The inherent problems of testing for fish allergens

More than 60 countries have mandatory allergen labelling and almost all of them require that fish be declared when it is present. Over 1,000 different species of fish are caught and sold around the world and the allergenic proteins differ between fish species. Unlike allergen sources such as egg, peanut and milk, there is no test that can detect the presence of all fish. Australian researchers have pin-pointed just how much of a problem this is.

Scientists at the James Cook University collaborated with the National Measurement Institute to test three enzyme-linked immunosorbent assay (ELISA) kits designed to detect fish in food products. They found the kits were more appropriate for detecting proteins from northern hemisphere fish species compared with fish commonly caught in the Asia-Pacific region.

Samples of 57 raw and heated bony fish products were used in the study. The kits returned positive results for between 26 per cent and 61 per cent of the samples. Seventeen canned fish products were tested yet the test kits only returned a positive result for between 65 and 86 per cent of them. None of the nine types of cartilaginous fish (sharks, skates and rays) tested positive using the kits, nor did any of the five types of shellfish. Common European and North American fish species including carp, cod, and salmon had a higher detection rate compared to those from the Asia-Pacific.

Professor Andreas Lopata from the James Cook University was one of the scientists leading the study. He says these findings show an urgent need for the development of improved detection methods.

Read the full media release from the James Cook University.