Maillard crosslinking of food proteins II: the reactions of glutaraldehyde, formaldehyde and glyceraldehyde with wheat proteins in vitro and in situ

As part of a study of the effects of the Maillard reaction on food texture, we have established, in the preceding paper, the capacities of formaldehyde, glyceraldehyde and glutaraldehyde to crosslink a model protein. In this paper, we validate our model study using wheat proteins, both in vitro and in situ. All three molecules were found to crosslink all fractions of wheat proteins (albumins and globulins, gliadins, SDS-soluble glutenins and SDS-insoluble glutenins) in vitro, with glutaraldehyde being the most reactive. Of the four fractions of wheat proteins, gliadins proved the least susceptible to Maillard crosslinking. Crosslinking was accompanied by a loss of lysine residues in all cases. In situ, only glutaraldehyde underwent protein crosslinking, and the reaction was specific to the albumin and globulin fraction. In the following paper, we explore the effects that this specific crosslinking of albumins and globulins in dough has on the texture of bread and croissants.