Robust microfluidic construction of konjac glucomannan-based micro-films for active food packaging

The objective of this study was to develop a novel active food packaging with high performance by using natural active compound. Here, a facile and green strategy was employed to construct the konjac glucomannan/polylactic acid/trans-cinnamic acid micro-films (KPTMF) via microfluidic spinning technology (MST). MST, a mild preparation approach, could remain the activities of natural compound during processing. Konjac glucomannan could drive the release of trans-cinnamic by using its hydrophilicity under our careful design. The results of fourier-transform infrared spectra and infrared images revealed that konjac glucomannan, polylactic acid, and trans-cinnamic acid had good compatibility through hydrogen bonds in the micro-films, which was consistent with the X-ray diffraction results. Also, the good swelling degree (81.36 ± 5.79%) of KPTMF could promote the release of trans-cinnamic. Besides, the KPTMF had excellent mechanical properties (Tensile strength: 14.09 ± 2.97 MPa, Elongation at break: 3.12 ± 0.57%), thermal stabilities and hydrophobicity (Water vapor permeability: 4.81 × 10^-6 g/(m·h·kPa), Water contact angle: 99.2°). The obtained micro-films with large specific surface areas exhibited great antibacterial activities against Staphylococcus aureus and Escherichia coli, which suggested the potential applications in active food packaging.