LC‐DAD/ESI‐MS/MS study of phenolic compounds in ash (Fraxinus excelsior L. and F. americana L.) heartwood. Effect of toasting intensity at cooperage

Abstract

The phenolic composition of heartwood extracts from Fraxinus excelsior L. and F. americana L., both before and after toasting in cooperage, was studied using LC-DAD/ESI-MS/MS. Low-molecular weight (LMW) phenolic compounds, secoiridoids, phenylethanoid glycosides, dilignols and oligolignols compounds were detected, and 48 were identified, or tentatively characterized, on the basis of their retention time, UV/Vis and MS spectra, and MS fragmentation patterns. Some LMW phenolic compounds like protocatechuic acid and aldehyde, hydroxytyrosol and tyrosol, were unlike to those for oak wood, while ellagic and gallic acid were not found. The toasting of wood resulted in a progressive increase in lignin degradation products with regard to toasting intensity. The levels of some of these compounds in medium-toasted ash woods were much higher than those normally detected in toasted oak, highlighting vanillin levels, thus a more pronounced vanilla character can be expected when using toasted ash wood in the aging wines. Moreover, in seasoned wood, we found a great variety of phenolic compounds which had not been found in oak wood, especially oleuropein, ligstroside and olivil, along with verbascoside and isoverbascoside in F. excelsior, and oleoside in F. americana. Toasting mainly provoked their degradation, thus in medium-toasted wood, only four of them were detected. This resulted in a minor differentiation between toasted ash and oak woods. The absence of tannins in ash wood, which are very important in oak wood, is another peculiar characteristic that should be taken into account when considering its use in cooperage.

Nontargeted GC–MS approach for volatile profile of toasting in cherry, chestnut, false acacia, and ash wood

“…Therefore, we have not detected in untoasted and toasted ash wood any volatile compound that can be used as a potential marker, because all compounds present in this wood are also detected in at least one other. These results contrast with those obtained in its polyphenolic composition that shows clear qualitative differences regarding the three other studied species and oak, because a great variety of compounds such as secoiridoids, phenylethanoid glycosides, di and oligolignols can be used to discriminate untoasted ash wood. As a result, the quantitative differences of volatile composition are the only useful tools to identify toasted ash wood.…”

Comprehensive identification of 125 multifarious constituents in Shuang–huang–lian powder injection by HPLC-DAD-ESI-IT-TOF-MS

“…The molecular masses of peaks 63 and 76 were 146 Da (i.e. rhamnose) less than that of 77 and 81 [27]. Peaks 66 and 72 exhibited 14 Da less than that of 77 and 81, hinting rhamnose was replaced by xylose [28].…”

GC-MS, FTIR and 1H ,13C NMR Structural Analysis and Identification of Phenolic Compounds in Olive Mill Wastewater Extracted from Oued Oussefrou Effluent (Beni Mellal-Morocco)

“…The organic content of the polluted water is still quite complex with the presence of 23 constituents. The identification of different compounds was based on their mass spectra, compared with data base of NIST and the published results in the literature [5,9,[27][28][29][30][31][32][33][34]. The GC profile showed the presence of a great diversity of the identified compounds and highlights an important heterogeneity in the organic composition of the contaminated and charged water by OMWW.…”