Preparation and Application of Polylactic Acid-Based Electrospun Photocatalytic Composite Films

To address the performance limitations of traditional polylactic acid (PLA) packaging materials, as well as to reduce the economic losses caused by ethylene-induced over-ripening and spoilage of mangoes during transportation and storage, a series of PLA/CS/nTiO₂ nanofibrous composite films were fabricated via electrospinning. In this process, chitosan (CS) was incorporated to ameliorate the inherent defects of the PLA matrix, while TiO₂ nanoparticles with different loading ratios were introduced as functional fillers. The microstructure of the composite films was characterized via scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction, followed by systematic evaluations of its mechanical properties, barrier performance, and hydrophobicity. Subsequently, photocatalytic experiments were conducted to investigate its ethylene degradation capability, and a 10-day mango preservation trial was carried out. During the storage period, the preservation effect of the composite films was evaluated by monitoring the fruit weight loss rate, firmness, peel color, total phenolic content, and malondialdehyde (MDA) accumulation. The results demonstrated that compared with pure PLA film, the composite film with 4% TiO₂ exhibited the optimal comprehensive performance. Its tensile strength and elongation at break increased to 7.93 MPa and 55.74%, respectively, accompanied by suitable water vapor and oxygen barrier properties as well as favorable hydrophobicity. Notably, this optimal formulation achieved an ethylene removal rate of 67.6%, compared with no-film treatment, which could effectively degrade the ethylene generated during mango storage. It significantly delayed the weight loss and firmness decline of mangoes, inhibited peel color deterioration, reduced the consumption of total phenolic, and lowered MDA accumulation, thereby retarding the spoilage process of mangoes effectively. This work aimed to provide a novel technical solution for the development of active food packaging for fruits and vegetables.