Evolution and Occurrence of 1,8-Cineole (Eucalyptol) in Australian Wine

Abstract

A new method has been developed for the quantitation of 1,8-cineole in red and white wines using headspace solid-phase microextraction (SPME) combined with stable isotope dilution analysis (SIDA) and gas chromatography-mass spectrometry (GC-MS). An extensive survey of Australian wines (44 white and 146 red) highlighted that only red wines contained significant amounts of 1,8-cineole (up to 20 μg/L). Hydrolytic studies with limonene and α-terpineol, putative precursors to 1,8-cineole, showed a very low conversion into 1,8-cineole (< 0.6%) over a 2 year period, which does not account for the difference between white and red wines. 1,8-Cineole was chemically stable in model wine solution over 2 years, and absorption from a Shiraz wine by bottle closures was most evident for a synthetic closure only (14% absorption after 1 year). Two commercial ferments at two different locations were monitored daily to investigate the evolution of 1,8-cineole throughout fermentation. Both ferments showed daily increases in 1,8-cineole concentration while in contact with grape solids, but this accumulation ceased immediately after pressing. This observation is consistent with the extraction of 1,8-cineole into the ferment from the solid portions of the grape berries.

Changes of Peel Essential Oil Composition of Four Tunisian Citrus during Fruit Maturation

“…Thus, camphor, which has green dry leave note [24], could mainly influence the aroma in the first stage of ripening while 1,8-cineole, characterised by a fresh and cool aroma [25], could participate actively to the citrus aroma at the middle stage. However, several minor compounds including α -terpinene (lemon aroma) [26], α -terpineol (green and floral-like aroma) [27], and carvacrol may influence the aroma at the mature stage.…”

Recent analyses using solid phase microextraction in industries related to food made into or from liquids

“…The concentration of terpenes in foodstuffs ranged from 0.4 ng/g of limonene in melons (Verzera et al, 2011) up to 1762 mg/L of the same terpene in mature clementines (Barboni, Muselli, Luro, Desjobert, & Costa, 2010). The aromas from terpenes were detected at the low mg/L concentrations making them important compounds in food production (Capone et al, 2011). They were often found in low concentrations in dairy and wine produce but can dominate the chemical composition of other fruit (e.g.…”

“…In wine, SPME analyses suggested that the terpenoid eucalyptol found in solution was not a by-product of terpene degradation but rather the contamination was coming from other sources (e.g. Eucalyptus trees) (Capone et al, 2011).…”

Quantifying the Contribution of Grape Hexoses to Wine Volatiles by High-Precision [U13C]-Glucose Tracer Studies

“…For example, limonene and α -terpeniol were added to model wines to evaluate the potential of these compounds to serve as precursors for 1,8-cineole (“eucalyptus” odor). 5 In another experiment, a glycoconjugate-enriched extract was added to a model juice medium prior to fermentation to quantify the contribution of yeast metabolic activity to the release of volatile aglycones. 6 Such approaches are appropriate for tracking must precursors at low initial concentrations, but are less useful for compounds with high endogenous concentrations (e.g., sugars, amino acids) where additions large enough to effect measurable changes in volatiles create the risk of altering microbial physiology.…”