【摘要】 本文用2,2-联苯-1-三硝基苯肼(DPPH·)比色法测定了番石榴叶(PsidiumguajavaL.)的抗氧化活性,并使用了三个不同参数抑制率、EC50和AE来评价其抗氧化活性。结果表明,浓度越高,番石榴叶提取物清除自由基的能力越强,其中AE是表示抗氧化活性的最有效的能数。本研究表明番石榴叶提取物是一种有效的、有开发价值的天然抗氧化剂。更多还原

【Abstract】 Antioxidant activity of Guava leaf was determined at ambient temperature by means of a 2,2-diphenyl-1-picrylhydryzyl (DPPH·) colorimetry with detection scheme at 515 nm. The activity was evaluated by the decrease inabsorbance as the result of DPPH· color change from purple to yellow. The higher the sample concentration used, the higherthe free radical-scavenging effect. The results showed that ascorbic acid was substantial powerful antioxidant than theextracts from guava leaf. The parameter EC50 and the time needed to reach the steady state to EC50 concentration (TEC50) affectedthe antiradical capacity of the sample. The antiradical efficiency (AE) has been shown to be a more adequate parameter toselect antioxidants than the widely used EC50. This study revealed that guava leaf extracts are an effective potential source ofnatural antioxidants.更多还原