12 research outputs found
Compendio de las alternativas para el desarrollo de materiales que brindan las estructuras celulósicas aisladas de residuos de la agroindustria de musáceas
Desde finales del siglo XX tanto a nivel científico como tecnológico se vienen analizando múltiples tipos de estructuras derivadas de plantas que puedan ser empleadas como reforzantes o aditivos para mejorar el desempeño mecánico, eléctrico, térmico, magnético, o químico de múltiples tipos productosque pueden ser empleados en campos tan diversos como la industria textil, el desarrollo o mejoramiento de alimentos o incluso para el desarrollo de baterías o sistemas de almacenamiento de energía. Las fibras naturales, también conocidos como haces fibrosos y en especial las derivadas de plantas, cada vez másrepresentan una importante alternativa en esta línea debido a las ventajas que ofrecen tanto desde el punto de vista técnico como ambiental y económico. Dentro de las fuentes alternativas para obtener fibras naturales y la gama de subestructuras de celulosa que pueden ser aisladas a partir de ellas, los residuos agroindustriales se consolidan como una importante fuente de materias primas, en especial cuando se desea promover procesos de economía circular, o el cierre de ciclos productivos bajo consideraciones de sostenibilidad. En el presente texto se abordan diferentes alternativas de uso de las fibras naturales y sus respectivas subestructuras celulósicas que pueden ser obtenidas a partir de los residuos generados por dos de los cultivos de Musáceas más importantes de Colombia, y que corresponden al bananero y el platanero. Las alternativas presentadas en este texto, además de actuar como un compendio, también puede mostrar ejemplos que puedan orientar la investigación y el desarrollo de productos empleando los desechos de cosecha y pos cosecha de otro tipo de cultivos.Fil: Zuluaga, Robin. Universidad Pontificia Bolivariana; ColombiaFil: Osorio, Marlon. Universidad Pontificia Bolivariana; ColombiaFil: Velásquez Cock, Jorge. Universidad Pontificia Bolivariana; ColombiaFil: Molina, Carlos. Universidad Pontificia Bolivariana; ColombiaFil: Correa, Carlos. Universidad Pontificia Bolivariana; ColombiaFil: Vélez Acosta, Lina. Universidad Pontificia Bolivariana; ColombiaFil: Castro, Cristina. Universidad Pontificia Bolivariana; ColombiaFil: Ruiz-Ramírez, Luis. Universidad Pontificia Bolivariana; ColombiaFil: Serpa, Angélica. Universidad Pontificia Bolivariana; ColombiaFil: Restrepo, Adriana. Universidad Pontificia Bolivariana; ColombiaFil: Álvarez, Catalina. Universidad Pontificia Bolivariana; ColombiaFil: Betancourt, Santiago. Universidad Pontificia Bolivariana; ColombiaFil: Montoya Rojo, Ursula Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnología en Polímeros y Nanotecnología. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnología en Polímeros y Nanotecnología; ArgentinaFil: Gañán, Piedad. Universidad Pontificia Bolivariana; Colombi
Matrices nanocompuestas de alcohol de polivinilo (PVA)/celulosa bacteriana (CB) para el crecimiento celular y la regeneración de tejidos
RESUMEN: En esta investigación se desarrollaron biomateriales de PVA, CB y nanocompuestos PVA/CB mediante fermentación in situ utilizando una bacteria productora de celulosa Gluconacetobacter medellinensis. Los biomateriales fueron caracterizados mediante microscopía electrónica de barrido (SEM), pruebas de hinchamiento y proliferación celular in-vitro utilizando células de piel humana (Fibroblastos). No se observaron cambios en la morfología celular por el uso de los biomateriales y su microestructura estuvo estrechamente ligada a la proliferación celular. Las células mostraron una mayor afinidad por la CB, resultado relacionado con su similitud en morfología y estructura química con el colágeno. La respuesta obtenida sumada a la capacidad de
la CB de imitar la forma de la interfaz gas-líquido durante su síntesis, permitió la construcción de una prenda apósito de CB en forma de guante que podría tener aplicaciones en el tratamiento de quemaduras y úlceras cutáneas.ABSTRACT: In this research, biomaterials of PVA, CB and in situ fermented PVA/CB nanocomposites were developed, using a cellulose producer bacterium, Gluconacetobacter medellinensis. The biomaterials were characterized through scanning electron microscopy (SEM), swelling and in vitro cell proliferation assay with skin cells (Fibroblast). Changes in the cell morphology were not found by the use of the biomaterials and the cell proliferation is associated with the microstructure of them. Cells showed a higher affinity to CB, outcome related to the morphological and chemical similitudes with collagen. Joining this response with the CB capacity of mimic the gas-liquid interface, was developed a glove shaped wound dressing that will have applications in burn and skin ulcer treatment
Celulosa : un polímero de siempre con mucho futuro
RESUMEN: Dentro de la gran cantidad de sustancias naturales que han sido de un valor significativo a lo largo
de todo el desarrollo científico – tecnológico de la humanidad se destaca sin lugar a dudas la
celulosa, considerada como uno de los polímeros naturales de mayor abundancia en la naturaleza,
y que puede ser obtenida desde las más variadas fuentes entre las que se encuentran: todo tipo de
cuerpos vegetales, en diferentes tipos de algas, de la actividad extracelular de múltiples tipos de
microorganismos y en el caparazón o estructura de algunos animales marinos (Zuluaga, 2014)
An Edible Oil Enriched with Lycopene from Pink Guava (<i>Psidium guajava</i> L.) Using Different Mechanical Treatments
According to the regulations of the United States Food and Drug Administration (FDA), organic solvents should be limited in pharmaceutical and food products due to their inherent toxicity. For this reason, this short paper proposes different mechanical treatments to extract lycopene without organic solvents to produce an edible sunflower oil (SFO) enriched with lycopene from fresh pink guavas (Psidium guajava L.) (FPGs). The methodology involves the use of SFO and a combination of mechanical treatments: a waring blender (WB), WB+ high-shear mixing (HSM) and WB+ ultrafine friction grinding (UFFG). The solid:solvent (FPG:SFO) ratios used in all the techniques were 1:5, 1:10 and 1:20. The results from optical microscopy and UV–vis spectroscopy showed a correlation between the concentration of lycopene in SFO, vegetable tissue diameters and FPG:SFO ratio. The highest lycopene concentration, 18.215 ± 1.834 mg/g FPG, was achieved in WB + UFFG with an FPG:SFO ratio of 1:20. The yield of this treatment was 66% in comparison to the conventional extraction method. The maximal lycopene concentration achieved in this work was significantly higher than the values reported by other authors, using high-pressure homogenization for tomato peel and several solvents such as water, SFO, ethyl lactate and acetone
Bioactive 3D-Shaped Wound Dressings Synthesized from Bacterial Cellulose: Effect on Cell Adhesion of Polyvinyl Alcohol Integrated In Situ
We investigated wound dressing composites comprising fibrils of bacterial cellulose (BC) grown by fermentation in the presence of polyvinyl alcohol (PVA) followed by physical crosslinking. The reference biointerface, neat BC, favoured adhesion of fibroblasts owing to size exclusion effects. Furthermore, it resisted migration across the biomaterial. Such effects were minimized in the case of PVA/BC membranes. Therefore, the latter are suggested in cases where cell adhesion is to be avoided, for instance, in the design of interactive wound dressings with facile exudate control. The bioactivity and other properties of the membranes were related to their morphology and structure and considered those of collagen fibres. Bioactive materials were produced by simple 3D templating of BC during growth and proposed for burn and skin ulcer treatment
Development of a fortified drink from the mixture of small colombian native fruits
Strawberry (Fragaria ananassa), blackberry (Rubus glaucus), Peruvian cherry (Physalis peruviana L.) and purple passion fruit (Passiflora edulis Sims) are important fruit crops in Colombia, due to their organoleptic properties and nutritional qualities, making them attractive for international markets. This study was undertaken to characterize the physicochemical properties of these four fruits and to present an alternative for their use. To achieve this goal, the moisture, pH, soluble solids, acidity, color, iron and vitamin C concentration were determined, and a fortified mixed fruit drink was developed. All of the fruits can be classified as high acidity products due to the acidity results. Purple passion fruit and Peruvian cherry presented the highest content of soluble solids, while blackberry, purple passion fruit and Peruvian cherry did not exhibit statistically significant differences in their iron contents, and strawberry exhibited the highest contribution of vitamin C.La fresa (Fragaria ananassa), la mora (Rubus glaucus), la uchuva (Physalis peruviana L.) y la gulupa (Passiflora edulis Sims) son cultivos frutales importantes en Colombia por sus propiedades organolépticas y nutritivas. Este estudio se realizó para caracterizar las propiedades fisicoquímicas de estos cuatro frutos y presentar una alternativa para su uso. Para lograr este objetivo, se caracterizaron las cuatro frutas determinando humedad, pH, sólidos solubles, acidez, color, contenido de hierro y la concentración de vitamina C. Posteriormente se desarrolló una bebida fortificada de frutas. De acuerdo a los resultados de acidez, todos los frutos se pueden clasificar como productos de alta acidez. La gulupa y la uchuva, presentaron el mayor contenido de sólidos solubles, mientras que la mora, la gulupa y la uchuva, no presentaron diferencias estadísticamente significativas en su contenido de hierro. La fresa presentó la mayor contribución de la vitamina C
Development of a fortified drink from the mixture of small colombian native fruits
Strawberry (Fragaria ananassa), blackberry (Rubus glaucus), Peruvian cherry (Physalis peruviana L.) and purple passion fruit (Passiflora edulis Sims) are important fruit crops in Colombia, due to their organoleptic properties and nutritional qualities, making them attractive for international markets. This study was undertaken to characterize the physicochemical properties of these four fruits and to present an alternative for their use. To achieve this goal, the moisture, pH, soluble solids, acidity, color, iron and vitamin C concentration were determined, and a fortified mixed fruit drink was developed. All of the fruits can be classified as high acidity products due to the acidity results. Purple passion fruit and Peruvian cherry presented the highest content of soluble solids, while blackberry, purple passion fruit and Peruvian cherry did not exhibit statistically significant differences in their iron contents, and strawberry exhibited the highest contribution of vitamin C
Influence of a Non-Ionic Surfactant in the Microstructure and Rheology of a Pickering Emulsion Stabilized by Cellulose Nanofibrils
Emulsion stabilization is a broad and relevant field with applications in oil, polymer and food industries. In recent years, the use of solid particles to stabilize emulsions or Pickering emulsions have been studied for their kinetic and physical properties. Nanomaterials derived from natural sources are an interesting alternative for this application. Cellulose nanofibrils (CNFs) have been widely explored as a Pickering emulsifier with potential food applications, however, in some cases the presence of surfactants is unavoidable, and the literature is devoid of an evaluation of the effect of a non-ionic food-grade surfactant, such as polysorbate 80, in the stabilization of a vegetable oil by CNFs. To better assess the possible interactions between CNFs and this surfactant emulsions containing coconut oil, an emerging and broadly used oil, were processed with and without polysorbate 80 and evaluated in their qualitative stability, morphological and physical properties. Fluorescence microscopy, dynamic light scattering and rheology were used for this assessment. Results indicate in absence of the surfactant, emulsion stability increased at higher CNFs content, creaming was observed at 0.15 and 0.3 wt.% of CNFs, while it was not evidenced when 0.7 wt.% was used. After the addition of surfactant, the droplets are covered by the surfactant, resulting in particles with a smaller diameter, entrapped in the cellulosic structure. Rheology indicates a lower network stiffness after adding polysorbate 80
Synthesis of thermoplastic starch-bacterial cellulose nanocomposites via in situ fermentation
In this paper, a nanocomposite based on thermoplastic starch (TPS) reinforced with bacterial cellulose (BC) nanoribbons was synthesized by in situ fermentation and chemical crosslinking. BC nanoribbons were produced by a Colombian native strain of Gluconacetobacter medellinensis; the nanocomposite was plasticized with glycerol and crosslinked with citric acid. The reinforcement percentage in the nanocomposites remained constant throughout the fermentation time because of the TPS absorption capability of the BC network. Nanocomposites produced after fermentation for seven days were characterized using thermogravimetric analysis (TGA); Fourier transformed infrared spectroscopy with attenuated total reflectance (FTIR-ATR), mechanical testing and scanning electron microscopy (SEM). The new TPS/BC nanocomposites exhibit strong interfacial adhesion, improved thermal behavior, water stability and enhanced mechanical properties. These findings support the applications of starch in the packaging industry