蓝光LED延缓黄瓜采后冷害的效果研究

Study on the Effect of Blue LED in Delaying Postharvest Chilling Injury in Cucumber

摘要:

为探究蓝色发光二极管（Light Emitting Diode，LED）对典型冷敏性蔬菜采后冷害的影响。实验以黑暗处理为对照组，以光照强度45 W·m-2，每天照射12 h的蓝光LED（460 nm）为处理组。黄瓜在4°C下冷藏10 d，每间隔2 d测定黄瓜冷害和品质指标，并对其活性氧代谢进行探究。结果表明：相较于对照组，蓝光LED处理使黄瓜的冷害指数降低了30%，失重率减少了11.69%，同时保持黄瓜较高的硬度、L*、叶绿素和可溶性固形物含量。此外，蓝光LED处理促进总酚和类黄酮含量增加，提升抗氧化酶活性，从而提高了自由基清除率，降低O2-含量。因此，蓝光LED处理通过激活抗氧化系统维持氧化稳态，进而延缓黄瓜冷害并保持其品质。研究结果为延长黄瓜低温贮藏期并减少其采后损耗提供了LED光保鲜条件。

Abstract:

To investigate the effects of blue light-emitting diodes (LEDs) on postharvest chilling injury in representative chilling-sensitive vegetable. Cucumbers were divided into two groups, with the first group of cucumbers were placed in the dark at all times. The second group of cucumbers was irradiated with 460-nm blue LED light at 45 W·m-2 for 12 h every day. All cucumbers were stored at 4 °C for 10 days, and the chilling injury indices, quality parameters, and reactive oxygen species (ROS) metabolism were analyzed at the intervals of two days. The results demonstrated that compared to the control group, blue LED treatment significantly reduced the chilling injury index by 30%, decreased weight loss rate by 11.69%, and effectively maintained higher firmness, L*, chlorophyll, and soluble solids of cucumber. Furthermore, blue LED treatment increased total phenolic and flavonoid content as well as antioxidant enzyme activities, collectively enhancing free radical scavenging capacity and reducing superoxide anion content. Thus, blue LED irradiation mitigates chilling injury and preserves postharvest cucumber quality through the activation of antioxidant systems, thereby sustaining oxidative homeostasis. The results of this study provide LED preservation conditions for extending the low-temperature storage of cucumbers and reducing their postharvest losses.