College of Food and Bioengineering, South China University of Technology, Guangzhou 510640, China.
Pharm Biol. 2011 Jul;49(7):734-40. doi: 10.3109/13880209.2010.490948.
Rosa laevigata Michx. (Rosaceae), widespread in China, contains many valuable nutrients and has long been used as food and medicine in Chinese folklore. Nowadays, due to its favorable property of coloring, the brown pigment of R. laevigata has an attractive potential as an available additive in food.
The aims of this study were to optimize the extraction process of brown pigment from R. laevigata and investigate its antioxidant activities on the basis of its abilities to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, hydroxyl radical and superoxide radical.
Extraction conditions of brown pigment from R. laevigata were investigated through an orthogonal design of L₉(3)⁴ assay. Ethanol concentration, extraction temperature, time, and ratio of material to solvent were the main factors affecting the extraction rate. Subsequently, the antioxidant activity of brown pigment was assessed using DPPH method, while hydroxyl radicals and superoxide free radicals were respectively determined by the Fenton-RhB (Rhodamine B) system and using the pyrogallol-luminol system.
The optimum extraction conditions were determined: temperature 70°C, ethanol concentration was 60%, extraction time 2 h and ratio of material to solvent was 1:6. Brown pigment showed a good radical scavenging activity, and exhibited a concentration-dependent inhibition of hydroxyl radical and superoxide free radical at low concentrations. When the concentration of brown pigment was 1 mg/mL, the scavenging percentage of hydroxyl radical reached 67.33%.
The brown pigment of R. laevigata could potentially be used as a promising natural antioxidant in the food and pharmaceutical industries.
野蔷薇（蔷薇科）在中国广泛分布，含有许多有价值的营养成分，在中国民间一直被用作食品和药物。如今，由于其良好的着色性能，野蔷薇的棕色色素作为一种可用的食品添加剂具有很大的吸引力。
本研究旨在优化野蔷薇棕色色素的提取工艺，并基于其清除 1,1-二苯基-2-苦基肼（DPPH）自由基、羟基自由基和超氧自由基的能力，研究其抗氧化活性。
通过 L₉(3)⁴ 正交设计考察了野蔷薇棕色色素的提取条件。乙醇浓度、提取温度、时间和料液比对提取率有重要影响。随后，采用 DPPH 法评价了棕色色素的抗氧化活性，并用 Fenton-RhB（罗丹明 B）体系测定了羟基自由基，用邻苯三酚-鲁米诺体系测定了超氧自由基。
确定了最佳提取条件：温度 70°C，乙醇浓度 60%，提取时间 2 h，料液比 1:6。棕色色素具有良好的自由基清除活性，在低浓度下对羟基自由基和超氧自由基具有浓度依赖性抑制作用。当棕色色素浓度为 1mg/mL 时，对羟基自由基的清除率达到 67.33%。
野蔷薇的棕色色素有望成为食品和制药工业中一种有前途的天然抗氧化剂。
