Desenvolvimento de filmes de pectina/quitosana/glicerol para produção de embalagens biodegradáveis para alimentos

Abstract

Recycling of plastic packaging has not been effective, mainly due to the presence of synthetic contaminants (paints and dyes) in the packs and incorrect disposal.Therefore, this study addresses the preparation of hydrogels (films) based on biodegradable polysaccharides (pectin and chitosan) containing different contents of glycerol (5, 10, 15, 20, 25, 30, 35 and 40% in mass. The films were prepared from pectin/chitosan blends (67/33 wt/at) obtained in 0.10 mol L−1 HCl at the presence of glycerol, followed by the solvent evaporation. Washed and unwashed films were obtained and characterized by mechanical measurements, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis, and contact angle measurements. An unwashed film containing 40% glycerol content showed the best result of elasticity until rupture (Ɛ = 19%). On the other hand, washed films with glycerol contents above 15%, presented high tensile strength (Ɛ = > 46 MPa). After washing, films containing glycerol above 15% reorganize, increasing the tensile strength. Contact angle measurements and thermogravimetric analysis confirmed the reorganization of the polymeric chains in the washed films. XPS spectra confirmed the presence of polysaccharides, as well as the glycerol on the film surfaces. The films presented cytocompatibility onto human adipose stem cells (ADSCs cells) and antimicrobial and anti-adhesive activities against Escherichia coli. The films promoted a low permeability rate to water vapor and oxygen gas and also acted as a barrier to UV light. The film containing 40% glycerol content can act as packaging for tomatoes.