## 4 Conclusions  
The use of static headspace analysis at equilibrium to study the interaction of aroma compounds with different types of oral components (centrifuged human saliva, artificial saliva with mucin, and buccal cells) in wines showed their significant effect on the volatility of four typical wine aroma compounds presenting different physicochemical characteristics (guaiacol, \(\beta\)-phenyl ethanol, ethyl hexanoate, and \(\beta\)-ionone). The extent of this effect depended on the type of aroma but also on the type of oral component. All tested aroma compounds showed higher volatiles in the wine systems containing BC. However, large differences in aroma volatility were found between wines with HS or AS. The lower volatility of some compounds (guaiacol, ethyl hexanoate) found in wines with HS can be related to their metabolic transformation by salivary enzymes; contrarily, the retention of the hydrophobic \(\beta\)-ionone by mucin present in AS can explain its lower volatility in this type of wines.  
Phenolic compounds also showed a different effect on aroma volatility depending on the type of odorants and the presence of different oral components in the wine. In general, gallic acid had little effect on polar compounds but it enhanced the volatility of the most hydrophobic ones (ethyl hexanoate and \(\beta\)-ionone). Furthermore, flavonoids significantly reduced the volatility of both polar (guaiacol and \(\beta\)-phenyl ethanol) and hydrophobic compounds (\(\beta\)-ionone in HS and BC wines), but through different mechanisms. The establishment of \(\pi\)-\(\pi\) interactions, in the case of the polar compounds (guaiacol, \(\beta\)-phenyl ethanol), or the formation of hydrophobic interactions in the case of \(\beta\)-ionone, are the most plausible mechanisms. However, flavonoid type polyphenols, and especially grape seed and wine extracts (constituted by procyanidins and anthocyanins respectively), enhanced the volatility of ethyl hexanoate, which might be due to the inhibition exerted by these phenolic compounds on some salivary enzymes (e.g., carboxyl esterase) involved in the metabolism of this odorant molecule.  
Overall, these results compare for the first time the impact of different types of oral components on wine aroma volatility, and also show the large relevance of these oral physiological components in the establishment of aroma-polyphenol interactions. Although the conditions used in this study do not exactly represent the dynamic situation of wine consumption, these results are highly valuable to help us in the understanding of the retronasal aroma release behavior of wine odorants during wine tasting.  
[PERSON] conceived the experiment. [PERSON] and [PERSON] conducted the analyses. [PERSON] and [PERSON] performed the data analysis. [PERSON] wrote the manuscript. All authors have read and agreed to the published version of the manuscript.  
This work was funded by the Spanish MINECO through the AGL201678936-R (AEI/FEDER, UE) Project. [PERSON] and [PERSON] thank the FPI and JdC programs (MINECO) for their PhD and postdoctoral contracts respectively. The authors also thank the technical assistance of [PERSON].  
The authors declare no conflict of interest.