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A novel composite edible coating film was developed from 0.8% chitosan (CS) and 0.5% sandalwood oil (SEO). Cellulose nanofibers (CNFs) were used as a stabilizer agent of oil-in-water Pickering emulsion. We found four typical groups of CNF level-dependent emulsion stabilization, including (1) unstable emulsion in the absence of CNFs; (2) unstable emulsion (0.006–0.21% CNFs); (3) stable emulsion (0.24–0.31% CNFs); and (4) regular emulsion with the addition of surfactant. Confocal laser scanning microscopy was performed to reveal the characteristics of droplet diameter and morphology. Antifungal tests against Botrytis cinerea and Penicillium digitatum, between emulsion coating stabilized with CNFs (CS-SEOpick) and CS or CS-SEO was tested. The effective concentration of CNFs (0.24%) may improve the performance of CS coating and maintain CS-SEO antifungal activity synergistically confirmed with a series of assays (in vitro, in vivo, and membrane integrity changes). The incorporation of CNFs contributed to improve the functional properties of CS and SEO-loaded CS including light transmission at UV and visible light wavelengths and tensile strength. Atomic force microscopy and scanning electron microscopy were employed to characterize the biocompatibility of each coating film formulation. Emulsion-CNF stabilized coating may have potential applications for active coating for fresh fruit commodities.

A novel composite edible coating film was developed from 0.8% chitosan (CS) and 0.5% n sandalwood oil (SEO). Cellulose nanofibers (CNFs) were used as a stabilizer agent of oil-in-water Pickering emulsion. We found four typical groups of CNF level-dependent emulsion stabilization, including (1) unstable emulsion in the absence of CNFs; (2) unstable emulsion (0.006–0.21% CNFs); (3) stable emulsion (0.24–0.31% CNFs); and (4) regular emulsion with the addition of surfactant. Confocal laser scanning microscopy was performed to reveal the characteristics of droplet diameter and morphology. Antifungal tests against Botrytis cinerea and Penicillium digitatum, between emulsion coating stabilized with CNFs (CS-SEOpick) and CS or CS-SEO was tested. The effective concentration of CNFs (0.24%) may improve the performance of CS coating and maintain CS-SEO antifungal activity synergistically confirmed with a series of assays (in vitro, in vivo, and membrane integrity changes). The incorporation of CNFs contributed to improve the functional properties of CS and SEO-loaded CS including light transmission at UV and visible light wavelengths and tensile strength. Atomic force microscopy and scanning electron microscopy were employed to characterize the biocompatibility of each coating film formulation. Emulsion-CNF stabilized coating may have potential applications for active coating for fresh fruit commodities.

Sazonalmente, massas de ar frio provenientes do sul do continente atingem a região do sudoeste da Amazônia Brasileira em alguns dias do ano. Estes eventos são capazes de ocasionar perturbação atmosférica e alterar os parâmetros micrometeorológicos de forma a influenciar na vida biológica da floresta. O objetivo deste trabalho foi descrever a sazonalidade micrometeorológica, bem como a chegada de um evento de friagem e seus efeitos na região do município de Humaitá-AM, para o ano de 2017. Foram utilizados dados de estações meteorológicas do Instituto Nacional de Meteorologia (INMET). A precipitação total foi de 2710,6 mm.ano-1, sendo sua sazonalidade bem definida por duas estações características, seca e chuvosa. A umidade relativa do ar manteve-se com padrões típicos da região na ordem de 70-90% durante todo o ano. A radiação solar global incidente apresentou o menor valor no período de seca e o maior na transição do período seco para o chuvoso. A temperatura máxima atingiu valores na ordem de 35 ºC, e a pressão e velocidade do vento demonstraram um aumento expressivo no mês de julho e valores mínimos em novembro. O evento da passagem da friagem gerou alterações em todos os parâmetros analisados, com queda brusca na temperatura e aumento na pressão e velocidade dos ventos. A umidade relativa do ar apresentou valores baixos devido a friagem ter massa de ar seca e fria.

In this study, edible films composed of 1% (w/v) alginate (Alg) and ylang‐ylang essential oil (YYEO, 0.1%, 0.3%, and 0.5%) were fabricated and characterized for the first time. The alginate suspension viscosity increased significantly from 255.8 to 290.5 Cp, with a corresponding significant film thickness increase from 0.029 to 0.043 mm. There was also a significant decrease in moisture content (MC%) from 30.22 to 23.93%. Scanning electron microscopy and atomic force microscopy analyses showed an increased Alg/YYEO film roughness. The presence of YYEO in the alginate film was confirmed by Fourier transform infrared spectroscopy and confocal laser scanning microscopy. YYEO addition induced no significant change in total color difference (ΔE). There was a decrease in tensile strength and a significant (p < 0.05) increased elongation at break (EAB%) by 83.11%. The Alg/0.3% YYEO film demonstrated improved water vapor permeability compared with the other films. The Alg/0.5% YYEO film had strong antioxidant scavenging properties (27.94%), and an opacity of 3.60 A/mm. Both the Alg/0.3% YYEO and 0.5% YYEO coating solutions greatly improved antifungal properties against Botrytis cinerea. Therefore, alginate films incorporating YYEO are viable materials for edible films and coatings in fresh produce packaging.

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Chitosan films enhanced with tea seed oil (TO) and montmorillonite were solution cast and the influence of montmorillonite additives on the physicochemical and antifungal properties was evaluated. The addition of TO and montmorillonite significantly increased both the pH and viscosity of the coating solutions. SEM and AFM showed montmorillonite addition increased membrane structure homogeneity. In addition, chitosan films incorporating montmorillonite exhibited significantly improved tensile strength, at 43.87% in chitosan with montmorillonite and 44.23% in chitosan with montmorillonite and TO. Antifungal activity of the chitosan coating increased sharply when TO was added, inhibiting spore germination and germ tube length by 65.05% and 51.95% respectively. The decay inhibition rates for strawberries treated with chitosan and TO, or chitosan, TO and montmorillonite were also high at 32.77% and 28.79% respectively. This demonstrates that chitosan-based TO/montmorillonite films are potential materials for packaging fruits or vegetables, to eventually replace synthetic polymers.