Antioxidant properties of thyme and lavender botanical extracts

Thyme and lavender were extracted with 50% acetone and 70% ethanol, and evaluated for antioxidant properties. Radical scavenging capacity in Trolox equivalent (TE) was determined against 2–2-diphenyl-1-picrylhydrazil (DPPH) and hydroxyl radicals. The total phenolic content (TPC) was also measured for each extract. The DPPH scavenging activity of thyme was 352µmol TE/g and 273.1µmol TE/g using 50% acetone and 70% ethanol as extraction solvents, respectively. Lavender contained 155.2µmol TE/g and 135.9µmol TE/g using 50% acetone and 70% ethanol as extraction solvents, respectively. Hydroxyl radical scavenging activity was 1567µmol TE/g for thyme and 906µmol TE/g for lavender, respectively, when 50% acetone was used for antioxidant extraction. The TPC value for thyme was 52.26mg gallic acid equivalents (GAE)/g and 40.07mg GAE/g using 50% acetone and 70% ethanol as extraction solvents, respectively. Lavender contained 34.45mg GAE/g and 17.19mg GAE/g when 50% acetone and 70% ethanol were used for extraction, respectively. The results of this study show that thyme and lavender may serve as natural dietary sources of radical-scavenging antioxidants. The type of extracting solvent was able to significantly alter the antioxidant property estimation, and 50% acetone is a preferred solvent for antioxidant extraction from both botanical materials. This study provides background for future research into the health benefits of thyme and lavender.