January 21, 2009

You Ask, I Answer: Salmonella in Peanut Butter

Okay, [I always thought] salmonella is usually [related to eating] eggs or meat.

Peanut butter is primarily three things: peanuts, oil, salt.

Sometimes [they add] sugar or another sweetener.

How, then, does salmonella end up in peanut butter?

-- Corey Clark

(Location withheld)

The ingredient list can even be shorter! Remember, many brands of peanut butter consist of nothing but peanuts.

Your question -- which is excellent, by the way -- is one that many food safety experts are asking themselves (while vividly remembering the eerily similar E.Coli-infested spinach outbreak of 2007.)

Part of the issue here is that the United States does not have one central agency overseeing issues of food safety.

Consequently, sources of contamination are hard to track and contain.

Additionally, most of the focus on food safety (from random inspections to consistent monitoring) is relegated to meat processing plants, as they are considered "high risk" operations.

In short, the vague answer to your question is: "unsanitary plant conditions."

This could mean anything from animal feces somehow ending up in the peanut butter (think a bird or two somehow getting inside the facility) or dirty equipment being used in the processing of peanut butter.

What is practically a given is that the contamination had to have occurred after the roasting and grinding process (both of these use extremely high temperatures that kill all strands of the salmonella virus.)


Corey said...

Thanks, I was confused. There aren't any animal products in most peanut butters so how salmonella ended up in one didn't make any sense. But surely food should be tested before it's released in the food supply? I always assumed that it was common procedure for all food products.

Kristin said...

When I was interviewed by the CDC after getting salmonella this summer, there were a long list of items they asked if I had eaten. The ones that were animal products themselves (i.e. ground beef, chicken, eggs, cheese) seemed obvious, but some others you would not suspect as a potential infection hazard: onions, uncooked salsa, cilantro, jalapenos, serranos, tortillas, lettuce, green onions, potatoes, tomatoes. I was also asked if I have a dog and if I'm the one that feeds him.

The mayo clinic says, "You can contract salmonella infection by touching or ingesting anything contaminated with salmonella bacteria. Reservoirs for the microorganism include pet reptiles, dogs and cats, pigs and cattle, infected humans, contaminated water, raw dairy products and chicken eggs. Salmonella can survive for months in water, ice, sewage and frozen meat." So really, anything that could come in contact with salmonella bacteria, including water could be a source. That leaves the list of possible sources pretty wide open.

Andy Bellatti said...


However, when it comes to things like contaminated water (which, thereby, affects raw produce), salmonella is almost always traced back to fecal matter.

I find it interesting that you were asked about cilantro, jalapenos, and tortillas.

Since you were asked those questions this past summer (at the height of the jalapeno pepper salmonella outbreak), I have a feeling those are not typical food items they would inquire about.

Seems to me like at the time they weren't too sure what ingredient in Mexican food was making people so ill, so they figured they would ask about everything, from tortillas to cilantro!

Kristin said...

That is probably true.

Although asking someone who lives in Texas about what they may have eaten in the past few weeks that is an ingredient in Mexican food is like asking a fish if it has seen water lately. I was sitting there talking to someone in Atlanta, Georgia trying to explain that at least one in every three dinners I eat is in the form of a taco. I had eaten every food on the list.

And interestingly enough I have heard that something in cilantro is supposed to help prevent food borne illness. But, of course it didn't work in my case :/

Andy Bellatti said...

Ha! Now you can understand why tracing a specific contaminated food can be so difficult. Of course, it would all be much easier if controls were tighter before food was shipped all over the country.

As for cilantro -- yes, there is a component that has been shown to be effective at killing salmonella, but if you are eating a contaminated food (i.e.: chicken), you would need to eat the same weight in cilantro to offset food poisoning.

So, a contaminated 6-ounce chicken breast would require you to eat 6 ounces of cilantro. Not the most feasible option...