Chiral analysis of cis-2-methyl-4-propyl-1, 3-oxathiane and identification of cis-2, 4, 4, 6-tetramethyl-1, 3-oxathiane in wine. (30th September 2021)

• Record Type: Journal Article
• Authors: Wang, Xingchen; Capone, Dimitra L.; Roland, Aurélie; Jeffery, David W.
• Is Part Of: Food chemistry. Volume 357(2021)
• Publication Date: 2021-09-30
• Subjects: 3-Sulfanylhexan-1-ol -- 4-Methyl-4-sulfanylpentan-2-ol -- Enantiomers -- Stable isotope dilution assay -- Chiral analysis; 3-SH 3-sulfanylhexan-1-ol -- 3-SHA 3-sulfanylhexyl acetate -- 4-MSP 4-methyl-4-sulfanylpentan-2-one -- 4-MSPOH 4-methyl-4-sulfanylpentan-2-ol -- ANOVA analysis of variance -- cis-2-MPO cis-2-methyl-4-propyl-1, 3-oxathiane -- EI electron ionisation -- FB frozen berry -- FJ frozen juice -- GC–MS gas chromatography–mass spectrometry -- HS-SPME headspace–solid-phase microextraction -- LOD limit of detection -- LOQ limit of quantification -- LRI linear retention index -- NMR nuclear magnetic resonance -- ODT odour detection threshold -- p-TsOH p-toluenesulfonic acid -- Rs peak resolution -- SD standard deviation -- SIDA stable isotope dilution assay -- SIM selected ion monitoring -- TLC thin layer chromatography -- TTMO 2, 4, 4, 6-tetramethyl-1, 3-oxathiane; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2021.129406
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: HS-SPME GC–MS method developed for enantiomers of two oxathianes in wine. Strong enantiomeric correlations between 3-SH and its related oxathiane were shown. Chemical formation of oxathiane from 3-SH and acetaldehyde was verified in wine. First identification of cis -2, 4, 4, 6-tetramethyl-1, 3-oxathiane ( cis -TTMO) in wine. Odour threshold of cis -TTMO determined to be 14.9 µg/L in a neutral white wine. Abstract: cis -2-Methyl-4-propyl-1, 3-oxathiane ( cis -2-MPO), arising from 3-sulfanylhexan-1-ol (3-SH) and acetaldehyde, was recently identified in wine, but the enantiomeric distribution was unknown. Such information could reveal influences on wine aroma, given the impact of chirality on odorant molecules. Herein, a stable isotope dilution assay employing headspace solid-phase microextraction with chiral gas chromatography–mass spectrometry was developed, validated, and applied to a selection of wines. Studies with (3 R )-3-SH revealed the elution order of the cis -2-MPO enantiomers and the concentrations of (2 R, 4 S )-2-MPO and (2 S, 4 R )-2-MPO in the studied wines ranged from undetected to 250 ng/L and 303 ng/L, respectively. Strong positive correlations were found between (3 R )-3-SH and (2 S, 4 R )-2-MPO (r = 0.654), and (3 S )-3-SH and (2 R, 4 S )-2-MPO (r = 0.860). Additionally, cis -2, 4, 4, 6-tetramethyl-1, 3-oxathiane, constituted from acetaldehyde and 4-methyl-4-sulfanylpentan-2-ol (4-MSPOH), was identified in wine for the first time. This new 1, 3-oxathiane, which presents a novel fate for 4-MSPOH, was detected in wines as a single enantiomer at up to 28 ng/L.