Guaiacol and 4‑Methylphenol as Specific Markers of Torrefied Malts.Fate of Volatile Phenols in Special Beers through Aging
(2014) Journal of Agricultural and Food Chemistry — Vol. 62, n° 39, p. 9522-9528 (2014)
Files
scholtes.pdf
Restricted Access - Adobe PDF
- 1.97 MB
Details
- Authors
- Abstract
- Phenol-specific extracts of 12 Belgian special beers were analyzed by gas chromatography hyphenated to olfactometry (AEDA procedure) and mass spectrometry (single ion monitoring mode). As guaiacol and 4-methylphenol were revealed to be more concentrated in brown beers (>3.5 and >1.1 μg/L, respectively), they are proposed as specific markers of the utilization of dark malts. Analysis of five differently colored malts (5, 50, 500, 900, and 1500 °EBC) allowed confirmation of high levels of guaiacol (>180 μg/L; values given in wort, for 100% specialty malt) and 4-methylphenol (>7 μg/L) for chocolate and black malts only (versus respectively <3 μg/L and undetected in all other worts). Monitoring of beer aging highlighted major differences between phenols. Guaiacol and 4-methylphenol appeared even more concentrated in dark beers after 14 months of aging, reaching levels not far from their sensory thresholds. 4-Vinylphenols and 4-ethylphenols, on the contrary, proved to be gradually degraded in POF(+)-yeast-derived beers. Vanillin exhibited an interesting pattern: in beers initially containing <25 μg/L, the vanillin concentration increased over a 14 month aging period to levels exceeding its sensory threshold (up to 160 μg/L). Beers initially showing an above-threshold level of vanillin displayed a decrease during aging.
- Affiliations
Citations
Scholtes, C., Nizet, S., & Collin, S. (2014). Guaiacol and 4‑Methylphenol as Specific Markers of Torrefied Malts.Fate of Volatile Phenols in Special Beers through Aging. Journal of Agricultural and Food Chemistry, 62(39), 9522-9528. https://doi.org/10.1021/jf5015654 (Original work published 2014)