目的 研究低强度LED白光处理对采后油麦菜品质的影响。方法 采用光照强度为5 μmol/(m2•s)的LED白光于(20±1)℃下持续照射油麦菜7 d，以黑暗条件下贮藏的样品为对照，测定贮藏期间样品的感官评分、腐烂率、呼吸强度，叶绿素、维生素C、总酚及丙二醛（MDA）含量，多酚氧化酶（PPO）、过氧化氢酶（CAT）、叶绿素降解酶（叶绿素酶、脱镁鳌合酶、叶绿素过氧化物酶、脱镁叶绿素酶）活性的变化。结果 与对照组相比，在贮藏期间，LED处理可有效维持油麦菜的感官品质，抑制其呼吸强度和MDA含量的上升，维持叶绿素、维生素C及总酚含量，提高抗氧化酶活性，并降低叶绿素降解酶的活性。结论 LED处理可通过抑制采后油麦菜的呼吸强度和叶绿素降解速率，维持非酶抗氧化物质含量和抗氧化酶活性，保持细胞膜完整性，从而延缓其采后衰老，并保持其较好的感官和营养品质。

The work aims to study the effect of low-intensity white LED irradiation on quality of postharvest Lactuca sativa. The white LED light (light intensity approximates to 5 μmol/(m2•s)) was used to continuously irradiate the Lactuca sativa at (20±1)℃ for 7 days. The samples stored in dark environment were used as control to determine the change of sensory score, decay rate, respiratory rate, content of chlorophyll, vitamin C, malondialdehyde (MDA), activity of polyphenol oxidase (PPO), catalase (CAT), and chlorophyll degrading enzymes (chlorophyllase, Mg-dechelatase, chlorophyll-degrading peroxidase, and pheophytinase). Compared with the control, LED treatment could effectively maintain the appearance quality of Lactuca sativa, inhibit the increase of respiratory rate and MDA content, keep the contents of chlorophyll, vitamin C and total phenolics, increase antioxidant enzyme activity, and reduce chlorophyll degrading enzyme activity during storage. LED treatment can delay postharvest senescence and maintain sensory and nutritional quality of Lactuca sativa by inhibiting the respiration and chlorophyll degradation rate, maintaining non-enzymatic antioxidant content and antioxidant enzyme activity and keeping cell membrane integrity.