Damian will be speaking in Session 9. Fresh Science B. Click here to see more.
Grape amino acid concentrations are often measured in relation to fermentation performance. However, the most abundant amino acid in wine, L-proline, is not metabolised by yeast and is often not considered. L-proline and L-glutamic acid/glutamate concentrations can be found in red wine above their reported sensory detection thresholds. Overlooked by early wine flavour research, the question has remained, could amino acids play a role in wine flavour directly? A series of experiments assessed the sensory effect of proline and glutamate and their interactions with aroma compounds and polyphenols in red wine. L-proline was found to increase sweetness, viscosity and red fruit flavours, and decrease bitterness and astringency, while glutamic acid imparted umami taste. A blending study, aimed at correcting climate change-induced flavour deficiencies in wines from warm inland regions, assessed a high proline SA Riverland Cabernet Sauvignon wine blended with two other components. Optimal blends, as determined by consumer acceptance testing, contained a high proportion of the proline-rich wine, and displayed enhanced flavour and mouthfeel characters. Together these foundational studies elevate amino acids as a new and important class of taste-active compounds. These amino acids likely help to explain desirable ‘fruit sweetness’, ‘savoury’, ‘fullness’ and ‘soft tannins’ in dry reds.
Sensory Scientist Damian Espinase Nandorfy is a member of the Sensory and Flavour Research teams at the Australian Wine Research Institute in Adelaide, South Australia. Damian has over fifteen years of experience selling, making, researching, and enjoying wine. Originally from Canada, Damian holds an honours degree in Viticulture & Oenology from Brock University, a post-graduate certificate in Sensory & Consumer Science from UC Davis and is currently undertaking a PhD through the CASS Food Research Centre at Deakin University investigating the perceptual interactions of wine flavour compounds. Damian’s research focuses on relating ‘key’ food and beverage compounds, and their interactions, with sensory properties and consumer acceptance. He has a strong interest in neuroscience and views disciplines such as neurophysiology as the missing link between flavour chemistry and sensory science. His research studies seek to incorporate aspects of fundamental neurophysiological research with classical sensory and consumer science methods to help explain our everyday experience of beverages such as wine.