Study on the interaction of tannins and salivary proteins affecting wine aroma volatility: Static HS-SPME and molecular dynamics simulation approaches

The interaction between tannins and salivary proteins might affect intraoral aroma release during wine consumption. In this study, the influence and underlying mechanism of interactions between EGCG and IB5 (salivary proline-rich protein) on wine aroma compounds was analysed by static HS-SPME in vitro and molecular dynamics (MD) simulation. The interaction between IB5 and EGCG could significantly reduce the volatility of most aroma compounds in the model wine by 20 %-70 % (p < 0.05). MD simulations indicated that the energy received by aroma compounds in the mixed system was more pronounced. In addition, the decline rate of rational correlation functions (RCF) of aroma compounds in the mixed system was obviously slower. The analysis of the independent gradient model (IGM) indicated that aroma compounds combined with aggregates of IB5 and EGCG through hydrogen bonds and van der Waals forces. The effect of the interaction between EGCG and IB5 on aroma compounds was confirmed by the volatility and molecular computational simulation. Overall, the results enhance the understanding of the mechanisms affecting retronasal aroma release during wine consumption.