Baquero-Aznar Víctor, Calvo Víctor, González-Domínguez José Miguel, Maser Wolfgang K, Benito Ana M, Salvador María Luisa, González-Buesa Jaime
Departamento de Ciencia Vegetal, Instituto Agroalimentario de Aragón-IA2, Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA), Av. Montañana 930, 50059 Zaragoza, Spain.
Grupo de Investigación en Alimentos de Origen Vegetal, Instituto Agroalimentario de Aragón-IA2, Universidad de Zaragoza, Miguel Servet 177, 50013 Zaragoza, Spain.
Polymers (Basel). 2025 Sep 19;17(18):2538. doi: 10.3390/polym17182538.
This study aims to develop egg white protein (EWP) biocomposite films reinforced with chitin nanocrystals (ChNCs, 1-5 wt.%) by compression molding to overcome the mechanical and barrier limitations of protein-based films for sustainable packaging. ChNC incorporation may modulate film microstructure, crystallinity, and thermal stability, thereby enhancing functional performance. Films were prepared by adding ChNCs either as aqueous suspensions or lyophilized powder, and their structural, thermal, mechanical, optical, and barrier properties were systematically evaluated. Scanning electron microscopy confirmed a more homogeneous dispersion of ChNCs when added as suspensions, while powder addition promoted partial aggregation. X-ray diffraction revealed increased crystallinity with ChNC reinforcement. Mechanical tests showed that films with 2 wt.% ChNCs in suspension exhibited the highest tensile strength, whereas those with 5 wt.% in powder form became stiffer but less extensible. Oxygen permeability was not significantly affected, while water vapor permeability decreased by up to 14.5% at 2 wt.% ChNCs incorporated as powder. Transparency and color remained largely unchanged by ChNC addition, except for a slight increase in yellowness. Overall, these findings demonstrate that the incorporation method and concentration of ChNCs play a crucial role in tailoring the physicochemical performance of EWP films. The results provide new insights into the design of EWP-based nanocomposites and support their potential as bio-derived materials for advanced food packaging applications.
本研究旨在通过压缩成型开发用几丁质纳米晶体（ChNCs，1-5重量%）增强的蛋清蛋白（EWP）生物复合膜，以克服基于蛋白质的薄膜在可持续包装方面的机械和阻隔性能限制。加入ChNCs可能会调节薄膜的微观结构、结晶度和热稳定性，从而提高功能性能。通过将ChNCs以水悬浮液或冻干粉末的形式加入来制备薄膜，并系统地评估了它们的结构、热、机械、光学和阻隔性能。扫描电子显微镜证实，当以悬浮液形式加入时，ChNCs的分散更均匀，而加入粉末则促进了部分聚集。X射线衍射显示，ChNCs增强后结晶度增加。力学测试表明，悬浮液中含有2重量%ChNCs的薄膜具有最高的拉伸强度，而粉末形式含有5重量%ChNCs的薄膜变得更硬但延展性更低。氧气透过率没有受到显著影响，而当以粉末形式加入2重量%ChNCs时，水蒸气透过率降低了高达14.5%。除了黄度略有增加外，ChNCs的加入对透明度和颜色的影响不大。总体而言，这些发现表明，ChNCs的加入方法和浓度在定制EWP薄膜的物理化学性能方面起着关键作用。研究结果为基于EWP的纳米复合材料的设计提供了新的见解，并支持了它们作为生物衍生材料用于先进食品包装应用的潜力。
