Polyelectrolyte complex of Aloe vera, chitosan, and alginate produced fibroblast and lymphocyte viabilities and migration.

Chitosan, sodium alginate and gel of Aloe vera (Aloe barbadensis Miller) were employed for the preparation of polyelectrolyte complexes at pH 4 and 6. FT-IR spectroscopy analysis showed evidence on complexes formation and incorporation of the Aloe vera gel. The ζ potential determination of the polyelectrolyte complexes revealed the presence of surface charges in the range of -20 to -24 mV, which results in stable systems. The dynamic moduli exhibited a high dependence on angular frequency, which is commonly found in solutions of macromolecules. The materials showed human fibroblast and lymphocyte viabilities up to 90% in agreement with null cytotoxicity. The polyelectrolyte complexes at pH 6 with Ca2+ were stable, showed high water absorption, satisfactory morphology, pore size and rigidity, characteristics that allowed significant human fibroblast migration in wound closure in vitro assays.

Rheological properties of tamarind (Tamarindus indica L.) seed mucilage obtained by spray-drying as a novel source of hydrocolloid.

Tamarind seed mucilage (TSM) was extracted and obtained by spray drying. The power law model well described the rheological behavior of the TSM dispersions with determination coefficients R2 higher than 0.93. According to power law model, non-Newtonian shear thinning behavior was observed at all concentrations (0.5%, 1%, 1.5% and 2%) and temperatures (25, 30, 40, and 60°C) studied. Increasing temperature decreased the viscosity and increased the flow behavior index, opposite effect was observed when increasing the concentration. The temperature effect was more pronounced at 2.0% TSM concentration with an activation energy of 20.25kJ/mol. A clear dependence of viscosity on pH was observed, as pH increased from acidic to alkaline conditions, the viscosity increased. It was found that the rheological properties of TSM were affected by the sucrose and salts and their concentrations as well due to the addition of ions (or sucrose) decreases repulsion and allows molecule expansion promoting a significant reduction in viscosity. These results suggest that TMS could be applied in the production of foods that require additives with thickening capacity.

Exploring the Potential of Mesquite Gum-Nopal Mucilage Mixtures: Physicochemical and Functional Properties.

In this work the physicochemical and functional properties of mesquite gum (MG) and nopal mucilage (NM) mixtures (75-25, 50-50, 25-75) were evaluated and compared with those of the individual biopolymers. MG-NM mixtures exhibited more negative zeta potential (ZP) values than those displayed by MG and NM, with 75-25 MG-NM showing the most negative value (-14.92 mV at pH = 7.0), indicative that this biopolymer mixture had the highest electrostatic stability in aqueous dispersions. Viscosity curves and strain amplitude sweep of aqueous dispersions (30% w/w) of the individual gums and their mixtures revealed that all exhibited shear thinning behavior, with NM having higher viscosity than MG, and all displaying fluid-like viscoelastic behavior where the loss modulus predominated over the storage modulus (G″>G'). Differential Scanning Calorimetry revealed that MG, NM, and MG-NM mixtures were thermally stable with decomposition peaks in a range from 303.1 to 319.6 °C. From the functional properties viewpoint, MG (98.4 ± 0.7%) had better emulsifying capacity than NM (51.9 ± 2.0%), while NM (43.0 ± 1.4%) had better foaming capacity than MG. MG-NM mixtures acquired additional functional properties (emulsifying and foaming) regarding the individual biopolymers. Therefore, MG-NM mixtures represent interesting alternatives for their application as emulsifying and foaming agents in food formulations. PRACTICAL APPLICATION: Mesquite gum (MG) and nopal mucilage (NM) are promising raw materials with excellent functional properties whose use has been largely neglected by the food industry. This work demonstrates MG-NM mixtures acquired additional functional properties regarding the individual biopolymers, making these mixtures multifunctional ingredients for the food industry.