Characterization of a Clove Essential Oil Slow-Release Microencapsulated Composite Film and Its Preservation Effects on Blueberry

In order to extend the shelf life of fruits and vegetables, a sodium alginate-sodium carboxymethyl cellulose composite film loaded with poly(vinyl alcohol) microcapsules was prepared in this paper. The optimal film substrate ratios were obtained after the response surface optimization. Poly(vinyl alcohol) microcapsules were prepared, clove essential oil was loaded into them to investigate the effects of microcapsules on the composite film properties, and the microcapsule composite film with the best overall performance was selected to be applied to blueberry preservation. The results showed that the composite film of 0.84% sodium alginate, 0.25% sodium carboxymethyl cellulose, and 0.56% glycerol presented excellent mechanical properties after adding 1.75% microcapsules. It had a good inhibitory effect on Escherichia coli, Staphylococcus aureus, and Penicillium and had a DPPH clearance rate of 83.78%. The low-temperature bonded composite film could slow down the respiration rate of blueberry, inhibit browning and water loss, effectively maintain the quality of blueberry, and have a significant preservation effect on the anthocyanin and soluble solid content of blueberry. The clove essential oil slow-release microencapsulated composite film can be used for blueberry preservation.