CHANGES IN ANTIOXIDANT ACTIVITY, PHENOLIC CONTENT AND COLOUR CHARACTERISTICS OF RED WINES FOLLOWING DEALCOHOLISATION

10.62591/Scien.Tech.Bull-Chem.FoodSci.Eng.2025.22.04

Abstract

The increasing interest and demand for low-alcohol and alcohol-free beverages has encouraged wine
producers to invest in the development of processes able to reduce ethanol content while preserving the main
characteristics of wine. This study evaluated the effect of dealcoholisation by rotary evaporation under reduced pressure
on the antioxidant, phenolic and chromatic properties of two experimental red wine blends, designated as Rubra Nova
and Armony. Antioxidant activity was determined by the DPPH assay, total phenolic content by the Folin–Ciocâlteu
method, while colour characteristics and visible absorption profiles were evaluated by UV–Vis spectrophotometry.
Dealcoholisation caused only a slight decrease in DPPH radical inhibition in both wines, while total phenolic content
showed a small increase. More evident changes were observed in the chromatic parameters, particularly in colour
intensity and hue. However, the overall shape of the UV–Vis spectra remained similar before and after treatment. These
results indicate that rotary evaporation under reduced pressure largely preserved the antioxidant and phenolic
characteristics of the analysed wines, although some minor changes in their colour properties were observed.