title: Evaluation of a dual-probe real time PCR system for detection of mandarin in commercial orange juice.
abstract: A dual-probe real time PCR assay, based on the simultaneous detection of two TaqMan® probes, was evaluated for the detection of mandarin in orange juice. A single conserved polymorphism, located at the 314 position of intron belongs to chloroplast trnL gene, was confirmed by sequencing in 30 mandarin, 28 orange cultivars and 13 hybrids. The assay was also successfully evaluated in a blind trial against analysing 60 samples from different industrial processes in different countries around the world. The detection limit of the assay was established in 1% presence of mandarin detectable in processed orange juice and with a 100% precision. The quantitative application of the assay on citrus mixtures was also investigated, pointing out that the number of chloroplast DNA copies is too variable for its possible use as quantitative analysis. This assay can be employed as a routine methodology to control the accidental mixing during industrial processes and to deter intentional fraud.
authors.affiliation: Food Research Division, AZTI-Fisheries and Food Technological Institute, Parque Tecnológico de Bizkaia, Astondo Bidea-Edificio 609, E-48160 Derio (Bizkaia), Spain. Electronic address: mpardo@azti.es.
authors.forename: Miguel Angel
authors.initials: MA
authors.lastname: Pardo
mesh_terms: D001628:Beverages / Q000032:analysis*; D002957:Citrus / Q000235:genetics*; D032084:Citrus sinensis / Q000235:genetics; D015342:DNA Probes / Q000378:metabolism*; D018742:DNA, Chloroplast / Q000032:analysis* / Q000378:metabolism; D005504:Food Analysis / Q000295:instrumentation / Q000379:methods*; D018515:Plant Leaves / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D015342:DNA Probes; D018742:DNA, Chloroplast
keywords: Adulteration; Citrus; Food quality; Mandarin; Orange juice; Real time PCR; Traceability