Disulphide interchange in dough proteins

Abstract

Appreciable disulphide interchange has been found between wheat proteins and cystamine when the latter was incorporated into doughs. If the extent of the protein‐protein reaction is of the same order it has been calculated that interchange of this magnitude would be enough to cross‐link the glutenin into a continuous structure. Cysteamine was more reactive than cystamine in the disulphide interchange reaction.

Changes in glutathione content (reduced and oxidised form) and the effect of ascorbic acid and potassium bromate on glutathione oxidation during dough mixing

“…12 The data reported here support this assumption. After addition of water to a flour its endogenous GSH is rapidly transformed to GSSG in the first minute of mixing.…”

“…In the literature a SH/SS-interchange reaction between low molecular SH-peptides such as GSH and the high molecular protein components of the gluten (left side of Figure 3) is discussed as one reason for the decrease in dough stability.ll. 12 The data reported here support this assumption. After addition of water to a flour its endogenous GSH is rapidly transformed to GSSG in the first minute of mixing.…”

Properties and Microstructure of Thermo-Pressed Wheat Gluten Films: a Comparison with Cast Films

“…Thus, the film formation may involve the formation of covalent bonds between prolamin chains. These cross-linkages should be due to disulfide bridges rearrangements resulting from the temperature treatment applied during thermo-pressing, since sulfhydryl/disulfide exchanges occur at high temperature in gluten. − It is the common suggestion that disulfide bridges may participate in the network connectivity and thus are responsible of at least a certain part of films mechanical strength. ,, To further investigate the role of these bridges and their rearrangements, gluten was treated with Nemi, to block free sulfhydryl groups and thus avoid or limit disulfide bridges rearrangements. A film was prepared from this Nemi-treated gluten by thermo-pressing, and both the gluten and the film were analyzed by sequential extraction and SE-HPLC (Table ).…”

Physical and Molecular Properties of Wheat Gluten Films Cast from Heated Film‐Forming Solutions

“…Besides formation of S-S bonds from free SH groups, most likely, sulfhydryl-disulfide interchange reactions also contribute to protein cross-linking by S-S bonds. Involvement of WG proteins in such interchange reactions has been reported (Stewart and Mauritzen, 1965;Redman and Ewart, 1967;Schofield et al, 1983). Similar film-formation mechanisms involving cross-linking by S-S bonds have been postulated for cast films from other sulfur-containing proteins such as soy protein (Gennadios and Weller, 1991), whey protein isolate (McHugh et al, 1994), and egg albumen (Gennadios et al, 1996b).…”