From gluten structure to immunogenicity: Investigating the effects of lactic acid bacteria and yeast co-fermentation on wheat allergenicity in steamed buns.

The aim of this study was to explore the reduction of allergenic proteins in sourdough by selecting lactic acid bacteria (LAB) to promote protein hydrolysis while maintaining the techno-functional properties of steamed buns. Here, we measured the protein hydrolysis activity of 37 LAB strains and identified three strains with significant protein hydrolysis effects (L. sanfranciscensis Fs5, L. sanfranciscensis Ls5, and P. pentosaceus P.p7). Co-fermentation of LAB and yeast led to the depolymerization of gluten macromolecules and a more severe decrease in immunoreactivity (46.93 % ∼ 78.51 %). Quantitative proteome measurement was used to investigate the impact of fermentation on proteome composition and allergenic protein abundances of sourdough. 128 celiac disease-related proteins were identified, of which 127 were down-regulated after fermentation (decreased more than 50 %). These proteins mainly included low-molecular-weight glutenin subunits (33.07 %), α-/β-gliadin (21.26 %), and γ-gliadin (25.98 %). Sourdough steamed buns still maintained good specific volume, texture, and digestive properties while reducing immunogenicity.