New tests for nut allergens

Scientists in Florida have developed sensitive new tests to detectm potentially fatal nut traces in food. Their study, published in the Journal of the Science of Food and Agriculture, originally set out to find ways of processing nuts to make them safe for allergy sufferers. The techniques they developed during the analysis included the discovery of sensitive "marker proteins" that can be used to detect trace amounts of nuts in processed foods.

"Definitely DOES contain traces of nuts"

Professors Shridhar Sathe and Professor Kenneth H. Roux at Florida State University and Professor Suzanne S. Teuber at the University of California , Davis looked at walnuts, cashew nuts and almonds, the three most common tree nuts that produce allergic reactions. For people with these allergies, mislabelling and cross-contamination of processed food can be extremely serious. US reports have shown that in more than half of products recalled because of nut contamination, it was consumers themselves who identified the allergens and alerted the manufacturers. The discovery of reliable markers for the detection of trace amounts of nuts could make more accurate food labelling a real possibility.

Proteins and glutelin

In previous studies, the team identified specific proteins relevant to human allergies: almond major protein (AMP), cashew major protein (CMP) and walnut glutelin (WG). They then tried to change these proteins and reduce the allergenicity of the nuts by subjecting them to gamma radiation and thermal processing. The allergens did not change, but the study proved that the new tests could still detect allergen traces in both raw and processed nuts.

Professor Sathe warns that there is still work to be done before the tests are ready for market: "The development of specific, reliable, sensitive and accurate tests for allergy-related proteins has significant implications for the food industry and for consumers who daily rely on accurate labelling.  Therefore continued and vigorous research in developing such assays is urgently warranted."

  (23/6/04)