Mechanistic evidence for the effect of sulphur-based additive: methionine, on acrylamide reduction

ABSTRACT

The unavoidable presence of acrylamide in foods has fuelled the search for a suitable food additive, one that can successfully mitigate dietary acrylamide levels without changing food quality or compromising the health of consumers. The purpose of this study was to investigate the effect of a sulphur-based additive and amino acid, methionine, on acrylamide reduction. Differential scanning calorimetry, supported by chromatographic measurements, has shown that methionine interacts with acrylamide at a possible optimum temperature of 160°C, thereby disfavouring acrylamide polymerisation. Analysis of the methionine–acrylamide interaction via density functional theoretical modelling (DFT/6-31 + G(d)/RCAM-B3LYP) revealed that methionine’s reducing effect may be driven by a Michael-type conjugation of the vinyl group of acrylamide at both the sulphur atom (∆G_f = −53 kJ mol⁻¹) and the amino group (∆G_f = −11.84 kJ mol⁻¹) of methionine. The former conjugation pathway results in a product that is more thermodynamically feasible.

Graphical abstract

KEYWORDS:

• Amino acid
• food toxin
• Maillard reaction
• Michael-type addition
• density functional theory
• differential scanning calorimetry
• liquid chromatography

Authors’ contributions

Authors DAA and GAB conceived the presented idea. Author DAA carried out the experiments, and wrote the manuscript with support from Authors PNN and GAB. Author PNN developed the theory and performed computations. Author GAB supervised the project, and managed proofreading and editing. All authors discussed the results and agreed upon the final manuscript.

Acknowledgments

This work was funded by the School of Graduate Studies and Research and the Department of Chemistry, The University of the West Indies (UWI), St. Augustine Campus. The authors would like to thank the Department of Chemistry at the Mona and St. Augustine Campuses (UWI) for instrumental and software support.

Conflicts of interest

Authors have declared that no conflicts of interest exist.

Ethical considerations

Authors have declared that there are no ethical considerations to be made.