title: Pulsed electric field treatment enhanced stilbene content in Graciano, Tempranillo and Grenache grape varieties.
abstract: The purpose of this paper was to study the effect of pulsed electric fields (PEF) on the stilbene content of three grape varieties. For this purpose, four different PEF treatments were applied using a continuous system over three varieties, Graciano, Tempranillo and Grenache, destemmed and crushed. In addition, the influence of PEF on their physicochemical composition was studied. PEF treatments did not affect the pH or total acidity of Graciano, however, musts from Tempranillo and Grenache had higher pH values and lower total acidity. In the three varieties, all treatments resulted in an increase of potassium content, deeper colour intensity and total polyphenol index and lower tonality, more pronounced in the treatments with higher time and energy. The stilbene content of the must significantly increased with respect to the control. This increase depended on the variety and the treatment applied. Tempranillo increased up 200% the total stilbene concentration, Grenache 60% and Graciano 50%. For the three varieties, the treatment with the highest time and energy was the most effective on the total stilbene extraction. These results indicate that PEF could be a suitable technology for obtaining musts with deeper colour and higher phenolic content, including resveratrol and piceid.
authors.affiliation: Instituto de Ciencias de la Vid y del Vino (Gobierno de La Rioja-CSIC-Universidad de La Rioja), Ctra. Mendavia-Logroño NA 134, Km. 90, 26071 Logroño, La Rioja, Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: López-Alfaro
authors.forename: Lucía
authors.initials: L
authors.lastname: González-Arenzana
authors.forename: Noelia
authors.initials: N
authors.lastname: López
authors.forename: Pilar
authors.initials: P
authors.lastname: Santamaría
authors.forename: Rosa
authors.initials: R
authors.lastname: López
authors.forename: Teresa
authors.initials: T
authors.lastname: Garde-Cerdán
mesh_terms: D003116:Color; D004560:Electricity; D005511:Food Handling; D005638:Fruit / Q000737:chemistry*; D010936:Plant Extracts / Q000032:analysis*; D059808:Polyphenols / Q000032:analysis; D013267:Stilbenes / Q000032:analysis*; D027843:Vitis / Q000737:chemistry* / Q000145:classification
chemical_list: D010936:Plant Extracts; D059808:Polyphenols; D013267:Stilbenes
keywords: Antioxidant capacity; Must; PEF; Phenolic compounds; Piceid; Resveratrol