Grape quality parameters that influence wine flavour and aroma
To identify links between fruit composition and wine sensory outcomes to develop objective measures of fruit quality
Objective measures of fruit flavour potential and a way to predict wine sensory attributes from grape composition are required. This will allow for better decisions about harvest timing as well as batching and streaming of fruit to consistently produce desired wine styles. More importantly, it will provide tools to optimise grape flavour potential and assess quality in the vineyard and deliver the means of producing grapes with a desired chemical profile that can be used to make wines of a specified flavour profile.
This proposal aims to identify compounds in grapes or other parameters that could be used to predict wine sensory attributes known to be important to consumer preferences. As well as measuring the concentration of grape precursors or predictors, the activity of enzymes involved in their biosynthesis and berry physical properties will also be tested as potential markers of grape quality. The initial focus will be on compounds in grapes from the carotenoid and lipoxygenase pathways, which are implicated in general fruity flavours rather than specific varietal compounds. This will make the outcomes likely to be transferable to varieties other than those utilised in the project plan.
Work will commence on Cabernet Sauvignon grapes and wines to examine relationships between perceived aroma and aroma compounds, their precursors and grape physical properties, before including studies on Chardonnay. After 18 months, activities will extend to methods to measure enzyme activity and gene expression, using the same sample set.
The knowledge generated by this project on linking grape composition to wine flavour will allow researchers to assess whether these compounds or proxies can be used to objectively measure grape quality. Such tools would allow grape growers and winemakers to tailor wine style through measuring and monitoring compositional and biochemical parameters throughout the grapegrowing and winemaking process.