Chinese researchers have taken a step towards removing a protein from prawns that cause an allergic response, without resorting to genetic manipulation.

Li Zhenxing led the research at the Ocean University of China. The team revealed that treating prawns with a combination of heat and irradiation significantly reduced the level of reactive proteins called allergens.

They took blood from patients with shrimp allergies, added samples of treated and untreated prawn, and measured how antibodies in the blood reacted.

They found that levels of 'Pen a 1', one of the major allergens, decreased 20-fold after treatment.

Zhenxing's team suggests that irradiation damages the proteins, revealing hidden reactive amino acid residues. Subsequent heating then destroys the exposed residues.

"Radiation and heat seems to be a promising method for reducing the immunoreactivity" said the researchers.

Samuel Lehrer of Tulane University in New Orleans, USA, is already working on removing allergens from prawns using genetic techniques. But Zhenxing's method could be preferable for people wary of eating genetically modified foods.