Detection by real time PCR of walnut allergen coding sequences in processed foods

A quantitative real-time PCR (RT-PCR) method, employing novel primer sets designed on Jug r 1, Jug r 3, and Jug r 4 allergen-coding sequences, was set up and validated. Its specificity, sensitivity, and applicability were evaluated. The DNA extraction method based on CTAB–phenol–chloroform was best...

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Bibliographic Details
Authors: Linacero De La Fuente, M. Rosario, Ballesteros Redondo, María Isabel, Sanchiz Giraldo, África, Prieto, Nuria, Iniesto, Elisa, Martínez, Yolanda, Martín Pedrosa, Mercedes, Muzquiz, Mercedes, Cabanillas Martín, Beatriz, Rovira, Mercè, Burbano, Carmen, Cuadrado Vives, María Carmen
Format: article
Publication Date:2016
Country:España
Institution:Universidad Complutense de Madrid (UCM)
Repository:Docta Complutense
Language:English
OAI Identifier:oai:docta.ucm.es:20.500.14352/23364
Online Access:https://hdl.handle.net/20.500.14352/23364
Access Level:Open access
Keyword:664
579.67
Juglans regia
Walnut allergen detection
Real-time PCR
Processed foods
Thermal processing
Pressure processing
Biotecnología
Genética
3399 Otras Especialidades Tecnológicas
2409 Genética
Description
Summary:A quantitative real-time PCR (RT-PCR) method, employing novel primer sets designed on Jug r 1, Jug r 3, and Jug r 4 allergen-coding sequences, was set up and validated. Its specificity, sensitivity, and applicability were evaluated. The DNA extraction method based on CTAB–phenol–chloroform was best for walnut. RT-PCR allowed a specific and accurate amplification of allergen sequence, and the limit of detection was 2.5 pg of walnut DNA. The method sensitivity and robustness were confirmed with spiked samples, and Jug r 3 primers detected up to 100 mg/kg of raw walnut (LOD 0.01%, LOQ 0.05%). Thermal treatment combined with pressure (autoclaving) reduced yield and amplification (integrity and quality) of walnut DNA. High hydrostatic pressure (HHP) did not produce any effect on the walnut DNA amplification. This RT-PCR method showed greater sensitivity and reliability in the detection of walnut traces in commercial foodstuffs compared with ELISA assays.