E. Drs. (a), S. Baumgartner (a), M. Bremer (b), A. Kemmers-Voncken (b), N. Smits (b), W. Haasnoot (b), J. Banks (c), P. Reece (c), C. Danks (c), V. Tomkies (c), U. Immer (d), K. Schmitt (d) and R. Krska (a)
Analytica Chimica Acta, 2004,520: 223-228
First International Symposium on Recent Advances in Food Analysis, Prague, Czech Republic, Nov. 2003
The development of an indirect competitive enzyme-immunoassay for the detection of hidden hazelnut protein in complex food matrices is described. A sensitive and selective polyclonal antibody was raised by immunisation of laying hens with protein extracts from roasted hazelnuts. In contrast to traditional antibody generation in mammals, the antibody was not isolated from the blood of immunised mammals but from the egg yolk of immunised chickens. A standard calibration curve was optimised using immunoaffinity purified antibody extract and a coating antigen concentration of 10 g ml-1. One percent skim milk powder was chosen for blocking. The assay has a minimum detection limit of 10 g l-1, with an IC50 of 618 g l-1 when a 50 mM phosphate buffer at pH 7.5 and 10 mM sodium chloride is used as assay buffer. The cross reactivity testing shows a high specificity for hazelnut proteins and various foods and food additives were found to be non reactive except beans, sunflower seed or poppy seed.
Author Keywords: ELISA; Hidden allergens; Hazelnut; Corylus avellana; Egg yolk antibodies; IgY
Corresponding author. Tel.: +43 2272 66280413; fax: +43 2272 66280403.
(a) IFA-Tulln Center for Analytical Chemistry, Institute for Agrobiotechnology, Konrad Lorenz Strasse 20, A-3430, Tulln, Austria
(b) RIKILT, Bornsesteeg 45, 6708 PD, Wageningen, The Netherlands
(c) Central Science Laboratory, Sand Hutton, YO41 1LZ, York, UK
(d) r-Biopharm, Landwehrstr. 54, 64293, Darmstadt, Germany