Sensory characterization during repeated ingestion of small-molecular-weight phenolic acids

Characterization of the sensory properties of small-molecular-weight phenolic acids such as ferulic and vanillic acids has been limited. The objectives of this study were to characterize the sensory perceptions of these acids and the effects of their repeated consumption on sourness, bitterness and astringency. This knowledge will further the understanding of the impact of these acids on the sensory characteristics of foods in which they are typically consumed.

Two time-intensity sensory evaluation experiments were conducted with nine trained panelists: a single-sip study and a sequential-sip study. Concentrations of phenolic acids typically found in whole grain bread were tested. For both experiments, vanillic acid was perceived to be significantly more sour than ferulic acid, and ferulic acid was perceived to be significantly more bitter than vanillic acid. Maximum sourness, bitterness and astringency intensities significantly increased with increasing molarity for both acids. During sequential sipping, astringency and bitterness intensity increased with each sip. Sourness, however, increased to sip 3 but did not significantly increase after that point.

This research demonstrates that even small quantities of phenolic acids can be perceived as increasingly bitter and astringent with repeated exposures.