Navegando por Assunto "Biodegradable film"

Agora exibindo 1 - 3 de 3

Acesso aberto (Open Access)
Efeito da adição de cera de abelha sobre as propriedades de filmes biodegradáveis elaborados com gelatina da pele de peixe
(Universidade Federal do Pará, 2022-08-22) MORAES, Vinicius Sidonio Vale; TEIXEIRA, Camilo Barroso; http://lattes.cnpq.br/7059706802675228; LOURENÇO, Lúcia de Fátima Henriques; http://lattes.cnpq.br/7365554949786769; https://orcid.org/0000-0001-5009-8235
Biodegradable films are defined as thin materials made from biomolecules, which act as a barrier against moisture, gases, light and mechanical injuries and, consequently, extend the shelf life of products. Biodegradable films made from biomolecules have gained visibility today, especially those made from gelatin extracted from fish skin. Despite having good optical and mechanical properties, they have high water vapor permeability (PVA). The addition of lipids such as beeswax is a good option to solve this problem. The objective of this work was the elaboration and characterization of a biodegradable film from yellow hake skin gelatin added with beeswax using sodium dodecyl sulfate (SDS) and stearic acid as a surfactant, aiming to improve the technological properties of the film. A complete factorial design was carried out to define the region with the best barrier and solubility of the films. The planning indicated the tendency of the concentrations for the best results of the characteristics of the film. Based on this, four films of film-forming solution containing 130 ml were prepared, the first being a Control film composed of 2% gelatin and 20% glycerol; second film (F1) composed of 2% gelatin, 20% glycerol, 5% beeswax, 80% SDS and 100% stearic acid; third film (F2) composed of 2% gelatin, 20% glycerol, 10% beeswax, 80% SDS and 100% stearic acid and the fourth film (F3) composed of 2% gelatin, 20% glycerol, 15% beeswax, 80% SDS and 100% stearic acid. The thickness of the films presented heterogeneous results due to the poor incorporation of the wax in the film matrix. Likewise, the addition of beeswax to the film did not have a positive influence on PVA because of the appearance of bubbles in the film-forming solution. However, all films obtained excellent solubility results, justified by the high hydrophobicity of the wax. The films obtained results that indicate opaque films with greenish yellow tones and high luminosity, with an excellent UV barrier, and can be used in foods with sensitivity to light. The microstructure analysis showed inhomogeneous films, with bi-layer-like structures, free spaces and cracks in the matrix.
Acesso aberto (Open Access)
Extrato polissacarídico de cogumelo Pleurotus ostreatus pode melhorar as propriedades tecnológicas do filme de gelatina de peixe
(Universidade Federal do Pará, 2020-02-19) FREITAS, Maurício Madson dos Santos; LOURENÇO, Lúcia de Fátima Henriques; http://lattes.cnpq.br/7365554949786769
The aim of this papert was to evaluate the influence of the polysaccharide extract (POP) obtained from the mushroom Pleurotus ostreatus on the technological properties of fish gelatin films. The optimization conditions of this study were: 3.0% gelatin (GA), 6.26% plasticizer and 1.0% polysaccharide extract (POP). Under these conditions it was possible to obtain values of 5.30x10-11 g.m.m-2, s-1.Pa-1 of WPV, 17.78% of tensile strength and 15.56% of elongation. The optimal film (POP-GA) showed antioxidant activity, adequate visual and structural characteristics, as demonstrated by FTIR, XDR and SEM analyzes. Therefore, the technological properties found in the film with polysaccharide extract and gelatin, have potential for application in the food industry, as well as in the pharmaceutical industry.
Acesso aberto (Open Access)
Obtenção e avaliação dos extratos e óleos de canela e cipó d’ alho e aplicação em filmes biodegradáveis: estudo experimental e teórico
(Universidade Federal do Pará, 2022-08-30) NASCIMENTO, Fabiana Cristina de Araújo; BRASIL, Davi do Socorro Barros; http://lattes.cnpq.br/0931007460545219; https://orcid.org/0000-0002-1461-7306; JOELE, Maria Regina Sarkis Peixoto; http://lattes.cnpq.br/2618640380469195; https://orcid.org/0000-0001-5442-0615
Various spices such as dried fruits and food grains are prone to contamination by filamentous fungi, such as the species Aspergillus Niger, increasing the risk of ingestion of mycotoxins by the population. The production of biodegradable films added to extracts and essential oils can give the same antifungal properties. Thus, this study aimed to develop biodegradable films based on cassava starch with addition of extracts and oils of cinnamon and garlic vine and evaluate its efficiency against the fungus Aspergillus Niger. The ethanol and aqueous extracts were obtained by Soxlet extraction and maceration, respectively, while the oils were obtained by hydrodistillation. To identify the major compounds of the extracts and oils, NMR and Gas Chromatography analyzes were performed. These compounds identified were selected as ligands before the enzyme glucose oxidase produced by the fungus for the theoretical study through Molecular Docking. The extracts and oils were evaluated in antifungal diffusion tests in discs and wells, respectively. The biodegradable films were prepared with extract and oils of cinnamon and garlic vine that showed better performance in antifungal tests. All the elaborated films were evaluated in the antifungal test by means of the technique of diffusion in discs. In the theoretical study through Molecular Docking, all the ligands present in the extracts and oils showed hydrogen bonds with the key amino acid residues of the enzyme glucose oxidase being Histidine (His 559 A), Threonine (Thr 110 A) and Arginine (Arg 512 A). In the antifungal tests, the ethanolic extract of the plant species garlic vine showed a higher inhibition halo of 15mm at a concentration of 20mg/ml while the antifungal tests for oils, at volumes of 1 µl; 5 µl and 10 µl revealed the formation of inhibition halos of 25mm; 28mm and 30mm for cinnamon oil. While, in the film with the oil of the vine of garlic, the inhibition of the germination of said fungus occurred during 9 days of experiment. The antifungal tests of the films revealed that the films with surfactant containing garlic vine oil did not present sporulation halos and neither mycelial growth on films 1 and 2 during the 48h of the experiment, inhibition of the growth of the fungus through the films.