The Maillard reaction (MR) is a non-enzymatic reaction between reducing sugars and amino acids, resulting in the production of volatile and flavour-active compounds. Existing MR research primarily addresses thermally processed foods, whereas limited studies have evaluated low-temperature MR environments including sparkling wine. Sparkling wine is produced in low-temperature conditions (15 ± 3°C), with low pH (pH 3-3.4) and high acidity (titratable acidity 7-12 g/L) 1. Various MR species including furans, acryl amides, and heterocyclic amines have been identified in aged sparkling wines and contribute to roasted, caramel, and nutty aromas 2–4. The aim of this research was to investigate the composition of finished sparkling wine during 18-months of ageing by measuring the formation of target MR-associated compounds and the relative levels of precursor species (amino acids, reducing sugars). Variable liqueur de dosage sugar-types were assessed for their impact on MR-associated compounds during ageing. Liqueur de dosage (composed of sugar, wine, and SO2) is an addition made post-disgorgement, and these sugars may degrade or interact with amino acids, thereby influencing the formation of MR compounds. To the best of our knowledge, no prior literature has investigated the role of Liqueur de dosage in the MR. In this research, six dosage sugar treatments were evaluated including D-glucose, D-fructose, sucrose (cane-derived), sucrose (beet-derived), maltose, and commercial rectified grape must concentrate (RCGM), in addition to a zero-dosage/control (no sugar added). Treatments were carried out on 2015 vintage sparkling wine (3 years on lees; 59% Chardonnay, 41% Pinot Noir) produced by Niagara College Teaching Winery in Niagara-on-the-Lake, ON. Dosage treatments were prepared from the sparkling wine base to approximately 6 g/L residual sugar. Bottles were sealed with cork closures and cellared on-site at the Cool Climate Oenology & Viticulture Institute with environmental controls for temperature and humidity. At intervals of 0, 9 and 18-months post-dosage addition, triplicate bottles of each wine were chemically analyzed. MR-associated products were quantified by HS-SPME-GC-MS. Precursors including sugars and amino acids were quantified by enzymatic assay and NMR techniques, respectively, and sugar purity was determined by HPLC. After 18 months of aging post-disgorging, four MRPs showed concentration differences (p < 0.05) between dosage sugar treatments (ethyl 3-mercaptopropionate, furfuryl ethyl ether, 2-ethylthiazole, and 2-furyl methyl ketone). Changes in sugar and amino acid content during ageing were used to relate changes in MR compound formation with precursor consumption. This study establishes the effect of dosage sugar-type on the formation of volatile MR compounds in traditional method sparkling wines during ageing.
Authors: Charnock Hannah1, Pickering Gary J.1,2,3,4, Kemp Belinda S.1,2
*corresponding author: hc18ay@brocku.ca
1Department of Biological Sciences, Faculty of Mathematics & Science, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON, Canada, L2S 3A1
2Cool Climate Oenology & Viticulture Institute, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, ON, Canada, L2S 3A1
3National Wine and Grape Industry Center, Charles Sturt University, McKeown Drive, Wagga Wagga, NSW 2678, Australia
4Sustainability Research Centre, University of the Sunshine Coast, 90 Sippy Downs Drive, Sippy Downs, QLD 4556, Australia
References
1. Kemp, B.; Alexandre, H.; Robillard, B.; Marchal, R. J. Agric. Food Chem. 2015, 63 (1), 19–38.
2. Le Menn, N.; Marchand, S.; De Revel, G.; Demarville, D.; Laborde, D.; Marchal, R. J. Agric. Food Chem. 2017, 65 (11), 2345–2356.
3. Keim, H.; De Revel, G.; Marchand, S.; Bertrand, A. J. Agric. Food Chem. 2002, 50 (21), 5803–5807.
4. Marchand, S.; Almy, J.; de Revel, G. J. Food Sci. 2011, 76 (6), 861-868.
Keywords: sparkling wine, Maillard reaction, time-course ageing
