4种藜麦抗氧化活性比较研究

Comparative study on antioxidant activity of four kinds of quinoa

以白、黄、红、黑等4种藜麦为材料,采用福林酚法、亚硝酸钠-硝酸铝法进行总多酚、总黄酮含量测定,以清除DPPH·、ABTS^+2种自由基的能力为评价指标,进行抗氧化活性测定。结果表明,4种藜麦的总多酚和总黄酮含量存在一定差异,分别为(1.6374±0.0047)^(2.8776±0.0699)mg/g和(4.4480±0.0646)^(10.3109±0.1131)mg/g。黑藜麦的总多酚和总黄酮含量均最高。4种藜麦醇提物对DPPH·自由基清除能力最强的为红藜麦(EC50=6.5440mg/mL),最弱的为黄藜麦(EC50=15.242 8 mg/mL)。只有红藜麦和黑藜麦醇提物均对ABTS^+自由基有一定的清除效果,其EC50分别为42.0292mg/mL、49.2832mg/mL。4种藜麦均含有一定量的总多酚和总黄酮,红藜麦和黑藜麦的抗氧化效果较好。

Four different kinds of quinoas included white quinoa, yellow quinoa, red quinoa, black quinoa were applied to measured the contents of total polyphenols and total flavonoids by Folin-reagent method and Sodium nitrite-aluminum nitrate method. Antioxidant activity was determined by scavenging effects of extracts from quinoa on DPPH·, ABTS^+ free radicals. The results showed that there were certain difference of total polyphenols and flavonoids among four kinds of quinoas. The content of total polyphenols and flavonoids in four kinds of quinoas ranged from(1.637 4±0.004 7) to(2.877 6±0.069 9) mg/g,(4.448 0±0.064 6) to(10.310 9±0.113 1) mg/g, respectively. The content of total polyphenols and flavonoids in black quinoa was the highest. Among four different kinds of quinoas, the ethanol extract of red quinoa showed the highest scavenging ability towards DPPH· free radicals(EC50 6.544 0 mg/mL). The ethanol extract of yellow quinoa exhibited the lowest antioxidant capacity with EC50 15.242 8. Only the ethanol extract of red quinoa and black quinoa showed the scavenging ability towards ABTS^+ free radicals(EC50 42.029 2 mg/mL, 49.283 2 mg/mL, respectively.).There are a certain amount of total polyphenols and flavonoids in four kinds of quinoas. The antioxidant activity of red and black quinoa are better.