Influence of Liqueur de Dosage Sugar Type on the Development of Maillard Reaction-Associated Products in Sparkling Wine
Hannah Charnock, Gary Pickering, and Belinda
Kemp*
*Cool Climate Oenology and Viticulture Institute (CCOVI) and
Dept. of Biological Sciences, Faculty of Math & Science, Brock
University, 1812 Sir Isaac Brock Way, St. Catharines, ON, L2S
3A1, Canada (bkemp@brocku.ca)
The Maillard Reaction (MR) is a non-enzymatic, multi-step reaction involving reducing sugars and amino acids, which produces a variety of volatile and flavor-active compounds. In aged sparkling wine, MR-associated products (MRPs), including furans, heterocycles, pyrazines, and thiazoles, have been identified and contribute distinct nutty, caramel, and roasted aromas. Liqueur de dosage (composed of sugar, wine, and SO2) is an addition made post-disgorgement. Sugars in dosage may degrade or interact with amino acids, thereby influencing the formation of MRPs. The aim of this study was to evaluate the influence of six dosage sugar-types: glucose, fructose, sucrose (cane-derived), sucrose (beet-derived), maltose, and rectified concentrated grape must, on the formation of MRPs in traditional method sparkling wine (2015 vintage; three years on lees; 59% Chardonnay, 41% Pinot noir) compared to zero-dosage wines (without sugar addition) over 18 months. Three bottles of each treatment were collected at 0, nine, and 18 months and analyzed in triplicate. MRPs were quantified by HS-SPME-GC-MS. Sugars and amino acids were quantified by enzymatic assay and NMR techniques, respectively, and sugar purity was measured by high-performance liquid chromatography. After 18 months of aging post-disgorging, four MRPs showed concentration differences between dosage sugar treatments at the 95% confidence interval (ethyl 3-mercaptopropionate, furfuryl ethyl ether, 2-ethylthiazole, and 2-furyl methyl ketone, with sensory descriptors of pleasant/fresh grape aroma, fruity, meaty/ savory, and balsamic, respectively). Final analysis of the 0-month sparkling wine samples is currently underway and we anticipate that formation of MRPs will increase with extended aging, due to slow rates of MR activity under low pH (~3.2), high acid (7-12 g/L titratable acidity), and low temperature (12 to 14°C) sparkling wine conditions. This study establishs the effect of sugar type on formation of volatile MRPs in traditional-method sparkling wines during aging after dosage addition.
Funding Support: Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery
