Biodegradable bilayer films prepared from individual films of different proteins

Abstract

Bilayer films propose to combine the characteristics of different individual polymer sources in a single structure, aiming to improve the properties of the films obtained. The objective of this study was to develop and characterize bilayer films prepared from individual films of zein, wheat gluten, and protein isolate from hake (Cynoscion guatacupa), and evaluate the biodegradability of these polymers. Through the casting technique, individual films and bilayers were prepared. The hake proteins isolate films, as well as the bilayers hake protein isolate/zein and hake protein isolate/wheat gluten (BI PI/WG) showed higher tensile strength, while wheat gluten films presented greater elongation at rupture and lower solubility. In addition to having good tensile strength, BI PI/WG presented the best elongation. All films and bilayers reached melting and glass transition temperatures above 100°C. Electromicrographs of the films presented an irregular surface with pores and grooves, being less pronounced in BI PI/WG. In the bilayers, it was not necessary to use any type of adhesive to form a single structure. Films and bilayers showed total biodegradability in 40 days, with the exception of the individual zein film. BI PI/WG proved to be the most suitable for the development of food packaging materials. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46721.

Development of active cassava starch films reinforced with waste from industrial wine production and enriched with pink pepper extract

“…Other studies reporting the behavior of biodegradable films, such as that of Nogueira and Martins, 98 which evaluated the biodegradability of gluten‐based films, achieved complete degradation in only 10 days. Torres et al 99 achieved 99.35% mass loss after 31 days in their analysis of biodegradable films made from cassava starch, whereas for gold potato starch film they observed a loss of 90.03% over the same time interval.…”

Effect of an active biodegradable package made from bean flour and açaí seed extract on the quality of olive oil

“…Color and transparency stand out among the optical properties of films for application in packaging, but these should not be a limiting factor of their use. [ 37 ] The color parameters L (brightness), a * (+ a red and − a green), and b * (+ b yellow and – b blue) shown in Table 1 indicate that the films did not differ from each other in average luminosity. As for the a * and b * coordinates, the films with extracts added presented significantly higher values than the control film, indicating that the addition of extracts accentuated the red and yellow color of the films.…”

Amazon‐sustainable‐flour from açaí seeds added to starch films to develop biopolymers for active food packaging

“…These macromolecules are advantageous because of their availability from biomass sources and their capacity to form three-dimensional networks. 4,5 Starch is one of the most abundant polymers in nature and it is available in high purity at a reasonably low cost 6,7 ; in the rice (Oryza sativa L.), it comprises about 90% of the dry mass of the grains. The rice processing results in around 14% of broken grains, which have lower commercial value compared to whole grains.…”

“…Active biopolymers are obtained by incorporating functional substances in polysaccharides, proteins, and/or lipids films. These macromolecules are advantageous because of their availability from biomass sources and their capacity to form three‐dimensional networks 4,5 . Starch is one of the most abundant polymers in nature and it is available in high purity at a reasonably low cost 6,7 ; in the rice ( Oryza sativa L.), it comprises about 90% of the dry mass of the grains.…”