November 2016

LGC's pioneering DNA allergen work highlighted by FSA Chief Scientist

The pioneering work carried out by molecular biologists in the Government Chemist programme in LGC has been highlighted in the 5th report by the Food Standards Agency’s Chief Scientific Advisor, Professor Guy Poppy, on Food Allergy and Intolerance. The work involved the development of new DNA tests for mahaleb and the common members of the Prunus species to help resolve two high profile referee cases.

In January 2015, the FSA were made aware of an issue with the presence of undeclared nuts in cumin based products. Samples of ground cumin and cumin seed were collected from across the UK and market intelligence was used to focus on imports from particular countries and types of retailers.  ELISA showed that proteins from almonds were present in samples. However, the manufacturer could not identify how almond could have contaminated the cumin and suspicion then fell on a spice called mahaleb, which was ground on the same equipment as the cumin. The mahaleb (Prunus mahaleb) is from a closely related species to almond (Prunus dulcis) and therefore has very similar proteins. The main test used for allergens (ELISA) was unable to distinguish between them, however pioneering new DNA tests were developed by the UK’s Government Chemist programme in LGC, for this and a related paprika case. 

The cases were resolved using the new methods alongside protein mass spectrometry and reappraisal of the original ELISA tests that had been carried out by other laboratories.

The Chief Scientific Advisor’s report on Food Allergy and Intolerance is an informative overview of FSA’s work on these topics. Striking new evidence is presented that these conditions are responsible for more hospitalisations each year than foodborne disease.