Pulsed electric fields (PEF) is a promising technology for promoting the extraction of compounds from grape berries, during skin maceration. PEF promotes the electrically-induced formation of pores in the cell membranes, facilitating the migration of anthocyanins, proanthocyanidins and total phenolics in the juice, in an even more efficient way respect to pectolytic enzymes. The intensity of the treatment affects the final results. PEF processing of crushed grapes showed no effects on the behavior of alcoholic fermentation, as well as on juice and wine basic quality control parameters, with the exception of a slight increase of juice pH, which basically disappeared in the final wines. Wines processed by PEF were generally perceived as more colored and full-bodied. The latter characteristic might be connected with a higher HCl and ethanol index, reflecting a more favorable composition of tannins in PEF treated samples. When PEF treatment is carried out after crushingdestemming, the maximum color extraction observed during maceration was achieved immediately after the treatment; this makes PEF technology particularly useful for reducing the processing time, allowing its application in several situations, such as the vinification of low-ripe grapes, grapes affected by molds, or the production of concentrated musts from red grape varieties.
Application of Pulsed Electric Fields on crushed grapes
COMUZZO, Piergiorgio;
2016-01-01
Abstract
Pulsed electric fields (PEF) is a promising technology for promoting the extraction of compounds from grape berries, during skin maceration. PEF promotes the electrically-induced formation of pores in the cell membranes, facilitating the migration of anthocyanins, proanthocyanidins and total phenolics in the juice, in an even more efficient way respect to pectolytic enzymes. The intensity of the treatment affects the final results. PEF processing of crushed grapes showed no effects on the behavior of alcoholic fermentation, as well as on juice and wine basic quality control parameters, with the exception of a slight increase of juice pH, which basically disappeared in the final wines. Wines processed by PEF were generally perceived as more colored and full-bodied. The latter characteristic might be connected with a higher HCl and ethanol index, reflecting a more favorable composition of tannins in PEF treated samples. When PEF treatment is carried out after crushingdestemming, the maximum color extraction observed during maceration was achieved immediately after the treatment; this makes PEF technology particularly useful for reducing the processing time, allowing its application in several situations, such as the vinification of low-ripe grapes, grapes affected by molds, or the production of concentrated musts from red grape varieties.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
