Biomassa de cascas de banana como fonte de matéria-prima na obtenção de filmes bionanocompósitos com potencial aplicação em embalagens biodegradáveis

Abstract

Bananas (Musa acuminata, AAA Group), one of the most important fruit crops because of their availability throughout the year and its high nutritional value, are mainly raw consumptions and their processed products banana flour, French fries and puree (which can be used to produce nectar and a variety of products). As banana peels constitute about 30% of the fruit and represent an environmental problem because of their high levels of nitrogen and phosphorus, as well as their high water content, making them highly susceptible to microbial degradation. The use of more shells as a source of high-value compounds, such as pectin, cellulose nanofibers and phenolic compounds, becomes interesting not only from the economic point of view but also from the environmental perspective. This work had as main objective the use of agroindustrial residues, in order to evaluate the influence of pH, temperature and time on the extraction of pectin with citric acid (CA). As banana peels were purchased on the market in Norwich, UK, in stage 6 Cavendish maturation. Pectin extraction was initially conducted by the preparation of an alcohol insoluble residue, a low mass feedstock remover, including traces of free galacturonic acid. A pectin was extracted from the AIR, according to a central compound design with 3 (three) variables: pH of the CA solution; temperature and extraction time to determine the following effects: pH (2.0-4.5), extraction temperature (70-90°C) and time (120-240min) on the yield and content of galacturonic acid and degree of methoxylation. The changes in composition during the main stages of pectin extraction were accompanied by the spectroscopy technique in the Fourier transform Infrared region, a reference for the determination of the degree of methoxylation and galacturonic acid. The extraction minimization conditions, defined as those that resulted in a maximum yield, maintaining a methoxylation degree, at a minimum of 51%, were: 87øC, 160 min and pH 2.0. Pectins from other sources for the development of bionanocomposite films, as part of the scientific research objectives of the present work. The incorporation of reforestation agents such as cellulose nanocrystals was developed to improve the performance of the films from pectin along with the effect of CA as a crosslinking agent on how the material resource. The films were plasticized with glycerol and prepared at different contents of cellulose nanocrystals (0-10% by weight) in the presence or absence of CA. FT-IR spectra confirm an occurrence of cross-linking. In addition, a tensile strength, a water solubility and a water vapor permeability improved by the presence of the acid. Solid 13 C NMR spectra indicated both the crosslinking agent and the reformer of the polymer chain stiffness. In view of the results obtained in the films made presented a potential profile for application in the area of food packaging.