beta-lactoglobulin (bLg) is known to interact with aroma compounds affecting their release, and hence, their perception. bLg, composed of two hydrophobic binding sites, was used as a simple model food protein to investigate binding mechanisms as a function of ligand nature. Indeed, binding of small ligands to bLg sites is often selective, although some ligands bind to both sites. Interactions between bLg and one ketone, beta-ionone, and one phenol, guaiacol were investigated by combining two techniques: 2D Nuclear Magnetic Resonance for binding site location, and fluorescence using the 6-propionyl-2-(N, N-dimethylamino)naphthalene (PRODAN) probe for surface hydrophobicity determination. While beta-ionone may preferentially bind onto protein surface and compete with PRODAN for the same binding sites, guaiacol affected the chemical shifts of residues located at the entrance of the central cavity and does not prevent PRODAN from binding.