title: Market analysis of food products for detection of allergenic walnut (Juglans regia) and pecan (Carya illinoinensis) by real-time PCR.
abstract: Two real-time polymerase chain reaction (PCR)-based assays for detection of walnut (Juglans regia) and pecan (Carya illinoinensis) traces in a wide range of processed foods are described here. The method consists on a real-time PCR assay targeting the ITS1 region, using a nuclease (TaqMan) probe labeled with FAM and BBQ. The method was positive for walnut and pecan respectively, and negative for all other heterologous plants and animals tested. Using a series of model samples with defined raw walnut in wheat flour and heat-treated walnut in wheat flour with a range of concentrations of 0.1-100,000 mg kg(-1), a practical detection limit of 0.1 mg kg(-1) of walnut content was estimated. Identical binary mixtures were done for pecan, reaching the same limit of detection of 0.1 mg kg(-1). The assay was successfully trialed on a total of 232 commercial foodstuffs.
authors: Departamento de Nutrición, Bromatología y Tecnología de los Alimentos, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040 Madrid, Spain. Electronic address: ilopezcalleja@vet.ucm.es.
authors: Inés María
authors: IM
authors: López-Calleja
authors: Departamento de Nutrición, Bromatología y Tecnología de los Alimentos, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040 Madrid, Spain.
authors: Silvia
authors: S
authors: de la Cruz
authors: Departamento de Nutrición, Bromatología y Tecnología de los Alimentos, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040 Madrid, Spain.
authors: Isabel
authors: I
authors: González
authors: Departamento de Nutrición, Bromatología y Tecnología de los Alimentos, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040 Madrid, Spain.
authors: Teresa
authors: T
authors: García
authors: Departamento de Nutrición, Bromatología y Tecnología de los Alimentos, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040 Madrid, Spain.
authors: Rosario
authors: R
authors: Martín
mesh_terms: D000485:Allergens / Q000032:analysis* / Q000276:immunology; D031325:Carya / Q000737:chemistry*; D005504:Food Analysis / Q000379:methods; D005512:Food Hypersensitivity; D031324:Juglans / Q000737:chemistry*; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*
chemical_list: D000485:Allergens
keywords: Commercial food products; Food allergy; Pecan (Carya illinoinensis); TaqMan real-time PCR; Walnut (Juglans regia)