Utilización de Flavonoides en recubrimientos comestibles para la conservación de productos acuícolas

Las matrices acuícolas se caracterizan por su amplia gama de constituyentes, convirtiéndolas en alimentos con un alto valor nutricional para el organismo humano. No obstante son susceptibles a la degradación por parte de microorganismos patógenos, procesos enzimáticos y reacciones de carácter oxidativo, lo cual hace necesario buscar alternativas para la conservación de los productos acuícolas. Como alternativa a los procesos tradicionales se ha recurrido al uso de recubrimientos comestibles, estos se han elaborado con diversos biopolímeros y metabolitos que les han conferido propiedades barrera y una notable bioactividad. Entre las sustancias bioactivas se destacan los extractos etanólicos de propóleos los cuales tienen un amplio rango de acción frente a microorganismos patógenos y especies reactivas de oxígeno. Por el otro lado se ha empleado una macromolécula como el quitosano debido sus propiedades mecánicas y a la capacidad que tiene de potenciar la bioactividad de otras moléculas .En el pasado se han usado ambas sustancias en distintas formulaciones de películas comestible y han aparecido inconvenientes que han obstaculizado su aplicación como la baja permeabilidad, la liberación no controlada, el aumento de algunos procesos oxidativos y la alteración de las propiedades sensoriales. En este estudio se buscó diseñar una formulación para recubrimientos comestibles a base de extracto etanólico de propóleos, primero se encapsuló el extracto en maltodextrina, después se diseñaron películas a base de quitosano y el encapsulado para evaluar sus propiedades mecánicas y efecto barrera frente al vapor de agua y finalmente la formulación se aplicó en forma de recubrimiento para proteger la matriz acuícola y se estudió su efecto en la vida útil. La matriz fue capaz de proteger al pescado de procesos degenerativos y redujo el impacto de los agentes externos sobre el producto acuícola.Abstract. Aquaculture matrices are characterized by their wide range of beneficial constituents for the body, which becomes part of the diet. But nevertheless they are susceptible to face damage due to the action of microorganisms, enzymatic processes and oxidation reactions, which makes it necessary to find alternatives for the conservation of aquaculture products. As an alternative to the traditional processes scientist have studied edible coatings, these have been developed with various biopolymers and metabolites that have given them notable barrier properties and bioactivity. Among these materials chitosan and the flavonoids from ethanolic propolis extract are some of the most effective ones, they have very good mechanical properties and a broad spectrum of action; the previously mentioned the past two substances have been used in different formulations of edible films and it have appeared drawbacks that are hampering its application as: Low permeability the uncontrolled release, increasing some oxidative processes and impaired sensory properties. Therefore we sought to design an optimal formulation for edible coatings with chitosan and propolis, first the extract is encapsulated in maltodextrin, after that, edible films based on chitosan and the encapsulated propolis were designed to evaluate their mechanical properties and barrier effect and finally the formulation was applied as an edible coating to protect the aquaculture matrix and its effect in the shell life of the fish was studied. The matrix was able to protect the fish from degenerative processes and reduced the impact of external agents on the aquaculture productMaestrí

Characterization of Planktochlorella nurekis Extracts and Virucidal Activity against a Coronavirus Model, the Murine Coronavirus 3

Certain members of the Coronaviridae family have emerged as zoonotic agents and have recently caused severe respiratory diseases in humans and animals, such as SARS, MERS, and, more recently, COVID-19. Antivirals (drugs and antiseptics) capable of controlling viruses at the site of infection are scarce. Microalgae from the Chlorellaceae family are sources of bioactive compounds with antioxidant, antiviral, and antitumor activity. In the present study, we aimed to evaluate various extracts from Planktochlorella nurekis in vitro against murine coronavirus-3 (MHV-3), which is an essential human coronavirus surrogate for laboratory assays. Methanol, hexane, and dichloromethane extracts of P. nurekis were tested in cells infected with MHV-3, and characterized by UV-vis spectrophotometry, nuclear magnetic resonance (NMR) spectroscopy, ultraperformance liquid chromatography-mass spectrometry (UPLC-MS), and the application of chemometrics through principal component analysis (PCA). All the extracts were highly efficient against MHV-3 (more than a 6 Log unit reduction), regardless of the solvent used or the concentration of the extract, but the dichloromethane extract was the most effective. Chemical characterization by spectrophotometry and NMR, with the aid of statistical analysis, showed that polyphenols, carbohydrates, and isoprene derivatives, such as terpenes and carotenoids have a more significant impact on the virucidal potential. Compounds identified by UPLC-MS were mainly lipids and only found in the dichloromethane extract. These results open new biotechnological possibilities to explore the biomass of P. nurekis; it is a natural extract and shows low cytotoxicity and an excellent antiviral effect, with low production costs, highlighting a promising potential for development and implementation of therapies against coronaviruses, such as SARS-CoV-2.This research was funded LVA-MIP-CCB-UFSC/Sigpex: 201917940, and CNPq, CAPES-DS