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Guaymas, Mexico

Morales-Ortega A.,Research Center en Alimentacion y Desarrollo | Nino-Medina G.,Autonomous University of Nuevo Leon | Carvajal-Millan E.,Research Center en Alimentacion y Desarrollo | Gardea-Bejar A.,CIAD Guaymas | And 4 more authors.
Revista Fitotecnia Mexicana | Year: 2013

FerulFerulated arabinoxylans are the primary non-starch polysaccharides in cereal grains. They are located in thecell walls of endosperm, aleurone layer and pericarp. There are reports of their presence in major cereal grains including wheat (Triticum aestivum L.), rye (Secale cereale L. M. Bieb.), barley (Hordeum vulgare L.), oat (A. Sativa), rice (Oryza sativa L.), sorghum (Sorghum vulgare), maize (Zea mays L.) and millet (Panicum miliaceum L.). Recent research has focused on arabinoxylan extraction from low-value cereal by-products in the food industry, such as bran cereal and 'nejayote' (maize nixtamalization wastewater). Ferulated arabinoxylans form highly viscous solutions, and they can form gels in the presence of certain oxidizing agents. Gelling capability of cereal arabinoxylans is determined by inherent physicochemical properties. Arabinoxylan gels are receiving increasing attention due to characteristics such as neutral odor and taste, stability to pH and electrolyte concentration changes, and macro porous structure. They can potentially be used as controlled-release matrices in food and non-food applications like biomedicine and cosmetics. Thus, cereal grains and by-products become more valuable. This review includes some of the most recent findings on the physicochemical properties and gelling capability of ferulated arabinoxylans from cereals.

Escobedo-Lozano A.Y.,Laboratorio Of Biopolimeros | Escobedo-Lozano A.Y.,Technological Institute of Mazatlan | Domard A.,French National Center for Scientific Research | Velazquez C.A.,University of Sonora | And 3 more authors.
Carbohydrate Polymers | Year: 2015

The aim of the present study was to investigate the mechanical and thermal properties of mixed chitosan-acemannan (CS-AC) mixed gels and the antibacterial activity of dilute mixed solutions of both polysaccharides. Physical hydrogels of chitosan comprising varying amounts of non-gelling acemannan were prepared by controlled neutralization of chitosan using ammonia. As the overall acemannan concentration in the mixed hydrogel increased while fixing that of CS, the mechanical strength decreased. These results indicate that AC perturbs the formation of elastic junctions and overall connectivity as it occurs in the isolated CS network. Heterotypic associations between CS and AC leading to the formation of more compact microdomains may be at play in reducing the density of the gel network consolidated by CS, possibly due to shorter gel junctions. Micro-DSC studies at pH 12.0 seem consistent with the suggestion that molecular heterotypic associations between CS and AC may be at play in determining the overall physical properties of the mixed gel systems. In dilute solution, CS showed antimicrobial activity against Staphylococcus aureus but not against Escherichia coli; AC did not exert antimicrobial activity against any of the two bacterial species. In blended solutions of both polysaccharides, as the amount of AC increased, the antimicrobial activity of the system against S. aureus ceased. In conclusion, this study demonstrates that it is feasible to incorporate acemannan in chitosan-acemannan gels and that although the mechanical strength decreases due to the presence of AC, the gel network persists even at high amount of AC. This study anticipates that the CS-AC mixed gels may offer promise for the future development of biomaterials such as scaffolds to be used in wound therapy. © 2014 Elsevier Ltd. All rights reserved.

Fernandez-Quiroz D.,CIAD Guaymas | Gonzalez-Gomez A.,CSIC - Institute of Polymer Science and Technology | Gonzalez-Gomez A.,CIBER ISCIII | Lizardi-Mendoza J.,CIAD Hermosillo | And 6 more authors.
Colloid and Polymer Science | Year: 2016

Conformational changes of the thermal transitions of chitosan-graft-poly(N-vinylcaprolactam) copolymers in aqueous solution were studied by varying of the length of the grafted poly(N-vinylcaprolactam) (PVCL) chains, as well as the ionic strength and the pH of the solution. The conformational properties of the copolymer were monitored by means of dynamic light scattering and ζ-potential measurements. A series of copolymers with defined molecular architecture were synthesized. Obtained results point out that hydrophobic hydration plays a crucial role on the solubility of this copolymer at neutral and slightly alkaline solutions. The evolution of the size of macromolecular aggregates indicates that, in the coil state, there is a monomodal distribution, passing through a bimodal distribution in the pre-transition region, just before the phase separation. The role of the charge of the copolymers on the cooperative transition is also analyzed. The phase transition of these amphiphilic copolymers shows a strong dependence on the ionic strength of the solution. © 2015, Springer-Verlag Berlin Heidelberg.

Recillas M.,CIAD Guaymas | Silva L.L.,CIAD Guaymas | Peniche C.,University of Habana | Goycoolea F.M.,CIAD Laboratory Biopolimeros | And 3 more authors.
Carbohydrate Polymers | Year: 2011

Non-stoichiometric polyelectrolyte complex membranes between chitosan-g-N-isopropylacrylamide (PNIPAm) and pectin were prepared and subjected to a thermal treatment by which ionic bonds were converted into amide bonds. Membranes are hydrophilic, with opaque appearance, but vitreous when dry. Swollen membranes undergo a sharp shrinking process with an inflexion point at 33.1 °C. Below LCST, NIPAm chains are hydrated and completely stretched. As temperature increases above LCST, NIPAm chains contract and water is expelled from the polymer matrix, giving rise to the phase transition that is associated to an endothermic peak and is fully thermoreversible. These membranes are not only sensitive to temperature, but also to the pH of the medium whose variation has no influence on LCST. Nevertheless, transition enthalpy decreases when pH increases within studied interval, showing the same trend as equilibrium swelling. © 2011 Elsevier Ltd. All rights reserved.

Rosas-Durazo A.,CIAD Guaymas | Lizardi J.,CIAD Hermosillo | Higuera-Ciapara I.,CICY | Arguelles-Monal W.,CIAD Guaymas | And 2 more authors.
Colloids and Surfaces B: Biointerfaces | Year: 2011

The aim of this work was to develop and characterize a new type of nanocapsules. To this end, a nanoemulsion bearing an oily core (Miglyol 812) was obtained by spontaneous emulsification and stabilized by dodecyl-trimethylammonium chloride (DTAC), a commercial cationic surfactant; this nanoemulsion was coated with proportionally very small amounts of κ-carrageenan (at molar charge ratios of Z≤ 0.0045) that interact predominantly by an electrostatic mechanism with the positively charged sites at the polar heads of DTAC at the nanoemulsion's surface to harness nanocapsules of average size ∼250-330. nm and zeta potential (ζ) ranging from ∼+80 to +7. mV. The potential application of the new type of developed nanosystems as drug delivery vehicles has yet to be investigated and fully realized. © 2011 Elsevier B.V.

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