Quality assessment of dealcoholized wines produced by dialysis, osmotic distillation, and hybrid membrane technologies

This study investigates dealcoholization approaches, including dialysis (Dia), osmotic distillation (OD), and a hybrid membrane system combining nanofiltration (NF) and OD (NF-OD), for producing dealcoholized white wines ( ≤ 0.5 % v/v ethanol) in compliance with regulatory standards. Physicochemical results showed an increase in density for all dealcoholized wines (DWs). OD showed no significant change in the total dry extract, and an increase in acidity and glycerol content compared to the original wine (OW). In contrast, Dia caused significant losses in acidity (-63 %), glycerol (-45 %), and dry extract (-32 %), while NF-OD showed intermediate effects. Minerals were best retained in OD and NF-OD, whereas Dia induced severe depletion ( > 80 % loss of K, Ca, Mg). Colour parameters for OD/NF-OD remained stable ( Δ E < 1), while Dia showed perceptible differences ( Δ E = 1.30). GC–MS analysis showed more than a 73% reduction in volatile compounds in the produced DWs compared to OW, with esters and higher alcohols being the most affected. Sensory evaluation indicated reduced sweetness, hotness and body/fullness in all DWs, but NF-OD preserved acidity, bitterness, and overall acceptability comparable to OW, outperforming OD and Dia. NF-OD emerges as the optimal technique for quality preservation.