PHYSICOCHEMICAL ANTIOXIDANT AND ANTIMICROBIAL PROPERTIES OF SWEET BASIL (Ocimum basilicum L.) LEAF AND INFLORESENCE ESSENTIAL OILS

Abstract

The emergence of increased multidrug resistant bacteria has initiated development of new antimicrobial agents. Essential oils from aromatic plants and herbal extracts have attracted scientific interest due to their potential use as antimicrobial and/or antioxidant compounds in foods.The present study was aimed to examine physicochemical properties and biological activities of essential oils extracted from sweet basil leaves and infloresence Evaluation of the Physicochemical properties of the essential oil extracts of Ocimum basilicum (L) showed significant difference between leaf and infioresence in oil yield, specific gravity, acid value (ACV), and free fatty acid values. The antioxidant activities of Ocimum basilicum (L) leaf and infloresence oil extracts recorded significantly higher antioxidant activities with respect topersentage scavenging activity DPPH(86.45%) for leaf oil extracts. However, significantly higher ascorbic acid content (13.42%) and hydrogen peroxide scavenging activity (5.50) were observed for O. basilicum infloresence oil extract. The highest antibacterial activity with a zone of inhibition of (15.47mm) was obtained at the highest concentration (3μl/ml) of the oil extract from O. basilicum (L.) inflorescence against S. aureus while the lowest antibacterial activity (12.50mm) was recorded for leaf oil extract against E. coli indicating that S. aureus was more susceptible than E. coli. On the other hand, the strongest antifungal activity with maximum zone of inhibition (15.90mm) was recorded for leaf oil against C. albicans and the weakest antifungal activity with minimum zone of inhibition (11.97mm) was recorded for infloresence oil against A. niger. The highest bacteriostatic (bacterial inhibitory) concentration with a MIC of 0.09μl/ml and a corresponding MBC of 0.19 μl/ml was obtained from infloresence oil extract against S. aureus while the lowest bacteriostatic concentration with minimum inhibitory concentration( MIC) of 0.38 μl/ml, the largest value) and a minimum bactericidal concentration (MBC)of 0.75 μl/ml was recorded for leaf oil extract against E. coli. O. basilicum (L.) leaf oil extract has demonstrated the strongest fungal inhibitory concentration with a MIC of 0.125μl/ml,( the least value) and a minimum fungicidal concentration with MFCof 0.09μl/ml against C. albicans whereas the weakest fungal inhibitory concentration with MICof 0.63μl/ml and MFC of 1.25μl/ml was obtained for the inflorsence oil extract against A.niger showing that C. albicans was the most susceptible to the oil extract From the present study In can be concluded that the sweet basil infloresence and leaf oil extracts can be potential sources of antioxidant, antibacterial and antifungal agents which can be used as natural antioxidants and antimicrobials in medicine, food industry and cosmetics