title: Microwave-based treatments of wheat kernels do not abolish gluten epitopes implicated in celiac disease.
abstract: Microwave based treatment (MWT) of wet wheat kernels induced a striking reduction of gluten, up to <20 ppm as determined by R5-antibodybased ELISA, so that wheat could be labeled as gluten-free. In contrast, analysis of gluten peptides by G12 antibody-based ELISA, mass spectrometry-based proteomics and in vitro assay with T cells of celiac subjects, indicated no difference of antigenicity before and after MWT. SDS-PAGE analysis and Raman spectroscopy demonstrated that MWT simply induced conformational modifications, reducing alcohol solubility of gliadins and altering the access of R5-antibody to the gluten epitopes. Thus, MWT neither destroys gluten nor modifies chemically the toxic epitopes, contradicting the preliminary claims that MWT of wheat kernels detoxifies gluten. This study provides evidence that R5-antibody ELISA alone is not effective to determine gluten in thermally treated wheat products. Gluten epitopes in processed wheat should be monitored using strategies based on combined immunoassays with T cells from celiacs, G12-antibody ELISA after proteolysis and proper molecular characterization.
authors.affiliation: Institute of Protein Biochemistry, CNR, Naples, Italy.
authors.forename: Carmen
authors.initials: C
authors.lastname: Gianfrani
authors.affiliation: Institute of Food Sciences, CNR Avellino, Italy.
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Mamone
authors.affiliation: Department. of the Sciences of Agriculture, Food and Environment, University of Foggia, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: la Gatta
authors.affiliation: Institute of Food Sciences, CNR Avellino, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Camarca
authors.affiliation: Institute of Food Sciences, CNR Avellino, Italy; Department of Agriculture, University of Naples, Portici (Na), Italy.
authors.forename: Luigia
authors.initials: L
authors.lastname: Di Stasio
authors.affiliation: Institute of Food Sciences, CNR Avellino, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Maurano
authors.affiliation: Institute of Protein Biochemistry, CNR, Naples, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Picascia
authors.affiliation: Department of Clinical and Experimental Medicine, University of Foggia, Foggia (Italy) and National Institute of Nuclear Physics, Section of Bari, Italy.
authors.forename: Vito
authors.initials: V
authors.lastname: Capozzi
authors.affiliation: Department of Clinical and Experimental Medicine, University of Foggia, Foggia (Italy) and National Institute of Nuclear Physics, Section of Bari, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Perna
authors.affiliation: Institute of Food Sciences, CNR Avellino, Italy.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Picariello
authors.affiliation: Department. of the Sciences of Agriculture, Food and Environment, University of Foggia, Italy. Electronic address: aldo.diluccia@unifg.it.
authors.forename: Aldo
authors.initials: A
authors.lastname: Di Luccia
mesh_terms: D000293:Adolescent; D000328:Adult; D002446:Celiac Disease / Q000178:diet therapy* / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D000939:Epitopes / Q000276:immunology*; D005260:Female; D005983:Glutens / Q000276:immunology* / Q000528:radiation effects*; D006801:Humans; D008297:Male; D013058:Mass Spectrometry / Q000379:methods; D008872:Microwaves / Q000627:therapeutic use*; D010446:Peptide Fragments / Q000276:immunology; D040901:Proteomics; D013059:Spectrum Analysis, Raman / Q000379:methods; D013601:T-Lymphocytes / Q000276:immunology*; D014908:Triticum / Q000528:radiation effects*; D055815:Young Adult
chemical_list: D000939:Epitopes; D010446:Peptide Fragments; D005983:Glutens
keywords: Celiac disease; Gluten; Mass spectrometry-based proteomics; Microwave treatment; R5 and G12 ELISA; T cell assay