title: Detection of hazelnut in foods using ELISA: challenges related to the detectability in processed foodstuffs.
abstract: Hazelnuts are widely used nowadays, and can pose a serious threat to allergic consumers due to cross-contamination that may occur during processing. This might lead to the presence of hidden hazelnut in foods. Therefore, reliable tests are needed to detect hazelnut, especially in processed foods. A hazelnut-specific indirect competitive ELISA based on polyclonal chicken antibodies was developed. The polyclonal antibodies were raised against modified hazelnut proteins in order to improve the detectability of hazelnut proteins in processed foods. The assay showed a detection limit of 1.36 microg hazelnut protein/mL of 5 mM urea in phosphate-buffered saline buffer (pH 7.4). Limited cross-reactivity with walnut and pecan nut was observed; no cross-reactivity was observed with other food ingredients. Blank cookies spiked before analysis showed recoveries of 73-107%. However, cookies spiked before baking showed that the detectability was severely decreased. Addition of lactose to the cookies, which led to more severe modification through the Maillard reaction, led to an increase in the detectability. These results indicate that using antibodies developed toward allergens modified through food processing-simulating reactions is a better approach for detection.
authors.affiliation: Ghent University, Department of Food Safety and Food Quality, Research Group on Food Chemistry and Human Nutrition, Coupure Links 653 B-9000 Gent, Belgium.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Cucu
authors.forename: Bart
authors.initials: B
authors.lastname: Devreese
authors.forename: Stanislav
authors.initials: S
authors.lastname: Trashin
authors.forename: Barbara
authors.initials: B
authors.lastname: Kerkaert
authors.forename: Maarten
authors.initials: M
authors.lastname: Rogge
authors.forename: Bruno
authors.initials: B
authors.lastname: De Meulenaer
mesh_terms: D000465:Algorithms; D000818:Animals; D000906:Antibodies / Q000032:analysis / Q000302:isolation & purification; D002021:Buffers; D002138:Calibration; D002645:Chickens; D031211:Corylus / Q000737:chemistry* / Q000276:immunology; D003429:Cross Reactions; D004530:Egg Yolk / Q000737:chemistry / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005504:Food Analysis / Q000379:methods; D005511:Food Handling; D005512:Food Hypersensitivity; D009754:Nuts / Q000737:chemistry; D010940:Plant Proteins / Q000032:analysis; D015203:Reproducibility of Results
chemical_list: D000906:Antibodies; D002021:Buffers; D010940:Plant Proteins