Understanding polysulfide evolution in wine: insights from accelerated ageing and real-time cellaring in different packaging.

Volatile sulfur compounds (VSCs) and non-volatile biothiols play a crucial role in wine quality. Certain sulfhydryl compounds can react to form odourless polysulfides (RSSnSR') that potentially contribute to the development of sulfur off-odours during winemaking and storage. This study investigated the evolution of sulfur species in Chardonnay and Shiraz wine during real-time and accelerated ageing in glass bottles with different closures and in aluminium cans. Moderate glutathione (GSH) accumulation was accompanied by disulfide formation, with GSH trisulfide (GS-S-SG), tetrasulfide (GS-S2-SG), and mixed cysteine-GSH tetrasulfide (Cys-S2-SG) displaying compound- and matrix-specific trends. Can packaging maintained higher amounts of VSCs, sulfur dioxide, and GSH, whereas closures with varying oxygen transmission had the most pronounced impact on glutathione disulfide (GS-SG) accumulation. Treatment with nitrogen gas or copper exhibited preservation effects under accelerated ageing. These findings highlight the role of wine packaging on polysulfide chemistry and clarify the effects of pre-bottling strategies for VSC management.