Naringenin-lactoferrin binding: Impact on naringenin bitterness and thermodynamic characterization of the complex

•Bovine lactoferrin reduces the perception of naringenin bitterness.•Naringenin forms a 1:1 complex with lactoferrin.•The complex formation is mainly driven by the entropy increase.•Naringenin binds in a predominantly hydrophobic site on lactoferrin. Naringenin (NG) is a flavonoid with many bioactive properties, however, its bitterness limits its use in foods. It is known that complex formation with proteins can mask this undesirable sensory property. Therefore, a trained panel evaluated the effect of bovine lactoferrin (LF) on NG bitterness using time-intensity analysis. LF reduced the maximum bitterness intensity and overall bitterness perception for NG by 27% and 33%, respectively. Isothermal titration nanocalorimetry (ITC), molecular docking (DC), and molecular dynamics (MD) were used to characterize NG-LF binding. These techniques provided similar values of ΔG° for binding (ΔG°ITC = −33.42 kJ mol−1; ΔG°DC = −32.22 kJ mol−1; ΔG°MD = −31.84 kJ mol−1). ITC showed that the complex formation is primarily entropy driven and DC suggested that NG binds at a hydrophobic site in LF. Here are presented strategic tools for promoting NG incorporation in food and health products.