title: Multiplex liquid chromatography-tandem mass spectrometry for the detection of wheat, oat, barley and rye prolamins towards the assessment of gluten-free product safety.
abstract: Celiac patients should feel confident in the safety of foods labelled or expected to be gluten-free. In this context, a targeted proteomic approach based on liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) technique was proposed to assess the presence of celiotoxic cereals, namely wheat, oats, barley and rye, in raw and processed food products. To this aim, unique marker peptides were properly selected in order to distinguish between the different cereal types. A revised cocktail solution based on reducing and denaturing agents was exploited for prolamin extraction from raw and processed food; in addition, defatting with hexane was carried out for sample clean-up, allowing to largely reduce problems related to matrix effect. Method validation on fortified rice flour showed good analytical performance in terms of sensitivity (limits of detection in the 2-18 mg kg(-1) range). However, poor trueness was calculated for self-made incurred bread (between 3 and 30% depending on the peptide), probably due to baking processes, which reduce gluten extractability. Thus, it is evident that in the case of processed foods further insights into sample treatment efficiency and reference materials for protein calibration are required to obtain accurate gluten determination. Finally, the developed method was applied for the analysis of market food products, offering the possibility to discriminate among cereals, with good agreement with labelled ingredients for gluten-containing foodstuffs.
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Parma, Parco Area delle Scienze 17/A, 43124, Parma, Italy.
authors.forename: Anita
authors.initials: A
authors.lastname: Manfredi
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Parma, Parco Area delle Scienze 17/A, 43124, Parma, Italy. Electronic address: monica.mattarozzi@unipr.it.
authors.forename: Monica
authors.initials: M
authors.lastname: Mattarozzi
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Parma, Parco Area delle Scienze 17/A, 43124, Parma, Italy; Centro Interdipartimentale SITEIA.PR, Università degli Studi di Parma, Parco Area delle Scienze 181/A, 43124 Parma, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Giannetto
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Parma, Parco Area delle Scienze 17/A, 43124, Parma, Italy; Centro Interdipartimentale SITEIA.PR, Università degli Studi di Parma, Parco Area delle Scienze 181/A, 43124 Parma, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Careri
mesh_terms: D018554:Avena / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D055050:Diet, Gluten-Free; D005504:Food Analysis / Q000379:methods*; D001467:Hordeum / Q000737:chemistry*; D055315:Prolamins / Q000032:analysis*; D012434:Secale / Q000737:chemistry*; D053719:Tandem Mass Spectrometry; D014908:Triticum / Q000737:chemistry*
chemical_list: D055315:Prolamins
keywords: Bottom-up proteomic analysis; Celiac disease; Celiotoxic cereals; Gluten; Gluten-free food; Liquid chromatography-ion-trap tandem mass spectrometry