The aim of the study was to better understand the behaviour of wine aroma compounds in the mouth under real consumption conditions and using real wines.
EXPERIMENTAL LAYOUT:
- A rosé wine of low aromatic intensity was spiked with five aroma compounds typically found in wine: esters: isoamyl acetate (banana), ethyl hexanoate (apple), ethyl decanoate (grape); a terpene alcohol, linalool (floral); and one C13-norisoprenoid, β-ionone (violets).
- This rosé wine was divided into three experimental wines: a control and two wines spiked with two different commercial tannins.
- Nine individuals took part in the study. Individuals were instructed to take a sip of wine, rinse their mouths for 30 seconds without opening the soft palate, then spit out the wine and then swallow. They had to swallow every 60 seconds for four minutes.
- The nose space of the individuals were monitored with a Teflon nose piece that connected both nostrils of the subjects to a proton transfer reaction-mass spectrometer (PTR-MS) instrument, equipped with a Time-of-Flight (ToF). The connection was ergonomic thanks to the use of a light helmet that enabled the subjects move their heads freely.
- The stimulated (chewing Parafilm for five minutes) and un-stimulated salivary flow of the nine individuals and its effect on wine persistence were also measured.
- Protein content of the salivary samples were measured.
MAIN RESULTS:
- Results showed that wine aroma persistence was highly compound-dependent: while esters disappeared very fast, other compounds such as linalool and the β-ionone remained in the oral cavity for longer times after wine expectoration.
- A low effect of tannins (at 50 mg/L) on nasal cavity parameters was observed, with the exception for the compound ethyl decanoate (grape) that was significantly higher in the presence of tannins.
- Un-stimulated salivary flow correlated with higher aroma in the nose space.  That is because less saliva has a higher protein content that can retain aroma compounds better.
- Strong inter individual differences on aroma persistence were also found.
SIGNIFICANCE OF THE STUDY:
The most important finding of the study is that certain aroma compound classes remain in the mouth and nose spaces for longer than others. What this means is that wines with higher concentrations of terpenols and C13-norisoprenoids can possibly have longer aftertastes. Certain grape varieties naturally have higher concentrations of these two compound groups. Viticulturally these compounds increase with ripening. So by picking later, one can potentially increase your wine’s persistence.
The study also suggests that it is not advisable to chew plastic while drinking wine. It tends to mess with the wine’s aftertaste:).
REFERENCE:
Carolina Muñoz-González, Francis Canon, Gilles Feron, Elisabeth Guichard and Maria Angeles Pozo-Bayón (2019). Assessment Wine Aroma Persistence by Using an in Vivo PTR-ToF-MS Approach and Its Relationship with Salivary Parameters. Molecules, 24(7), 1277; https://doi.org/10.3390/molecules24071277
