Effects of the oleic acid-rich glycerolipids and thermal-mechanical treatment on the functionality of wheat gluten: Multi-spectroscopy and molecular simulation analysis

Lipids have been used to regulate dough's processing characteristics; however, how they affect gluten properties remains unclear. In this study, the effects of different acid-based glycerolipids and thermomechanical treatments on gluten functionalities were investigated. The results demonstrated that exogenous oleic acid-based lipids regulate gluten secondary structure. Oleic acid increased the α-helix content and improved the viscoelasticity of gluten, whereas triolein and rapeseed oil reduced the viscoelasticity and enhanced its tensile properties. Thermomechanical treatment promoted the aggregation and formation of more disulfide bonds in gluten, whereas clear fluorescence quenching was observed in gluten-containing exogenous lipids. Moreover, molecular simulation analysis indicated that hydrogen bond and hydrophobic interactions are key non-covalent forces that promoted the interaction of exogenous lipids and gluten. Compared with other oleic acid-based glycerolipids, monoolein-gliadin systems exhibited the highest binding energies (−20.6 kJ/mol). Our results deepen the understanding of why oils and fats regulate the processing characteristics of wheat-based foods.