The pyroligneous liquor is a product obtained during the production of charcoal, with well-known antimicrobial activity. In this work, we characterized the physical chemistry properties of a formulation composed of distilled pyroligneous liquor (DPL), obtained from Eucalyptus grandis, and chitosan. A good interaction between the polymer and the solvent was observed. Auto-supported films were prepared with these systems and characterized with respect to their structure and photo-protection properties, water vapor permeability, and resistance to water and to thermal degradation. They present a semi-crystalline structure and are hygroscopic, but are stable under immersion for up to 7 days. The swelling degree in water is 300% in weight and the permeability to water vapor was between 30 and 45 g m −1 h −1 (for films with 80 to 10 μm, respectively). The obtained films are able to efficiently block the incident UVB and UVC radiation; the molar absorptivity decreases exponentially with increasing wavelength and is stable up to 300°C. These properties confer desirable properties to the films, obtained from these precursors of a renewable source, to be used as coatings.
Amino acids and polypeptides thin films, pure or attached to polymers, present large application as sensors and biosensors. The interactions between such films and the supports, their sensorial properties, as well as the development of techniques to produce thin regular films, are still challenges in the area. In this work, we present the preparation of L-glutamine thin films on silicon substrates, the factors that determine amino acid/silicon substrate interaction, and the morphology of the films. For this purpose, a 2 4 factorial design is used, taking into account the effects of the solvent system, the glutamine concentration, the temperature, as well as the pretreatment of the substrate surface. The contact angles between a drop of glutamine solution and the silicon substrate were taken for the preliminary evaluation of the affinity between the amino acid and the substrate. The results have shown six promising experimental combinations with oxidized silicon as substrate to improve the solution/substrate interaction. Three of these promising conditions involved aqueous solution of L-glutamine and three alkalis solution. The obtained films were characterized by scanning electron microscopy (SEM), Rutherford backscattering (RBS), and Fourier transform infrared (FTIR) spectroscopy. The selected experimental conditions permitted to prepare a variety of films with L-glutamine, like small crystals, lamellas, needles, and smoothed regular films. The systems prepared in presence of alkalis solution yielded regular and smooth films.
Pereskia aculeata Mill., known as Ora-Pro-Nobis or Barbados gooseberry, arouse the interest of food and pharmaceutical industries due to its bioactive compounds and mucilage. We conducted a peer-reviewed survey using Web of Science, Scopus, Scielo, Science Direct, and Scifinder platforms, as well as patent bases for new products.We selected articles which highlighted composition of leaves and applications in the development of new products. Mucilage shows great potential in the development of complexes or microparticles to transport active molecules. Reports on anti-inflammatory and anticancer properties of P. aculeata leaves open a research field to obtain pharmaceutical products. Emulsifying properties of mucilage have been explored in food processing. Another potential use is the development of films for functional and/or edible packaging. The polysaccharide chain, the main mucilage constituent, can interact with other biopolymers to be explored in colloidal chemistry for the production of biomaterials in the next years.
Resumo -Este trabalho teve como objetivo avaliar as diferenças no comportamento térmico de lipídios estruturados obtidos mediante a interesterificação de banha suína com óleo e ésteres de pescado. Os lipídios estruturados foram obtidos através da interesterificação química de blendas contendo banha suína:óleo pescado e de blendas de banha suína: ésteres de pescado, sendo variadas a quantidade de catalisador e proporção das blendas. A partir dos resultados obtidos foi possível determinar que apenas as proporções das blendas (80:20 e 70:30) apresentaram influências significativas no comportamento de fusão e composição em ácidos graxos dos lipídios estruturados produzidos.
The objective of this work was to evaluate a phytoprotective film of chitosan-pyroligneous extract in promoting growth, productivity, induction of systemic resistance in strawberry cultivars managed in an organic production system. Treatments consisted of rates (0, 25, 50, and 100 mL L-1) of Chi-Pyro-Film and a reference resistance inducer (dipotassium hydrogen phosphate - K2HPO4), evaluated in three strawberry cultivars ('Albion', 'San Andreas' and 'Portola'). Growth, yield, anthracnose incidence, and enzymatic activity were evaluated. The experimental design was a randomized block design with four replications. Chi-Pyro-Film increases the growth, yield, and anthracnose resistance of strawberry plants. The best concentration of Chi-Pyro-Film varies between 50 and 60 mL L-1, according to strawberry cultivar.
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