魔芋葡甘聚糖/油酸修饰纳米ZnO复合抗菌膜的制备与表征

为提高纳米氧化锌（ZnO）在魔芋葡甘聚糖（konjac glucomannan，KGM）中的分散性，以增强纳米复合膜的抗紫外线性能和抗菌性能，通过油酸（oleic acid，OA）对纳米ZnO进行修饰，制备OAZnO溶液，并采用浇铸法制备KGM/OAZnO纳米复合膜，通过流变学分析、傅里叶变换红外光谱分析、X射线衍射分析、微观结构观察、热重分析以及理化性质测定，研究OAZnO的添加对KGM膜结构和理化性质的影响。结果表明，OA提高了纳米ZnO的分散性，傅里叶变换红外光谱分析证实纳米ZnO与KGM分子间形成了较强的氢键，X射线衍射光谱结果表明纳米ZnO中的Zn2＋与KGM链上的—OH形成配位键；同时，适量OAZnO（0.49 mL）使纳米复合膜包装机械性能和阻水性能得到增强，其水蒸气透过率较KGM膜降低了35.62%，拉伸强度提高了79.26%。此外，紫外光谱分析和抗菌实验结果表明KGM/OAZnO纳米复合膜具有较强的紫外阻隔性能和抗菌性能。综上，OAZnO的添加可以提高纳米复合膜综合性能，且OAZnO溶液添加量为0.49 mL时最强，可以作为功能性食品包装膜。

Preparation and Characterization of Konjac Glucomannan/Oleic Acid Modified ZnO Nanocomposite Antibacterial Film

In order to improve the dispersion of zinc oxide (ZnO) nanoparticles in konjac glucomannan (KGM)-based films, and enhance the anti-ultraviolet (UV) and antibacterial properties of nanocomposite films, ZnO nanoparticles modified with oleic acid (OAZnO) was used to prepare KGM/OAZnO nanocomposite films by a casting method, and the effects of OAZnO on the structure and physicochemical properties of KGM-based films were studied by rheological analysis, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), microstructural observation, thermogravimetric analysis (TGA) and physicochemical measurements. The results showed that oleic acid (OA) improved the dispersity of ZnO nanoparticles. The FTIR analysis confirmed the formation of strong hydrogen bonds between ZnO nanoparticles and KGM. The XRD spectra showed that Zn2+ in ZnO nanoparticles formed coordination bonds with –OH on the KGM chain. Meanwhile, the appropriate amount (0.49 mL) of OAZnO nanoparticles enhanced the packaging-related mechanical and water barrier properties of nanocomposite films, decreasing water vapor permeability (WVP) by 35.62% and increasing tensile strength by 79.26% when compared with those of KGM films. In addition, KGM/OAZnO nanocomposite films had strong UV barrier and antibacterial properties. Therefore, addition of OAZnO especially at 0.49 mL could improve the overall performance of nanocomposite films, making it a candidate for use as a functional food packaging film to extend the shelf life of packaged foods.