p. Medellín, Colombia Universidad de Medellín * Artículo escrito en el marco del proyecto de investigación Estudio de tejidos vegetales como adsorbentes naturales para la remoción de colorantes en medio líquido desarrollado en el año 2016 con recursos del Programa de

Objective: To evaluate the CaO made from oyster shell (C. virginica) as a heterogeneous catalyst in the transesterification of edible vegetable oil used for the production of biodiesel. Design / methodology / approach: A completely randomized experimental design was used, which grouped 3 treatments with 3 repetitions, generating a total of 9 experimental units. The response variable was the performance of the transesterification reaction that was evaluated with 2%, 3% and 4% of CaO obtained from oyster shells. The density, kinematic viscosity, acidity, and conversion efficiency to methyl esters were determined by 1H NMR of the products of each treatment. Results: The treatment with 3% catalyst showed the highest reaction yield (92.2%) compared to the treatments with 2% (86.8%) and 4% catalyst (87.13%). The 1H NMR spectra confirmed the presence of methyl esters in the product of the three treatments. The treatment with 3% and 4% by weight of catalyst presented products with similar characteristics with acceptable values ​​of density, viscosity and acid number in accordance with the ASTM D6751 and EN1421 standards. Study limitations / implications: A concentration of 2% by weight of CaO generates a conversion percentage far from the content of methyl esters established by the ASTM D6751 and EN14214 Standards (> 96.5%). Findings / conclusions: 1H NMR results indicate that the conversion efficiency to methyl esters is positively affected by the amount of catalyst. In the treatments with catalyst loading greater than 2%, the conversion to methyl esters increased significantly to values ​​around 90%.

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Objetivo: Obtener y caracterizar un material biodegradable, utilizando como materia prima el almidón del fruto del pan de sopa (Artocarpus altillis (s. park) fosberg) Diseño/metodología/aproximación: Se extrajo el almidón del fruto del pan de sopa por el método húmedo. El almidón seco, se mezcló con glicerol, agua y HCl 1N aproximadamente a 75 °C hasta obtener un bioplástico, el cual se caracterizó por espectroscopia de FT-IR y SEM-EDX. Resultados: El mayor contenido de almidón se obtiene en la etapa intermedia de desarrollo del fruto (verde-maduro) con un 10% de rendimiento. Se realizaron pruebas de infrarrojo y SEM-EDX, tanto del almidón como del bioplástico obtenido. El SEM-EDX mostró que para el almidón el diámetro de granulo promedio es entre 2.5 ± 0.2 a 8.4 ± 0.2 µm con una geometría de tipo esférica, con cortes en direcciones aleatorias. Limitaciones del estudio/implicaciones: No se observan limitaciones tecnológicas importantes, pero si implicaciones que impactan en el desarrollo acelerado del comercio de bioplásticos. Hallazgos/conclusiones: Se aisló almidón del fruto pan de sopa y se caracterizó con técnicas de Infrarrojo y SEM-EDX. Se obtuvo un material bioplástico a partir del almidón, empleando como plastificante glicerol y agua, encontrándose que la proporción (1:10, almidón:agua)  genera un material con las mejores características de termoplástico.

Objective: To evaluate the anthelmintic activity of aqueous and ethanolic extracts of Musa balbisiana Colla, against H. contortus eggs. Design / methodology / approach: The anthelmintic activity was evaluated using an egg hatching inhibition test. The aqueous extracts from leaves, peels and roots were obtained by infusion and subsequently lyophilized. Ethanolic extracts were obtained by maceration and later concentrated in a rotary evaporator. Spectroscopic, phytochemical, chemical and total polyphenol content analyzes were performed. The 50 % lethal concentration to inhibit H. contortus eggs from hatching was calculated following a Probit analysis. Results: The identified functional groups in the FT-IR analysis were hydroxyl (-OH) and methyl groups (CH3). The proximal analysis revealed significant differences in the dry matter percentage (P < 0.05). No significant differences were found in the protein content (P > 0.05). The egg hatching inhibition rates at the highest concentration 4.8 mg / mL were 100 % for the aqueous and ethanolic extracts from leaves, and 93.7 and 62 % for the shell and roots, respectively. Study limitations / implications: Further studies are required in in vivo systems. Findings / Conclusions: With a LC50 of 225 µg / mL and a 95 % confidence interval, with a range between 33 and 418.4 µg / mL, the aqueous extract from the leaves was the most active.