Popis: |
The aim of this research was to investigate the influence of off-vine drying of the grapes of Plavac mali cv. on the aromatic compounds of must in the production of traditional dessert wine Prošek. The grapes selected (23.8° Brix, pH value 3.76) for the experiment were taken from the germplasm of the Institute for Adriatic Crops and Karst Reclamation, harvested in 2009. They were dried in a glasshouse for 15 days at 21-37 °C. The must obtained from the dried grapes had 35.7° Brix, pH value 3.87 and total acidity of 8.34 g/L. SPME-GC-MS analysis was used to determine the volatile compounds before and after drying. Total acidity increased 1.96-fold during the process of drying. As many as 35 volatile compounds were determined and quantified. Their relative concentration in the must from dried grapes increased, especially the concentration of terpenes. Among terpenes, the most prevalent were 4-terpineol, linalool, linalool oxide, and cis- and trans-limonene epoxide. Norisoprenoids are products of degradation of carotenoids, among which β-damascenone was found in musts. Among higher alcohols, 3-methyl-1-butanol is quantitatively most significant component. Apart from the effect of concentration due to evaporation, anaerobic metabolism can also influence the increase of the volatile compounds ratio. |