Effects of salt and kansui on rheological, chemical and structural properties of noodle dough during repeated sheeting process

•Both salt and kansui could increase the rupture stress. Salt could increase while kansui decrease the rupture elongation.•The large polymeric glutenin (LPP) disaggregated from glutenin macropolymer (GMP) through physical disentanglement.•The addition of kansui especially at 1% concentration could inhibit the disaggregation of GMP through protein cross-linking. Effects of different levels of salt (1–2%, fwb) and kansui (0.5–1%) on the rheological, chemical and structural characteristics of noodle dough developed by repeated sheeting were studied. The rupture stress was increased by salt and kansui. The rupture elongation was increased by salt while reduced by kansui. The rupture stress and elongation increased to a maximum at 3 or 4 sheeting passes then decreased. The larger polymeric glutenin (LPP) increased while glutenin macropolymer (GMP) and free SH contents declined with the increased sheeting passes except for the dough contained 1% kansui at which these indicators remained constant. The β-sheet was increased while the β-turn was decreased by salt and kansui. The results showed the LPP disaggregated from GMP through physical disentanglement and experienced a reaggregation process with the SS bonds participate in, but the addition of kansui especially at 1% concentration could inhibit the disaggregation of GMP through protein cross-linking.