Dr. Andrei Prida, Seguin Moreau’s Research & Development Manager, recently presented at the 2013 ASEV National Conference during an Enology – Flavor/Analysis Session.
Prida’s research presentation, “Evolution of Oak Lactone from Glycoconjugate Precursors during Toasting and Wine Maturation” addressed a study Prida undertook, with Kerry Wilkinson (The University of Adelaide, Australia) and Yoji Hayasaka (The Australian Wine Research Institute, Australia).
The study, “Evolution of oak lactone from glycoconjugate precursors during wine maturation,” published in the Journal of Agricultural & Food Chemistry in April 2013, addressed oak lactone’s occurrence in glycoconjugate precursor forms and not just as a natural component of oak wood.
The team looked at French oak and the oak lactone precursors (conjugated derivatives of 3-methyl-4-hydroxyoctanoic acid) by conducting aging trials and using liquid chromatography-tandem mass spectrometry. They followed the concentration of different acids (galloylglucoside, glucoside, and rutinoside) during first coopering and toasting and then later wine aging. The team tracked these precursors to determine their prevalence in the French oak as raw wood, toasted wood, and wood holding wine.
From their abstract, during barrel aging they found that:
“Maturation trials indicated the galloylglucoside undergoes acid-catalyzed hydrolysis after extraction into wine; after 12 months of maturation, the glucoside was the most abundant precursor, present at between 2- and 11-fold higher concentrations than those observed for powdered oak.”