视频扫描测定油菜饼粕自由基清除活力方法的研究

Evaluation of free radical scavenging activity of rapeseed meal by video scanning technology on TLC

用视频扫描平板色谱和稳定自由基 1,1 二苯基 2 间三硝苯基偕腙肼 (DPPH)检测油菜饼粕自由基清除活力的方法 ,研究抗坏血酸、维生素E、酚酸和类黄酮等 17种常见酚类化合物对自由基的清除活力 ,发现自由基清除面积与样品量的相关系数为 0 .947～ 0 .996 ,检测下限为 40～ 6 90ng。以维生素E指数为清除活力指标 ,视频扫描法与常规标准比色法的测定结果具有良好的相关性。测定油菜饼粕提取液自由基清除活力发现 ,6 8%～ 75 %的化合物具有自由基清除能力 ,Rf值为 0 .41的化合物清除活力最高 ,占总活力的 38%。

A reversed phase thin layer chromatography (TLC) method combined with video scanning detection for quantitative evaluation of free radical scavenging activity of antioxidative fractions from rapeseed meal by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) is reported. DPPH scavenging activity of L-ascorbic acid and 17 well-known phenolic compounds including α-tocopherol, phenolic acids and flavonoids was determined by this TLC-DPPH method. Correlation coefficients (R 2) between activity and sample amount applied were 0.947～0.996 and the detection limits were 40～690ng depending on compounds. Comparison of the results based on α-tocopherol index showed a good correlation between the activities measured by TLC-DPPH and by the conventional cuvette assay . The method was used to measure free radical scavenging activity of rapeseed meal fractions. Ten free radical scavenging bands were detected which R f values from 0.04 to 0.85. Radical scavenging activity of the one with R f value 0.41 was highest, possessing 38% of the total scavenging activity.