The importance of research on beef jerky

I've eaten beef jerky on occasion and rather liked its spiciness. I'm not an aficionado, however, and didn't know much about it. I did look at the Wikipedia article on beef jerky where you will find more than any sane person would want to know about the food aspects of the subject, but with the increasing concern about food safety and particularly the safety of the meat supply in the US and elsewhere I was curious about it from the public health perspective.

For those who don't know, here's the wikipedia description:

Jerky is meat that has been cut into strips trimmed of fat, marinated in a spicy, salty or sweet liquid, and then dried with low heat (usually under 70°C/160°F) or occasionally salted and sun-dried. The result is a salty, stripped, semi-sweet snack that can be stored without refrigeration. Jerky is an early application of food preservation techniques. (Wikipedia)

The preservation comes from decreasing the available water in the food by drying and salting. Smoking adds flavor and also is a deterrent to insects laying eggs in the food (not as much of a preoccupation these days). This keeps the food from spoiling but not necessarily prevents pathogens. Like other specialty foods jerky is now being made in more small, artisanal operations. Recently I ran across a report of a project done by food science researchers at Kansas State University which asked two questions: were the current U.S. Department of Agriculture's Food Safety and Inspection Service's standards for commercial preparation of beef jerky adequate to handle a worst case scenario of contamination by E. coli O157/H7 or Salmonella? And if not, could the standards be modified in ways that would not be unduly burdensome for small producers? The answer to the first question was, "No". The answer to the second question was "Yes":

The research team first surveyed plants in several states to find out what processes were being used to control pathogens, and what the "worst-case" processing scenario was. Researchers then evaluated the efficacy of the worst-case scenario thermal process to destroy E. coli O157:H7 and Salmonella.

A commercial processor provided samples of the batter used to make chopped and formed beef jerky. The researchers then inoculated the raw batter with either E. coli O157:H7 or Salmonella and extruded it into strips measuring 2.54 long by 0.64 centimeters wide. The strips were then thermally processed in K-State's own pathogen dedicated commercial smokehouse for nearly seven hours, using varying rates of relative humidity and temperature.

Researchers determined that the worst-case scenario for a commercial jerky process does not adequately reduce the pathogens as required by the U.S. Department of Agriculture's Food Safety and Inspection Service. In order to ensure that both pathogens were destroyed, researchers found that an additional hour and a half of drying at 68 degrees Celsius was needed.

"Though the worst-case scenario for a commercial jerky process did reduce the presence of Salmonella to the required level, it didn't have the desired effect on E. coli O157:H7," [Kansas State researcher Kelly] Getty said. "Additional drying was needed to kill off both pathogens at the levels required by the Food Safety and Inspection Service."


"We hope that our research has provided a process for small processors that produce safe beef jerky without creating an extra burden," Getty said. "Really, the adjustments were suggesting are minor and will enhance the safety of jerky for the consumer." (Nutrition Horizon)

This is a glimpse into the kind of applied research that is the foundation for modern food safety protection. It's not molecular biology or high energy physics or x-ray crystallography. But it's extremely important that it be done and done right. It should remind us that the basic research supported by the NIH is vital to all of us in the long run, but there is a vast body of fairly routine applied research outside that golden aura just as important in a different way.

Just thought I'd mention it.

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And this is more important than the latest advances in string theory?? :-)

Hey, it's stringy beef theory...

I make Salami, Chorizo and 'Parma' type hams (whole leg salted and dried on the bone - drying takes about 4 months) but have not tried jerky. I have never tried to sell any as I assumed the red tape and liability insurance would make it a waste of time but I give it away to family and friends and have not had any reported deaths (hmm there are a few friends I haven't heard from in a while perhaps I had better give them a call)

I, sir, am an aficionado - beef, turkey, deer, elk - I can't think of a better protein source while backpacking (well, car-camping these days). Yes, the Reverend has the right idea but sometimes you're at the top of some Colorado pass and a vendor is selling eleven types of jerky from five different species and I just can't resist.

Great info and some very interesting insights on food preservation methods. Indeed, this kind of research on real-life issues isn't solving 3-D protein structures but it addresses critical daily scenarios in public health.

There have been outbreaks of salmonellosis associated with commercially produced beef jerky (e.g. MMWR 1995 44(42);785-788), of E. coli O157 associated with homemade venison jerky (JAMA 1997 Apr 16;277(15):1229-31) and of trichinellosis associated with homemade bear, cougar, and wild boar jerky (MMWR 2003 SS-6: Trichinosis Surveillance Summary, 1997-2001.)

The trichinosis data suggest it's not a good idea to rely on just brining and smoking to eradicate worms from wild carnivores and omnivores (Abel, you might keep that in mind when you're up in the pass.)

But the publication of prior outbreaks of bacterial foodborne illness in both commercial and household-smoked product suggests that this jerky's not just a potential source of illness - for every reported case of foodborne illness, another 25 are estimated to occur, suggesting that in the absence of other mitigating factors, for every outbreak reported there are dozens of silent sporadic cases.

So it's not sexy research, but it's a good use of resources, or will be if the information is broadly disseminated to those who make jerky at home and in smaller commercial venues. (I hope this story goes beyond "Nutrition Horizon.")

Smoking adds flavor and also is a deterrent to insects laying eggs in the food (not as much of a preoccupation these days).

It's true! What with the popularity of low-carb diets people are far less bothered by the addition of a few delicious high-protein maggots.

Is drying at 68 degrees C considered "cooking"? I have always wondered whether jerky is considered a cooked food or not. I've asked people who eat it, and they don't seem to know.

Miss Cellania: Yes, that's definitely cooking (it's 154 degrees F.) Few pathogens can live at that temperature.

Maria: LOL. I guess you could read it that way. Sort of like the one line recommendation allegedly given by John Kenneth Galbraith: "I cannot recommend this student too highly."

I personally prefer African style biltong.

As for American commercial beef jerky, the large choice cuts of meat are fairly obviously not going to be sliced up to make small bits of snack food. One quite common part of the animal which you will find being rendered for jerky -- there being no retail demand for them -- are beef cheeks.

What's not to like about beef cheeks? They are in immediate proximity to tissues for which the spongiform encephalopathies have a strong affinity. And the rendering process is hardly of surgical accuracy: it's a crude high speed mechanized process in which tissue other than the cheek meat is likely to be removed and mixed in to the resultant.

Of course, George W. Bush's FDA and Agriculture Department jointly assure us that there is zero risk of BSE in American cattle. They're so confident about this that they have gone to court to prevent small cattle processors from paying out of pocket to do their own independent testing. Which certainly puts my mind at ease. How about you?


DOWN with string theory!! O_o

hmmmm. makes me wonder about some of the smaller (and yummier) jerky producers here in san diego county. and Alien Fresh Jerky in Baker, CA - also very yummy.

thanks revere!

Dried meat is extremely popular in Switzerland, a kind of staple food, eaten in sandwiches, or as an hors d oeuvre, or as is, for a snack. Take a cow s thigh, salt it (usually with some spices) wrap it up in something like netting and hang it up to dry in a windy loft for 16 weeks. Then press it into a shape like a loaf.