title: Development of a Quantitative GC-MS Method for the Detection of Cyclopropane Fatty Acids in Cheese as New Molecular Markers for Parmigiano Reggiano Authentication.
abstract: Cyclopropane fatty acids (CPFA), as lactobacillic acid and dihydrosterculic acid, are components of bacterial membranes and have been recently detected in milk and in dairy products from cows fed with corn silage. In this paper, a specific quantitative gas chromatography-mass spectrometry (GC-MS) method for the detection of CPFA in cheeses was developed, and the quality parameters of the method (limit of detection, limit of quantitation, and intralaboratory precision) were assessed. Limit of detection and quantitation of CPFA were, respectively, 60 and 200 mg/kg of cheese fat, and the intralaboratory precision, determined on three concentration levels, satisfied the Horwitz equation. This method was applied to 304 samples of PDO cheeses of certified origin, including Parmigiano Reggiano (Italy), Grana Padano (Italy), Fontina (Italy), Comté (France), and Gruyère (Switzerland). Results showed that CPFA were absent in all of the cheeses whose Production Specification Rules expressly forbid the use of silages (Parmigiano Reggiano, Fontina, Comté, and Gruyère). CPFA were instead present in variable concentrations (300-830 mg/kg of fat) in all of the samples of Grana Padano cheese (silages admitted). A mix of grated Parmigiano Reggiano and Grana Padano was also prepared, showing that the method is able to detect the counterfeiting of Parmigiano Reggiano with other cheeses up to 10-20% Grana Padano content. These results support the hypothesis that CPFA can be used as a marker of silage feedings for cheeses, and the data reported can be considered a first attempt to create a database for CPFA presence in PDO cheeses.
authors.affiliation: Dipartimento di Scienze degli Alimenti, Università degli Studi di Parma , Parco Area delle Scienze 17/A, 43124 Parma, Italy.
authors.forename: Augusta
authors.initials: A
authors.lastname: Caligiani
authors.affiliation: Servizio Tecnico Consorzio del Formaggio Parmigiano Reggiano , Via J. F. Kennedy, 18 42124 Reggio Emilia, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Nocetti
authors.affiliation: Dipartimento di Scienze degli Alimenti, Università degli Studi di Parma , Parco Area delle Scienze 17/A, 43124 Parma, Italy.
authors.forename: Veronica
authors.initials: V
authors.lastname: Lolli
authors.affiliation: Dipartimento di Scienze degli Alimenti, Università degli Studi di Parma , Parco Area delle Scienze 17/A, 43124 Parma, Italy.
authors.forename: Angela
authors.initials: A
authors.lastname: Marseglia
authors.affiliation: Dipartimento di Scienze degli Alimenti, Università degli Studi di Parma , Parco Area delle Scienze 17/A, 43124 Parma, Italy.
authors.forename: Gerardo
authors.initials: G
authors.lastname: Palla
mesh_terms: D000818:Animals; D002417:Cattle; D002611:Cheese / Q000032:analysis*; D003521:Cyclopropanes / Q000032:analysis*; D005060:Europe; D005227:Fatty Acids / Q000032:analysis*; D005506:Food Contamination / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D012820:Silage / Q000032:analysis
chemical_list: D003521:Cyclopropanes; D005227:Fatty Acids; C028775:cyclopropane fatty acids
keywords: GC−MS; PDO cheese; Parmigiano Reggiano; authentication; cyclopropane fatty acid; dihydrosterculic acid