foods and Nutrition, and Mark A. Harrison, Department of Food Science and Technology) and from Colorado State University (Patricia Kendall, Department of Food Science and Human Nutrition and John N. Sofos, Department of Animal Sciences ).
Marinating meat doesn't make raw meat safe. "Marination alone did not result in significant reduction of the pathogen compared with whole beef slices that were not marinated," concluded the study.
In the jerky studies, some samples showed total bacterial destruction and other samples showed some bacterial survival — especially the jerky made with ground beef. Further experiments with lab-inoculated venison showed that pathogenic
E. coli could survive drying times of up to 10 hours and temperatures of up to 145 °F.
A study by the Harrisons and Ruth Ann Rose, also with the University of Georgia, was published in the January 1998
Journal of Food Protection, Vol. 61, No. 1. The authors analyzed ground beef jerky made with a commercial beef jerky spice mixture with and without a curing mix containing salt and sodium nitrite.
Half of the ground beef was inoculated with
E. coli O157:H7 before making it into jerky strips and dehydrating it. The authors found that in both the heated and unheated samples, the jerky made with the curing mix had greater destruction of bacteria than jerky made without it. The jerky made with the mix and heated before dehydrating had the highest destruction rate of bacteria.
They concluded, "For ground beef jerky prepared at home, safety concerns related to
E. coli O157:H7 are minimized if the meat is precooked to 160 °F prior to drying."
https://www.fsis.usda.gov/wps/porta...at-preparation/jerky-and-food-safety/CT_Index
