979 THE ANTIMICROBIAL AND ANTIOXIDANT POTENCIES OF SATUREJA KHUZISTANICA ESSENTIAL OIL FOR PRESERVING OF VEGETABLE OILS Behnaz Bahrami 1 , Mohaddese Mahboubi 2* , Reza Yari 1 , Mehdi Mehran 3 Address(es): 1 Biology Department, Faculty of Sciences, Boroujerd Branch, Islamic Azad University, Boroujerd, Iran. 2 Microbiology Department, Medicinal Plant Research Center of Barij, 87135-1178 Kashan, Iran. 3 Phytochemistry Department, Medicinal Plants Research Center of Barij, 87135-1178 Kashan, Iran. *Corresponding author: mahboubi1357@yahoo.com ; mahboubi@barijessence.com ABSTRACT Keywords: Preservative, Essential oil, Satureja khuzistanica, Antioxidant, Vegetable oil INTRODUCTION Inadequate drying process of oilseeds or poor situation in extracting the vegetable oils from oilseeds usually leads to microbial contamination in final products (Okpokwasili and Molokwu, 1996). Microbial contaminations can make considerable changes in vegetable oils and finally affect on quality of these vegetable oils. In contrast, the difference in intrinsic properties of vegetable oils can change the microbial load of vegetable oils. The fatty acid profile, phenolic compounds, tocopherol and sterol contents of vegetable oils have critical role in their intrinsic properties (Gromadzka and Wardencki, 2011). In addition to microbial contaminations in vegetable oils, the oxidants can affect on their shelf life (Aluyor and Ori-Jesu, 2008). Benzoic acid, nitrites, sulfites as antimicrobial agents and butylated hydroxyltoluene (BHT), butylated hydroxyanisole (BHA), tocopherols and ascorbic acid as antioxidants are used for prevention the vegetable oils from spoilage. The application of chemical antioxidants and preservatives are associated with major health hazardous problems and toxicity (Parke and Lewis, 1992). Furthermore, replacement the chemical and synthetic ones with natural agents in vegetable oils has great importance for many consumers of food, pharmaceutical and cosmetic industries in different parts of the worlds. In these years, the use of essential oils as natural preservatives and antioxidants has increased as a new approach to overcome on these adverse effects (Davidson and Taylor., 2007; Lambert et al., 2001; Mahboubi et al., 2014; Smith- Palmer et al., 2001). Satureja khuzistanica essential oil (Lamiaceae family) has been known for its antiseptic effects in traditional medicines. The antimicrobial activities of S. khuzistanica essential oil have been determined against a large number of bacteria and fungi in vitro conditions (Akbari-Shahabi et al., 2014; Sadeghi- Nejad et al., 2010; Zarrin et al., 2010). Other biological effects of S. khuzistanica such as anti-inflammatory (Ghazanfari et al., 2006), antinociceptive and analgesic (Saberi et al., 2013) activities have been confirmed. Therefore, inoculation of S. khuzistanica essential oil into vegetable oils may be proposed it as suitable candidate for different industries especially in aromatherapy related therapies. So, the aim of this study was to evaluate the preservative and antioxidant potencies of S. khuzistanica essential oil in sesame and flaxseed oils. These vegetable oils are two popular vegetable oils in different industries. Due to a positive relation between the chemical composition of essential oil and biological activities, we analyzed the chemical composition of S. khuzistanica essential oil and fatty acid profiles of vegetable oils in presence of this essential oil as natural preservative. MATERIAL AND METHODS S. khuzistanica essential oil and analysis of its chemical composition by Gas Chromatography (GC) and Gas chromatography–mass spectrometry (GC- MS) Satureja khuzistanica essential oil with pale yellow color had been dedicated by Barij Essence Pharmaceutical Company of Iran. The chemical composition of essential oil were conducted on coupled Agilent technology (HP) 6890 with capillary column of HP-1MS (30 m × 0.25 mm, film thickness 0.25 μm) and Agilent technology (HP) 6890 with 5973 network mass selective detector system using GC and GC-MS apparatuses. The oven temperature program was initiated at 40 °C, held for 1 min then raised up to 230 °C at a rate of 3 °C /min, held for 10 min. Helium as the carrier gas at a flow rate of 1.0 ml/min with a split ratio equal to 1/50 injector were used. The detector and injector temperatures were 250 and 230 °C, respectively. Components of essential oil were identified by comparison with Retention indices (RI) relative to homologous series of n- alkanes (injected in conditions equal to samples ones) and by computer search using libraries of Wiley 275.L and Wiley 7n.1, as well as comparison of the fragmentation pattern of the mass spectra with data published in the literature (Adams, 2001). In recent years, the use of natural preservatives for protection of vegetable oils against microbial and chemical deterioration is one of the interesting issues. The purpose of this study was to evaluate the preservative activity of Satureja khuzistanica essential oil (SKEO) against microbial and chemical deterioration in sesame and flaxseed vegetable oils. Chemical composition of SKEO, chemical profiles, antioxidant and preservative potencies of inoculated vegetable oils with different concentration of SKEO were determined. Carvacrol was the main component of SKEO. The chemical profile of vegetable oils in presence of SKEO had no changes. Sesame and flaxseed vegetable oils had the IC50 equal to 26 and 22 µg/ml, respectively. Inoculation the SKEO (1%v/v) in vegetable oils decreased the IC50 for vegetable oils. SKEO showed promised antimicrobial activity against food microorganisms. Inoculation the SKEO (0.75%v/v) in sesame oil inhibited completely the bacteria and fungi after 14 days. Flaxseed oil inoculated with SKEO (1% v/v and lower concentrations) decreased the bacteria and fungi populations after 28 days. Therefore, the use of SKEO as natural preservative can protect vegetable oils from deterioration; also it gives the vegetable oils the other pharmacological effects such as anti-inflammatory and analgesic effects with applications in different industries. ARTICLE INFO Received 16. 2. 2016 Revised 26. 10. 2016 Accepted 1. 11. 2016 Published 1. 12. 2016 Regular article doi: 10.15414/jmbfs.2016/17.6.3.979-982