| Abstract: | Astringency and sourness of lactic, acetic and citric acids,each adjusted to pH 3, 5 and 7, were evaluated in two experiments,one starting at equal concentrations in wt/vol before neutralizationand the second starting at equal molarity. Astringency and sournessdecreased with increasing pH. However, acids were differentiallysour at equal pH, consistent with previous findings. In contrast,the tactile attributes associated with astringency (drying,roughing of oral tissues and puckery/tightening sensations)were similar across acids; pH was the major influence on astringency.Strong dependence on pH suggests that astringency of these acidsis a direct result of their acidic properties, and not solelydue to the hydrogen bonding mechanisms previously suggestedas an explanation of astringency in tannin interactions withsalivary proteins. Chem. Senses 21: 397–403, 1996. |
