title: New method of DNA isolation from two food additives suitable for authentication in polymerase chain reaction assays.
abstract: Locust bean gum and guar gum are galactomannans used as additives (E 410 and E 412, respectively) in the food industry as stabilizing agents. Analytical discrimination between the two additives in gums and foods is now feasible by molecular techniques. However, only complex and time-consuming DNA isolation protocols are available to date. We have developed simple improved protocols to obtain enough DNA suitable for PCR amplification from a few milligrams of commercial E 410 and E 412 additives (containing more than 75% polysaccharides). The suspension of additives in water or 10 mM Tris-HCl, pH 8.5, efficiently recovers DNA suitable for authentication in PCR assays. However, the Tris method was much more efficient for the extraction of DNA from E 410 than for E 412 additives. Conversely, the water method was the most suitable for detecting DNA extracted from E 412 or from E 410/E 412 mixtures. Combined with the use of the two specific ribosomal primer pairs previously designed, our methods are well-suited for a fast and simple high-throughput sample treatment of commercial gums for molecular certification.
authors.affiliation: Microbiologia, Departament de Biología, Universitat de les Illes Balears, E-07071 Palma de Mallorca, Spain.
authors.forename: Mercedes
authors.initials: M
authors.lastname: Urdiaín
authors.forename: Antonio
authors.initials: A
authors.lastname: Doménech-Sánchez
authors.forename: Sebastián
authors.initials: S
authors.lastname: Albertí
authors.forename: V Javier
authors.initials: VJ
authors.lastname: Benedí
authors.forename: Josep A
authors.initials: JA
authors.lastname: Rosselló
mesh_terms: D004247:DNA / Q000302:isolation & purification*; D005503:Food Additives / Q000032:analysis* / Q000737:chemistry*; D005685:Galactans / Q000032:analysis / Q000235:genetics; D008351:Mannans / Q000032:analysis / Q000235:genetics; D053149:Plant Gums; D016133:Polymerase Chain Reaction; D011134:Polysaccharides / Q000032:analysis / Q000235:genetics
chemical_list: D005503:Food Additives; D005685:Galactans; D008351:Mannans; D053149:Plant Gums; D011134:Polysaccharides; D004247:DNA; C007894:guar gum; C017471:locust bean gum