Correlation among molecular structure, air/water interfacial behavior and foam properties of naringin-treated chickpea protein isolates

The effects of naringin treatment on molecular structure, interfacial adsorption behavior and foam properties of chickpea protein isolate (CPI) were investigated in this study. Exploration of intermolecular interactions shows that naringin and CPI can form complex through non-covalent interactions. The addition of naringin reduces the electrostatic repulsion on the protein surface and decreases the content of alpha-helices in the protein by about 1.98%, which may be closely related to the improvement of foaming properties. An in-depth investigation into the behavior of air/water interface reveals that the complex improves the foaming capacity of system by increasing surface activity and accelerating interfacial adsorption process. The system endows nanoparticles with excellent foaming stability by increasing the viscoelastic modulus of the interfacial film and reducing bubble size. In addition, the interfacial adsorption layer of complex is predominantly elastic. The foaming capacity of the system is the strongest when the mass ratio of CPI and naringin is 1:0.1 (88.01%), and the foaming stability is also improved (66.51%). Meanwhile, the system is also endowed with a higher antioxidant capacity. When naringin is added in excess (>0.4% w/v), insoluble substances successively appear in solution, the foaming capacity of the system and the viscoelasticity of the interfacial film show a decreasing trend. The results of this work suggest that the addition of naringin may be a potential strategy to enhance the foaming properties of proteins, and this work provides better insight into the foaming mechanism of small-molecule polyphenol-treated protein complexes.