title: Gelation of wheat arabinoxylans in the presence of Cu(+2) and in aqueous mixtures with cereal β-glucans.
abstract: The effect of copper ions (0.63-0.16 mM) on the rheological behavior of arabinoxylan (AX) aqueous solutions was investigated. Moreover, the influence of β-glucan addition (BG, 0.5-3% w/v) on the gelation of mixed AX/BG solutions with and without addition of the peroxidase/H2O2 was examined. Generally, gels formed with inclusion of transition metal-ions differed from those obtained by adding peroxidase/H2O2. Copper ions induced viscosity increase of the AX-solutions and form stronger thermoreversible gels with increasing ion-concentration; optimal gelation was at 15 °C. For added β-glucan at levels >1%, the lower the concentration and the higher the molecular weight of β-glucan, the weaker the gelling ability of the mixed AX/BG system treated with peroxidase/H2O2. The polysaccharide-ratio affected both the gelling rate and the network melting temperature, with the β-glucan itself giving the strongest network. Calorimetry provided evidence for existence of β-glucan ordered domains in the mixed gel structures of AX/BG1, indicative of phase separation events.
authors.affiliation: Laboratory of Food Chemistry & Biochemistry, Department of Food Science and Technology, School of Agriculture, Aristotle University, Greece. Electronic address: andrianaskendi@hotmail.com.
authors.forename: Adriana
authors.initials: A
authors.lastname: Skendi
authors.affiliation: Laboratory of Food Chemistry & Biochemistry, Department of Food Science and Technology, School of Agriculture, Aristotle University, Greece. Electronic address: biliader@agro.auth.gr.
authors.forename: Costas G
authors.initials: CG
authors.lastname: Biliaderis
mesh_terms: D002413:Cations, Divalent; D003300:Copper / Q000737:chemistry*; D004040:Dietary Carbohydrates / Q000032:analysis; D002523:Edible Grain / Q000737:chemistry*; D005782:Gels / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry; D008970:Molecular Weight; D012212:Rheology; D012996:Solutions; D013696:Temperature; D014908:Triticum / Q000737:chemistry*; D014783:Viscosity; D014867:Water / Q000737:chemistry; D014990:Xylans / Q000737:chemistry* / Q000302:isolation & purification; D047071:beta-Glucans / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D002413:Cations, Divalent; D004040:Dietary Carbohydrates; D005782:Gels; D012996:Solutions; D014990:Xylans; D047071:beta-Glucans; D014867:Water; D003300:Copper; C085118:arabinoxylan; D006861:Hydrogen Peroxide
keywords: Arabinoxylan; Copper ions gelation; Dynamic rheometry; Melting; Molecular weight; β-Glucan