An integrative salivary approach regarding palate cleansers in wine tasting

Wine sensory sessions normally involve the tasting of several samples, to remove food residues from the mouth the use of palate cleansers (PC) is needed. Until now, there is no agreement on the best PC to use during wine tasting sessions. The aim of this work is to study the relationship between the components retained in saliva after wine tasting and the remnant sensory feeling (astringency, alcohol, and acidity). For that, different common PC (water, carbonated water, and milk) were tested and saliva samples (expectorated and scraped) from nine trained panelists were collected after wine with and without PC trials. Results showed that after palate cleansing and not cleansing, astringency, alcoholic and acidity perception were influenced by time, PC and panelist. Astringency perception showed the greatest intensity in comparison to alcoholic and acidity. Milk was the only PC which reduced quantifiable polyphenols in expectorated saliva, as well as reducing astringency feelings. Although compositions of expectorated and scraped saliva correlated between them, polyphenols accumulated in the expectorated saliva significantly more. Retained polyphenols were correlated with astringency perception, but no correlation was found with salivary proteins. These findings assessed the astringency build-up effect during wine tasting due to polyphenols accumulation in saliva, remarking the importance of an adequate PC selection. All things considered, the present work confirmed the relationship between after-swallow mouthfeel perception and mouth residues instrumentally quantified. Also, milk has proven to be the most effective of the three PC.

[Practical applications] During tasting the accumulation of residues from previous wine samples tasted, could mislead the judgment of wine sensory qualities by oenologists. Therefore, between tasting samples it is highly important to choose the right PC. However, until now the selection of PC remains empirical, therefore in this work, we proposed to study the residues in saliva by using different PC and quantifying instrumentally, the wine residues. The methodology selected to quantify the wines residues in saliva was quick and easy to use. Furthermore, instrumental results were related with the sensory feeling of mouth cleanliness without considering individual panel member's preferences of PC. In this study, to remove astringency feeling, milk was shown to be the best cleanser in comparison with water, carbonated water or nothing, but oenologist/winemakers could use this instrumental methodology in saliva to select which one is the best among their current PC used.

The authors of this work were funded by the projects AGL2015-64522-C2-R-01 and RTC-2016-4556-1. L.L. would like to thank the Spanish “Juan de la Cierva” program for her contract (ref FJCI-2014-19907).

Peer reviewed