title: Shear, heat and pH induced conformational changes of wheat gluten - Impact on antigenicity.
abstract: Processing can induce conformational changes of food proteins depending on the conditions used that may affect their antigenicity. This study investigated the effect of pH (3,5,7) temperature (80,90,100 °C) and shear (500,1000,1500 s(-1)) on the conformational changes (surface hydrophobicity, FTIR, SDS-PAGE and thiol content) of gluten in relation to its antigenicity (determined by Enzyme-linked Immunosorbent Assay). Overall, at pH 3, up to 90 °C, conformational changes and possible burial of some antigenic hydrophobic residues resulted in reduction of antigenicity to one-third that of control. Further heating to 100 °C caused increase in antigenicity due to exposure of some hidden epitopes. However, at pH 5 and 7, the antigenicity declined only at 100 °C due to modification in thiol content and related structural changes causing destruction and/or masking of some epitopes. Shear alone had no effect on antigenicity of gluten but could have a synergistic influence at pH 7 and 100 °C.
authors.affiliation: Advanced Food Systems Research Unit, College of Health and Biomedicine, Victoria University, Melbourne, VIC, Australia.
authors.forename: Toheder
authors.initials: T
authors.lastname: Rahaman
authors.affiliation: Advanced Food Systems Research Unit, College of Health and Biomedicine, Victoria University, Melbourne, VIC, Australia.
authors.forename: Todor
authors.initials: T
authors.lastname: Vasiljevic
authors.affiliation: Advanced Food Systems Research Unit, College of Health and Biomedicine, Victoria University, Melbourne, VIC, Australia. Electronic address: lata.ramchandran@vu.edu.au.
authors.forename: Lata
authors.initials: L
authors.lastname: Ramchandran
mesh_terms: D052179:Antigens, Plant / Q000737:chemistry* / Q000276:immunology; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D005983:Glutens / Q000737:chemistry* / Q000276:immunology*; D006358:Hot Temperature; D006801:Humans; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D011487:Protein Conformation; D033081:Shear Strength; D017550:Spectroscopy, Fourier Transform Infrared; D013438:Sulfhydryl Compounds / Q000032:analysis; D014908:Triticum / Q000276:immunology*
chemical_list: D052179:Antigens, Plant; D013438:Sulfhydryl Compounds; D005983:Glutens
keywords: Antigenicity; Conformation; Gluten; Heat; Shear; Wheat; pH