Preparation and Characterization of Microcapsule Sustained-Release Bioactive Membranes Co-Encapsulated with Cinnamon Essential Oil and Tea Polyphenols

Co-encapsulated microcapsules were prepared via complex coacervation using cinnamon essential oil and tea polyphenols (TPPs) as core materials, and sodium alginate and gelatin as wall materials. The microcapsules were added to a chitosan matrix containing TPPs to prepare microcapsule membranes. The microcapsule membranes added with 6% microcapsules showed optimal mechanical properties, low water vapor permeability and low oxygen permeability. Within the tested concentration range, the microcapsules and microcapsule membranes had good antioxidant activities against 1,1-diphenyl-2-picrylhydrazyl radical (DPPH•) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical (ABTS+) in an obvious dose-effect relationship, and the microcapsule membranes much outperformed the microcapsules.The microcapsules and microcapsule membranes can significantly inhibit the growth of Staphylococcus aureus and Escherichia coli in a significant dose-effect relationship. Fourier transform infrared spectroscopy and differential scanning calorimetry showed the microcapsules combined with chitosan to form new groups, which improved the thermal stability of the microcapsules. The microcapsules had good sustained-release effects in neutral and acidic systems. The sustained-release effects were further improved in the microcapsule membranes and were the most significant in the 10% ethanol system. In summary, the microcapsule membranes have excellent antioxidant, antibacterial and sustained-release properties, and can be used as active packaging membranes to prolong the shelf life of foods.