Differences in the oral responsiveness to the bitter compound 6-n-propylthiouracil (PROP) between taster (T) and non-taster (NT) individuals have also been related to differences in the long-lasting wine astringency perception, which could be linked to differences in the dynamics of the salivary protein profile upon wine stimulation, depending on the individual PROP taste status (PTS). To check this, the time-course changes in the early protein salivary profile (30 and 60 seconds) after the oral stimulation with a red wine (CRW) and with the same tannin-enriched wine (TRW) in Ts and NTs (young women) were tested by using an untargeted proteomic approach. Results showed that Ts exhibited more pronounced protein changes (measured as the ratio of protein abundance before and after wine stimulation), compared to NTs, including proteins such as cystatins (SN, S, SA and D), alpha-amylase, prolactin (PIP), carbonic anhydrase VI (CA-VI) and acid proline-rich proteins (aPRP). These changes were more evident in 30 s (t1) than 60 s (t2) after the oral exposure to the wine and they were of higher magnitude after the exposure to TRW. These results suggest that differences in the salivary proteome profile induced by the oral stimulation with wine depending on PTS might contribute to explain individual variations in wine astringency perception over time.
