The role of the oral microbiome and its effect on dental diseases is gaining interest. Therefore, it has been sought to decrease the bacterial load to fight oral cavity diseases. In this study, composite materials based on chitosan, chitosan crosslinked with glutaraldehyde, chitosan with zinc oxide particles, and chitosan with copper nanoparticles were prepared in the form of thin films, to evaluate a new alternative with a more significant impact on the oral cavity bacteria. The chemical structures and physical properties of the films were characterized using by Fourier transform infrared spectroscopy (FTIR,) Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), elemental analysis (EDX), thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), and contact angle measurements. Subsequently, the antimicrobial activity of each material was evaluated by agar diffusion tests. No differences were found in the hydrophilicity of the films with the incorporation of ZnO or copper particles. Antimicrobial activity was found against S. aureus in the chitosan film crosslinked with glutaraldehyde, but not in the other compositions. In contrast antimicrobial activity against S. typhimurium was found in all films. Based on the data of present investigation, chitosan composite films could be an option for the control of microorganisms with potential applications in various fields, such as medical and food industry.

Chitosan is a natural polymer that can sustain not only osteoblast adhesion and proliferation for bone regeneration purposes, but it is also claimed to exhibit antibacterial properties towards several Gram-positive and Gram-negative bacteria. In this study, chitosan was modified with sodium hyaluronate, crosslinked with polyethylene glycol diglycidyl ether (PEGDE) and both osteoblast cytotoxicity and antibacterial behavior studied. The presence of sodium hyaluronate and PEGDE on chitosan was detected by FTIR, XRD, and XPS. Chitosan (CHT) films with sodium hyaluronate crosslinked with PEGDE showed a better thermal stability than pristine hyaluronate. In addition, osteoblast cytocompatibility improved in films containing sodium hyaluronate. However, none of the films exhibit antimicrobial activity against Escherichia coli, Enterococcus faecalis, and Staphylococcus aureus while exhibiting low to mild activity against Salmonella typhimurion.

RESUMENEfecto de la composición en antioxidants incluidos en la dieta sobre la retención del valor nutricional de salmón coho (Oncorhynchus kisutch) de cultivo durante su conservación en congelación Salmones coho (Oncorhynchus kisutch) fueron alimentados con una dieta enriquecida en antioxidantes sintéticos (butil-hidroxi-tolueno y etoxiquina, dieta I) y su efecto comparado con dos dietas enriquecidas en antioxidantes naturales (una mezcla rica en isómeros de tocoferol, dieta II; una mezcla de isómeros de tocoferol y extracto de romero, dieta III). Una vez sacrificado, el pescado fue conservado a -18 °C durante 18 meses. El empleo de la dieta II llevó a muestras congeladas con contenido superior en proteínas sarcoplás-micas y en γ-y δ-tocoferol al ser comparados con pescado previamente alimentado con la dieta I. Sin embargo, no se observaron diferencias a nivel de composición proximal, contenido en α-tocoferol y astaxantina y parámetros de color (L*, a*, b*). A nivel de composición en ácidos grasos, los individuos correspondientes a la dieta II reflejaron mayores contenidos en C22:6ω3 y monoinsaturados, pero menores en C20:5ω3 y saturados al ser comparados con sus homólogos de la dieta I.

The physicochemical properties, proximate composition, minerals, total polyphenols, carotenoids, phenolic compounds, antioxidant, and antibacterial activities of ciricote (Cordia dodecandra A. DC.) tropical fruit were investigated. Minerals were quantified by using micro-Energy Dispersive X-Ray Fluorescence. Lutein and βcarotene were identified in ciricote fruit by using UPLC-PDA analysis. The highest values of the total polyphenols content and antioxidant activity were presented in ethanolic crude extracts obtaining by the ultrasonic-assisted method with freeze-dried fruit. The phenolic acids profile was identified and quantified by UPLC-PDA-ESI-MS. The main phenolic acids were caffeoyl hexoside, rufescenolide, quercetin 3-Orutinoside, and rosmarinic acid. The ciricote extracts presented antibacterial activity against Staphylococus aureus (Gram+) and Salmonella typhymurium (Gram−). In conclusion, the ciricote (Cordia dodecandra A. DC.) tropical fruits could be very useful source of biological macromolecules, micro-elements, and phytochemical compounds for the food and pharmaceutical industry.

The effect of temperature (60, 70, 80 and 90 ºC) and time (30, 45, 60, 75 and 90 min) on citric acid extraction of Haden mango ( Mangifera indica L . cv. Haden) peel pectin was evaluated in the present study. In order to obtain a better understanding of both the extraction process and the characteristics of the pectin (obtained from an agro-industrial waste) for a future scaling process, the following characterizations were performed: 1) Kinetic, with the maximum extraction times and yields at all evaluated temperatures; 2) thermodynamic, obtaining activation energies, enthalpies, entropies and Gibbs free energies for each stage of the process; 3) physicochemical (chemical analysis, monosaccharide composition, degree of esterification, galacturonic acid content, free acidity, Fourier-transform infrared spectroscopy, thermogravimetric and derivative thermogravimetric analyses) and; 4) economical, of the pectin with the highest yield. The mango Haden peel pectin was found to be characterized by a high-esterified degree (81.81 ± 0.00 %), regular galacturonic acid content (71.57 ± 1.26 %), low protein (0.83 ± 0.05 %) and high ash (3.53 ± 0.02 %) content, low mean viscometric molecular weight (55.91 kDa) and high equivalent weight (3657.55 ± 8.41), which makes it potentially useful for food, pharmaceutical and environmental applications such as delivery system, gelling agent or as an emulsifier.Statement of NoveltyThe novelty of this work lies in the valorization of an agro-industrial waste (Haden mango peel) through the kinetic, thermodynamic, physicochemical, and economic characterization of a product obtained (pectin). This work contributes to laying the groundwork for an industrial scale-up for pectin production in a mango processing industry.