Session: General Poster:

Abstract

Background: FDA has received consumer complaints about food products, most notably sardines, containing krill as an undeclared crustacean shellfish allergen. The Food Allergen Labeling and Consumer Protection Act (FALCPA) requires that food products containing crustacean shellfish be labeled with the type of crustacean. Antibody based assays such as ELISA, which are most often used for allergen detection, cannot distinguish type of crustacean, so there is a need for additional methods. Previous work at FDA-CFSAN has resulted in the successful development of real-time PCR based assays for differentiation of crustaceans through detection of their DNA.

Purpose: The purpose of this work was to develop and evaluate a real-time PCR based method for specific detection of krill contamination in foods, with a focus on detection in sardines.

Methodology: While krill is morphologically similar to shrimp, it is not a close relative taxonomically and therefore cannot be expected to give a similar response in DNA assays. Methodology included first examining the response of the current crustacean real-time PCR assays to krill, and then adapting a previously developed shrimp assay to specifically detect krill through modification of primer and probe sequences.

Results: Two different sets of modified primer and probe sequences were found to work equally well. Both yielded specific detection of krill in sardines with lower limits of detection at 0.1-1 mg/kg and linearity over 7-8 orders of magnitude. The krill assay does not cross-react with shrimp.

Conclusion: FDA consumer complaints about undeclared krill have highlighted the need for a detection assay specific for this crustacean. While krill is not a close taxonomic relative of shrimp, this work has shown that minor changes in shrimp primers and probe were nonetheless able to yield an effective and specific krill assay.

Dr. Anne Eischeid Ph.D.

Research Scientist, US Food and Drug Administration

Appearances