Applied GC-MS: Analysis of Wine Samples
4-Methoxy-3-methyl phenol was detected in samples for the first time by our laboratory. It was
present at the highest level in both free and bound forms of any of the volatile phenolics. We were
unable to see references to this specific chemical in smoke tainted wine. While the odor threshold
of this chemical is unknown, it is likely similar to the 64-ppb level reported for 4-methylguaiacol
and is, therefore, likely the most significant smoky odor contributor of any of the volatile
phenolics. The contribution of glycosidically bound phenolics to smoky malodor is significant.
The results provide an indication of the extent of smoke taint odor/flavor actively present in the
wine and the potential for the release of additional smoke taint chemicals over shelf life. While
fermentation tends to free glycosidically bound chemicals, not all of these malodor chemicals may
be released. Over time, the smoke taint chemicals that remain bound to sugars in wine may be
released, increasing the smoky malodor of the wine during shelf life storage.
The sequential SBSE-GC-TOFMS provides an easy, solvent free method for determining both
free and bound phenolics.
- “Sequential Stir Bar Sorptive Extraction for Uniform Enrichment of Trace Amounts of Organic Pollutants in Water Samples”, N. Ochiai, K. Sasamoto, H. Kanda and E. Pfannkoch, J. Chrom. A, 1200 (2008) 72-791. “Sequential Stir Bar Sorptive Extraction for Uniform Enrichment of Trace Amounts of Organic Pollutants in Water Samples”, N. Ochiai, K. Sasamoto, H. Kanda and E. Pfannkoch, J. Chrom. A, 1200 (2008) 72-792.
- “Quantitating Organoleptic Volatile Phenols in Smoke-Exposed Vitis vinifere Berries”, M. Noestheden, K. Thiessen, E. Dennis, B. Tiet, and W. Zandberg, J. Agric. Food Chem., 2017, 65, 8418−8425. This method was recommended by Susan Ebler, UC Davis Enology Department.
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