Spice may be nice, but spices also can carry very bad bugs. About 7 percent of spices tested by Food and Drug Administration researchers were contaminated with salmonella, which can cause serious illness and death. Because of this finding and others, the FDA and international food safety organizations are putting more effort into how to reduce the risk.
A New York Times article this week really brought the issue to everyone's attention. Here are some of the questions we've been asking about spices and salmonella here at The Salt:
How much of the spices on grocery shelves are contaminated?
The FDA researchers tested 20,000 samples of imported spices between 2006 and 2009. About 7 percent of imported spices were contaminated with salmonella. The bacterium was most common in coriander, basil, oregano, sesame seeds, pepper, cumin and curry powder. Ground and cracked spices were slightly more likely to be contaminated than whole spices. Almost all spices used in the United States are imported. Their research was published in the June issue of the journal Food Microbiology.
How do spices get contaminated?
After spices are harvested from plants, they're often laid on the ground to dry. Salmonella comes from birds and other animals, so the animals are getting access to the spices somewhere in picking, drying, processing or storage.
How much would a person have to consume to get sick?
Not much. In 2009, 272 people got sick from eating salami. It turned out that the pepper used to season the sausage was contaminated with salmonella. The microbe can go into hibernation while dry and reactivate in contact with water, perhaps in your stomach.
Does cooking with spices eliminate the danger?
Yes, if by cooking you mean "heating." Cooking is the same as pasteurization, which is a commercial method used to kill salmonella. Just make sure you get it hot enough. The Centers for Disease Control and Prevention says that salmonella is killed at 160 degrees F.
Theodore LaBuza, a professor of food safety at the University of Minnesota, says that after he became aware of the issue with contaminated spices, he quit putting rosemary on his salads. "Mostly I use it in sauces and cooking," he tells The Salt.
Do we have a sense of how many foodborne illnesses in the United States are caused by spices?
There were three major salmonella outbreaks between 2007 and 2010 that were traced back to spices. In other cases, spices were found to be contaminated and recalled, but they weren't known to cause illness. But the technology has only recently gotten good enough to make such precise tracing possible. Food sleuths can now match the DNA on a spice to the DNA on a given strain of salmonella.
How can spices be made safer?
There are several widely used methods to kill off salmonella and other bacteria in spices. They include irradiation, heat treatment (pasteurization), and treatment with the gas ethylene oxide. Food safety experts say that large importers of spices either require that the products be decontaminated before they enter the United States, or process them stateside. But there's no requirement that spices be labeled as treated. So it's hard for consumers to know. And some of the treated spice samples that the FDA tested still had traces of salmonella.
An FDA spokeswoman told The Salt that the agency will release an in-depth analysis of the risk posed by salmonella in imported spices later this fall.
"If I were in FDA, I would demand that all spices get some type of pasteurization treatment before they can enter the U.S.," LaBuza told The Salt.
Even though spice exporters like India have been trying to improve practices, as The New York Times reported, LaBuza says that won't be enough. "You're not going to change what happens in a farm in India or in the Spice Islands," he says. "They just don't have the technology for that."