PEF-dependency on polyphenol extraction during maceration/fermentation of Grenache grapes

MAZA, MARCOS ANDRÉS; MARTÍNEZ, JUAN MANUEL; DELSO, CARLOTA; CAMARGO, ALEJANDRA; RASO, JAVIER; ÁLVAREZ, IGNACIO

INNOVATIVE FOOD SCIENCE & EMERGING TECHNOLOGIES

ELSEVIER SCI LTD

Año: 2020 vol. 60

1466-8564

Application to different electric field strengths (E) and specific energies (W) with the pulsed electric fields (PEF) technology on the rate of extraction of phenolic compounds during maceration/fermentation of Grenache grapes was studied. A response surface model between the total polyphenol index extraction rate (TPI) and the E and W of the PEF treatments was established, which permitted the determination of PEF processing conditions to achieve a certain TPI. To achieve a TPI of 50, treatments ranged from high intensity and short time (8 kV·cm− 1 and 45 μs) to low intensity and long time (1 kV·cm− 1 and 2800 μs) applying an optimum W of 4 kJ·kg− 1 in all cases. The application of these PEF treatments reduced maceration time by a rate of 25 to 37% with respect to the untreated grape. Quality characteristics (color intensity, tannins, and total anthocyanins) were neither affected after fermentation nor after 12 months aging in bottles.