Fatty acids composition, antimicrobial potential and cosmeceutical utilization of prosopis africana seed oil

Abstract

The physicochemical properties, fatty acids profile, antimicrobial activity and soap potential of the seed oil of Prosopis africana were examined. The prepared natural antiseptic soap was absolutely devoid of all forms of synthetics such as alkaline, antimicrobial agents, preservatives, colourants and fragrances. The seed had an oil yield of 4.98% while the saponification, acid, free fatty-acids and iodine values were found to be 11.60 ± 0.54 mgKOH/g, 16.96 ± 0.57 mgKOH/g, 14.60 ± 0.45% oleic and 145.47 ± 0.66 I 2 100 g -1 of the oil respectively. The GC-MS result of the prepared fatty acid methyl ester (FAMEs) indicated the presence of oleic acid (33.67%), a monounsaturated fatty acid as the most prominent fatty acid in the oil, followed linoleic acid (18:2), a polyunsaturated acid making up 31.92% of the oil. Palmitic acid (24.96%) is the most abundant saturated fatty acid while stearic acid and valeric acid makes up (7.3%) and (1.96%) respectively. The antimicrobial activity of the oil tested against ten strains of organisms which include: Streptococcus aureus, Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, Salmonella typhi, Klebsiella pneumoniae, Candida albicans, Penicillium notatum, Rhijoptius stoloniter and Aspergillus niger showed good activity. The Minimum Inhibition Concentration (MIC) values obtained for the oils ranges from 31.25 to 125 mg/mL against all the test organisms and within the range 0.125-0.5 mg/mL for the prepared soap. The physicochemical analysis of the P. africana soap was comparable to commercial antiseptic soaps. The result indicated that quality renewable natural antiseptic soaps ccould be obtained from P. africana seed oil. The result confirms that soaps made from natural lye (alkaline solution) has the capacity to replace existing commercial antiseptic soaps made of synthetic sodium or potassium hydroxides, antimicrobial agents, artificial preservatives and colourants which partly accounts for environmental pollution, increase in antimicrobial resistance and endocrine disruption. The adoption of this green antiseptic soap synthesis technique utilising underexplored P. africana seed oil can help mitigate the negative environmental impact of non-biodegradable synthetic reagents.