Fabrication and characterization of blue honeysuckle anthocyanins-loaded nanocomposite films and the application in pork preservation

In this experiment, blue honeysuckle anthocyanins (BHA) and nanocomplexes loaded with blue honeysuckle anthocyanins (NC-BHA) were added to a chitosan (CS)/polyvinyl alcohol (PVA) blend matrix for food packaging. The anthocyanin composition in blue honeysuckle and its nanocomplex were determined and analyzed. Meanwhile, the anthocyanins-loaded nanocomplexes and anthocyanin-containing films were measured and compared for their functionality and stability. The zeta potential, polydispersity index and average particle size of anthocyanins-loaded nanocomplexes were +31.80 mV, 0.379 and 659.5 nm, respectively. The encapsulation was effective under transmission electron microscope (TEM) observation. Although CS/PVA-free anthocyanin (CP-FA) film showed better pH sensitivity and oxidation resistance than that of the CS/PVA-anthocyanin nanocomplex (CP-AN) film in short term, the CP-AN film were found to be more stable than the CP-FA film after 30 days at high temperature and light radiation. In summary, the CP-AN film possessed better mechanical property, thermal stability, denser microstructure, higher water vapor barrier, stronger intermolecular interactions and more stable pH sensitivity and oxidation resistance than those of the CP-FA film. Finally, three films were used in the preservation of pork, CP-AN film also showed better antibacterial properties and more durable antioxidant properties. Therefore, CP-AN film was promising active packaging material in pork preservation in our experiment.