Wine components and interactions influencing the in-mouth sensory properties of Australian wine

Summary

Objective

This project will develop fundamental knowledge about the compounds in wine that give rise to important in-mouth sensory properties, including tastes such as bitterness, savouriness and sweetness, as well as textural attributes such as astringency, viscosity and fullness. 

Recent work has found high concentrations of strong-tasting amino acids in Australian red wines from warm regions, which may add value to these products. Research will aim to understand how amino acids influence the in-mouth sensory properties of wine by interacting with other important taste-active wine components. 

For other tastes such as bitterness and savouriness, the project will aim to identify new target compounds, to understand their origin and impact in wine. Work will elucidate how these compounds can be manipulated in the vineyard and winery, allowing producers to more accurately achieve distinct wine styles. For all aspects of the project, a focus will be to understand the extent that interactions between compounds (or classes of compounds) underpin sensory response. Longer-term outcomes of the research will provide producers with strategies for the vineyard and winery to manage texture and taste outcomes in wine.

Background

The primary tastes of sweet, salty, sour, bitter and savoury (umami) are well defined and understood to direct our food choices. Overt bitterness in wine is generally considered unacceptable and it is important to identify and learn to control bitterants in wine. Savoury characters in wine, although commonly reported in tastings, are virtually unstudied. Sweet taste, even at low levels, can strongly drive consumer preferences of beverages. Although wine sweetness is often ascribed to residual sugar it does not explain the sensation often described by winemakers as 'fruit-sweetness', which appears in 'dry' red wines. Beyond these basic tastes, there are the mouth-feel sensations, such as astringency, fullness (body) and viscosity, which together elicit the more complex experience of wine texture.

Together with important volatile aroma compounds, wine non-volatile compounds strongly direct the in-mouth sensory experience. Since individual compounds rarely function in isolation to confer a given attribute in beverages and foods, understanding how compounds interact is critical to unravelling the mechanism(s) of sensory perception. It is recognised that in-mouth sensory properties, such as the taste and texture of a wine, are multi-modal experiences.

This project builds on findings from previous research in AWRI 1701-3.1.3 (Molecular drivers of wine texture and taste).