Influence of salts on the protein composition and functionality of gluten

Different salts were added to gluten to investigate the effects of different cations on a fully developed gluten network. The chloride salts KCl, NaCl, MgCl$_2$, CaCl$_2$ were mixed with pre-isolated wet gluten in a low and high dose, and the gluten was dried at 40 °C and 80 °C to yield vital gluten. The impact of the individual cations on the gluten protein composition and functionality was determined by analysis of chemical and rheological properties of vital and wet gluten. All cations influenced the gluten protein composition and the rheological behaviour. While the observed changes could not be attributed to the order of the Hofmeister series, monovalent, kosmotropic cations K$^+$ and Na$^+$ and divalent, chaotropic cations Mg$^{2+}$ and Ca$^{2+}$ showed similar behaviour in terms of protein composition and functional properties. Salts therefore have an influence on the gluten protein composition of a fully developed gluten network and gluten protein composition and functionality can be altered by an after-treatment process in a targeted way.