The effect of dough mixing speed and work input on the structure, digestibility and celiac immunogenicity of the gluten macropolymer within bread.

ABSTRACT

Modern high-speed mechanical dough development (MDD) alters the gluten macropolymer's (GMP) structure. Changes to both the protein and food matrix structure can influence protein digestibility and immunogenicity. This study investigated the relationship between protein structural changes imparted by MDD and gluten's digestibility plus celiac reactivity. Dough was prepared at three mixing speeds (63 rpm, 120 rpm and 200 rpm) to different degrees of development (between 10 and 180% wh.kg-1). Protein structural changes were characterised by confocal microscopy, free thiol determination and protein extractability assays. MDD altered the structure of gluten within bread, changing the protein's surface area and macrostructure. Breads were digested using the INFOGEST in vitro protocol. Gluten's antigenicity and digestibility were monitored using ELISA and mass spectrometry, by monitoring the concentration of six immunogenic peptides causative of celiac disease. The structural changes imparted by mixing did not affect bread's digestibility or celiac reactivity.