The Maillard reaction in traditional method sparkling wine

Abstract

The development of “aged” aromas in sparkling wine is often an indicator of quality and is characterized by caramel and toasted qualities. Compounds responsible for these aromas are derived via the Maillard reaction (MR), a non-enzymatic condensation between sugars and amino acids capable of generating a myriad of aroma compounds in a complex reaction cascade. During the production of traditional method sparkling wines, several major aging intervals take place, including the storage of reserve base wines, after the second alcoholic fermentation, and during the storage of finished wines. The work presented in this dissertation investigated the influence of amino acid and sugar precursors, plus the potential catalytic role of metal ions, on the formation of MR-associated products (MRPs) during base wine and sparkling wine aging. Four primary research objectives were addressed. The metal ion content of commercial sparkling wines produced in Niagara was established, and to our knowledge, this study represents the first report on sparkling wine metal profiles. Differences in metal composition were identified between production methods and styles, and calcium and magnesium were confirmed to be the most abundant divalent metal ions, highlighting their candidacy for involvement in MR pathways in wine. In a subsequent study, the influence of calcium and magnesium on the formation of MRPs was assessed in modified base wine treated with varying sugar and amino acid combinations during accelerated aging at 50 degrees C. Aging duration and amino acid additions were primary drivers of variation among MRPs, with calcium and magnesium having a lesser effect. A separate set of studies aimed to identify the impact of different sugar-types in dosage, the final sugar addition during production, on the formation of both MRPs and metabolite levels in sparkling wines during cellar aging. Aging duration had a greater influence on MRP and metabolite composition compared to sugar type, demonstrating that aging conditions for sparkling wine are central to the evolution of the wine matrix. This work contributes novel information to understanding the MR in mild conditions and can inform future research focused on optimizing sparkling wine composition and aging to enhance flavour in accordance with consumer preferences.