This project will investigate grape glycosides as a potential wine additive, including timing of additions and dose rates to achieve measurable sensory effects during wine consumption.
It has recently been demonstrated that glycosides are a valuable, novel opportunity to add flavour, through enzymatic release during winemaking but also by in-mouth breakdown during wine consumption, contributing flavour intensity and flavour persistence.
Glycoside extracts from various grape varieties will be characterised using non-targeted liquid and gas chromatography mass spectrometry analysis. The glycosides from different varieties will be extracted and partially purified, their stability investigated during fermentation and wine ageing, and their sensory impact assessed.
The concentration of residual precursors in wines following fermentation will be measured to determine whether these may act as quality markers.
Additional precursor systems such as thiol precursors will also be assessed, providing a complementary avenue for building additional flavour during wine consumption.
A better understanding of the factors underlying individual variability in sensory response to in-mouth release of precursors will be obtained.
This project will provide wine producers with the ability to extract flavour and flavour precursors from grape marc; a means to recover value from a winery by-product background and with an enhanced understanding of the flavour contributions of non-volatile precursors in grapes and wine.