Electrically assisted extraction of soluble matter from chardonnay grape skins for polyphenol recovery.
The objective of this study was to investigate the effects of pulsed electric field (PEF) and high-voltage electrical discharges (HVED) application on the efficiency of aqueous extraction of total soluble matter and polyphenols from grape skins ( Vitis vinifera L.) at different temperatures within 20-60 degrees C. The highest level of polyphenol concentration C was reached after about 60 min of extraction for HVED treatment: C(HVED) = 21.4 +/- 0.8 micromol of gallic acid equivalent (GAE)/g of dry matter (DM). Almost the same level of C was reached after 180 min of extraction for the PEF-treated skins. These levels exceeded the value C = 19.1 +/- 0.5 micromol of GAE/g of DM for the untreated samples. The difference between degrees Brix values for HVED-treated and untreated systems decreased with temperature increase (from 40 to 60 degrees C), but a large difference in the total amount of polyphenols was observed for HVED-treated and untreated systems. The activation energies were W(u) = 31.3 +/- 3.7 kJ/mol and W(PEF) = 28.9 +/- 5.5 kJ/mol for untreated and PEF-treated systems, respectively.
Boussetta
Nadia
N
Unité Transformations Intégrées de la Matière Renouvelable and UMR 6022-CNRS, Génie Enzymatique et Cellulaire, Université de Technologie de Compiègne, Centre de Recherches de Royallieu, B.P. 20529, 60205 Compiègne Cedex, France. nadia.boussetta@utc.fr
Lebovka
Nikolaï
N
Vorobiev
Eugène
E
Adenier
Hervé
H
Bedel-Cloutour
Catherine
C
Lanoisellé
Jean-Louis
JL
D004553:Electric Conductivity; D004560:Electricity; D005419:Flavonoids / Q000032:analysis / Q000302:isolation & purification*; D005638:Fruit / Q000737:chemistry*; D010636:Phenols / Q000032:analysis / Q000302:isolation & purification*; D059808:Polyphenols; D013696:Temperature; D013816:Thermodynamics; D027843:Vitis / Q000737:chemistry*
D005419:Flavonoids; D010636:Phenols; D059808:Polyphenols