香茅草精油/羧甲基壳聚糖复合膜的性能及对沃柑采后青绿霉病防治效果

为探寻安全高效的可食性涂膜应用于沃柑保鲜，以羧甲基壳聚糖（Carboxymethyl chitosan，CMCS）和香茅草精油（XMC）两种天然材料为原料制备复合涂膜材料，并检验复合涂膜材料的理化性质，后以蒸馏水为对照，研究0.5%香茅草精油与1.0%羧甲基壳聚糖复合涂膜处理（0.5% XMC-1.0% CMCS）对沃柑果实青霉、绿霉病害的防控效果及其对果实抗病防御酶活性和果实品质的影响。结果表明，香茅草精油的添加提高了膜的韧性、完整性、粗糙度、不透明度，降低了水蒸气透过率。同时，0.5%香茅草精油与1.0%羧甲基壳聚糖复合处理显著（P<0.05）抑制了沃柑果实青霉、绿霉病的发病率及病斑直径的扩展。此外，与对照组相比，0.5%香茅草精油与1.0%羧甲基壳聚糖复合涂膜处理诱导提高了沃柑果皮中苯丙氨酸解氨酶（PAL）、过氧化物酶（POD）、多酚氧化酶（PPO）、几丁质酶（CHI）活性及苯酚、类黄酮、花青素等抗性物质的含量，且在整个贮藏过程中保持了果实品质。综上，香茅草精油的加入提高了复合膜的整体性能，0.5% XMC-1.0% CMCS复合涂膜处理诱导提高了采后沃柑果实的抗病防御酶活性和抗性物质含量，增强沃柑果实抗青绿霉病的能力，维持了果实贮藏品质。

Study on the effect of compound treatment of volatile oil of Vanilla and chitosan on the control of postharvest Bergamot cyanosis

In order to find a safe and efficient edible coating material for the preservation of fertile orange, a composite coating material was prepared using Carboxymethyl chitosan (CMCS) and citronella essential oil (XMC) as raw materials. The physicochemical properties of the composite coating material were tested, and then distilled water was used as a control. To study the effect of 0.5% citronella essential oil and 1.0% carboxymethyl chitosan coating (0.5% XMC-1.0% CMCS) on the prevention and control of penicillium and green mold diseases in fertile orange, as well as the effect of enzyme activity and fruit quality. The results showed that the addition of citronella essential oil improved the toughness, integrity, roughness and opacity of the film, and decreased the water vapor transmittance. At the same time, the combination treatment of 0.5% citronella essential oil and 1.0% carboxymethyl chitosan was significant (P<0.05) inhibited the incidence of penicillium and green mold disease and the expansion of lesion diameter of fertile orange. In addition, compared with the control group, the composite coating treatment of 0.5% citronella essential oil and 1.0% carboxymethyl chitosan induced increased the activities of phenylalanine ammonia lyase (PAL), peroxidase (POD), polyphenol oxidase (PPO), chitinase (CHI) and the content of phenol, anthocyanins, flavonoids and other resistant substances in fertile orange peel. The fruit quality was maintained during the whole storage process. In conclusion, citronella essential oil to improve the whole performance of the composite membrane, 0.5% XMC - 1.0% composite coating of CMCS to induce improved postharvest fertile orange disease resistance in defense enzyme activity and resistance levels, strengthen the ability of walter fertile orange green mildew resistance, maintain the fruit storage quality.