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.

Polyphenolic distribution in organs of Argylia radiata, an extremophile plant from Chilean Atacama desert.

The polyphenolic distribution on different organs of Argylia radiata, an extremophile plant from the Atacama "Flowering Desert", is presented herein for the first time. For this purpose, the total phenolic content and antioxidant capacity of ethanolic extracts from leaves, tuberous root and flowers of different colors were evaluated. Orange and red flowers showed the highest polyphenolic and flavonoid content. The maximum anthocyanin concentration was found in red flowers and the antioxidant activity (FRAP) of extracts changed according to the organ. The UPLC-MS/MS analysis of the extracts allowed to identify 10 new polyphenols belonging to different families. Rutin was identified as the most abundant polyphenol in all plant organs, followed by quercetin and coumaric acid. Their role in plant response to abiotic and biotic stress, as well as their potential biotechnological application are discussed.

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.

Enhancing the Membranolytic Activity of Chenopodium quinoa Saponins by Fast Microwave Hydrolysis.

Saponins are plant secondary metabolites. There are associated with defensive roles due to their cytotoxicity and are active against microorganisms. Saponins are frequently targeted to develop efficient drugs. Plant biomass containing saponins deserves sustained interest to develop high-added value applications. A key issue when considering the use of saponins for human healthcare is their toxicity that must be modulated before envisaging any biomedical application. This can only go through understanding the saponin-membrane interactions. Quinoa is abundantly consumed worldwide, but the quinoa husk is discarded due to its astringent taste associated with its saponin content. Here, we focus on the saponins of the quinoa husk extract (QE). We qualitatively and quantitively characterized the QE saponins using mass spectrometry. They are bidesmosidic molecules, with two oligosaccharidic chains appended on the aglycone with two different linkages; a glycosidic bond and an ester function. The latter can be hydrolyzed to prepare monodesmosidic molecules. The microwave-assisted hydrolysis reaction was optimized to produce monodesmosidic saponins. The membranolytic activity of the saponins was assayed based on their hemolytic activity that was shown to be drastically increased upon hydrolysis. In silico investigations confirmed that the monodesmosidic saponins interact preferentially with a model phospholipid bilayer, explaining the measured increased hemolytic activity.

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.

A Novel Hydrocolloid Film Based on Pectin, Starch and Gunnera tinctoria and Ugni molinae Plant Extracts for Wound Dressing Applications.

BACKGROUND: The biodegradable and biocompatible nature of pectin-based films is of particular interest in wound dressing applications, due to its non-toxicity, pH-sensitivity and gelling activity. An approach to improve the mechanical properties, the release profile of bioactive compounds as well as the performance in wet environments of pectin-based films is mixing with other biopolymers. OBJECTIVE: To prepare hydrocolloid films based on crosslinked pectin / starch blend loaded with bioactive extracts from leaves of G. tinctoria and U. molinae with controlled release of bioactive compounds and healing property. METHODS: The hydrocolloid films were characterized by FTIR, SEM, and TGA-FTIR techniques and their tensile properties, water uptake, and polyphenolic release profile in aqueous media were evaluated. The dermal anti inflammatory activity of the hydrocolloid films was assessed by the mouse ear inflammation test. The wound healing property of the loaded hydrocolloid films was explored in a rat model and in a clinical trial (sacrum pressure ulcer). RESULTS: The films showed an adequate water-uptake capacity between 100-160%. The release of active compounds from the hydrocolloid films followed the Korsmeyer-Peppas equation. The mechanical properties of hydrocolloid films were not affected by the plant extracts within the concentration range used. The incorporation of the bioactive extracts in the polysaccharide films inhibited the topical edematous response by about 50%. The topical application of the loaded hydrocolloid film on the pressure ulcer is completely closed after 17 days without showing any adverse reaction. CONCLUSION: A novel hydrocolloid matrix was produced from crosslinked starch-pectin, which exhibited suitable chemical-physical properties to be used as a carrier of plant extracts with wound healing properties.