Comparison of Procedures for Resveratrol Analysis in Beer: Assessment of Stilbenoids Stability through Wort Fermentation and Beer Aging

Abstract

Three resveratrol extraction procedures were compared in beer. Two-step pre-cleaning with toluene and cyclohexane allows 76% trans-resveratrol recovery by solid-phase extraction (SPE) before RP-HPLC-MS/MS analysis. This procedure proved much more efficient than liquid/liquid extraction, which requires solvents that are too hydrophobic for stilbenoids. SPME-GC-MS, where the main limiting factor is non-reproducibility from fibre to fibre, is an interesting alternative for resveratrol quantification in complex mixtures where pre-cleaning is too difficult. With the optimized SPE procedure, 5 µg.L 1 trans-resveratrol was detected in four commercial beers. However, concentrations of stilbenoids in beer should be higher taking into account the presence of cis-stilbenoids. During fermentation, trans-resveratrol was partially regenerated from its glucoside, more stable through beer aging. Adding a stilbenoids-enriched ethanolic hop extract after fermentation significantly increases the beer stilbenoids potential.

Profile of Volatile Compounds in 12 Chinese Soy Sauces Produced by a High-Salt-Diluted State Fermentation

“…It has also been employed for the analysis of volatiles and aroma compounds in soy sauce 1,16,34 . However, the main limiting factor of SPME is non-reproducibility from fibre to fibre 13 . Thus if possible, the same fibre should be employed during an experiment in order to ensure the accuracy of results.…”

Analytical Methods for Determination of Polyphenols in Beer

“…Later, trans-resveratrol and trans-piceid were identified in red sorghum grains, which are used in African countries for local production (Bröhan et al, 2011). Stilbenoids, specifically trans-resveratrol, cis-resveratrol, trans-piceid, and cis-piceid, have also been found in beer (Jerkovic et al, 2008;Chiva-Blanch et al, 2011).…”

“…Two procedures based on solid-phase microextraction (SPME) combined with GC-MS and HPLC-MS/MS, with atmospheric pressure chemical ionization (APCI), were compared for analysis of both stilbenoids (Jerkovic et al, 2008). The results showed that SPME-GC-MS allows the direct determination of transresveratrol (detection limit (LOD): 5 μg/l), without previous pre-cleaning and long extraction steps, although a derivatization by silylation has to be performed due to the low volatility of this stilbenoid.…”

“…The analytical signal was measured in the solid-phase, after the retention of the monitored species on an appropriate solid-support (Sephadex QAE A-25) filling the flow-cell. Delipidation of the samples was carried out by following a previously reported method (Jerkovic et al, 2008) and, next, resveratrol was extracted by a SPE procedure, using C 18 cartridges and methanol as eluent. The interference of piceid was circumvented by eluting this from the cartridge with 40% methanol before eluting resveratrol.…”

The Modern Art of Identification of Natural Substances in Whole Plants

“…For example, Muñoz-González et al (2012) carried out a liquid-liquid extraction of phenolic acids using ethylacetate in acidic condition prior to their analysis by gas chromatography coupled to mass spectrometry (GC-MS). A similar approach was conducted for the extraction of resveratrol and other stilbenoids from beer (Jerkovic et al 2008) before their analysis by liquid chromatography coupled to mass spectrometry (LC-MS)…”