Sour and sweet taste identification and intensity perception as affected by oral rinses of various alcohol contents and wait period

Oral rinses are commonly used by consumers. Although menthol and alcohol are common ingredients in over-the-counter oral rinses, their sensory properties alone and in combination have not been studied extensively. The objective of this sensory study was to evaluate the effects that oral rinses have on a panelist's ability to identify tastants at their thresholds after rinsing and waiting a set period of time. The oral rinses evaluated were water, 3 alcohol concentrations-9, 18 and 27%. Tastant recognition and intensity were evaluated after 15, 30 or 60 min. Listerine® was the oral rinse of choice because it is the only American Dental Association (ADA) approved oral rinse. Before the panelists participated in this study they took part in a test to determine their recognition thresholds of all four basic tastes. Twenty-four panelists evaluated 24 oral rinse treatment combinations.

Oral rinse used and the length of wait period can play a role in panelists' ability to identify sweet and sour tastants correctly. Chi-square statistics showed that there are relationships prevalent in the oral rinse used and the length of wait period. As the alcohol concentration of the oral rinse increased, the panelists' ability to identify the samples decreased for both the sweet and sour tastant. The length of wait period had an influence on the ability of panelists to correctly identify the sour tastant. Analysis of variances of both the sweet and sour tastants found no significant differences (p>0.05) in the intensity levels assigned by panelists to correctly identified samples attributable to wait times, alcohol concentrations, or their interactions. With the sweet tastant, panelists perceived a second sample (above threshold) to be equal in intensity to the first sample (threshold). For the sour tastant results indicated panelists perceived the intensity of the second sample to be more intense than the first with means of 66.4 and 42.4, respectively. It was concluded that oral rinses used within 60 min of a sensory test may influence results. Therefore, directions to the panelists should be changed to include instructions not to use mouth care products before participating in a sensory panel.