Positive interaction between amino and sulfhydryl groups for acrylamide removal

The reaction of acrylamide with glutamic acid (Glu), N-acetylcysteine (AcCys), glutamic acid/N-acetylcysteine mixture, glutathione (GSH), and cysteine was studied to analyze the combined action of amino and sulfhydryl groups on acrylamide reduction. Their reactivities for decreasing acrylamide content were inversely correlated (r = − 0.975, p = 0.025) to the Ea of the reaction and acrylamide disappearance decreased in the following order: Cys > GSH > AcCys >> Glu. In addition, Ea of acrylamide/nucleophile reactions seemed to be determined not only by the simultaneous presence of amino and sulfhydryl groups but also by the distance among them. Thus, when both groups were present in different molecules, an interaction between the protective effects of amino and sulfhydryl groups was only observed when small concentrations of AcCys and Glu were employed. However, this interaction was always positive when amino and sulfhydryl groups were simultaneously present in the same molecule and the closer the position of both groups, the higher the positive interaction observed. All these results suggest that, in the search of potential acrylamide-mitigating substances, nucleophiles should have both amino and sulfhydryl groups and these groups should be as close as possible in the molecule.