Measurement of saliva volume in the mouth of members of a trained sensory panel using a beetroot (Beta vulgaris) extract

The volume of saliva in the mouth of sensory panelists was measured by a dilution assay using a freshly prepared beetroot extract as probe solution. An aliquot of the extract absorbing linearly at 531-nm (probe) was placed in the mouth, mixed with saliva and returned to a clean container within a period of time shorter than the one spanning a single swallowing cycle. Beetroot pigments were neither partitioned into sub-fractions of saliva nor affected spectroscopically by their mixing with saliva. Three-milliliter was the minimum volume of probe per assay for a determination to be reliable. Observed volumes of saliva in the mouth of 13 panelists were distributed over the range 230–1310 μL with a median of 704 μL and a mean and standard deviation of 696 ± 312 μL. All but one of the subjects displayed salivary volumes within 1.41 standard deviations from the mean. Duplicate determinations per subject showed a median deviation of 13.5%. The procedure yielded highly repeatable and reproducible measurements.