A word on spicing up foods

ARE spices safe enough to add to cooked food? Wait, is that a trick question?  Whilst most of us will say yes, Patrick Williams, will answer, no, not really.  A research assistant professor at K-State Olathe, Kansas, Mr Williams works at a bio-molecular testing and has been studying spices as these relate to food safety. What he has found out may be to some degree alarming.

“Spices are somewhat of the last frontier in food safety,” he says. “In fact, the FDA (U.S. Food and Drug Administration) recently published a white paper calling attention to foodborne pathogens and other materials present in spice products.”

The recent FDA report  mentions that spices could contain microbial pathogens may such as salmonella, bacillus and staphylococcus aureus. Filth adulterants found have included live and dead whole insects and insect parts; excrement from animals, birds and insects; hair from humans and animals; and many other foreign materials.

The FDA reports that some12% of spices that enter the United States are contaminated.  Mr Williams and colleagues found the amount to be higher in the bulk spices they tested in the Kansas city metro. Four out of 10 tested for one or more contaminants including heavy metals, mycotoxins and bacteria.

“Our research has found that some of the spices we’ve purchased from farmers’ markets and bulk spice vendors are positive for salmonella,” he says. “There are four spices that are typically associated with salmonella contamination: black pepper, thyme, oregano and turmeric.”

Spices were also contaminated with a variety of non-pathogenic, soil-associated bacteria, such as enterobacter, klebsiella, pseudomonas and bacillus subtilis.  Meanwhile, ginger and cinnamon bulk spices were free of contaminants, and this may be because both these spices are high in antioxidant and antimicrobial properties.

Bulk spices have more contaminants

The study shows that spices sold in bulk are more prone to contamination particularly at the point where they are being sold since it is at that point where the quality control measures tend to cease, Mr Williams says.

“If you’ve been to a farmers’ market or bulk vendor where they have the spices out in barrels or boxes that don’t have lids on them, they are open to the public. You can watch people put their hands in them and savour the spices, which means there is a high risk for contamination.”

There is a risk at farmers’ markets, Mr Williams also says, and also in U.S. grocery stores that sell bulk spices. Many spices sold in stores are imported, as the United States is not a major producer of spices.

U.S. governmental organisations continue to push hard to establish safe-handling food and agricultural practices across the entire food industry, he said, including working outside the United States with other countries to establish similar practices. But, this will take time.

“One aspect of this research that we find particularly intriguing is some spices that come from mostly India and Asia are contaminated with bacteria associated with soils,” Mr Williams says. “These soil bacteria are considered non-pathogenic and could be carrying plasmids, which carry genes for antibiotic resistance.”

Because one of the key public health concerns today is antibiotic resistance, he hopes to study this area further with imported spices.

Reducing the risk

Using spices is inevitable, but we can lower our risk of acquiring foodborne illnesses, according to Mr Williams. One is to understand how spices could have been contaminated and another is to cook bulk spices properly. However, heavy metals (iron, lead or other metals associated with industry) that get into spices may cause metal toxicity.

“There’s been concern that some spices are being irrigated with industrial wastewater,” he says. “If that’s the case, the plants will take up these heavy metals, and they will ultimately end up in the spice product.”

Mycotoxins are toxic molecules that are left behind by molds and fungi, Mr Williams says. They likely contaminate the spice product shortly after harvest or if the spice is allowed to get damp from farm to vendor.

“The molds grow on the spices, and they leave behind toxins,” he explains. “Many of these toxins, like aflatoxin, are considered to be carcinogens. Mycotoxins like ochratoxin may in fact be a carcinogen.”

Williams said he continues to catalog toxins present in the spices he’s tested and focus mostly on those bulk spices consumers can buy in and around Kansas City.

Cook spices

For those who buy bulk spices to cook with, they have little need to worry. Always cooking these spices to at least 160 degrees will eliminate the bacteria, he says.

“If you use spices a lot at home and you’re cooking them, it should be fine. If you’re going to use them on an item that’s already been prepared, sprinkling oregano on your pizza for example, I would tend to favour brands of spices that are prepackaged for you at your local grocery store.”

For more information about food safety, click on K-State Research and Extension’s food safety and the K-State Rapid Response Center.