This work aimed at providing some novel aspects pertaining to flavan-3-ols, flavonols and stilbenes extraction
from grape stems using high voltage electrical discharges (HVED). Treatment time, pH and ethanol concentration
affecting the extractability of these compounds were optimized through response surface methodology. The results
from the optimized extraction technique (pH = 2.5; Time = 4.0 ms: Ethanol = 50%) were compared to a
conventional hydro-alcoholic extraction.
HVED improved significantly the extraction of flavan-3-ols and flavonols but was less efficient on stilbenes. The
efficiency of HVED is directly correlated with the other processing conditions (pH, ethanol concentration).
Prolonged HVED treatment at low pH value was a positive combination for flavan-3-ols. The proposed procedure
(pH = 2.5; Time = 4.0 ms; Ethanol = 50%) allowed the release of almost 35% of additional phenolic compounds,
which can be attributed to a better extractability of flavan-3-ols (+21%) and of flavonols (+12%), compared to
conventional hydro-alcoholic extraction