Evolution of volatile compounds during the maturation process of silver tequila in new French oak barrels

Abstract

New oak barrels from four French regions were used to mature Silver tequila 100% agave. Changes in minor volatile profile of tequila were evaluated through 32 maturation weeks. The generation and/or disappearance of volatile compounds was followed by using liquid-liquid batch extraction and subsequent GC/MS analysis of obtained samples. Globally, 173 compounds were identified, and 67 were relatively quantified. Analysis of variance exposed 10 individual compounds and the peak of 2-methoxyphenol + (2Z)-3,7-dimethylocta-2,6-dien-1-ol showing significant differences (p ≤ 0.05) between barrels’ origin and 49 compounds and the peak of 2-methoxyphenol + (2Z)-3,7-dimethylocta-2,6-dien-1-ol by maturation time. Compounds such as 2,6-dimethoxyphenol (p ≤ 0.030), 1-decanol (p ≤ 0.000), 2-methoxyphenol + (trans)-3,7-dimethyl-2,6-octadien-1-ol (p ≤ 0.038), 2-methylbutanoic acid (p ≤ 0.012), 3-methyl-1-butyl acetate (p ≤ 0.031), furan-2-carbaldehyde (p ≤ 0.010) and octanoic acid (p ≤ 0.043), marked significant differences by time and barrel origin. Forward stepwise general discriminant analysis made it possible to classify correctly 81.7% of the samples according to the barrel origin using 8 compounds and 96.7% according to the maturation time with 24 compounds. All the samples were correctly classified as tequilas in maturation transition (G, 2–8 weeks) and Aged tequilas (A, 10–32 weeks), from the changes in the minor volatile profile.