Evaluation of mechanical and antimicrobial properties for indigenously developed Biofilm for food packaging industries

Characterization of quinoa protein–chitosan blend edible films

Abstract: Quinoa protein/chitosan films were obtained by solution casting of blends of quinoa protein extract (PE) and chitosan (CH). Films from a PE/CH blend were characterized by FTIR, X-ray diffraction, thermal analysis, and SEM. The tensile mechanical, barrier, and sorption properties of the films were also evaluated. The blend of PE with CH yielded mechanically resistant films without the use of a plasticizer. The film had large elongation at break, and its water barrier properties showed that they were more hydrophilic than CH film. The thickness and water-vapor permeability of PE/CH (v/v) 1/1 blend film increased significantly compared to pure CH films. CH films are translucent in appearance and yellowish in blend with PE. By blending anionic PE with cationic CH an interaction between biopolymers was established with different physicochemical properties from those of pure CH. Drying and sorption properties show significant differences between PE/CH blend film and CH film. The structural properties determined by XRD, FTIR and TGA showed a clear interaction between quinoa proteins and CH, forming a new material with enhanced mechanical properties.

Sustainability of Biobased and Biodegradable Plastics

Abstract: Advances in science and technology have resulted in the rapid development of modern society, which is clearly unsustainable because of the strain it places on current resources. The energy and materials needed to sustain the present society are derived primarily from non-renewable fossil resources, which will be depleted at some point. Plastics are one example of an important commodity in the modern lifestyle. While plastics are undoubtedly superior materials in terms of their costs, processability and functional properties, they are currently derived from fossil resources and they are not readily assimilated by the various ecosystems upon disposal. The search for biodegradable plastics that are derived from renewable resources has been ongoing since the 1970s. Two of the most promising biobased plastics, i. e., polylactic acid and polyhydroxyalkanoates, have received much attention as potential alternatives to existing processes. This article will discuss the current status and sustainability of these two next generation biobased plastics by taking into consideration the raw materials required, as well as the post-consumption effects of these materials on the environment. In addition, important issues surrounding the development and sustainability of biobased and biodegradable plastics will be highlighted.

Soy protein – Poly (lactic acid) bilayer films as biodegradable material for active food packaging

Abstract: The preparation and characterization of biodegradable bilayer films from isolated soy protein (SPI) and poly (lactic acid) (PLA) were carried out in this work. The films showed high transparency and strong adhesion between layers without adding an extra component, or without chemically modifying the film surfaces. The application of the PLA layer largely increased the mechanical properties of the films with respect to those of pure SPI films. Furthermore, the hydrophobic characteristics of the PLA layer improved film performance under conditions in which water was involved, markedly decreasing the amount of total soluble matter, the swelling index and the water vapor permeability. The biodegradation under soil burial conditions was evaluated measuring weight loss as a function of time, showing a two-step degradation and a faster degradation rate for the protein component compared to those of PLA layer. The films prepared were evaluated as active packaging by incorporation of an antifungal and an antibacterial agent (natamycin and thymol, respectively) to the SPI layer, showing a marked growth inhibition of mold, yeast and two strains of bacteria by in-vitro microbiological assays.

Antimicrobial Films Based on Na-alginate and κ-carrageenan

Abstract: Na-alginate- and κ-carrageenan-based antimicrobial films were prepared, to examine their antimicrobial effect and mechanical properties. Antimicrobial agents: lysozyme, nisin, grape fruit seed extract (GFSE) and ethylenediaminetetraacetic acid (EDTA) were incorporated into films, both alone and in combination. Na-alginate-based films exhibited larger inhibitory zones compared to κ-carrageenan-based films even within similar combinations and levels of antimicrobial agents. GFSE-EDTA in both Na-alginate- and κ-carrageenan-based films showed inhibitory effect against all indicator microorganisms. Tensile strength (TS) values were weaker and elongations (E) before breakage less frequent for films with antimicrobial compounds compared to that of films without the antimicrobial compounds.