Acolein in wine : bacterial origin and analytical detection

[摘要] ENGLISH ABSTRACT: Wine quality is compromised by the presence of 3-hydroxypropionaldehyde (3-HPA)due to spontaneous conversion into acrolein under wine making conditions. Acroleinis highly toxic and is presence has been correlated with the development ofbitterness in wine. Lactic acid bacterial strains isolated from South African red wine,Lactobacillus pentosus and Lactobacillus brevis, are implicated in accumulating 3-HPA during anaerobic glycerol fermentation. The environmental conditions leadingto its accumulation are elucidated. In aqueous solution 3-HPA undergoes reversibledimerization and hydration, resulting in an equilibrium state between differentderivatives. Interconversion between 3-HPA derivatives and acrolein is a complexand highly dynamic process driven by hydration and dehydration reactions. Acroleinis furthermore highly reactive and its steady-state concentration in complex systemsvery low. As a result analytical detection and quantification in solution is problematic.This study highlights the roles played by natural chemical derivatives and shows thatthe acrolein dimer can be used as a marker for indicating the presence of acrolein inwines. Solid-phase microextraction (SPME) coupled to gas chromatograph massspectrometry (GC-MS) was validated as a technique for direct detection of theacrolein dimer in wine. The potential of a recently introduced sorptive extractivetechnique with a sample enrichment probe (SEP) was also investigated. The SPMEtechnique simplifies the detection process and allows for rapid sampling of theacrolein marker, while SEP is more sensitive.

[发布机构] Stellenbosch University