Análise dos ácidos clorogénicos e avaliação do seu papel na interacção Coffea a...

• Author(s): Leitão, Ana Sofia de Sousa Pinho
• Date: 2010
• Persistent ID: http://hdl.handle.net/10400.5/3144
• Origin: Repositório da UTL
• Subject(s): Coffea arabica; Hemileia vastatrix; chlorogenic acids; HPLC-DAD-MS/MS; ácidos clorogénicos; resistência
• Document Type: Master Thesis
• Language: Portuguese
• Advisor(s): Almeida, Maria Helena Guimarães

Description

Mestrado em Engenharia Alimentar - Instituto Superior de Agronomia This work aims to understand the role of chlorogenic acids (CGA) in the resistance response of coffee to leaf rust (Hemileia vastatrix) particularly during the hypersensitivity reaction. Young leaves of Coffea arabica S4 Agaro in the early stages of the infection (compatible and incompatible interactions) were analyzed by HPLC-DAD-ED and HPLC-MS/MS after extraction with methanol and water. Chlorogenic acids were identified by MS/MS and quantified using 3-CQA as an external standard. The chromatograms showed about 40 peaks where 27 CGA were identified, that correspond to about 460 µg/g of leaf. The total content of the CGA and other identified compounds in inoculated leaves (compatible and incompatible interaction) showed no significant differences when compared to the healthy leaves (control). The possible involvement of CGA in the resistance response of coffee to H. vastatrix was only evidenced for compounds present in peaks 7 and 29 (4,5-DICQA, CFQA, DiFQA, pCoFQA, trihidroxicinamoilquínico acid and a non identified compound), which increased in the incompatible interaction in the early stages of the infection process (by 30h after inoculation), being 4,5-DiCQA probably the CGA in greater concentration among them