Elaboração e caracterização de filmes a partir de farinha de pupunha (Bactris gasipaes), quitosana e glicerol pelo método de casting

Abstract

Environmental problems caused by packaging manufactured from non-biodegradable and renewable sources have led to increased interest and attention from industry and researchers in terms of films and edible toppings development. Films are usually obtained from polymers such as polysaccharides, proteins and lipids, used to help maintain the quality and food shelf life. Thus, the aim of this study was to develop films using the casting technique from biodegradable sources with antimicrobial activity, in addition to evaluate the mechanical, barrier, optical, structural and thermal properties as well as to analyze the rheological behavior of the different filmogenic suspensions. The films were prepared with different ratios of peach palm flour, chitosan and glycerol. The presence of chitosan led to an improvement in the mechanical, optical and morphological properties of the films; however, they did not show antimicrobial activity against foodborne pathogens as E. coli and S. aureus. The rheological study showed that all the filmogenic suspensions presented non-Newtonian fluid behavior, with dilating characteristics. The Herschel-Bulkley and Bingham models were tested, and both fit satisfactorily to the rheological data, presenting high values for the R2 factor and low values for the χ2 factor. The results obtained for the fluid behavior index (n) presented values of n> 1 for all the samples, proving the dilator behavior of the suspensions. The films obtained presented a smooth and homogeneous surface, slightly soluble, permeable to water vapor, yellow coloration due to the high content of carotenoids present in the peach palm. FTIR spectra revealed the presence of the group amide I and the films exhibited the type C X-ray pattern. After 15 days in soil, the films lost 30% of its initial weight. Therefore, films obtained exhibit properties / properties similar to conventional films, with the advantage of being biodegradable from renewable sources and can replace the current packaging.