Proteomic Characterization of Wheat Protein Fractions Taken at Different Baking Conditions

Food processing conditions
affect the structure, solubility, and
therefore accurate detection of gluten proteins. We investigated the
influence of dough, bread, and pretzel making on the composition of
different wheat protein fractions obtained by Osborne fractionation.
The albumin/globulin, gliadin, and glutenin fractions from flour,
dough, crispbread, bread, and pretzel were analyzed using RP-HPLC,
SDS-PAGE, and untargeted nanoLC-MS/MS. This approach enabled an in-depth
profiling of the fractionated proteomes and related compositional
changes to processing conditions (mixing, heat, and alkali treatment).
Overall, heat treatment demonstrated the most pronounced effect. Label-free
quantitation revealed significant changes in the relative abundances
of 82 proteins within the fractions of bread crumb and crust in comparison
to flour. Certain gluten proteins showed shifts or reductions in particular
fractions, indicating their incorporation into the gluten network
through SS and non-SS cross-links. Other gluten proteins were enriched,
suggesting their limited involvement in the gluten network formation.