Interaction mechanism between cereal phenolic acids and gluten protein: protein structural changes and binding mode

Deciphering the interactions between altertoxins and glutenin based on molecular dynamic simulation: inspiration from detection

BACKGROUND

Mycotoxin contamination of food has been gaining increasing attention. Hidden mycotoxins that interact with biological macromolecules in food could make the detection of mycotoxins less accurate, potentially leading to the underestimation of the total exposure risk. Interactions of the mycotoxins alternariol (AOH) and alternariol monomethyl ether (AME) with high-molecular glutenin were explored in this study.

RESULTS

The recovery rates of AOH and AME (1, 2, and 10 μg kg-1) in three types of grains (rice, corn, and wheat) were relatively low. Molecular dynamics (MD) simulations indicated that AOH and AME bound to glutenin spontaneously. Hydrogen bonds and π-π stacking were the primary interaction forces at the binding sites. Alternariol with one additional hydroxyl group exhibited stronger binding affinity to glutenin than AME when analyzing average local ionization energy. The average interaction energy between AOH and glutenin was -80.68 KJ mol-1, whereas that of AME was -67.11 KJ mol-1.

CONCLUSION

This study revealed the mechanisms of the interactions between AOH (or AME) and high-molecular glutenin using MD and molecular docking. This could be useful in the development of effective methods to detect pollution levels. These results could also play an important role in the evaluation of the toxicological properties of bound altertoxins. © 2024 Society of Chemical Industry.

Molecular Mechanisms and Applications of Polyphenol-Protein Complexes with Antioxidant Properties: A Review

Proteins have been extensively studied for their outstanding functional properties, while polyphenols have been shown to possess biological activities such as antioxidant properties. There is increasing clarity about the enhanced functional properties as well as the potential application prospects for the polyphenol-protein complexes with antioxidant properties. It is both a means of protein modification to provide enhanced antioxidant capacity and a way to deliver or protect polyphenols from degradation. This review shows that polyphenol-protein complexes could be formed via non-covalent or covalent interactions. The methods to assess the complex's antioxidant capacity, including scavenging free radicals and preventing lipid peroxidation, are summarized. The combination mode, the type of protein or polyphenol, and the external conditions will be the factors affecting the antioxidant properties of the complexes. There are several food systems that can benefit from the enhanced antioxidant properties of polyphenol-protein complexes, including emulsions, gels, packaging films, and bioactive substance delivery systems. Further validation of the cellular and in vivo safety of the complexes and further expansion of the types and sources of proteins and polyphenols for forming complexes are urgently needed to be addressed. The review will provide effective information for expanding applications of proteins and polyphenols in the food industry.

The interaction between tea polyphenols and wheat gluten in dough formation and bread making

The effect of tea polyphenols (TPL) on the gluten network structure in TPL-fortified bread and dough systems was investigated. In the bread system, the addition of tea polyphenols (TPL) dose-dependently (0, 0.5, 1.0, 1.5, and 2%) deteriorated the bread quality in terms of the loaf volume, hardness and sensory properties. In the gluten dough system (2% TPL), farinograph results showed that the stability and development time of the bread dough were decreased, resulting in a weak dough with a significantly increased elastic modulus (G'). The disulfide bonds, key to the dough network formation, were decreased by 9.9 μmol g^-1 (24.2%), and their stability was also reduced due to the reduction (15.0%) of the relative content of the gauche-gauche-gauche structure. The addition of tea polyphenols also increased the internal hydrogen bonds and hydrophobic forces along with the increased random coil and decreased α-helix secondary structure of gluten. The water distribution experiment showed that the bound water peak in the nuclear magnetic resonance (NMR) spectrum disappeared, but the adsorbed water and free water were increased by 17.3% and 0.4%, respectively. Collectively, the interaction between wheat gluten and tea polyphenols affects the water-gluten relationship and the protein structure, which leads to a disrupted network structure of the wheat dough and deteriorated bread quality. Strategies to prevent gluten-phenolic interaction in functional bread preparation warrant further investigation.