Pectins from the pulp of gabiroba (Campomanesia xanthocarpa Berg): Structural characterization and rheological behavior

Publication date: Available online 15 March 2019Source: Carbohydrate PolymersAuthor(s): Shayla Fernanda Barbieri, Sarah da Costa Amaral, Andrea Caroline Ruthes, Carmen Lúcia de Oliveira Petkowicz, Nicole Cristine Kerkhoven, Elisangela Rodrigues Assunção da Silva, Joana Léa Meira SilveiraABSTRACTThe pulp of gabiroba fruits was submitted to a hot water extraction, giving rise to a crude pectin named GW. GW was shown to be composed mainly of arabinose (54.5%), galacturonic acid (33.5%), galactose (7.6%), and rhamnose (1.6%). GW was characterized by chromatographic and spectroscopic methods indicating the presence of homogalacturonans (HG) with a degree of methyl-esterification (DM) of 60% and rhamnogalacturonans I (RG-I). HG domain represents 31.9% and RG-I domain 65.3%. Furthermore, GW was submitted to sequential fractionation methods, giving rise to GWP-TEP fraction, structurally characterized by the predominance of HG regions, and confirmed by NMR analysis. The rheological behavior of GW was analyzed at 1%, 3%, and 5% (w/v) concentration with 0.1 mol L-1 NaCl. All samples showed shear thinning behavior. In the oscillatory measurements, the 1% GW showed a liquid-like behavior, while the 3% presented a concentrated solution behavior and the 5% GW a gel behavior.
Source: Carbohydrate Polymers - Category: Biomedical Science Source Type: research