Shen Guanghui, Yu Guoxian, Wu Hejun, Li Shanshan, Hou Xiaoyan, Li Meiliang, Li Qingye, Liu Xingyan, Zhou Man, Chen Anjun, Zhang Zhiqing
College of Food Science, Sichuan Agricultural University, Ya'an 625014, China.
Institute of Food Processing and Safety, Sichuan Agricultural University, Ya'an 625014, China.
Membranes (Basel). 2021 Dec 24;12(1):18. doi: 10.3390/membranes12010018.
This work evaluated the improvement effects of lipids incorporation on water resistance of composite biodegradable film prepared with wheat bran cellulose/wheat gluten (WBC/WG) using an alkaline-ethanol film forming system. Four types of lipids, paraffin wax (PW), beeswax (BW), paraffin oil (PO), and oleic acid (OA), were tested. We found that PW, BW, and PO incorporation at 5-20% improved water vapor permeability () and surface hydrophobicity of prepared films. Particularly, incorporation of 15% BW could best improve the water resistance properties of the film, with the lowest of 0.76 × 10 g/cm·s·Pa and largest water contact angle () of 86.18°. Incorporation of OA led to the decline in moisture barrier properties. SEM images revealed that different lipids incorporation changed the morphology and of the composite film, and cross-sectional morphology indicated BW-incorporated film obtained more uniform and compact structures compared to other films. Moreover, Fourier transform infrared spectra indicated that the incorporation of PW or BW enhanced the molecular interactions between the film components, confirmed by the chemical shift of characteristic peaks at 3277 and 1026 cm. Differential scanning calorimetry results revealed that incorporation of PW, BW, and PO increased films' melting point, decomposition temperatures, and enthalpy values. Furthermore, the presence of most lipids decreased tensile strength and elongation at the break of the film. Overall, the composite film containing 15% BW obtained the most promising water resistance performance and acceptable mechanical properties, and it thus most suitable as a hydrophobic biodegradable material for food packaging.
本研究采用碱性乙醇成膜体系，评估了脂质掺入对以麦麸纤维素/小麦面筋（WBC/WG）制备的复合可生物降解膜耐水性的改善效果。测试了四种脂质，即石蜡（PW）、蜂蜡（BW）、石蜡油（PO）和油酸（OA）。我们发现，掺入5%-20%的PW、BW和PO可改善制备薄膜的水蒸气透过率（）和表面疏水性。特别是，掺入15%的BW能最佳地改善薄膜的耐水性能，最低水蒸气透过率为0.76×10 g/cm·s·Pa，最大水接触角（）为86.18°。掺入OA导致防潮性能下降。扫描电子显微镜图像显示，不同脂质的掺入改变了复合膜的形态，横截面形态表明，与其他薄膜相比，掺入BW的薄膜结构更均匀、更致密。此外，傅里叶变换红外光谱表明，PW或BW的掺入增强了薄膜组分之间的分子相互作用，这由3277和1026 cm处特征峰的化学位移证实。差示扫描量热法结果表明，掺入PW、BW和PO提高了薄膜的熔点、分解温度和焓值。此外，大多数脂质的存在降低了薄膜的拉伸强度和断裂伸长率。总体而言，含有15%BW的复合膜具有最有前景的耐水性能和可接受的机械性能，因此最适合作为食品包装用的疏水性可生物降解材料。
