Abstract In this study, the natural fungicide natamycin (N) was encapsulated in zein/carboxymethyl chitosan core-shell nanoparticles (Z/CMCS NPs) to improve its aqueous dispersibility and photostability for application in postharvest fruit preservations. The N-Z/CMCS NPs were spherically shaped with a particle size of 223 ± 2 nm, a polydispersity index of 0.07 ± 0.01 and a surface charge of −50.7 ± 2.3 mV. The NPs were characterized by FTIR spectroscopy and scanning electron microscopy. The encapsulation efficiency of natamycin was improved from 68.3 ± 2.4% to 78.4 ± 1.7% by the addition of CMCS to the NPs. The optimized N-Z/CMCS NPs remained stable and were resistant to neutral pH (6.0–8.0), ion strength (0–100 mM) and long-term storage (30 days). The degradation of natamycin under UV light was reduced, with a half-life time (t1/2) of 47.2 min in the pure state to a t1/2 of 147.5 min in the N-Z/CMCS NPs. The stabilized N-Z/CMCS NPs retained the property of redispersibility after freeze-drying. The bacteriostatic properties of N-Z/CMCS NPs against Botrytis cinerea were tested in vitro and in vivo. The in vitro results demonstrated that the application of N-Z/CMCS NPs completely inhibited the spore germination rate, and 10 mg/L N-Z/CMCS NPs inhibited the mycelial growth by 64.4%. The in vivo results indicated that the NPs not only reduced the occurrence of rot and mildew in inoculated strawberries, with the lowest decay index of 30.3% after 3 days storage, but also inhibited the occurrence of gray mold disease in postharvest strawberries, with the lowest decay rate of 31.1% after 8 days of storage. This study will be beneficial for the development of colloidal delivery systems for postharvest fruit industries.

中文翻译：

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羧甲基壳聚糖稳定载纳他霉素的玉米醇溶蛋白纳米颗粒：评价胶体/化学性能及其在收获后处理中的应用

摘要 在这项研究中，天然杀菌剂游霉素（N）被包裹在玉米醇溶蛋白/羧甲基壳聚糖核壳纳米粒子（Z/CMCS NPs）中，以提高其水分散性和光稳定性，用于果实采后保鲜。NZ/CMCS NPs 呈球形，粒径为 223 ± 2 nm，多分散指数为 0.07 ± 0.01，表面电荷为 -50.7 ± 2.3 mV。通过 FTIR 光谱和扫描电子显微镜对纳米颗粒进行表征。通过向纳米颗粒中添加 CMCS，游霉素的包封效率从 68.3 ± 2.4% 提高到 78.4 ± 1.7%。优化后的 NZ/CMCS NPs 保持稳定，对中性 pH（6.0-8.0）、离子强度（0-100 mM）和长期储存（30 天）具有抵抗力。紫外光下游霉素的降解减少，半衰期 (t1/2) 为 47。在 NZ/CMCS NPs 中，纯态下的 t1/2 为 147.5 分钟。稳定的 NZ/CMCS NPs 在冷冻干燥后保留了再分散性。NZ/CMCS NPs 对灰葡萄孢菌的抑菌特性在体外和体内进行了测试。体外结果表明，NZ/CMCS NPs的应用完全抑制了孢子萌发率，10 mg/L NZ/CMCS NPs抑制了64.4%的菌丝生长。体内试验结果表明，NPs不仅减少了接种草莓的腐烂和霉变的发生，3天后的腐烂指数最低为30.3%，而且对采后草莓灰霉病的发生有抑制作用，最低储存 8 天后衰减率为 31.1%。