16 research outputs found
The Relative Contribution of Ehrlich and Biosynthetic Pathways to the Formation of Fusel Alcohols
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
Adjustment of Nonlinear Models for Lignin and Its Degradation Products during the Aging of Armagnac
Studies on the Respiration of Whole Cells and Cell-Free Preparations of the Red Alga Porphyridium cruentum
A novel X-ray radiography approach for the characterization of granular activated carbons used in the rum production
Changes in the concentration of volatile oak compounds and esters in red wine stored for 18 months in re-used French oak barrels
Studies were made of changes in concentration of oak-wood-derived volatiles and the evolution of esters in red wine during storage in twice-used French oak barrels. Wine samples were taken after 8, 10, 12, 15, and 18 months maturation in the barrels. Results showed that most of the volatile compounds extracted from the wood (furanic compounds, volatile phenols, lactones) reached maximum concentration between 10 and 12 months of barrel storage. After 18 months of maturation many of the compounds showed concentrations similar to those found after 10 to 12 months. However, the concentrations of furfural, 5-methyl furfural, furfuryl alcohol, coniferaldehyde, acetovanillone and phenol in wines aged for 18 months were lower than those reached after 10 to 12 months. The concentration of the ethylphenols increased right up to 18 months of ageing, which can only have a negative impact on the quality of the wine. There were few modifications in the concentration of esters, except for ethyl lactate which reached peak concentration after 12 months maturation and decreased thereafter