Interactions between Volatile Substances and Proteins             

Flavour binding may involve adsorption at the surface of food or penetration to the food interiority by diffusion (absorption). By adsorption we mean, a surface phenomenon that involves adhesion of  the molecules of gases, dissolved substances, or liquids in more or less concentrated form to the surface of solids/liquids with which they are in contact. Flavour binding by adsorption implies the mechanism of physical or chemical adsorption and hydrophobic interaction. Polar compounds, such as, alcohols are bound via hydrogen binding but  hydrophobic  interactions  with nonpolar amino acids predominate in the binding of low  molecular weight volatile compounds.

In some cases, volatile compounds bind to proteins via covalent linkages and the process is usually irreversible.  Irreversible fixation is more likely to occur with the volatiles of high molecular weight.