Guarana powder polysaccharides: Characterization and rheological properties of starch

Abstract

Guarana seeds are described to contain starch as the main constituent. In this work, two fractions of starch were isolated from guarana seeds using dimethyl sulfoxide. The samples, named GD‐I and GD‐II were characterized and their rheological properties investigated. 13C NMR analysis confirmed the presence of starch in both fractions. GD‐I showed higher amylose content (51.4%) than GD‐II (33.0%). Elution profiles of GD‐I and GD‐II by high performance size exclusion chromatography indicated they were heterogeneous and polydisperse and GD‐II had higher molar mass than GD‐I. The rheological behavior of solutions in concentrations of 10%, 15%, 20%, and 25% in dimethyl sulfoxide was evaluated. In all concentrations studied GD‐I had values of G′ higher than G″. GD‐II had higher values of G′ and apparent viscosity than GD‐I, due the higher molar mass and amylopectin content. GD‐II displayed a weak gel‐like behavior in concentrations above 15%. All solutions displayed a shear thinning behavior (flow behavior index < 1). The consistency coefficient (K) increased with an increase in the concentration of guarana seed starch and the values were higher for GD‐II. The best fit of the data was obtained with the Ostwald de Waele (power law) and Herschel‐Bulkley models.

Preparation and physicochemical properties: a new extruded rice using cassava starch and broken rice flour

“…Previous studies have established a strong correlation between starch viscosity and amylopectin content. Amylopectin, with its intricate, reticulated structure and stronger intermolecular forces compared to amylose, plays a pivotal role in determining viscosity (Dalonso and de Oliveira Petkowicz, 2014). Notably, there were insignificant differences (p>0.05) in BD values among ER samples, indicating that their thermal stability is comparable.…”

Effects of the consumption of guarana on human health: A narrative review

“…Besides the characterization of polyphenols and methylxanthines, several studies have investigated other aspects of guarana seed composition. Dalonso and Petkowicz (2014) characterized the polysaccharides of guarana seeds and showed that different starch fractions had distinct amylose and amylopectin content. Avato et al (2003) reported that guarana seed oil contained F I G U R E 2 Chemical structures of catechin and epicatechin, and simplified representation of proanthocyanidins type-A and type-B linkage 3% of cyanolipids and 28% of acylglycerols.…”

“…Besides the characterization of polyphenols and methylxanthines, several studies have investigated other aspects of guarana seed composition. Dalonso and Petkowicz (2014) characterized the polysaccharides of guarana seeds and showed that different starch fractions had distinct amylose and amylopectin content. Avato et al.…”