Antioxidant activity and free radical-scavenging capacity of ethanolic extracts of thyme, oregano, and marjoram

Phenolic compounds were extracted from thyme (Thymus vulgaris L.), oregano (Origanum vulgare L.) and marjoram (Origanum majorana L.) with 95% ethanol. A number of antioxidant and radical-scavenging capacity tests were performed on the prepared extracts using colorimetric assays and model system studies. Specifically, these included determining the content of total phenolics, antioxidant efficacy in a linoleic acid-ferric thiocyanate model system, reducing power, scavenging effect on 2,2'-diphenyl-1-picrylhydrazyl radical, and hydroxyl radical-scavenging activity by electron paramagnetic resonance spectroscopy. Moreover, the efficacies of the prepared herb extracts were investigated in a real-life food product: the stabilization of butter against oxidation.