Characterization of Cider Brandy on the Basis of Aging Time

To characterize cider brandies on the basis of age, chemometric techniques (principal component analysis, linear discriminant analysis, and Bayesean analysis) together with contents of volatile, furanic, and phenolic compounds were used. Significant principal components computed by a double cross-validation procedure allowed us to visualize the structure of the database as a function of the aging time to which the cider brandies had been subjected. Feasible and robust discriminant rules were computed and validated by a cross-validation procedure that allowed suitable classification of fresh and aged brandies, obtaining classification hits >; 90%. The most discriminant variables for characterizing cider brandies according to their aging level were as follows: ethyl caprylate > ethyl isovalerate > 1-propanol > hexyl acetate

Main odorants in Jura flor-sherry wines. Relative contributions of sotolon, abhexon, and theaspirane-derived compounds

The aromatic profile of Jura flor-sherry wines (also called “yellow wines”) has been little studied. Only acetaldehyde, diethoxy-1,1-ethane, and sotolon have been described as key odorants. In the present work, three wines (vintages 2002 and 2003) were investigated by gas chromatography–mass spectrometry and gas chromatography–olfactometry (GC-O) aroma extract dilution analysis. The goal was to assess the relative impact of varietal, fermentation, and oak-barrel compounds by using two complementary extraction procedures. No grape terpenoids were found after the long barrel aging (6 years and 3 months). On the other hand, two candy/fruity esters issued from yeast exhibited high flavor dilution factor (FD) values: ethyl isobutyrate (64–1024) and ethyl isovalerate (128–1024). As expected, many oak-related odorants were found in the XAD 2 flavor extracts, mainly homofuraneol [2-ethyl-4-hydroxy-5-methyl-3(2H)-furanone] (cotton candy, FD = 16–256) and cis-β-methyloctalactone (butter, woody, FD = 256). Most probably issued from oxidation of the grape constituent theaspirane, an exceptional grenadine odor was perceived by GC-O up to dilution 64–1024. Chemical oxidation experiments and GC–high-resolution mass spectrometry (HRMS) allowed us to identify it as 4-hydroxy-7,8-dihydro-β-ionone (RICPsil5CB = 1373), a hydrolysis-derived product of dihydrodehydro-β-ionone. With an extraction dedicated to hydrophilic compounds, the key role of sotolon was confirmed (112–387 μg/kg; FD = 256–1024). This procedure enabled us to also evidence its ethyl analogue, abhexon (31–74 μg/kg; FD = 64–256)