The agency found nearly 7% of spices tested were tainted with Salmonella, which is double that of other FDA-regulated food shipments (including fresh produce and ready-to-eat foods) sampled during the same time period.
The larger prevalence of Salmonella in imported shipments of spices is surprising because the low water activity of spices does not support Salmonella growth.
Many spices have inhibitory compounds that provide antibacterial activity against Salmonella, said van Doren et al.
High prevalence of spices from fruit/seed or leaves of plants
Shipments of spices from the fruit/seed or leaves of plants had a larger prevalence for Salmonella than shipments of spices from the bark/flower of spice plants.
A larger proportion of ground/cracked capsicum and coriander spice shipments were contaminated than their whole spice counterparts.
15% of coriander and 12% of oregano and basil shipments were contaminated.
8.3% of spice shipments were contaminated with antimicrobial-resistant Salmonella strains.
The agency also found some spice shipments that were supposed to have been subject to a pathogen reduction treatment prior to entry in the US were still contaminated.
Shipments of imported spices for entry to the US were sampled during the fiscal years 2007–2009.
79 different countries were examined during the study period and contaminated products came from 37 countries.
Mexico accounted for the highest percentage of contaminated product with 14% of samples, while India was found to have almost 9% but imports more than four times as much as Mexico.
The most common serotypes found in spices do not differ substantially from all FDA-regulated imported foods sampled, found the study.
Weltevreden and Newport were the two most common serotypes isolated from spices during FY2007–FY2009 and were among the top four serotypes isolated in 2000 and 2001 from examined imported shipments of FDA-regulated foods offered for US entry.
Additional research is needed to distinguish prevalence values among the spice types but the data demonstrate that Salmonella shipment contamination is common among a wide range of spice types, concluded the study.
Spices from plant seeds, such as cumin, mustard and sesame, or fruit spices, such as black, white, and red pepper, were grouped together in the “fruit” category.
Those from plant roots included dried roots, such as turmeric and ginger and dehydrated onion and garlic.
Examples of spices included in the leaf category are oregano, basil, and varieties of mint. Examples of spices included in the bark/flower category include cinnamon/cassia, cloves, and saffron.
Salmonella isolates were tested for susceptibility to antimicrobials such as: amikacin, amoxicillin/clavulanic acid, ampicillin, cefoxitin, ceftriaxone, chloramphenicol, ciprofloxacin, gentamicin, kanamycin, nalidixic acid, sulfisoxazole, and trimethoprim/sulfamethoxazole, tetracycline, and streptomycin.
“Prevalence, serotype diversity, and antimicrobial resistance of Salmonella in imported shipments of spice offered for entry to the United States, FY2007–FY2009”
Authors: Jane M. Van Doren, Daria Kleinmeier, Thomas S. Hammack, Ann Westerman
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