Chemical composition and antioxidative activity of essential oil of Thymus serpyllum L.
Authors: Petrovic Slobodan , Ristic Mihailo , Petrovic Nada , Lazic Miodrag , Franciskovic Marina , Petrovic Slobodan 
Published: July 2013

Wild thyme (Thymus serpyllum L.) is a popular remedy regarding both
traditional and conventional medicine. It is used as the antiseptic,
aromatic, expectorant, stomachic, antispasmodic, carminative and preservative
substance. For the purpose of this paper, wild thyme essential oil was
isolated from the dried herb T. serpyllum by hydrodistillation. Original
semi-industrial distillation device SP-130 performing distillation by water
and steam was used for the hydrodistillation of T. serpyllum essential oils.
The temperature during the hydrodistillation in the device SP-130 ranged from
100?C - 102?C at atmospheric pressure, and the whole process lasted 5 hours.
The isolated essential oil is a liquid of light yellow colour and the odour
characteristic of the genus Thymus. Obtained yield of essential oil was 0.08
%, with 65 components identified in the tested essential oil. The most
represented chemical groups are sesquiturpene hydrocarbons with 35.1%, and
oxygenated sesquiturpenes with 34.8%. The main components of essential oil of
T. serpyllum were: trans-nerolidol (24.2%), germacrene D (16.0%), thymol
(7.3%), ?-cadinene (3.7%) and ?-bisabolene (3.3%). The essential oil showed
significantly better ability to neutralize DPPH free radicals (IC50 = 0.503
?L / mL) compared with synthetic antioxidants BHA and BHT. Synthetic chemical
compounds such as BHA and BHT are used in food industry as antioxidants due
to their ability to prolong the shelf-life of foodstuffs by protecting them
against deterioration caused by oxidation, such as fat rancidity, colour
changes, degradation of the flavor and loss of nutrient value. In recent
years, there is a considerable interest in finding natural compounds that
could replace sinthetic antioxidants because of adverse toxicological reports
on many synthetic compounds. Lamiaceae herbs and their essential oils or
extracts application has proven to be the effective preservation agents for
the extension shelf-life of foodstuffs, indicating their potential use in
food industry as functional ingredients and food additives. The antioxidant
activity of extracts from some Lamiaceae herbs is comparable to that of the
most common synthetic antioxidants BHT and BHA. Free radicals are a major
cause of many degenerative diseases, such as atherosclerosis, cancer,
cardiovascular diseases, inflammatory bowel diseases, skin aging, old age
dementia and arthritis. Epidemiological data and randomized clinical trials
provide sample indications that antioxidants play a fundamental role in the
prevention of cancer and cardiovascular diseases. They act as scavengers of
reactive oxygen species and metal chelators that protect human cells and
reduce oxidative damages. Natural antioxidants are important in the food
industry because they can have a double functionality, that is, they can be
useful as a food preservation agents while providing important health
benefits for humans by maintaining our health and preventing disease. This
investigation showed that the essential oil of T. serpyllum can be an
important source for the production and application in the food industry as
nutritional supplements, functional food components or natural food
antioxidants.