INVESTIGADORES
PONCE Nora Marta Andrea
artículos
Título:
Compositional Changes in Cell Wall Polysaccharides from Five Sweet Cherry (Prunus avium L.) Cultivars during On-Tree Ripening
Autor/es:
MARIA F. BASANTA; NORA M. A. PONCE; MARIA L. SALUM; MARÍA D. RAFFO; ARIEL R. VICENTE; ROSA ERRA-BALSELLS; CARLOS A. STORTZ
Revista:
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
Editorial:
AMER CHEMICAL SOC
Referencias:
Lugar: Washington; Año: 2014 vol. 62 p. 12418 - 12427
ISSN:
0021-8561
Resumen:
Excessive softening is a major cause of postharvest deterioration during transportation and storage of freshcherries. In continuing our studies to identify the factors determining the textural differences between sweet cherry fruitgenotypes, we evaluated the solubilization, depolymerization, and monosaccharide composition of pectin and hemicellulosesfrom five sweet cherry cultivars (‘Chelan’, ‘Sumele’, ‘Brooks’, ‘Sunburst’, and ‘Regina’) with contrasting firmness and crackingsusceptibility at two developmental stages (immature and ripe). In contrast to what is usually shown in most fruits, cherrysoftening could occur is some cultivars without marked increases in water-soluble pectin. Although polyuronide andhemicellulose depolymerization was observed in the water-soluble and dilute-alkali-soluble fractions, only moderate associationoccurs between initial polymer size and cultivar firmness. In all the genotypes the Na2CO3-soluble polysaccharides (NSF)represented the most abundant and dynamic wall fraction during ripening. Firm cultivars showed upon ripening a lower neutralsugars/uronic acid ratio in the NSF, suggesting that they have a lower proportion of highly branched polyuronides. The similarmolar ratios of arabinose plus galactose to rhamnose [(Ara+Gal)/Rha] suggest that the cultivars differed in their relativeproportion of homogalacturonan (HG) and rhamnogalacturonan I (RG-I) rather than in the size of the RG side chains; withgreater proportions of HG in firmer cherries. Ultraviolet matrix-assisted laser desorption/ionization time-of-flight massspectrometry was useful to identify the depolymerization patterns of weakly bound pectins, but gave less accurate results onionically bound pectins, and was unable to find any pattern on covalently bound pectins.