Sustainability challenges in the wine sector have intensified the need for alternatives to conventional oak barrel maturation, a practice associated with high wood consumption, long maturation periods, and considerable economic and environmental cost. This study evaluates a resource-efficient maturation strategy for white wine using an experimental design comparing conventional oak alternatives with ultrasound-assisted extraction. Experiments were conducted in triplicate (n = 3) considering oak type (French chips vs. granules), dosage, toasting level (fresh, light, medium), and contact time (10 vs. 20 days). To enhance mass transfer, a 15 min ultrasound treatment (35 kHz) was applied. Statistical analysis (ANOVA One Way) indicated that oak fragment type and contact time significantly governed phenolic extraction (p < 0.05). Gallic acid concentrations increased significantly from 1.54 ± 0.03 mg L−1 in the control to 4.41 ± 0.12 mg L−1 in the most intensive ultrasound-assisted extraction treatment (p < 0.05). Syringaldehyde concentrations also showed a significant rise (1.13 to 1.44 mg L−1; p < 0.05). Ultrasound significantly accelerated extraction kinetics while mitigating the loss of flavan-3-ols (≤28%) compared to conventional oak treatments (up to 34%). Economic assessment demonstrated a substantial reduction in production costs, from 0.21–0.56 € L−1 range for standard fragment treatments to 0.05–0.07 € L−1 when ultrasound was applied. Cost-efficiency metrics (<0.03 € mg−1 gallic acid) confirmed that the combination of ultrasound and alternative oak materials provides an optimal, statistically significant balance between phenolic yield and economic viability.
Luchian et al. (Wed,) studied this question.