Taste sensitivity in healthy adults: gustatory test validation and observational study

Gustatory sensitivity has important biological functions and taste disorders are generally difficult to diagnose and treat. The aim of this study was to investigate taste sensitivity on a sample of adult healthy patients through the validation and administration of a gustatory test, to describe a possible baseline of reference. A gustatory test was performed following a standardized protocol, using primary flavors solutions at 4 known increasing concentrations for a total of 16 sapid solutions. Taste sensitivity was investigated considering (a) the threshold of the flavor identification and (b) the intensity of stimulus perception. Seventy-one healthy patients were included in the study. Reliability measures were evaluated, supporting the validity of the test itself. Sweet, bitter, and salty flavors could be identified within the first concentration, sour flavor was detected within the second concentration in the majority of cases (p<0.05). Sour flavor showed the lowest value of perceived intensity for the less concentrated solution, sweet flavor showed the highest value. Regarding the most concentrated solution, bitter flavor showed the highest intensity value, while sour remained the lowest one. Both gender-based and age-based differences regarding threshold and intensity of perception were not statistically significant. However mean threshold averagely increased along with age. Within its limitations, this study validates a useful, easy-to-use tool for assessing taste function and it provides a possible baseline for perception of primary flavors in a healthy adult population, which can be used as a reference for future studies considering specific cohorts of patients.