Bioactive Pectin-Murta (Ugni molinae T.) Seed Extract Films Reinforced with Chitin Fibers.

This study investigated the biocomposite pectin films enriched with murta (Ugni molinae T.) seed polyphenolic extract and reinforced by chitin nanofiber. The structural, morphological, mechanical, barrier, colorimetric, and antioxidant activity of films were evaluated. The obtained data clearly demonstrated that the addition of murta seed extract and the high load of chitin nanofibers (50%) provided more cohesive and dense morphology of films and improved the mechanical resistance and water vapor barrier in comparison to the control pectin film. The antioxidant activity ranged between 71% and 86%, depending on the film formulation and concentration of chitin nanofibers. The presented results highlight the potential use of chitin nanofibers and murta seed extract in the pectin matrix to be applied in functional food coatings and packaging, as a sustainable solution.

Valorization of food waste to produce intelligent nanofibrous ß-chitin films.

The efficient use of waste from food processing industry is one of the innovative approaches within sustainable development, because it can be transferred into added value products, which could improve economic, energetic and environmental sectors. In this context, the squid pen waste from seafood industry was used as raw material to obtain nanofibrous ß-chitin films. In order to extend functionality of obtained films, elderberry extract obtained from biomass was added at different concentrations. The tensile strength of chitin-elderberry extract films was improved by 52%, elongation at break by 153% and water vapor barrier by 65%. The obtained material showed distinct color change when subjected to acidic or basic solutions. It was proven by CIELab color analysis that all color changes could be easily perceived visually. In addition, the obtained nanofibrous film was successfully used to monitor the freshness of Hake fish. Namely, when the film was introduced in a package that contained fresh fish, its color was efficiently changed within the time during the storage at 4 °C. The obtained results demonstrated that food processing waste could be efficiently valorized, and could give sustainable food package design as a spoilage indicator of high protein food.

Phytostimulant properties of highly stable silver nanoparticles obtained with saponin extract from Chenopodium quinoa.

BACKGROUND: Quinoa (Chenopodium quinoa Willd) is an Andean original pseudocereal with high nutritional value. During quinoa processing, large amounts of saponin-rich husks byproducts are obtained. Quinoa saponins, which are biologically active, could be used for various agriculture purposes. Silver nanoparticles have increasingly attracted attention for the management of crop diseases in agriculture. In this work, silver nanoparticles are synthesized by a sustainable and green method, using quinoa husk saponin extract (QE) to evaluate their potential for application in agriculture as biostimulants. RESULTS: Quinoa extract was obtained and characterized by liquid chromatography with tandem mass spectrometry (LC-MS/MS). Sixteen saponin congeners were successfully identified and quantified. The QE obtained was used as a reducing agent for silver ions to synthesize silver nanoparticles (QEAgNPs) under mild conditions. The morphology, particle size, and stability of Ag nanoparticles were investigated by transmission electron microscopy (TEM), ultraviolet-visible spectroscopy (UV-visible), energy-dispersive X-ray (EDS), zeta potential, and Fourier transform infrared spectroscopy with attenuated total reflection (FTIR-ATR). Ultraviolet-visible spectroscopy measurements confirmed the formation of silver nanoparticles in the presence of QE, with estimated particle sizes in a range between 5 and 50 nm. According to the zeta potential values, highly stable nanoparticles were formed. The QE and QEAgNPs (200-1000 µg/mL) were also tested in radish seed bioassay to evaluate their phytotoxicity. The seed germination assays revealed that QEAgNPs possessed a phytostimulant effect on radish seeds in a dose-dependent manner, and no phytotoxicity was observed for both QE and QEAgNPs. CONCLUSION: Silver nanoparticles obtained by a so-called 'green' method could be considered as good candidates for application in the agricultural sector for seed treatment, or as foliar sprays and plant-growth-promoters. © 2020 Society of Chemical Industry.

Physical-Chemical Evaluation of Active Food Packaging Material Based on Thermoplastic Starch Loaded with Grape cane Extract.

The aim of this paper is to evaluate the physicochemical and microbiological properties of active thermoplastic starch-based materials. The extract obtained from grape cane waste was used as a source of stilbene bioactive components to enhance the functional properties of thermoplastic starch (TPS). The biomaterials were prepared by the compression molding technique and subjected to mechanical, thermal, antioxidant, and microbiological tests. The results showed that the addition of grape cane extract up to 15 wt% (TPS/WE15) did not significantly influence the thermal stability of obtained biomaterials, whereas mechanical resistance decreased. On the other side, among all tested pathogens, thermoplastic starch based materials showed antifungal activity toward Botrytis cinerea and antimicrobial activity toward Staphylococcus aureus, suggesting potential application in food packaging as an active biomaterial layer.

Design of pectin-sodium alginate based films for potential healthcare application: Study of chemico-physical interactions between the components of films and assessment of their antimicrobial activity.

In this study, pectin based films including different amounts of sodium alginate were prepared by casting method. All the films, with and without polyglycerol as plasticizer, were crosslinked with zinc ions in order to extend their potential functionality. The development of junction points, occurring during the crosslinking process with zinc ions, induced the increasing of free volume with following changing in chemico-physical properties of films. The inclusion of alginate in pectin based formulations improved the strength of zinc ions crosslinking network, whereas the addition of polyglycerol significantly improved mechanical performance. Finally, zinc-crosslinked films evidenced antimicrobial activity against the most common exploited pathogens: Staphylococcus Aureus, Escherichia Coli and Candida Albicans. These results suggest that zinc-crosslinked based films can be exploitable as novel bio-active biomaterials for protection and disinfection of medical devices.

Novel composite films based on amidated pectin for cationic dye adsorption.

Pectin, with its tendency to gel in the presence of metal ions has become a widely used material for capturing the metal ions from wastewaters. Its dye-capturing properties have been much less investigated, and this paper is the first to show how films based on amidated pectin can be used for cationic dye adsorption. In the present study amidated pectin/montmorillonite composite films were synthesized by membrane casting, and they are stable in aqueous solution both below and above pectin pKa. FTIR, thermogravimetry and SEM-EDAX have confirmed the presence of montmorillonite in the cast films and the interactions between the two constituents. In order to evaluate the cationic dye adsorption of these films Basic Yellow 28 was used, showing that the films have higher adsorption capacity compared to the others reported in the literature. The results were fitted into Langmuir, Freundlich and Temkin isotherms indicating an exothermic process and setting the optimum amount of montmorillonite in the films to 30% of pectin mass. According to the Langmuir isotherm the maximum adsorption capacity is 571.4 mg/g.

Complexation of amidated pectin with poly(itaconic acid) as a polycarboxylic polymer model compound.

Complexes based on amidated pectin (AP) and poly(itaconic acid) (PIA) were prepared by casting films from solutions of AP and PIA in different ratios with the pectin amount ranging from 10% to 90% by mass. The complexes were investigated by elemental analysis, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetry (TG). In all investigated ratios of AP/PIA glassy transparent films with a uniform structure were obtained. The results of elemental analysis confirmed the composition of the complexes, and FTIR spectroscopy has shown carboxylic and amide peak shifting, indicating complex formation between AP and PIA. Comparison of thermograms of AP/PIA films with different ratios of AP indicated that the increase of the amount of AP increases the thermal stability of the films by retarding the onset of the main degradation processes.