DPPH free radical scavenging activity The DPPH radical scavenging capacity of extracts was determined based on the method described by Shimada et al. (22) with some modifications. Aliquots of 1 mL methanolic sample solution added 5 mL of freshly prepared 0.1 mM DPPH methanolic solutions. After thoroughly mixed, and kept for 50 min in the dark place. Subsequently, the absorbance of oils was measured at 517 nm using UV-spectrophotometer(UVIKON933; Kontron Instruments). One mL of ascorbic acid in methanol (10,000 ppm) was used for control. One mL of the methanol, replacing the extracted oil, was used as the blank. All tests were carried out in triplicate. The percentage of DPPH radical scavenging capacity was calculated using this equation:Scavenging effect (%) =[1−(A517nm,sample/A517nm,blank)]×100All tests were carried out in triplicate.
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