The role of ascorbate peroxidase, guaiacol peroxidase, and polysaccharides in cassava (Manihot esculenta Crantz) roots under postharvest physiological deterioration

Abstract This study aimed to investigate the role of ascorbate peroxidase (APX), guaiacol peroxidase (GPX), polysaccharides, and protein contents associated with the early events of postharvest physiological deterioration (PPD) in cassava roots. Increases in APX and GPX activity, as well as total pr...

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Bibliographic Details
Main Author: Uarrota, Virgílio Gavicho (author)
Other Authors: Moresco, Rodolfo (author), Schmidt, Eder Carlos (author), Bouzon, Zenilda Laurita (author), Nunes, Eduardo da Costa (author), Neubert, Enilto de Oliveira (author), Peruch, Luiz Augusto Martins (author), Rocha, Miguel (author), Maraschin, Marcelo (author)
Format: article
Language:eng
Published: 2016
Subjects:
Antioxidant enzymes
Cassava roots
Postharvest
L-ascorbic acid peroxidase
Polysaccharides
Science & Technology
Online Access:http://hdl.handle.net/1822/38530
Country:Portugal
Oai:oai:repositorium.sdum.uminho.pt:1822/38530
Description
Summary:Abstract This study aimed to investigate the role of ascorbate peroxidase (APX), guaiacol peroxidase (GPX), polysaccharides, and protein contents associated with the early events of postharvest physiological deterioration (PPD) in cassava roots. Increases in APX and GPX activity, as well as total protein contents occurred from 3 to 5 days of storage and were correlated with the delay of PPD. Cassava samples stained with periodic acid-Schiff (PAS) highlighted the presence of starch and cellulose. Degradation of starch granules during PPD was also detected. Slight metachromatic reaction with toluidine blue is indicative of increasing of acidic polysaccharides and may play an important role in PPD delay. Principal component analysis (PCA) classified samples according to their levels of enzymatic activity based on the decision tree model which showed GPX and total protein amounts to be correlated with PPD. The Oriental (ORI) cultivar was more susceptible to PPD.

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