Desenvolvimento de nanobiocompósitos antifúngicos poliméricos para revestimento de sementes

Abstract

Biodegradable films are made with biological materials with the role of acting as a barrier to external elements, protecting the product and adding its useful life. They are prepared from proteins, polysaccharides, lipids or from compressors. Thus, new packaging has been developed in recent years to meet the consumer preferences on products with an extended shelf life. However, there are several challenges inthe adequacy of barrier properties and incorporation of new functionalities (such as the antimicrobialpropertie) into pectin films to make their use suitable for packaging. A promising system to modify the filmscharecteristics is the nanostructures incorporation to them. However, in Brazil there is still no legislation for nanomaterials and for this technology usage, being important to evaluate the impact of these new materials to better target the research. This study aimed to develop an active pectin package with nanoemulsion of carnauba wax and neem oil and to evaluate its antimicrobial activity and toxicity. Lipid nanoemulsion was produced through the ultrasonication process and it was incorporated into pectin, via solution, obtaining films by casting. Analysis of Particle Size, Rheology, X-Ray Diffraction, Zeta Potential, Water Vapor Permeability, Infrared Spectrophotometry, Thermogravimetry, Differential Scanning Calorimetry, Mechanical Traction and Puncture Testing, Film Solubility in Water, Scanning Electron Microscopy (MEV / FEG).The composite nanocomposite films elaboration was feasible. A particle size stability was observed for the nanoemulsions produced and it was essential during the polymerization to prepare uniform films. The Neem oil nanoemulsion with the smallest particle size was the most effective in the antifungal control, both in in vitro and contaminated seed tests. The oily phasepresence increased these films elongation, improving their mechanical properties. The water barrier properties of the pectin films were positively affected by the Neem oil nanoemulsions incorporation. It was confirmed that the Neem oil-based nanoemulsion was efficient in controlling the studied fungi without causing phytotoxic effects on the seeds. Therefore, this study showed that the developed nanocomposites have a great potential of application in agriculture, especially for the grains and seeds coating.