摘要：The aim of the study was to investigate the effect of drying method, solvent concentration, extraction time and temperature on antioxidant activities and total phenolic content (TPC) of lemongrass leave extract. The antioxidant activities were evaluated using DPPH radical scavenging ability, ferric reducing antioxidant power (FRAP), and β-carotene bleaching inhibition (BCB) assays; while TPC was determined using Folin-Ciocalteau method. The optimum extraction conditions obtained were oven dried lemongrass leave extracted using 40% ethanol at 25°C for 300 min with a sample to solvent ration of 1:10 in a water bath shaker (150 rpm). Lemongrass leave extract possesses reasonably antioxidant potential with EC50(DPPH) of 192 μg/ml, antioxidant activity (as measured by BCB inhibition) of 67%, and FRAP of 129 mg TE/g; as well as a TPC value of 67 mg GAE/g. However, lemongrass leave extract exhibited lower antioxidant activity in comparison with BHA and α-tocopherol. TPC was positively correlated with antioxidant activities of lemongrass leave extract assessed by FRAP (r = 0.995), BCB assay (r = 0.932), and DPPH (r = 0.777); indicating the presence of phenolic compounds contributed to the antioxidant activities of lemongrass leave. In conclusion, lemongrass leave could be a source of natural antioxidants with nutraceutical potential for food ind ustry application
关键词：Antioxidant activity; Extraction conditions; Lemongrass leave; Total phenolic
