title: Changes on grape phenolic composition induced by grapevine foliar applications of phenylalanine and urea.
abstract: Grapevines may require the input of nitrogen to grow and to guarantee an appropriate grape composition. Recently there has been a growing interest in foliar fertilization, which entails a fast and efficient assimilation of the products. The aim of this work was to study the influence of foliar applications of phenylalanine and urea, at two different doses, on grape anthocyanins, flavonols, flavan-3-ols, phenolic acids, and stilbenes. All treatments were applied at veraison and one week later at doses of 0.9 and 1.5 kg N/ha. The results showed that the synthesis of phenolic compounds was favoured by foliar applications of phenylalanine and urea. The application of the lowest dose of urea was the most effective treatment, increasing the content of several anthocyanins and flavonols. Moreover, none of the foliar treatments worsened the grape phenolic composition. In conclusion, foliar application of phenylalanine and especially urea, could be an interesting management tool for improving grape quality and their health-promoting properties.
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, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Portu
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, Spain.
authors.forename: I
authors.initials: I
authors.lastname: López-Alfaro
authors.affiliation: Parque Científico y Tecnológico de Albacete, Paseo de la Innovación, 1, 02006 Albacete, Spain; Instituto Regional de Investigación Científica Aplicada, Universidad de Castilla-La Mancha, Campus Universitario s/n, 13071 Ciudad Real, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Gómez-Alonso
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, Spain.
authors.forename: R
authors.initials: R
authors.lastname: López
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, Spain. Electronic address: Teresa.GardeCerdan@gmail.com.
authors.forename: T
authors.initials: T
authors.lastname: Garde-Cerdán
mesh_terms: D005638:Fruit / Q000737:chemistry*; D010636:Phenols / Q000032:analysis; D010649:Phenylalanine / Q000737:chemistry*; D059808:Polyphenols / Q000737:chemistry*; D014508:Urea / Q000737:chemistry*; D027843:Vitis / Q000187:drug effects*
chemical_list: D010636:Phenols; D059808:Polyphenols; D010649:Phenylalanine; D014508:Urea
keywords: Anthocyanins; Flavonols; Grape; Nitrogen; Tempranillo; Vitis vinifera L.