Rauf Ayesha, Nawaz Haq, Shad Muhammad Aslam
Institute of Chemical Sciences, Bahauddin Zakariya University, Multan, Pakistan.
Department of Biochemistry, Bahauddin Zakariya University, Multan, Pakistan.
Pak J Pharm Sci. 2018 Sep;31(5):1889-1897.
Effect of solvent polarity and extraction time on antioxidant properties of Brassica oleracea seeds was optimized by response surface methodology using central composite design. A significant linear negative effect of solvent polarity on total extractable components (TEC), total phenolic acids (TPA), linoleic acid reduction capacity (LARC) and hydroxyl radical scavenging capacity (HRSC) and significant positive effect on iron chelating activity (ICA), reducing power (RP) and (DPPH RSC). Linear effect of solvent polarity on total antioxidant activity (TAOA) was also found to be positive but not significant. Significant linear negative effect of extraction time was observed on ICA and HRSC. Only RP was found to be significantly increased with increase in extraction time. Quadratic effect of solvent polarity was found to be negative on TAOA, DPPH RSC and HRSC. However, quadratic effects of both variables were found to be positive on TEC, TPA, ICA and LARC. The polarity dependent increase in TAOA indicates the extraction of phytochemicals with comparatively stronger antioxidant properties in polar solvents. The decrease in antioxidant properties in response to increase in extraction time may be attributed to the time dependent loss of antioxidant activity of extracted compounds.
采用中心复合设计的响应面法优化了溶剂极性和提取时间对甘蓝种子抗氧化性能的影响。溶剂极性对总可提取物（TEC）、总酚酸（TPA）、亚油酸还原能力（LARC）和羟自由基清除能力（HRSC）有显著的线性负效应，对铁螯合活性（ICA）、还原力（RP）和二苯基苦味酰基自由基清除能力（DPPH RSC）有显著的线性正效应。还发现溶剂极性对总抗氧化活性（TAOA）的线性效应为正，但不显著。提取时间对ICA和HRSC有显著的线性负效应。仅发现RP随提取时间的增加而显著增加。发现溶剂极性对TAOA、DPPH RSC和HRSC的二次效应为负。然而，发现这两个变量对TEC、TPA、ICA和LARC的二次效应均为正。TAOA中极性依赖性的增加表明在极性溶剂中提取了具有相对较强抗氧化性能的植物化学物质。提取时间增加时抗氧化性能的下降可能归因于提取化合物抗氧化活性的时间依赖性损失。
