Researchers at the Ocean University of China have taken a promising step towards removing the proteins from prawns that cause an allergic response.
Scientists, led by Li Zhenxing, found that treating prawns with a combination of heat and irradiation caused a significant decrease in allergenicity.
They took blood from patients with shrimp allergies, added samples of treated and untreated prawn, and measured how antibodies in the blood reacted to allergens. Pen a 1, one of the major
allergens, decreased 20-fold after treatment.
Treating prawns with irradiation alone appeared to increase reactivity with antibodies. Zhenxing’s team suggests this is because irradiation damages the proteins, revealing hidden
reactive amino acid residues. Subsequent heating, however, destroys the exposed residues.
‘Radiation and heat seems to be a promising method for reducing the immunoreactivity [of prawn],’ said the researchers.
Samuel Lehrer of Tulane University in New Orleans, US, is already working on removing allergens from prawns using genetic techniques.
But Zhenxing’s method could be preferable for people wary about eating genetically modified foods.
However, a spokesperson from one of the large food companies is sceptical. ‘It seems highly unlikely there would be a viable market for such an artificially manipulated product,’ he
said. The next step is to test the treated prawns in animal models of the human allergic response.
‘If I was sensitive I wouldn’t risk eating these [prawns] until in vivo experiments have been performed,’ said Flemming Jessen of the department of seafood research in
Denmark. More than 2.1% of the adult population suffers from shellfish allergies, according to some studies.
Symptoms range from localised swelling and rashes to anaphylactic shock, which can be fatal.

Lisa Richards

www.soci.org