Higher alcohols and other volatiles in non or low alcoholic (NOLO) wines: insights from GC-FID and NMR analysis

Abstract

Climate change and changing consumer preferences are driving the growth of no- and low-alcohol (NOLO) wines, increasing the use of dealcoholization technologies such as reverse osmosis. However, ethanol reduction presents analytical and sensory challenges, particularly regarding accurate alcohol quantification and aroma preservation. This study evaluates the chemical profile of dealcoholized wines, with emphasis on higher alcohols and volatile compounds. Nuclear Magnetic Resonance (NMR) spectroscopy and Gas Chromatography–Flame Ionization Detection (GC-FID) were applied as complementary techniques to assess compositional changes in dealcoholized wines. Dealcoholization led to significant reductions in key aroma compounds, including ethyl acetate, alongside increased acetaldehyde levels, particularly in white wines, suggesting oxidation effects or altered yeast metabolism. Higher alcohols such as 3-methylbutan-1-ol and isobutanol also decreased, potentially affecting aroma and mouthfeel. NMR demonstrated strong performance for ethanol quantification at low concentrations, providing reliable results in complex wine matrices with minimal interference. These results highlight the need for robust analytical approaches and support NMR as a promising alternative for alcohol determination and quality control in NOLO wines.