Contamination of wines and spirits by phthalates: types of contaminants present, contamination sources and means of prevention.

This research determines the concentrations of various phthalates in French wines and grape spirits marketed in Europe or intended for export. Dibutyl phthalate (DBP), diethylhexyl phthalate (DEHP) and butyl benzyl phthalate (BBP) were the most frequently detected compounds in the wines analysed. While only 15% of the samples examined contained quantifiable concentrations (> 0.

Origin and incidence of 2-methoxy-3,5-dimethylpyrazine, a compound with a "fungal" and "corky" aroma found in cork stoppers and oak chips in contact with wines.

This study identifies a previously isolated bacterium as Rhizobium excellensis, a new species of proteobacteria able to form a large quantity of 2-methoxy-3,5-dimethylpyrazine (MDMP). R. excellensis actively synthesizes MDMP from L-alanine and L-leucine and, to a lesser extent, from L-phenylalanine and L-valine.

Identification of a new source of contamination of Quercus sp. oak wood by 2,4,6-trichloroanisole and its impact on the contamination of barrel-aged wines.

Thanks to practical experience in various wineries in recent years, it is now clear that, similarly to the well-known phenomenon in corks, there are several sources of unpredictable contamination of oak wood by 2,4,6-trichloroanisole (TCA). TCA affects staves in the same barrel very sporadically, with extremely limited contaminated areas on the surface that may reach several millimeters in depth. The precise origin of the TCP and TCA in oak wood is not known at this stage.

Rapid headspace solid-phase microextraction/gas chromatographic/mass spectrometric assay for the quantitative determination of some of the main odorants causing off-flavours in wine.

In this study we present a rapid and simultaneous assay method using headspace (HS) solid-phase microextraction (SPME)/gas chromatography (GC)/electron impact (EI) mass spectrometry (MS) (selected ion monitoring) for contaminants causing the principal organoleptic defects of wine (2,4,6-trichloroanisole, 2,3,4,6-tetrachloroanisole, pentachloroanisole, 2,4,6-tribromoanisole, 1-octen-3-ol, geosmin, 2-methylisoborneol, 3-isopropyl-2-methoxypyrazine, fenchol, fenchone, 2-methoxy-3,5-dimethylpyrazine, 4-ethylphenol, 4-ethylguaiacol, 4-vinylphenol, 4-vinylguaiacol, 3-isobutyl-2-methoxypyrazine, guaiacol and ethyl acetate). The method was validated according to protocols NF ISO 5725-1, 2 and NF V03-110. Its characteristics (limit of detection (LOD), limit of quantification (LOQ), uncertainties) were determined after having optimised the SPME parameters.

Identification and responsibility of 2,4,6-tribromoanisole in musty, corked odors in wine.

In this work, gas phase chromatography analysis coupled with selective selected ion monitoring (SIM) identified 2,4,6-tribromoanisole (TBA) in wines found on tasting to have significant "musty or corked" character, although they did not contain noteworthy quantities of chloroanisoles or chlorophenols, the contaminants generally reported to cause this type of defect. The perception thresholds were studied, together with contamination conditions during winemaking, storage, and bottle-aging. A "musty" off-odor was perceptible on smelling wine containing as little as 4 ng L(-)(1) TBA, and spoilage may be detected by retro-olfaction at even lower concentrations.