Cheung Ka Man, Jiang Zhuolun, Ngai To
Department of Chemistry, The Chinese University of Hong Kong, Hong Kong, Shatin, China.
J Sci Food Agric. 2023 Oct;103(13):6625-6639. doi: 10.1002/jsfa.12758. Epub 2023 Jun 15.
The pervasive presence of plastic packaging has led to significant environmental contamination due to excessive reliance on petrochemicals and the inherent non-biodegradability of these materials. Bacterial cellulose (BC) films present a viable alternative for food packaging applications, owing to their environmentally friendly synthesis process, non-toxic nature, robust mechanical strength, and biodegradability. However, the high hygroscopicity of such bio-based materials has limited their widespread adoption, as it results in diminished strength and barrier properties. In this study, a novel approach for creating edible, transparent, robust, and high-barrier BC-based composite packaging was proposed through biosynthesis with the incorporation of soy protein isolate and the physical interpenetration of calcium alginate-polyethylene glycol as a composite coating.
The finding demonstrated that the synthesized bio-based composite material exhibits stability in water, high optical transparency, complete oil resistance, and full degradability within 1 to 2 months. Furthermore, the composite material displayed enhanced mechanical properties in both dry and wet conditions, with a tensile strength of approximately 84 MPa, outperforming commercially available kraft paper and low-density polyethylene.
Soy protein isolate established a rigid, coherent, and homogeneous network with BC fibrils, thereby augmenting mechanical properties. Calcium alginate can be effectively combined with BC, utilizing polyethylene glycol as a binder and plasticizer, to generate a densely packed structure with reduced hygroscopicity. This bio-based composite material demonstrated considerable potential for application in food packaging and other value-added sectors as a substitute for non-degradable plastics. © 2023 Society of Chemical Industry.
由于过度依赖石化产品以及这些材料固有的不可生物降解性，塑料包装的普遍存在已导致严重的环境污染。细菌纤维素（BC）薄膜因其环境友好的合成过程、无毒性质、强大的机械强度和生物降解性，为食品包装应用提供了一种可行的替代方案。然而，这种生物基材料的高吸湿性限制了它们的广泛应用，因为这会导致强度和阻隔性能下降。在本研究中，通过生物合成并结合大豆分离蛋白以及将海藻酸钙 - 聚乙二醇作为复合涂层进行物理互穿，提出了一种制备可食用、透明、坚固且具有高阻隔性的基于BC的复合包装的新方法。
研究结果表明，合成的生物基复合材料在水中具有稳定性、高光学透明度、完全耐油性，并且在1至2个月内可完全降解。此外，该复合材料在干燥和潮湿条件下均表现出增强的机械性能，拉伸强度约为84 MPa，优于市售牛皮纸和低密度聚乙烯。
大豆分离蛋白与BC原纤维形成了刚性、连贯且均匀的网络，从而增强了机械性能。海藻酸钙可以与BC有效结合，利用聚乙二醇作为粘合剂和增塑剂，形成紧密堆积的结构，降低吸湿性。这种生物基复合材料作为不可降解塑料的替代品，在食品包装和其他增值领域显示出巨大的应用潜力。© 2023化学工业协会。
