Aroma characteristics of 'Riesling' low-alcohol wine based on HS-SPME-GC-MS

'Riesling' low-alcohol wine was prepared from 'Riesling' dry white wine by using pervaporation method. The differences in volatile flavor components between 'Riesling' dry white wine and 'Riesling' low-alcohol wine were analyzed by headspace-solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). Key flavor substances were screened by relative odor activity value (ROAV), and the results were subjected to principal component analysis (PCA). The results showed that 48 and 35 volatile flavor substances were detected in 'Riesling' dry white wine and 'Riesling' low-alcohol wine, respectively. By using the osmotic evaporation method, the alcohol content of the dry white wine was significantly reduced from 11.01%vol to 1.52%vol (low-alcohol wine). Meanwhile, the proportion of acid and alcohol substances in the low-alcohol wine increased by 16.45% and 4.20%, respectively, while the proportion of esters decreased by 20.52%. Principal component analysis indicated that there were significant differences in volatile flavor components characteristics between the 2 types of wine samples, and the dry white wine and low-alcohol wine could be distinguished effectively by PCA. Eight key volatile flavor components substances (ROAV>1) were screened in the low-alcohol wine, including ethyl octanoate, α-ionone, and ethyl caproate, etc. These compounds contributed the fruity aromas of pineapple and apple, violet aroma, herbal aroma and woody aroma to the low-alcohol wines. The study provided a theoretical basis for the application of pervaporation technology in aroma regulation of low-alcohol wine production.