Phenolic compounds in juice of “Isabel” grape treated with abscisic acid for color improvement

¹ Departamento de Agronomia, Universidade Estadual de Londrina. Rodovia Celso Garcia Cid (PR 445), km 380, PO Box 10.011, ZIP 86057-970, Londrina, PR, Brazil
² Departamento de Fitotecnia, Universidade Federal de Pelotas, Campus Universitário s/n Capão do Leão, 96010-610, Pelotas, RS, Brazil
³ Departamento de Química, Universidade Estadual de Londrina, Laboratório DIA, Rodovia Celso Garcia Cid (PR 445), km 380, PO Box 10.011, ZIP 86057-970, Londrina, PR, Brazil
⁴ Instituto de la Vid y el Vino de Castilla-La Mancha, Carretera Toledo-Albacete s/n, 13700 Tomelloso, Spain
⁵ Instituto Regional de Investigación Científica Aplicada, Universidad de Castilla-La Mancha, Campus Universitario s/n, 13071 Ciudad Real, Spain

^a Corresponding author: isidro.hermosin@uclm.es

Abstract

Isabel grape is the main cultivar used to produce juice in Brazil, which has rusticity and high productivity, but it is deficient in anthocyanins, a pigment responsible for the color. Thus, an alternative is the application of abscisic acid (S-ABA), which is responsible to promote the synthesis of anthocyanins. The aim of this work was to evaluate the phenolic compounds composition in “Isabel” grape juice treated with S-ABA, by HPLC-DAD–ESI-MS/MS technique. The results showed the increasing in total anthocyanin concentration in juices, with S-ABA treatments, as well as the proportion of B-ring tri-substituted anthocyanidins. Regarding total flavonols, differences were only significant in juices obtained in 2012 season. S-ABA treatments did not significantly affect the hydroxycinnamic acid derivatives, flavan-3-ols, resveratrol and antioxidant capacity of juices. Juice from “Isabel” grapes treated with S-ABA provides an enhancement of total anthocyanin concentration, mainly when grapes are treated before or at the onset of véraison.