Department of Chemistry, Karnatak Science College, Dharwad, 580001 Karnataka, India.
Department of Chemistry, Karnatak University, Dharwad, 580003 Karnataka, India.
Carbohydr Polym. 2020 May 15;236:116049. doi: 10.1016/j.carbpol.2020.116049. Epub 2020 Feb 20.
Ethyl vanillin (EV) incorporated chitosan (CS)/poly(vinyl alcohol)(PVA) blend films of various ratios (1:3, 1:1 and 3:1) were prepared by solvent casting technique. The effect of EV on the mechanical, structural, barrier, optical, food compatibility and antibacterial properties of the CS/PVA films were investigated. Mechanical properties showed that addition of EV increased tensile strength of CPEV-1, CPEV-2 and CPEV-3 films by 39 %, 45 % and 86 %, respectively compared to CS/PVA matrix. The FTIR results confirmed the formation of a Schiff base (CN) and intermolecular hydrogen bonds between CS, PVA, and EV. Incorporation of EV into CS/PVA matrix (i.e. CPEV) showed the marked influence on the water vapor transmission rates (WVTRs) and oxygen transmission rates (OTRs) and exhibited excellent UV barrier capability. Surface morphology of CPEV blend films becomes smooth, homogeneous and dense as visualized through scanning electron microscopy. Contact angle measurements demonstrated the increased hydrophobicity of CPEV blend films with increasing CS content. Strong antibacterial activity was exhibited by CPEV-3 blend films against both E. coli (Escherichia coli) and S. aureus (Staphylococcus aureus) bacteria. The overall migration values of CPEV blend films were 10 times lower than acceptable limits of 10 mg/dm. Therefore, CPEV blends have good potential to be considered as sources of active films for food packaging applications.
乙基香草醛（EV）掺入壳聚糖（CS）/聚乙烯醇（PVA）不同比例（1:3、1:1 和 3:1）的共混膜通过溶剂浇铸技术制备。研究了 EV 对 CS/PVA 膜的机械、结构、阻隔、光学、食品相容性和抗菌性能的影响。力学性能表明，与 CS/PVA 基体相比，EV 的加入分别使 CPEV-1、CPEV-2 和 CPEV-3 膜的拉伸强度提高了 39%、45%和 86%。FTIR 结果证实了 CS、PVA 和 EV 之间形成了席夫碱（CN）和分子间氢键。EV 掺入 CS/PVA 基体（即 CPEV）对水蒸气透过率（WVTR）和氧气透过率（OTR）有明显影响，并表现出优异的紫外阻隔能力。扫描电子显微镜观察到 CPEV 共混膜的表面形貌变得光滑、均匀和致密。接触角测量表明，随着 CS 含量的增加，CPEV 共混膜的疏水性增加。CPEV-3 共混膜对大肠杆菌（Escherichia coli）和金黄色葡萄球菌（Staphylococcus aureus）均表现出较强的抗菌活性。CPEV 共混膜的总迁移值比 10mg/dm 的可接受限值低 10 倍。因此，CPEV 共混物具有良好的潜力，可以被认为是用于食品包装应用的活性膜的来源。
