ANTIOXIDANT ACTIVITY OF LAVANDULA LATIFOLIA, SALVIA LAVANDULIFOLIA AND THYMUS MASTICHINA COLLECTED IN SPAIN

Most of the antioxidants used by industry are synthetic; however, it might be highly desirable to find out natural compounds with antioxidant activity. Owing to this, the antioxidant activity of some populations of Lavandula latifolia (LL), Salvia lavandulifolia (SL) and Thymus mastichina (TM) have been evaluated. Samples of 10 populations of TM and 12 of each SL and LL have been collected at flowering stage during the summer of 2009 around Castilla y León (Spain). Dry plant material and dry residues after hydrodistillation were used for analysis. Total phenol content and antioxidant activity were determined. Two methods have been used to determine the antioxidant activity: 1) free-radical scavenging (DPPH), and 2) reducing power assay. The results showed that TM had the higher content in essential oil, although there was high variability among the populations in the three species. Total phenol content and antioxidant activity of dry plant material were higher in TM. In the case of hydrodistilled dry material, there were no differences between TM and SL, both species had higher phenol content and antioxidant activity than LL. Although there was variability among the populations and selection would be possible, TM is postulated as the most interesting species from an antioxidant activity point of view.