Antibacterial Activity of Marula [Sclerocarya Birrea] and Brominated Marula Seed Oil

Abstract

Over the last decade, the use of hand sanitizers has increased substantially. Recently, with this outbreak of COVID 19 virus, all natural hand sanitizers have taken the spotlight for their simplicity, powerful cleaning abilities, natural moisturizing formulas and the ability to never leave the skin feeling dry. Marula [Sclerocarya birrea] seed oil was soxhlet extracted with n-hexane and then brominated. The oil quality parameters of marula oil (MO) and brominated Marula oil (BMO) were found to be; for MO: oil content (58.5 ± 0.435 %), moisture content (4.3 ± 0.158 %), saponification value (180 ± 0.7150 mgKOH/g ), peroxide value (10.52 ± 0.006 meq/kg), acid value (3.48 ±0.002) meq/kg ), FFA (1.73 ± 0.000 % as oleic),iodine value (61.02 ± 0.477 gI2/100g ). For brominated marula oil (BMO) ; saponification value ( 168.7 ± 0.930 mgKOH/g ), iodine value ( 8.6 ± 0.490 gI2/100g ), peroxide value (10.63 ± 0.505 meq/kg ), acid value ( 3.42 ± 0.000 meq/kg ), FFA (1.61 ± 0.000 % as oleic). Fourier Transform Infrared (FTIR) spectroscopy was used to confirm the bromination process. The following peaks of absorptions were observed for BMO: C–Br at 600 cm-1 , C–H stretch, (2950 to 2850 cm-1 for alkane), 1750cm-1 for carbonyl stretch, 1450 cm-1 for ester, 1680 cm-1 for alkene. The BMO showed a broad spectrum activity against E. coli, Salmonella sp, Staphylococcus aureus and Streptococcus epidermidis microorganism which gave the inhibitions zones of 19.50 mm, 20.50 mm, 19.00 mm, 18.60 mm respectively. DMSO was used as the negative control while streptomycin as the positive control at 400 mg/ml concentration. Based on these findings, BMO may be use as disinfecting oils or hand sanitizers and will discourage its use as food additive.