Lee Seom, Park Chang Ha, Kim Jin Kyung, Ahn Kyungmin, Kwon Haejin, Kim Jae Kwang, Park Sang Un, Yeo Hyeon Ji
Department of Biological Sciences, Keimyung University, Daegu 42601, Republic of Korea.
Department of Microbiology, Keimyung University School of Medicine, Daegu 42601, Republic of Korea.
Antioxidants (Basel). 2023 Aug 29;12(9):1686. doi: 10.3390/antiox12091686.
Light-emitting diodes (LEDs) are regarded as an effective artificial light source for producing sprouts, microgreens, and baby leaves. Thus, this study aimed to investigate the influence of different LED lights (white, red, and blue) on the biosynthesis of secondary metabolites (glucosinolates, carotenoids, and phenolics) and the biological effects on kale microgreens. Microgreens irradiated with white LEDs showed higher levels of carotenoids, including lutein, 13--β-carotene, α-carotene, β-carotene, and 9--β-carotene, than those irradiated with red or blue LEDs. These findings were consistent with higher expression levels of carotenoid biosynthetic genes ( and ) in white-irradiated kale microgreens. Similarly, microgreens irradiated with white and blue LEDs showed slightly higher levels of glucosinolates, including glucoiberin, progoitrin, sinigrin, and glucobrassicanapin, than those irradiated with red LEDs. These results agree with the high expression levels of , , and in white- and blue-irradiated kale microgreens. In contrast, kale microgreens irradiated with blue LEDs contained higher levels of phenolic compounds (gallic acid, catechin, ferulic acid, sinapic acid, and quercetin). According to the total phenolic content (TPC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) inhibition assays, the extracts of kale microgreens irradiated with blue LEDs had slightly higher antioxidant activities, and the DPPH inhibition percentage had a positive correlation with TPC in the microgreens. Furthermore, the extracts of kale microgreens irradiated with blue LEDs exhibited stronger antibacterial properties against normal pathogens and multidrug-resistant pathogens than those irradiated with white and red LEDs. These results indicate that white-LED lights are suitable for carotenoid production, whereas blue-LED lights are efficient in increasing the accumulation of phenolics and their biological activities in kale microgreens.
发光二极管（LED）被视为用于生产芽苗菜、嫩茎菜和幼叶的一种有效人工光源。因此，本研究旨在探究不同LED光（白色、红色和蓝色）对次生代谢产物（硫代葡萄糖苷、类胡萝卜素和酚类化合物）生物合成的影响以及对羽衣甘蓝嫩茎菜的生物学效应。与用红色或蓝色LED照射的羽衣甘蓝嫩茎菜相比，用白色LED照射的嫩茎菜中类胡萝卜素水平更高，包括叶黄素、13-β-胡萝卜素、α-胡萝卜素、β-胡萝卜素和9-β-胡萝卜素。这些发现与白色照射的羽衣甘蓝嫩茎菜中类胡萝卜素生物合成基因（和）的较高表达水平一致。同样，与用红色LED照射的相比，用白色和蓝色LED照射的羽衣甘蓝嫩茎菜中硫代葡萄糖苷水平略高，包括葡糖异硫氰酸酯、前致甲状腺肿素、黑芥子硫苷酸钾和葡糖芸苔素。这些结果与白色和蓝色照射的羽衣甘蓝嫩茎菜中、和的高表达水平相符。相比之下，用蓝色LED照射的羽衣甘蓝嫩茎菜中酚类化合物（没食子酸、儿茶素、阿魏酸、芥子酸和槲皮素）含量更高。根据总酚含量（TPC）和2,2-二苯基-1-苦基肼（DPPH）抑制试验，用蓝色LED照射的羽衣甘蓝嫩茎菜提取物具有略高的抗氧化活性，且嫩茎菜中的DPPH抑制率与TPC呈正相关。此外，与用白色和红色LED照射的相比，用蓝色LED照射的羽衣甘蓝嫩茎菜提取物对正常病原体和多重耐药病原体表现出更强的抗菌性能。这些结果表明，白色LED光适合用于类胡萝卜素的生产，而蓝色LED光在增加羽衣甘蓝嫩茎菜中酚类化合物的积累及其生物学活性方面效率更高。
