Perceptual properties of benzoic acid derivatives.

Sensory properties of equimolar concentrations of benzoic acid derivatives were examined using time-intensity procedures. Significant differences in maximum intensities (P < 0.005) were found for astringency, bitterness, prickling, sourness and sweetness. Although these compounds differed only in the number and position of the hydroxy groups, they exhibited quite different profiles. Gentisic acid had the highest sourness and bitterness maximum intensity, salicylic and gentisic acids were highest in astringency, and m-hydroxybenzoic acid was the sweetest sample. Benzoic acid had the highest intensity of prickling feeling which lasted 20 s longer than salicylic acid and 40 s longer than the other samples which elicited lowest intensity of prickling sensation.