Antioxidant properties of essential oils

Abstract

By the method of capillary gas-liquid chromatography we studied antioxidant properties and stability during the storage of hexane solutions of 14 individual essential oils from black and white pepper (Piper nigrum L.), cardamom (Elettaria cardamomum L.), nutmeg (Myristica fragrans Houtt.), mace (Myristica fragrans Houtt), juniperberry (Juniperus communis L.), seed of fennel (Foeniculum vulgare Mill., var. dulce Thelling), caraway (Carvum carvi L.), dry leaves of cinnamon (Cinnamomum zeylanicum Bl.), marjoram (Origanum majorana L.), laurel (Laurus nobilis L.), ginger (Zingiber officinale L.), garlic (Allium sativum L.), and clove bud (Caryophyllus aromaticus L.). We assessed the antioxidant properties by the oxidation of aliphatic aldehyde (trans-2-hexenal) into the according carbon acid. We established that essential oils of garlic, clove bud, ginger and leaves of cinnamon have the maximal efficiency of inhibition of hexenal oxidation (80-93%), while black pepper oil has the minimal (49%). Antioxidant properties of essential oils with a high content of substituted phenols depended poorly on its concentration in model systems. We studied the changes in essential oils content during the storage of its hexane solutions for 40 days in the light and out of the light and compared it with the stability of essential oils stored for a year out of the light.