Preparation of polylactic acid/chitosan oligosaccharide films loaded metal-organic framework composite L-theanine and eugenol and its antibacterial and antioxidant properties

In this study, based on the porous characteristics of the metal-organic framework, the inclusion complex of L-theanine (L-the) and Eugenol (Eug) was prepared, and polylactic acid (PLA)/chitosan oligosaccharide (CSO) was used as polymer scaffold to fabricate fibrous films by electrospinning. The results showed that with the addition of inclusion complexes, the solution viscosity and the diameter of the fiber increased, the thermal stability improved, hydrophobicity enhanced, water vapor permeability reduced, mechanical properties destroyed, and brittleness increased. The surface of the plate inhibition zone showed a high inhibition effect on Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Botrytis cinerea (B. cinerea). With the increase of inclusion complexes' concentration, the fiber film could effectively inhibit the mildew of fruits, reduce the loss of Vitamin C (VC) and total phenol contents (TPC), and significantly prolong the storage period of fruits, having an excellent fruit preservative effect.