Development and characterization of active bilayer film incorporated with dihydromyricetin encapsulated in hydroxypropyl-β-cyclodextrin for food packaging application

The development of bio-based and active food packaging materials is an effective way to alleviate the growing environmental concern and extend the shelf life of food. This study aimed to prepare a novel bilayer film composed of chitosan (CS) and sodium alginate (SA) incorporated with inclusion complex of dihydromyricetin with hydroxypropyl-β-cyclodextrin (ICDH) by layer-by-layer casting. The results of structural and physical characterization revealed that CS/SA/ICDH films were hydrophilic and had good compatibility, thermal stability, and UV blocking capability, with a smooth and uniform appearance. Compared with CS/SA film, CS/SA/ICDH-10% film exhibited improved tensile strength (45.57 MPa) and elongation at break (22.46%). More importantly, incorporation of ICDH was shown to enhance the antioxidant activity of the bilayer film, as well as the antibacterial activity against Staphylococcus aureus. CS/SA/ICDH-10% film had a superior performance as a food packaging material on preservation of fried meatballs by effectively reducing lipid oxidation and microbial growth. After storage for 7 days, the thiobarbituric acid reactive substance (TBARS) and total plate count (TPC) of fried meatballs packaged with CS/SA/ICDH-10% film were 31.72 μg/g and 3.29 log10 CFU/g, respectively, which were significantly lower than those of the control group (37.00 μg/g, 5.34 log10 CFU/g) and plastic film group (41.07 μg/g, 5.97 log10 CFU/g). Therefore, this study suggested that CS/SA/ICDH film could be used as a promising active packaging material for application in food industry.