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-beta-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 lig/g and 3.29 log(10) CFU/g, respectively, which were significantly lower than those of the control group (37.00 lig/g, 5.34 log(10) CFU/g) and plastic film group (41.07 lig/g, 5.97 log(10) 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.

Automated summary

The study successfully prepared a novel chitosan/sodium alginate/inclusion complex film and demonstrated its good thermal stability, hydrophilicity, UV blocking capability, as well as antibacterial and antioxidant activities. When used for packaging fried meatballs, the film effectively reduced lipid oxidation and microbial growth.