漆蜡涂膜对鲜莲蓬采后褐变的影响

摘要

In this experiment, fresh lotuspods were treated with water (as the control) and different concentrations of lacquer wax, respectively, and then stored at (25 ± 1)℃. The physiological and biochemical changes of lotus pods were investigated. The results indicated that 3 g/100 mL lacquer wax coating treatment signiifcantly inhibited the postharvest browning and respiration rate of fresh lotus pods during storage, retarded the increase in browning degree, malondialdehyde (MDA) content and superoxide anion (O2−·) production rate, maintained low hydrogen peroxide (H2O2) content, and inhibited the activities of phenylalanine ammonialyase (PAL) and polyphenol oxidase (PPO) during storage as well as peroxidase (POD) activity at the late stage of storage. At the same time, total phenol content, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and superoxide anion radicalscavenging abilities, as well as the activities of catalase (CAT) and superoxide dismutase (SOD) were maintained at relatively high levels. In conclusion, lacquer wax coating at 3 g/100 mL inhibited the postharvest browning and consequently maintained the quality of fresh lotus pods.%以鲜莲蓬为材料，在常温（25±1）℃条件下，以清水处理为对照，先进行漆蜡处理鲜莲蓬适宜质量浓度的筛选，并研究质量浓度为3 g/100 mL的漆蜡涂膜处理对鲜莲蓬采后褐变相关指标的影响。结果表明：3 g/100 mL的漆蜡涂膜处理对鲜莲蓬采后的褐变有明显的抑制作用；可有效抑制鲜莲蓬贮藏期间的呼吸强度，延缓莲子褐变度、丙二醛含量和O2－•生成速率的上升，维持莲子内部较低的过氧化氢H2O2含量，降低莲子贮藏期间的多酚氧化酶和苯丙氨酸解氨酶活性以及贮藏后期的过氧化物酶活性；同时，漆蜡涂膜处理维持了莲子较高的总酚含量、1,1-二苯基-2-三硝基苯肼自由基和O2－•清除能力及过氧化氢酶和超氧化物歧化酶活性。这些结果表明3 g/100 mL的漆蜡涂膜处理可延缓采后鲜莲蓬的褐变，从而维持其品质。