Preparation of natural complex waxy structure for the evaluation of preservation performance of blueberry

As a perishable fruit, the quality of blueberries is rapidly decayed after harvesting due to their weight loss, softening of tissues, color changes and microbial proliferation. In order to mimic the waxy layer of the blueberry epidermis, the waxy layer of wax gourd epidermis were investigated by scanning electron microscopy, energydispersive X-ray spectroscopy, and fourier transform infrared spectroscopy. Moreover, the magnolol-loaded shellac/zein nanoparticles were fabricated using coaxial electrospraying method. The average particle size of the optimal nanoparticles was 2.84 & PLUSMN; 0.03 nm, and the encapsulation rate of magnolol was 79.18% & PLUSMN; 0.61%. Finally, the optimized nanoparticles and wax gourd epidermis were dispersed in an arabic gum solution to obtain a coating and sprayed on the surface of postharvested blueberries. The shellac/zein/magnolol nanoparticles exhibited potential thermal stability, excellent DPPH radical scavenging, antifungal activities against four different types of molds including Penicillium, Botrytis cinerea, Alternaria alternaria and Pestalotiopsis. Overall, the shellac/zein/magnolol nanoparticles are suitable coating to retain the freshness and quality of blueberries during the storage.