Rheological and structural characterization of gels from albumin and low methoxyl amidated pectin mixtures

The rheological behavior of gels prepared from albumin (ALB) and a mixture of ALB and low methoxyl amidated pectin (PEC) with different proportions were studied using oscillatory rheological tests, Fourier transform infrared spectroscopy (FT-IR spectroscopy), zeta potential measurements and confocal...

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Bibliographic Details
Authors: Chaux-Gutiérrez, Ana María [UNESP], Pérez-Monterroza, Ezequiel José [UNESP], Mauro, Maria Aparecida [UNESP]
Format: article
Status:Published version
Publication Date:2019
Country:Brasil
Institution:Universidade Estadual Paulista (UNESP)
Repository:Repositório Institucional da UNESP
Language:English
OAI Identifier:oai:repositorio.unesp.br:11449/188688
Online Access:http://dx.doi.org/10.1016/j.foodhyd.2019.01.025
http://hdl.handle.net/11449/188688
Access Level:Open access
Keyword:Biopolymers
Confocal microscopy
Gelation
Polysaccharides
Protein
Rheology
Description
Summary:The rheological behavior of gels prepared from albumin (ALB) and a mixture of ALB and low methoxyl amidated pectin (PEC) with different proportions were studied using oscillatory rheological tests, Fourier transform infrared spectroscopy (FT-IR spectroscopy), zeta potential measurements and confocal microscopy. The mixture was always 5% of the total solute. Assays were performed in two series, one in which all mixtures were adjusted to pH = 8 and another one without pH adjustment. The zeta potential values indicated the presence of a negative net charge on ALB-PEC gels. The rheological tests indicated a frequency dependence of the storage (G′) and loss (G”) moduli, with G’ > G’’. The presence of 1% and 2% of pectin in the mixture caused an increase in G’. However, a PEC concentration above 2% led to a decrease in G′ regardless of the pH or frequency. FT-IR spectroscopy indicated that as the PEC content increased, a higher proportion of β-sheet structures was found. Confocal microscopy also confirmed aggregation of ALB particles due to the PEC concentration.