La macération pelliculaire dans la vinification en blanc. Incidence sur la composante volatile des moûts

Abstract

The effect of skin contact on the composition of volatiles in the three varieties Chenin, Chardonnay and Bourboulenc was studied using gas chromatography. 32 components were identified in all the musts : 6 alcohols with 6 carbon atoms, 12 other alcohols, 4 carbonyl compounds, 2 lactones, 1 phenol, 6 terpenols and 1 ester. These were assayed in triplicate. Analysis of variance was carried out to determine whether skin contact made a significant contribution to the variability observed in the extracts. Musts prepared with skin contact were all richer (2.3 to 2.8 times) in all the volatiles assayed than the control musts. Aldehydes and alcohols with 6 carbon atoms were quantitatively the most important (2 to 3 times more plentiful in skin contact musts) and formed 58 to 93 p. 100 of the components determined. Principal component analysis was carried out to classify the musts according to the neutral volatiles that they contained ; this was effected using the components that were significantly different quantitatively according to the type of must.