黄玉米粗类黄酮提取工艺正交试验优化及其体外抗氧化活性

以黄玉米纪元1号为材料，采用单因素试验与三元二次正交试验，考察乙醇体积分数、料液比、浸提温度及浸提时间对粗类黄酮提取量的影响及黄玉米粗类黄酮清除1,1-二苯基-2-苦肼基（1,1-diphenyl-2-picrylhydrazyl，DPPH）自由基和•OH的能力。得出最优工艺参数为料液比1∶35.5（g/mL）、69 ℃浸提1.85 h，此条件下粗类黄酮提取量为85.88 mg/g。当粗类黄酮质量浓度为20 mg/mL时，对DPPH自由基和•OH的清除率分别为76.47%和32.62%，分别相当于芦丁标准品（0.1、0.2 mg/mL）清除能力的81%～84%和40%～50%。黄玉米粗类黄酮对DPPH自由基的清除率明显大于对• OH的清除率，且随质量浓度提高，清除率显著提高（P＜0.05）。

Optimization of Extraction Conditions for Flavonoids from Yellow Maize and Their Antioxidant Activity in Vitro

Single-factor experiments combined with three-factor quadratic rotation orthogonal composite design were
adopted to analyze the effects of ethanol concentration, solid to solvent ratio, extraction temperature, and extraction time
on the yield of flavonoids from yellow maize (Zea mays Jiyuan 1) and the radical scavenging abilities of the extracted
flavonoids against 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radicals (·OH) in vitro. The results indicated that the
optimum parameters for extracting flavonoids were found to be extraction at 69 ℃ for 1.85 h with a solid/liquid ratio of
1:35.5 (g/mL). The yield of flavonoids was 85.88 mg/g under the optimized conditions. The scavenging rates of 20 mg/mL
yellow maize flavonoids against DPPH and hydroxyl radicals were 76.47% and 32.62%, respectively, which were equivalent
to 81%–84% and 40%–50% as compared to rutin (0.1 and 0.2 mg/mL, respectively). The yellow maize flavonoids showed
more powerful scavenging activities against DPPH radical than against hydroxyl radical, which increased significantly with
increasing flavonoid concentrations.