Antimicrobial activity of moringa peregrina seed oil: chemical composition and effect of extraction procedure

Abstract

Background and objective: The importance of new sources of oils has recently emerged, one such source being Moringa. There is an urgent need to choose the most appropriate extraction method regarding its impact on the properties and stability of the extracted oil.The objective of this research work is to study the impact of two extraction methods on the chemical and thermal properties as well as the antimicrobial activity of Moringa peregrina seed oil.Methods: Moringa peregrina seeds were collected from their original growing locations in Sudan. Cold pressing (CP) and maceration inn-hexane (MH) was used to extract the oil, and their yields were found to be 9.12% and 21.87%, respectively. Chemical properties of the oil were studied and in each case triplicate analyses were completed. The mean and the standard deviation were then determined (mean±SD).Results: Besides the peroxide value, the chemical properties of the oil extracted by the two methods remained relatively unchanged. Additionally, the results revealed a higher activity of the cold pressed oil against all tested organisms (Bacillus subtilis, Staphylococcus aureus Escherichia coli, Pseudomonas aeruginosa, Candida albicans) compared to the one obtained by maceration method. Furthermore, the thermogravimetric analysis and derivative thermogravimetric analysis (TGA and DTGA) demonstrated significant variations in the onset of degradation between the oil samples extracted by the two methods: 200◦C (cold pressing) against 274◦C (maceration). The maximum mass loss for the oil extracted by the two methods does not differ significantly, and the final degradation temperature was similar. Conclusion: The differential scanning calorimeter (DSC) thermograms for the oil extracted by the two methods showed somewhat similar characteristics regarding the heating curves, while the cooling curves differed considerably. Keywords: Antimicrobial activity; Cold press; Maceration; Moringa peregrina; Thermal properties.