Abstract：
This work aimed to develop edible emulsion-based barriers in the form of chitosan composite films, with a focus on assessing the impacts of carnauba wax, rosin resin, and zinc oxide nanoparticles on their properties. Six films were produced by casting using chitosan as polymer base and glycerol as plasticizer. Acetic acid and polysorbate 80 were also used to facilitate the dissolution and mixing of the components. The six filmogenic solutions contained chitosan at 1.2% w/v, wax or resin content with 0 or 0.6% m/v and ZnO with 0 or 0.05% m/v. The dried films were characterized according to their chemical, barrier, mechanical, thermal and optical properties. All treatments resulted in flexible films. Chitosan films appeared smoother and more uniform under SEM imaging, while carnauba wax films displayed roughness due to their hydrophobic nature. Wax and resin films were less transparent and water soluble than the chitosan-only films. On the other hand, the addition of ZnO in the formulations increased the solubility of the films. The sorption degree was in line with the solubility results, i.e., films with ZnO presented higher sorption degree and solubility values. All treatments showed low or non-light UV transmission, indicating that the films provide good barrier to UV light. In the visible light region, films of resin with ZnO showed the lowest transmittance values, hence offering a good barrier to visible light. Among the evaluated films, chitosan, and resin films with ZnO nanoparticles were more rigid and resistant to deformation. Overall, films produced with rosin resin and ZnO nanoparticles showed potential improvements in barrier, mechanical, thermal, and optical properties, mainly due to their low water solubility, good UV protection and low permeability to water vapor and oxygen, which are suitable for using in formulations, intended to produce edible films and coatings.
摘要：
这项工作旨在开发壳聚糖复合膜形式的可食用乳液型屏障，重点评估巴西棕榈蜡的影响，松香树脂,和氧化锌纳米颗粒的性能。通过使用壳聚糖作为聚合物基质和甘油作为增塑剂的流延来生产六种膜。乙酸和聚山梨醇酯80也用于促进组分的溶解和混合。六种成膜溶液含有1.2%w/v的壳聚糖，蜡或树脂含量为0或0.6%m/v，ZnO含量为0或0.05%m/v。根据其化学特性对干燥的薄膜进行表征，屏障,机械,热和光学性能。所有处理产生柔性膜。壳聚糖膜在SEM成像下显得更光滑，更均匀，而巴西棕榈蜡膜由于其疏水性而显示出粗糙度。蜡和树脂膜的透明度和水溶性低于仅壳聚糖膜。另一方面,在制剂中添加ZnO增加了膜的溶解度。吸附程度与溶解度结果一致，即，ZnO薄膜具有较高的吸附度和溶解度值。所有处理显示低或非光UV透射,这表明该膜对UV光提供良好的屏障。在可见光区域,具有ZnO的树脂薄膜显示出最低的透射率值，因此对可见光提供了良好的屏障。在评价的电影中，壳聚糖,和具有ZnO纳米颗粒的树脂膜更具刚性和抗变形性。总的来说,用松香树脂和ZnO纳米颗粒生产的薄膜显示出屏障的潜在改善，机械,热,和光学性质，主要是由于它们的水溶性低，良好的紫外线防护和对水蒸气和氧气的低渗透性，适合在配方中使用，用于生产可食用薄膜和涂层。
