Anyone who knows even a little about wine can tell you how important tannins are for wine quality, particularly in red wines. Surprisingly, however, we still don’t fully understand exactly how it is that tannins – or polyphenols – influence wine flavour, ageing, colour and colour stability. Wine is a highly complex and evolving mixture of many diverse compounds and no-one really knows how tannins – which come in several different kinds themselves – interact with other molecules in wine such as anthocyanins (colour compounds), proteins and polysaccharides (from grape berry cell walls).
Rachel Kilmister and Peta Faulkner from the Victorian Department of Environment and Primary Industries in Mildura joined forces with Nigel Kirby in September 2013 to determine the size and shape of a variety of tannins from wine and model systems. The aim was to obtain some preliminary information about tannin size and structure, and to develop the purification and SAXS techniques in tandem to enable further in-depth studies.