Interactions between β-lactoglobulin and flavour compounds of different chemical classes. Impact of the protein on the odour perception of vanillin and eugenol

Abstract

Interactions between β-lactoglobulin and flavour compounds were analysed by instrumental and sensory studies. Affinity chromatography was used to determine binding constants of flavour substances belonging to different chemical classes. A systematic study on esters, pyrazines and phenolic compounds revealed that the increase in the hydrophobic chain length increases the affinity for the protein. Concerning the 4 diastereoisomers of 3-oxo-p-menthane-8-thiol, only the cistrans isomery led to different binding constants. In general, binding constants increased with increasing log P values, except for the terpenic compounds studied, for which another explanation has to be found, taking into account the geometry of the molecule. Sensory analyses applying a matching test showed that the addition of β-lactoglobulin had no effect on the odour perception of vanillin, but brought about a significant decrease in the odour perception of eugenol.