title: Quantitative sandwich ELISA for determination of traces of hazelnut (Corylus avellana) protein in complex food matrixes.
abstract: A hazelnut-specific sandwich-type ELISA based on polyclonal antisera was developed for detection of hidden hazelnut protein residues in complex food matrixes. In the absence of a food matrix, extractable protein from different native and toasted hazelnuts was detected at rates of 94 +/- 13 and 96 +/- 7% applying standards prepared from native and toasted hazelnuts, respectively. From complex food matrixes, 0.001-10% of hazelnut was recovered between 67 and 132%, in average by 106 +/- 17%. Depending on the food matrix, hazelnut protein could be detected down to the ppb (ng/g) level. Intraassay precision was <6% for hazelnut >/= 0.001% and interassay precision was <15% for hazelnut >/= 0.01%. In 12 of 28 commercial food products without labeling or declaration of hazelnut components, between 2 and 421 ppm of hazelnut protein was detected, demonstrating a remarkable presence of potentially allergenic hazelnut protein "hidden" in commercial food products.
authors.affiliation: Department of Allergology, Paul-Ehrlich-Institut, Paul-Ehrlich-Strasse 51-59, D-63225 Langen, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Holzhauser
authors.forename: S
authors.initials: S
authors.lastname: Vieths
mesh_terms: D000485:Allergens / Q000302:isolation & purification*; D004797:Enzyme-Linked Immunosorbent Assay / Q000592:standards*; D005512:Food Hypersensitivity / Q000517:prevention & control; D006801:Humans; D015151:Immunoblotting; D009754:Nuts / Q000009:adverse effects / Q000737:chemistry*; D010940:Plant Proteins / Q000302:isolation & purification*; D012680:Sensitivity and Specificity
chemical_list: D000485:Allergens; D010940:Plant Proteins