Dimethyl sulfide transfers through closure during accelerated model wine ageing: proof-of-concept & prospects

Area of Science:

• Enology
• Food Chemistry
• Sensory Science

Background:

• Dimethyl sulfide (DMS) is a volatile sulfur compound influencing wine aroma.
• DMS concentration is critical for wine's sensory profile, contributing both desirable and undesirable notes.
• DMS typically accumulates during aging via S-methylmethionine (SMM) degradation.

Purpose of the Study:

• To investigate the potential loss of DMS through wine closures.
• To determine if DMS can permeate wine closures during bottle aging.
• To assess the impact of closure permeability on DMS levels in aged wine.

Main Methods:

• Model wines spiked with DMS were aged under accelerated conditions (35°C).
• Gas chromatography was used to detect DMS in Tenax tubes placed above bottles.
• Syrah wines sealed with closures of varying permeability were analyzed for DMS content after aging.

Main Results:

• DMS was detected in Tenax tubes, confirming permeation through closures, accounting for up to 12% of initial DMS.
• Syrah wines sealed with more permeable closures showed lower DMS concentrations post-aging.
• DMS levels increased in all Syrah wines due to SMM breakdown, but the net effect was influenced by closure permeability.

Conclusions:

• Wine closures are permeable to DMS, representing a previously unrecognized loss pathway.
• Closure permeability significantly influences the concentration of DMS and thus the aromatic evolution of aged wines.
• Selection of appropriate wine closures is crucial for managing DMS levels and maintaining wine quality during aging.