Humidity-responsive antimicrobial properties of EVOH nanofibers loaded with cuminaldehyde/H8CD inclusion complexes and its application in chicken preservation

The application of cuminaldehyde (CUM) in the food industry is limited by its low water solubility, stability and bioavailability. In this work, the inclusion complex (IC) of CUM and 2-hydroxypropyl-8-cyclodextrin (H8CD) was synthesized (CUM/H8CD-IC), and then ethylene vinyl alcohol copolymer (EVOH) containing CUM/H8CD-IC was prepared via coaxial electrospinning (CUM/H8CD-IC-EVOH-NF, CHIE-NF). The encapsulation efficiency and loading efficiency of CUM/H8CD-IC were 78.00% and 8.51%, respectively. The formation of solid CUM/H8CD-IC was confirmed by X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, thermogravimetric analysis and field emission scanning electron microscopy (FESEM). Also, the CUM could enter the hydrophobic cavity of H8CD and be stabilized by hydrogen bond between CUM and H8CD. Transmission electron microscopy verified the successful preparation of core-shell nanofiber, and FESEM showed that the average diameter of CHIE-NF was 444 +/- 127 nm. In addition, CHIE-NF achieved controlled release of CUM through EVOH responsive to humidity, improved the thermostability of free CUM, increased mechanical strength, and exhibited antibacterial ability against Escherichia coli and Staphylococcus aureus. In the application for chicken meat preservation, CHIE-NF significantly slowed down the increase of total volatile basic nitrogen, pH value, total viable count, Enterobacteriaceae and lactic acid bacteria in minced chicken meat, and the shelf life of the meat increased by nearly 3 days compared to the control group based on the tested parameters. In summary, CHIE-NF has the potential for application in food field such as active packaging.