Nectarine Coated with Biopolymeric Nanocapsules Containing Eugenol to Control Brown Rot

Infections in fruits caused by fungi reduce the quantity and quality of food for human consumption, in addition to causing economic losses. In this sense, this study aimed to address the effects of eugenol nanocapsules (NCs) based on chitosan and carboxymethylcellulose in protecting nectarines against Monilinia fructicola, a brown rot agent, a worldwide important disease. NCs were prepared by layer-by-layer (LbL) self-assembly starting from an anionic template and deposition with up to two polymeric layers. The hydrodynamic diameters ranged from 158 nm (nanoemulsion), 360 nm (one polymeric layer) to 398 nm (two polymeric layers). NCs presented, during the in vitro release, the release of eugenol following a first order process. In addition to being in the region of stability (zeta potential ca. |30| mV), the capsules showed good adhesion to the nectarine surface. In relation to brown rot, the eugenol NCs with chitosan proved to be the best formulation compared to nanoemulsion and NCs with two polymeric layers for its control, increasing the probability that the fruits remain without symptoms, even after 7 days. Therefore, this study demonstrated that chitosan NCs containing eugenol could be an alternative to preserve fruit for longer periods in post-harvest.真菌引发的果实侵染不仅会降低人类食用果品的数量与品质，还会造成经济损失。有鉴于此，本研究旨在探究基于壳聚糖与羧甲基纤维素制备的丁香酚纳米胶囊（nanocapsules, NCs）对油桃抵御果生核盘菌（Monilinia fructicola，一种全球性重要褐腐病致病菌）的防护效果。本研究采用逐层（layer-by-layer, LbL）自组装法制备纳米胶囊，以阴离子模板为起始，依次沉积最多两层聚合物。其流体动力学直径分别为158 nm（纳米乳液组）、360 nm（单聚合物层组）及398 nm（双聚合物层组）。体外释放实验结果显示，丁香酚的释放遵循一级动力学过程。除具备良好稳定性（ζ电位约为|30| mV）外，该纳米胶囊还可在油桃表面展现出优异的粘附性能。针对褐腐病防控而言，与纳米乳液及双聚合物层纳米胶囊相比，含壳聚糖的丁香酚纳米胶囊被证实为最优配方，可提升果实在7天后仍无病症的概率。综上，本研究证实，载有丁香酚的壳聚糖纳米胶囊可作为一种延长果实采后保鲜期的备选方案。