Evaluation of antioxidant activity, total phenols and phenolic compounds in thyme (Thymus vulgaris L.), sage (Salvia officinalis L.), and marjoram (Origanum majorana L.) extracts
Highlights
► The safety of synthetic antioxidants as food additives has received increasing attention. ► There is need components to act as antioxidants and to make food products safer. ► Detection of natural antioxidant sources for food use would be beneficial for healthy life. ► Antioxidant capacity of thyme, sage and marjoram extract was screened using DPPH assay. ► Thyme sage and marjoram exhibited stronger antioxidant activity than BHT and BHA.
Introduction
Herbs and spices have been used since antiquity for their flavoring qualities, and also, for their preservative and medicinal properties. Their extracts had been used in times BC in the Middle East to cure various disorders, spasmodic gastric-intestinal complaints, cough, bronchitis, laryngitis, tonsillitis and acting as carminative and diuretic agents. Topical applications of their preparations were used in the treatment of wounds, disorders of oral cavity and in oral hygiene.
For food uses, they are still employed to flavor meats, sausages, salads and soups (Novak et al., 2000).
Therefore, the demands for these plants are increasing in both industrialized and non-industrialized countries which lead to increasing their prices. Although Egypt is one of the countries having favorable conditions for the production of aromatic plants e.g. suitable environment and available low wages manpower (essential for service procedures, agriculture, collection and marketing) the cultivated area of these plants is not satisfactory because the farmers not interested in this kind of plants.
One of the principal causes of food quality deterioration is lipid peroxidation (Gordon, 1991). Lipid peroxidation results in formation of reactive oxygen species and free radicals; which are purportedly associated with carcinogenesis, mutagenesis, inflammation, DNA changes, aging, and cardiovascular diseases (Shahid et al., 2008, Siddhuraju and Becker, 2003).
The use of antioxidants in lipids and lipid-containing foods is one method to minimize rancidity, retard the formation of toxic oxidation products, maintain nutritional quality and increase the shelf life of food products (Pitchaon Maisuthisakul et al., 2007).
Synthetic antioxidants, such as butylated hydroxy anisole (BHA), butylated hydroxy toluene (BHT) and tert-butyl hydroquinone (TBHQ), are widely used in the food industry because they are effective and less expensive than natural antioxidants (Pin-Der et al., 1997). Their safety, however, has been questioned. TBHQ is banned in Japan and certain European countries (Shahidi, 1997) and BHA and BHT are reported to be carcinogenic (Ito et al., 1982). Hence, research for a safer and effective natural antioxidant is underway and several natural sources are being examined.
Antioxidants such as flavonoids, tannins, coumarins, curcumanoids, xanthons, phenolics, lignans and terpenoids are found in various plant products (such as fruits, leaves, seeds, and oils) (Jeong et al., 2004). For this reason, there is a growing interest in separating these plant antioxidants and using them as natural antioxidants. Different solvent systems have been used for the extraction of polyphenols from plant material (Pinelo et al., 2004). Extraction yield is dependent on the solvent and the method of extraction (Goli et al., 2004).
Water and aqueous mixtures of ethanol, methanol, and acetone are commonly used in plant extraction (Sun and Ho, 2005). Wang and Helliwell (2001) reported that aqueous ethanol was superior to methanol and acetone for extracting flavonoids from tea. However, in another work, water was found to be a better solvent, for extracting tea catechins, than 80% methanol or 70% ethanol (Khohar and Magnusdottir, 2002).
Among these herbs and spices, marjoram (Origanum majorana L.), of Lamiaceae family was known to the ancient Egyptians, Greeks and Romans (Tainter and Grenis, 1993). The Greeks felt it as a symbol of happiness and that if grown on the grave, the deceased would be eternally happy. Thyme (Thymus vulgaris L.) and sage (Salvia officinalis L.), also of the Lamiaceae family are the most important herbs from the aromatic and medicinal points of view (Stahl-Biskup and Saez, 2004).
Recently, spices have received attention also in their useful physiological functions and antimicrobial activity. More research is required on antioxidant activity of herbs and spices. The present paper deals with the chemistry and antioxidative behavior of oleoresins (extracted in ethanol, methanol, hexane and diethyl ether) of thyme, sage, marjoram.
Section snippets
Collection of plant materials
Leaves of thyme – Thymus vulgaris L. (Lamiaceae), sage – Salvia officinalis L. (Lamiaceae), marjoram – Origanum majorana L. (Lamiaceae) were randomly collected from Shambolia farm located at Fayoum area and stored in deep freeze at −20 °C until use.
Chemicals, solvents, reagents
2,2-Diphenyl-1-picrylhydrazyl (DPPH), butylated hydroxy anisole (BHA), tertiary-butylated hydroquinone (TBHQ), gallic acid, caffeic acid, chlorogenic acid, p-coumaric acid, ferulic acid, cinnamic acid, rosmarenic acid, hesperidin, quercetin, quinic
Extract yields and total phenols
The yield extracted from three aromatic plants by four solvents (methanol, ethanol, diethyl ether, and hexane) is represented in Table 1.
It could be noticed from the results that the highest extract yield was obtained by methanol extraction of all plant materials, followed by ethanol, diethyl ether and finally by hexane. The yields of both methanol and ethanol were: 24 and 14% for thyme; 23 and 18% for sage and 28 and 15% for marjoram. Hexane efficiency as a solvent was lower than the
Conclusion
As observed, extracts with higher antioxidant capacity also had higher polyphenol contents. It can be concluded that the extracts obtained using higher polarity solvents were more effective radical-scavengers than were those obtained using less polar solvents. Methanol showed better characteristics as a solvent for phenolic compounds than ethanol, but differences are not big, so for using in food industry ethanol is more adequate solvent. Furthermore, it is notable that the extracts from thyme
References (30)
- et al.
Use of a free radical method to evaluate antioxidant activity
Lebensm. -Wiss. U. -Technol.
(1995) - et al.
Characterization of the antioxidant properties of de-odourised aqueous extracts from selected Lamiaceae herbs
Food Chem.
(2003) - et al.
Antioxidant effect of rosemary (Rosmarinus officinalis L.) and oregano (Origanum vulgare L.) extracts on TBARS and colour of model raw batters
Meat Sci.
(2009) - et al.
Use of different methods for testing antioxidative activity of oregano essential oil
Food Chem.
(2004) - et al.
Antioxidant activity of polyphones from sage (Salvia officinalis)
Food Chem.
(2001) - et al.
Ratios of cis- and trans-sabinene hydrate in Origanum majorana L. and Origanum microphyllum
Biochem. Syst. Ecol.
(2000) - et al.
Extraction of antioxidant phenolics from almond hulls (Prunus amygdalus) and pine sawdust (Pinus pinaster)
Food Chem.
(2004) - et al.
Analysis of total phenols and other oxidation substrates and antioxidants by means of Folin-Ciocalteau reagent
Methods Enzymol.
(1999) - et al.
Antioxidant activities of buckwheat extracts
Food Chem.
(2005) - et al.
Determination of flavonols in green and black tea leaves and green tea infusions by high-performance liquid chromatography
Food Res. Int.
(2001)
Antioxidant activity and phenolic compound in 32 selected herbs
Food Chem.
Multiple range, multiple F-tests
Biometrics
Antioxidant activity, total phenolic compounds of pistachio (Pistachia vera) hull extracts
Food Chem.
Oils, fats: taint or flavour?
Chem. Brit.
Induction of squamous cell carcinoma in the forestomach of F344 rats treated with butylated hydroxyanisole
Gann
Cited by (459)
Antioxidant and antimicrobial potential of compounds isolated from Carissa opaca
2024, Food BiosciencePolyphenol antioxidants in vegetable oils: A scientific and technological prospecting
2024, Studies in Natural Products ChemistryCo-processed [Argania spinosa L. (Skeels)] oil with thyme (Thymus vulgaris L.) leaves—New product optimization
2023, Food Chemistry Advances